From: "Nat Puffer" Subject: Re: COZY: Prop Question? Date: Fri, 1 Jan 1999 12:34:33 -0600 Dear Eric, The 180 and 200 hp Lycomings are at the extreme limit of the amount of horsepower which can be transmitted from a 7" diameter flange to a wooden propellor by friction (I have been told by more than one source). All the wooden propellors I have seen for a 7" diameter flange have at least a 7-1/2" hub. When you apply the amount of torque on the bolts required to provide the friction necessary, you are on the verge of crushing the wood, even when the prop hub is 7-1/2" in diameter. I don't know whose propellor you purchased (and you don't have to tell me), but I don't think much of the designer/manufacturer if he said it's okay for a 200 hp 4-cylinder engine. He has used up a significant amount of the safety factor you are entitled to. I suggest you tell him the designer of your airframe states that his propellor isn't satisfactory and you should ask for you money back. I have an extra propellor I could loan you if this causes you a bind. Clark Lydick is in the same building as Judy Sabor. Why don't you get his opinion as well? I don't like to see anyone putting one of my builders at risk! Best regards, Nat ---------- > From: Eric Westland > To: canard-aviators@canard.com; Cozy Builders > Subject: COZY: Prop Question? > Date: Thursday, December 17, 1998 10:27 PM > > Well, after waiting much longer than I should have, my 2-blade prop > showed up for my Lycoming 200 hp engine. It looks just fine, but when I > went to mount it on my 7" extension from Judy Saber, I realized that the > prop's hub was slightly undersize, 6.65" in diameter to be precise. So > I called the maker and he assured me this was OK. I'm not so sure if > it's OK or within the range of acceptability, what do you folks think? > I guess I just figured it would be as large (or slightly larger) as the > flange and crush plate surfaces. > > > Thanks, > > Eric Westland > From: "Nat Puffer" Subject: COZY: Hub diameter Date: Sat, 2 Jan 1999 12:31:21 -0600 People, Eric called and told me he checked with Clark Lydick (Performance Props), as I suggested, and Clark said a 6.6" hub diameter for a wooden propellor on a 200 hp 4-cylinder Lycoming is okay. This really surprises me, but I respect Clark's opinion. However, for myself, I will insist on a 7.5" diameter hub. I consider wood shavings on the floor in the same category as altitude above you and runway behind you. Best regards, Nat From: cdenk@ix.netcom.com Date: Fri, 22 Jan 1999 16:53:31 -0600 (CST) Subject: COZY: Fwd: prop flange size versus horsepower The following is from Steve Boser, Sensenich Wood Propeller Co. engineer. He has prepared it for this group and asked that I forward it. ------Begin forward message------------------------- To: "Carl Denk (E-mail)" , , "Nat Puffer (E-mail)" Subject: prop flange size versus horsepower Date: Fri, 22 Jan 1999 16:32:19 -0500 I've paraphrased some earlier sensenich documents regarding this subject, and have added some specific notes regarding the Lycoming O-320, O-360, and spool spacers. Drive-Torque Capacity of Crankshaft Flanges, 1999 Experience has shown that it is important to ensure that the drive-torque capacity of a crankshaft flange / propeller hub is adequate. Since only one of the four strokes accomplished by a four stroke engine makes a positive contribution to rated engine torque, the torque contribution by the engine during the other three strokes is negative. It follows that the instantaneous peak torque must be greater than rated engine torque. The ratio of instantaneous peak torque to rated torque will vary with the number and arrangement of engine cylinders and the type of prop extension, among other things. Most common flanges designed to drive wood propellers can be idealized into two distinct torque-transmission systems. The flat hub face can be thought of as driven by static friction or the propeller can be considered as driven by the drive-bushings incorporated in the flange. It is not possible to add the drive-capacity of one system to that of the other. If the propeller is considered to be driven by static friction, the drive bushings will not feel an imposed load and when the drive bushings experience a fluctuating torque load, some movement of the hub against the flange must occur so that the static-friction mechanism can not apply and scorching of the hub boss will occur. It is well known that the maximum friction force parallel to a contact face is defined by the compression force perpendicular to that face multiplied by a coefficient of friction dependent on the two materials in contact. This fact can be used to calculate the maximum resisting torque due to compression of the wood propeller hub against the engine flange if the compression stress in the hub and applicable friction coefficient are known. Sensenich has derived an equation calculating maximum allowable peak torque by static friction, with engine flange diameter being the single most important factor. If it is assumed that the drive bushings in the flange must bear the torque load, then the maximum allowable peak torque equals the product of allowable bearing stress for the drive bushings against the side of the holes provided for them, the total drive bushing bearing area, and the drive bushing radius from the crankshaft axis (equals bolt circle radius). Calculations for both torque transmission systems reveal drive bushing torque capacities at best only a quarter of static friction torque capacities. This is why maintaining proper bolt torque compression on the wooden propeller hub is critical, since the drive bushings can only provide a short term back-up. Installations with satisfactory service histories indicate that the drive torque capacity of that crankshaft flange is adequate. It follows that the instantaneous peak engine torque is less than the static-friction drive-torque capacity of the flange. One new factor in the last 20 years is the increased use of extensions or spacers to move the propeller forward (or rearward) for more streamlining. Any type of extension/spacer which moves the propeller off the crankshaft flange will reduce the torsional rigidity of the crankshaft system and lower the RPM at which torsional resonance can be excited. Spool extensions in particular** are torsionally "softer", which can cause the propeller to lag behind and then race ahead of nominal engine RPM. This lag/lead may appear as increased peak torque at the propeller / engine interface. Thus, a propeller mounted on a spool extension requires a larger drive torque capacity than a direct installation on the same engine. **Torsional stiffness of a shaft is directly proportional to the fourth power of its diameter and inversely proportional to its length. I will get together some tables with all the values when time becomes available. Below is a general rating of torque capacities: ENGINE TYPE AND HORSEPOWER EXTENSION TYPE / EXTENSION LENGTH / PROP CONTACT AREA WITH FLANGE / NOTES Lycoming O-320 engine / 160 HP stock engine flange / none / 6" diameter / satisfactory, no heavy aerobatics spacer (solid extension) / 2-4" / 6" diameter / satisfactory, no heavy aerobatics spool / up to 4" / 6" diameter / satisfactory spool / 4-6" / 6" diameter / marginal, especially for props with medium-high mass moments of inertia spool / 4-6" / 6.5"+ diameter / satisfactory spool / +6" / 6"+ diameter / unknown, test data not available Lycoming O-360 engine / 200 HP stock engine flange / none / 6" diameter / unsatisfactory spacer (solid extension) / 2-4" / 6" diameter / unsatisfactory spacer (solid extension) / .5-4" / 7" diameter / satisfactory, with drive bushings for backup spool / 4-6" / 6" diameter / unsatisfactory spool / 4-6" / 6.5" diameter / marginal, no aerobatics or high mass moment of inertia props spool / 4-6" / 7.0"+ diameter / satisfactory ------End forward message--------------------------- From: cdenk@ix.netcom.com Date: Wed, 10 Feb 1999 17:48:21 -0600 (CST) Subject: COZY: Prop info wanted - URGENT For those flying with a 320 or 360 I could use the following info quickly: Engine: Prop Manufacture: Aluminum prop hub diameter Bolt Dia. Prop material Birch or Maple Approx. lamination thickness (thin, 0.3", or 3/4") Normal bolt torque you use: Prop wood hub diameter Any problems with mounting installation (bolt torque, etc) Mounting face condition (any evidence of movement at perimeter) Quicker is better than being very accurate, indicate where your memory wasn't super. Thanks..... Date: Fri, 12 Feb 1999 20:16:08 -0500 From: Gary Dwinal Subject: COZY: Catto Props Hi Folks, I have recently purchased a Catto three bladed prop from a fellow who decided not to complete his Cozy MKIV. I would like to contact Catto but have no phone number or e-mail address. Is there anyone who can help me out with one or both of these. BTW - I have successfully fitted a Hal Hunt 4 pipe, in-cowl exhaust system under the cowl of my AeroCanard with a very minor cowl mod and slight pipe mod. The AeroCanard cowlings are nearly identical to the Velocity cowlings, so I'm sure this would be very easy to do on a Velocity as well. It should result in a noted reduction in drag in not having the large exhaust fairings hanging down under my cowling. Are there any other 4-place canards that have the 4 pipe, in-cowl system. Gary Dwinal From: "DL Davis" Subject: RE: COZY: Performance or Catto Date: Thu, 11 Mar 1999 06:56:51 -0500 One of the biggest advocates for the Performance three-blade has been Ken Miller. He praised them endlessly, and convinced quite a few other builders to go for it (me included). But now, with a series of incidents involving cracks and blade failures in the Performance prop, plus the extraordinary price difference, even Ken Miller has switched to Catto. He sent some email recently to all his three-blade disciples explaining his decision. The Catto three-blade has a fiberglass surface over the wood core. MIGHT be less prone to cracking. It certainly is less expensive. Several people that have tried them, report good performance. Dewey Davis > -----Original Message----- > From: owner-cozy_builders@betaweb.com > [mailto:owner-cozy_builders@betaweb.com]On Behalf Of marcna > Sent: Wednesday, March 10, 1999 10:09 PM > To: Cozy Builders Group > Subject: COZY: Performance or Catto > > > I'm getting ready to order the Propeller for a Cozy MKIV and called > Performance Propeller about a June delivery and was told that the > three blade goes for $2150. I remembered reading a recent Cozy > newsletter about Catto who was also selling props for the Cozy. I > called and got a quote for $1200 for the Catto 3 blade prop. I know > that Performance makes a good product, does anyone have any experience > with Catto? The price is very good. > > Marc Parmelee > Cozy N425CZ > From: cdenk@ix.netcom.com Date: Thu, 11 Mar 1999 17:06:11 -0600 (CST) Subject: RE: COZY: Performance or Catto I have had 2 performance props that split about midchord from the tip that were repaired by gluing the crack and wrapping the tip with BID @45 degreesa and UNI strong axis perpendicular to length of the blade. Both fiberglasses were about 3" from the tip. Both damages were from debris picked off the tarmack. The current prop (which is an experimental, experimental I'm testing for Sensenich) was too flexible and had vibration problems without glass. It now has 2 plys of BID at 45 degrees from tip to within 1" of the hub. One ply is considered sacrifical and is OK to sand through. I had another prop (the best performing of the lot I have been testing, that picked up debris and split lengthwise at mid chord to within 10 inches of the crank centerline. The debris was small, and the prop scrap. The prop I'm expecting any day now, will be the same design as the one above, and have the tips fiberglassed. This will become an extra charge item, along with urethane leading edge rain protection from Sensenich. With a little luck I will have that one at Sun N Fun. I would recommend the fiberglassed tips as added protection from splits caused by debris impacting near the tips. This will hopefully keep the prop from zipping a crack from a small impact at the wrong spot. From: "Nat Puffer" Subject: Re: COZY: Performance or Catto Date: Thu, 11 Mar 1999 17:48:10 -0600 Gee, guys, I have been flying canard pushers since 1978 (21 years) starting with a Varieze, and have used wooden props from at least 5 different manufactures, and never split a prop. Am I doing something wrong? Nat ---------- > From: cdenk@ix.netcom.com > To: dldavis@erols.com; cozy_builders@canard.com > Subject: RE: COZY: Performance or Catto > Date: Thursday, March 11, 1999 5:06 PM > > I have had 2 performance props that split about midchord from the tip that were repaired by > gluing the crack and wrapping the tip with BID @45 degreesa and UNI strong axis perpendicular to > length of the blade. Both fiberglasses were about 3" from the tip. Both damages were from debris > picked off the tarmack. Date: Fri, 19 Mar 1999 18:16:42 -0800 From: Randel & Nancy Livingood Subject: COZY: Cato Props Greetings all you airworthy canard flyers and builders, I have a question for you. I have been trying to do some research about propellors and thought that I might be interested in getting a three bladed prop. I saw some folks talking about Cato props and wondered if anyone has the address or phone number or web page where I could contact them? Any help will be put to good use. Regards, Randel Livingood Cozy Mark IV -- N727RN (Reserved) http://www.members.home.net/doognivil/index.html Date: Sat, 20 Mar 1999 09:43:36 -0500 From: Gary Dwinal Subject: Re: COZY: Cato Props Hi Randel, You can contact Craig Catto at craigcatto@hotmail.com or call him at 209-754-3553. He builds very nice stuff. Gary Dwinal Randel & Nancy Livingood wrote: > I saw some folks talking about Cato props and wondered if anyone has > the address or phone number or web page where I could contact them? > Date: Wed, 24 Mar 1999 19:25:08 -0800 From: marcna Subject: COZY: Mail for Wilcott I recived this email from Chuck Wilcott and am passint it along to the group. Hi Marc and Nadine - The picture of your airplane in the latest Newsletter looks great! Maybe you are already flying by now. I'm really responding to your request for Catto Prop information. I have been flying with one of his 3 blade props on my Cozy since new. I started with his 6481. That was too much pitch. Never got more than 2450 rpms with that. Then went to his 6480, which I am running now. Rpm's still a little low, max at 2600 (static @ 2340). If I were to order another for my 180 hp Lycoming, I might kick the pitch down another inch, but you could discuss that with him. He is very good to work with. He let me use a loaner prop while I was waiting for the second one to be built. I just don't think I am developing full horsepower at less than rated rpm. The prop has "weathered" fine. About 250 total flight hours on it. It has a few rock dings, but overall looks OK. I do have one comment on the finish. I had the prop painted again, to match the grey stripe on my plane. In the last 50 or so hours, I have noticed some very small cracks in the paint. I looked at these very closely, and have had these inspected by other, more knowledgeable, people. Their opinion is the same as what I concluded. The cracks are only from the paint flexing, and probably don't extend into the fiberglass covering. All this said...would I purchase another from him...YES. >From the introductory comments in the Newsletter, it appears as this was a thread from the Internet group. I removed myself from the list several years ago, so I was NOT aware of your interest. If you would like to put the remarks above on the Internet, go ahead. Chuck Wolcott Cozy Mark IV #154 (been flying for 4 1/2 years now) chuckw@qnet.com From: cdenk@ix.netcom.com Date: Sun, 25 Apr 1999 18:37:30 -0500 (CDT) Subject: COZY: Hershey Kiss spinners At Sun N Fun, someone commented my spinner was wobbling, not having equipment to check it there, and being conservative, I removed the spinner, leaving the bulkhead and fairing in place. Coincidental the Prop bolts had loosened a bit (not near enough to be dangerous) more than I would have expected. Prop bolts do, on occasion need checking while at a distant airport and setting the tracking of the spinner is difficult, if not possible with the luggage space available. Someone recently had a method of using small alignment holes, which I am going to try, but the thought of using a smaller spinner, where tracking was not an issue is being considered. Then I felt that good data on the possible benefits of the Kiss spinner became an interest. This morning I flew 3 test flights with kiss spinner, spinner removed but bulkhead and fairing in place, and finally nothing but the prop bolted to the extension. Spinner assembly: Lightspeed engineering spinner, composite backing plate made from Ken Miller's mold, and Spruce AC-1 fairing Aircraft Loading: 190 lbs pilot, 150 lbs. sand other front seat, 52 gallons fuel at start, about 10 gallons used. Note: prop is too flat pitch for this low altitude, low manifold pressure to prevent overspeeding engine. Flight: 3000' MSL with altimeter set to 29.92", 23.5" manifold pressure, lean for maximum RPM (very little leaning required), flight over Lake Erie with smooth air and very little if any thermals, same basic route. Equipment outside CAS TAS RPM Manifold Pressure Air (F) Inches With Spinner 43 167K 174K 2680 23.5 With Bulkhead& Fairing 45 163K 170K 2640 23.5 No Bulkhead or Fairing 47 162K 169K 2630 23.5 I consider the airspeed numbers plus or minus 1K accuracy, the manifold pressure and RPM are JPI slimline digital. I believe that the spinner with fairing a reasonable claim would be 5 knot increase at low altitudes. Note that for more accuracy, data should be collected at different altitudes and temperatures. It is difficult to align the kiss spinners, they need reinforcement after cutting the prop blade holes, and then should be balanced. I tried static balance of the components, it was nearly impossible, and maybe I did more harm than good. This area need attention. Maybe someone need to tool up to do the reinforcement and balancing. Any thoughts? From: "Nat Puffer" Subject: COZY: Sensenich propellors. Date: Fri, 21 May 1999 16:04:38 -0500 Dear Builders, As you may or may not know, I have been flying a 64 x 76 3-blade Performance prop for almost 7 years now, which I purchased because of good reports from others who had purchased 3-blade Performance props. I even purchased a spare, which I have just recently tried out. In the meantime, Sensenich wanted me to try one of their 2-blade wood props (70 inch diameter). After a number of delays, I finally put it on, and when I ran it up on the ground, only got 2150 rpm, so I decided not to fly it. But after talking to Sensenich and Carl Denk, was talked into trying it. The first time was without a spinner. It had good acceleration, and after rotation, turned up to 2350 in a 120 kt climb. I was beginning to like it, inspite of the fact that it had more vibration than a 3-blade prop. I took down the data at 5 different altitudes, and 5 different rpms. It was almost as good as my Performance. So then I made a spinner and air flow guide for it and tried it again. At each rpm, it was anywhere from 1 to 4 kts. faster with the spinner than without, and with the spinner, I got it to turn up to 2650 rpm at 8,000' for a TAS or 218 mph, which was somewhat better than my new Performance. So my conclusions are these: The Performance 3-blade is a good prop, very smooth, but expensive. The Sensenich 2-blade has more vibration than the Performance, might be 1 or 2 kts faster, is a lot cheaper, and looks to be very husky. I don't know how much the Sensenich costs, because I haven't agreed to buy it yet. Hope this helps. Nat From: cdenk@ix.netcom.com Date: Fri, 21 May 1999 19:57:08 -0500 (CDT) Subject: Re: COZY: Sensenich propellors. Nat questions price? First I want to qualify my position with respect to Sensenich Wood Propeller Co. as someone has recently suggested: I was promised a propeller at no cost for flight testing 2 or 3 props to determine the drag of a Cozy with a Lycoming 320 160 Hp. engine. I was to provide test data on all the props. THe Sensenich engineer spent 2 nights at my home, while we got started testing, to make sure I provided meaningful accurate data. He flew as passenger, recording data for the first flight which was a Performance Prop. All other flights were made with the engineer replaced with 150 lbs of sand bags. To date I have done more than a dozen flight tests, each one reaching 12,000 feet, and lasting about 1:40. I have data on various prop designs, effect of paint ridges near the leading edges, sand the blades with 600 grit sandpaper, with and without spinners, minimum blade thickness. I have laid up BID on a prop that fluttered, and then flown it for many hours. The regulars at my airport know me a the guy carrying a prop in or out. The effort and cash expended at this point far exceeds the cost of a prop, but I have continued in a effort to find safe props for the rest of us. There is no other agreement between Sensenich and myself beyond this. I do not, nor in the future receive a commission or ther compensation for a prop sold. At this point all the props have been received with paperwork indicating for evaluation, and officially have not been titled to me. At this point excuse if I stretch the rules slightly, and then I'll try to remain quiet on the subject. For a 320 in a Cozy the price (the last I heard) with urethane leading edges was $755 US, and for a 360 was $795 US. I would suggest adding the fiberglass on the tips for additional protection from splitting from debris hitting the tip. Since I have the only one like this they have made, I don't know the additional cost. The props are made exactly the same materials and processes as their certified props. If anyone has interest, feel free to contact me privately. From: "Nat Puffer" Subject: COZY: Sensenich propellor Date: Sat, 22 May 1999 13:36:25 -0500 Builders, I would like to pass on a couple of things that I learned in my propellor testing: 1) You cannot rely only on static rpm. With some props, like Performance, the rpm changes only slightly from static to climb at 120 kts. From 2390 to 2420, for example. With other props, like Sensenich, the rpm can change substantially from static to rotation and climb at 120 kts. From 2150 to 2350, for example. There is probably a reason, but I can't tell you what it is. So you really need to get flight data. 2) It is very difficult to hold altitude and rpm steady long enough for the airspeed to stabilize, so you need a lot of data points. Four different rpms and 5 different altitudes, for example, to give 20 data points. Some points will be obviously out of line, so you hope the average of 20 points will be closer to the truth. 3) The average of 20 points for the Sensenich prop with a 10-1/4" dia spinner was 2.7mph faster than the average for the same prop without a spinner. I don't remember how to calculate the standard deviation, but I think the 2.7 mph figure is significantly different. 4) The other indication that a spinner reduces drag was that at full throttle my Lycoming turned 50 to 60 rpm faster with the spinner, and the top speed was 7 to 8 mph faster with the spinner than without. So, at the same rpm the spinner gave me 2.7 mph faster, but at full throttle, the spinner produced more rpm and even more speed. 5) Another interesting finding was that at the same altitudes and rpms, the Sensenich and Performance (both with spinners) gave essentially the same performance. Below 2400 rpm, the Performance was slightly better, and above 2400 rpm the Sensenich was slightly better, so they averaged out the same. However, at full throttle at altitude, the Sensenich turned about 50 rpm more than the Performance, and at the higher rpm, produced 6 to 8 more mph. I think this means the Sensenich 2-blade is slightly more efficient than a 3-blade. According to my FBO, this is usually the case. Hope this is interesting to you. Nat From: cdenk@ix.netcom.com Date: Sun, 23 May 1999 07:45:57 -0500 (CDT) Subject: Re: COZY: Sensenich propellor Nat said: 3 Comments 1: One prop may be better at a given altitude and loading/C.G. than another. This fine tuning is why probably the first prop won't fit your flying style and airframe drag, and everyone is a little different, and I am talking changes that cruise would change several MPH. Since you should always have a spare prop at home ready to ship when you damage one, accurate data on the first prop, combined with a discusion with your prop builder should result in better performance for your conditions. With the first prop the discussion should include how you prefer to run your engine (cruise RPM/manifold pressure, altitude, temperature, etc.). For most operators, you really won't know some of this until you have some hours on the airframe since flying a Cozy is not the same style as say a Skyhawk. Many times you will cruise a higher altitudes, go further, longer time legs, etc. 2: The Sensenich prop Nat has been flying is the first MKIV with a 360 engine prop Sensenich has built. The prop was computer designed, with the output transfered to a CNC (computer controlled) lathe that cut the wood blank to the exact shape of the prop including the cutout for the urethane leading edge. A craftsman, then sands and smooths ready for finish. The computer input for the aircraft was based on my Cosy flight tests for drag, adjusted for what was thought to be differences, and Lycoming engine power tables. It would be easy to duplicate or slightly adjust this prop by gluing up a blank, feeding the lathe the same or a new digital file. 3: If anyone is near Plant City, Florida, just West of Lakeland, Sensenich does offer plant tours, call ahead to be sure someone is available. Date: Sat, 22 May 1999 02:13:11 +0200 From: Jean-Jacques CLAUS Subject: Re: COZY: Sensenich propellor Carl Denk wrote: > Carl and all, Do you know what is the Cosy's drag found by sensenich ? I'm using the D.BATES program to design my own propeller. The D.BATES program can compute an aircraft's drag by reverse engeneering from flight and propeller datas. Based on a COZY III datas I found a drag of 1.97 ( equivalent as a plate of 1.97 sq/ft ). My Cosy Classic is a bit wider and longer than a COZY III so I would like to be more accurate. Thank you, Jean-Jacques CLAUS FRANCE ps: For those who are interrested I found a propeller manufacturer ( also COZY III owner ) who can use the D.BATES's output to make your 'best' propeller ( wood + metal edge + glass + carbon tips ) on a CNC machine. Prices are reasonnable ( $900 for a 2 blades, $2000 for a 4 blades ). From: cdenk@ix.netcom.com Date: Tue, 25 May 1999 21:59:47 -0500 (CDT) Subject: Re: COZY: Sensenich propellor On 05/22/99 02:13:11 you wrote: > >Do you know what is the Cosy's drag found by sensenich ? No, I don't, I provided flight test data to Sensenich, they determined such numbers for their own computer program, and I assume that the info Sensenich determined is proprietory and confidential. From: "Schuler, Larry" Subject: RE: COZY: Sensenich propellor Date: Wed, 26 May 1999 08:11:00 -0500 > >Do you know what is the Cosy's drag found by sensenich ? Hmmmm. CAFE should have the info for typical Cozy-IV. Larry From: extensionsystems@mindspring.com Subject: COZY: Cozy Propeller Thrust Date: Mon, 21 Jun 1999 14:37:56 -0500 Does any one know how much thrust the typical 180HP Cozy Propeller produces. Thanks Brian From: "Nat Puffer" Subject: Re: COZY: Cozy Propeller Thrust Date: Sun, 27 Jun 1999 11:38:24 -0500 Builders, 400 lbs. for 180 horsepower sounds about right. We measured the thrust on our 85 hp Varieze, and it was 200 lbs. Regards, Nat ---------- > From: Jean-Jacques CLAUS > To: extensionsystems@mindspring.com > Cc: Cozy Group > Subject: Re: COZY: Cozy Propeller Thrust > Date: Sunday, June 20, 1999 8:12 AM > > extensionsystems@mindspring.com a écrit: > > > Does any one know how much thrust the typical 180HP Cozy Propeller produces. > > > > Thanks > > Brian > > In some propeller design that I did with the Don BATES's program, the > static > thrust at 0 ft and 2400 rpm goes to approx 400 lbs. > > Jean-Jacques CLAUS > FRANCE > From: cdenk@ix.netcom.com Date: Sun, 27 Jun 1999 07:36:55 -0500 (CDT) Subject: Re: COZY: Cozy Propeller Thrust Was said I think most people cruise at 75% power, and with a prop that will give maximum TAS at 8000' (the altitude where full trottle = around 22.5" manifold pressure results in engine RPM redline, 2700 for a 320). Below this, and respecting the RPM redline, full trottle is not possible. THerefore at 0 feet, the trottle will be significantly closed with manifold pressure as low as 23.5". The TAS will be possibly 8 knots less then the higher altitude. A 2" increase in pitch will bring that point where full trottle can be reached without overspeeding the engine down around 7000' I have one 84" pitch prop that I can use full trottle above 12,000' gives 172K TAS (talking only cruise in level flight for this whole discussion), and a same design with 86" pitch gives 186K at 5000' full trottle, both respect 2700 RPM, and 25.5" manifold as an indicator of 75% power. Date: Mon, 05 Jul 1999 23:12:21 -0400 From: Rob and Carla Kittler Subject: COZY: prop selection Was wondering whether ther might be a consensus among cozy builders/flyers regarding the most suitable propeller. I'm not enamored with the performance prop as recommended in the plans. Too many failures over the years for my comfort. I'd be most interested in input regarding some of the other types out there. Thanks for you input everyone Robert Kittler SN 589 A year away (we hope) Date: Sat, 10 Jul 1999 09:57:27 -0500 From: tazcat@zebra.net (Lori Cruger) Subject: COZY: Prop extention I'm about to order my prop extention and am trying to decide which length to use. What is the advantage/disadvantage of the 8 inch compared with the 6 inch extention? I have purchased a Lycoming IO 360 for my engine. The air intake interfears with the X part of the engine mount. I'm about to alter the X to an H and was wondering if someone had the currect dementions to make this change. Is there an alternative to cutting and welding my engine mount? What is my best option for installing the air filter? Dan and Lori Cruger #586 working on the fuel strakes Date: Sat, 10 Jul 1999 20:24:57 -0400 From: "Marc J. Zeitlin" Subject: Fwd: COZY: Prop extention Lori Cruger writes; > >I'm about to order my prop extention and am trying to decide which >length to use. What is the advantage/disadvantage of the 8 inch compared >with the 6 inch extention? My understanding is that the further back you put the prop, the less interference with the airflow off the strakes/fuselage, and the more efficient it can be. Apparently it's less noisy, too. I purchased the 8" extension from Judy Saber, and it's a beauty. The downside of the longer extension is that it has to be even more concentric than the shorter one, as any imbalance will be magnified. I assume that this is one of the reasons for the higher cost (along with the extra material). I also got the larger crush plate (7", IIRC). -- Marc J. Zeitlin mailto:marcz@ultranet.com http://www.ultranet.com/~marcz/ Date: Sun, 11 Jul 1999 21:20:08 -0400 From: Jeff Russell Subject: Re: COZY: Prop extention David Domeier wrote: > Dan and Lori, > > You might check with Jeff Russell on the 8" extension. I think they > use it on the Aerocanard and I believe the Velocity goes with 8" also. Correct :-) -- Jeff Russell/AeroCad Inc. From: "Richard Goodwin" Subject: COZY: Prop Extensions Date: Sat, 17 Jul 1999 22:25:24 +0100 Cosy Classic, 0320 Lycoming. What length prop extension, 6 or 8 inch? If I go for 8 inch should I be concerned about any extra loading on the crankshaft under G? Thanks for your help Richard Goodwin From: "Will Chorley" Subject: Re: COZY: Prop Extensions Date: Sun, 18 Jul 1999 15:53:50 -0500 Depends on your engine mount but I have the Brock "Heavy" mount. I bought a 6" at first after careful measurement, however, when I actually got everything together it was too short so I exchanged it (and some more cash!) for an 8", particularly with all the discussion about clearance between cowling trailing edge and prop. Moral - don't buy the extension until you have the engine on its mount and the cowling jigged in position, then measure. By the way, I bought mine directly from Saber. The lady at Saber is one of those people you would like to do business with everyday and when you see the quality of the parts you don't feel so bad about the cost! (Bill Bainbridge's 90 degree oil filter adapter is another example of superb quality that you don't mind quite so much about paying for when you see it!) Will From: Robert Donatz Subject: COZY: Re: mufflers and noise Date: Tue, 27 Jul 1999 09:10:06 -0700 John Slade wrote: but reducing the noise level by 50% or more would be worth a LOT of trouble. So what am I missing? Why are there no mufflers on airplanes? David Domeier wrote: Why aren't they on our airplanes? Probably 'cause they are dead weight, reduce HP, and could come off and wipe out the prop. dd Jack Wilhelmson wrote: >From a purely technical thing. A prop airplane's noise level cannot appreciable be reduced by mufflers on the engine. The prop is the noise maker. Listen to a turbo prop fly over sometime. Ok, guys. I know the topic isn't specific to Cozy building, but as long as someone else brought it up I think I can justify posing my question. Has anyone had experience with the Felix Prop? To refresh some memories, this was featured in EAA's Sport Aviation some time back (can't seem to find that issue). If I remember the article correctly, this propeller was a bi-cambered airfoil and had no appreciable affect on performance. However, it did (reportedly) reduce prop noise. This prop was placed on several aircraft and an everglades swamp boat. Since the noise reduction was dramatic on the swamp boat (a pusher) and Cozy's are pushers (I know it's thin, but that's my tie-in) I was wondering if anyone has tried this propeller on a Cozy or any other airplane. Thanks, Robert Donatz Robert.donatz@precisionint.com Cozy Mk IV gonnabe (aka, Pre-build) Date: Tue, 27 Jul 1999 13:49:07 -0500 From: David Domeier Subject: COZY: Felix Prop Robert, re "Has anyone had experience with the Felix Prop?" All I can say is I talked to the Felix people at OSH last year and if I had not already spent a bundle for the Performance Prop, I would have tried theirs. They appear to know their stuff, but I do not know anyone running one. They have been around for some time so I'm sure their are people out there who can attest to their product. dd From: Todd Carrico Subject: RE: COZY: Felix Prop Date: Tue, 27 Jul 1999 14:10:53 -0700 re "Has anyone had experience with the Felix Prop?" I saw bit on TV about a similar prop (if not the same). It was originally supposed to be a boat prop (in the water type, not air-boat), but someone convinced him to try it on a plane. The first time they tried it they thought they had it pitched too steeply. It was turning rated RPM, it was just so much quieter. I would like to know if any are flying behind pushers. tc From: cdenk@ix.netcom.com Date: Tue, 27 Jul 1999 17:08:52 -0500 (CDT) Subject: Re: COZY: Felix Prop As I understand, Nat has had excellent results with a Sensenich, that was the first one they made for a Cosy MKIV with a 360. I believe it is on his aircraft at OSH. The prop is made in every way like a certified prop, and could be if there is enough call for them. From: "Alpha" Subject: COZY: Felix prop Date: Tue, 27 Jul 1999 18:59:55 -0400 From:Newsletter-Mirage Marathon, Celerity and other experimental homebuild aircraft. Volume 4, No. 6 - December 1998 I was just re-reading a magazine article by Fred Felix wherein he relates the story of his development of a new, lower-noise and higher-thrust propeller. (EAA's Sport Aviation magazine, November 1997) In case you missed it, the Felix prop is REALLY different! It has a double camber airfoil shape--in cross-section it's sort of like a dog bone with a narrow part about mid way between the leading edge and the trailing edge. Two cambered surfaces connected by a web, in other words. Felix says his new, revolutionary prop design produces equivalent thrust with less drag, and much less noise, than a conventional prop. It has been tested on a Wittman Tailwind and on air boats with very good results. But here is the really interesting part--Fred says that he drew his inspiration from the invention of the compound bow with its pulleys and several strings. He was amazed that, after thousands of years of development and refining, and at a time when a bow is no longer necessary to hunt game for meat, there was still room for significant improvements, an opportunity that someone fortunately seized. The result is a bow that allows a "letoff" of tension when fully drawn, resulting in more accurate shots for those of us who are not built like Hercules. This breakthrough probably increased the number of participants in sport archery by several orders of magnitude. That observation led Felix to the conclusion that there were other common, simple tools that might allow for improvement and so he began experimenting. For him it began with a canoe paddle, another very simple tool which, like the bow and arrow, has been around for thousands of years. Mr. Felix is a canoe and kayak enthusiast, and after a great deal of research and experimentation he invented that "better mouse trap," a more efficient canoe paddle that happens to be double cambered. Felix then figured that this technology might also be applicable to airplane propellers. It is, and his double camber prop created quite a sensation when first displayed at Oshkosh in 1997. ---------------------------------------------------------------------------- ------------------------ Hopefully, we will soon have some info from someone who has tried one. Jim Brewer Albemarle, NC From: cdenk@ix.netcom.com Date: Tue, 27 Jul 1999 22:11:27 -0500 (CDT) Subject: Re: COZY: Felix Prop Welsh asked Last I heard: For a 320 - $755, For a 360 - $785 (I may be off by $10). These include the urethane leading edge. I would also recommend having the tips fiberglassed to minimize cracks zipping if debris catches the blade near the tip. I haven't heard the cost of the glass. Delivery usually is around 5 weeks. Would recommend converstion with Steve Boser, Sesenich engineer to include your flying style in selecting a pitch. From: "Kyle Howard" Subject: COZY: Mr. Brewer- Felix Prop Date: Tue, 10 Aug 1999 12:58:31 -0500 Isaac Solomon is trying to send you this e-mail. Dear Mr. Brewer, I have not done any scientific analysis of the performance of the two props that I have used but here is my opinion for what it is worth. I started flying a little over six years ago with a Sterba prop. Ed Sterba makes good props and the price was right ($350.) Only recently he has raised the price just a little bit. The prop performed satisfactorily but the static RPM was a bit high. I thought that I could trade some of that for the top speed by getting it re-pitched. Since he lived only about 70 miles away I took it to him and he worked on it but I did not see any significant difference in the performance. About that time Fred Felix started to bring some of his experimental props to our airport for my neighbor Jim Clement to try on his Tailwind for evaluation. Fred also lives about an hours drive from here (Baraboo, WI.) Fred thought that he could build a prop which would be more to my liking, and he did. I have been using his prop for four years. This prop has a little more pitch than my Sterba prop. It has SIGNIFICANTLY MORE blade area and it is much thicker. The static RPM is considerably lower ( I do not want to give any numbers because I never recorded the weather conditions etc.) It gives the same excellent climb perfromance but I get a higher top speed with this prop. It is a well made prop. I do not think that it is less noisy than other props. Sincerely, Isaac Solomon Kyle Howard Network Administrator University of Wisconsin Washington County (414) 335-5266 From: cdenk@ix.netcom.com Date: Fri, 13 Aug 1999 15:53:24 -0500 (CDT) Subject: Re: COZY: Mr. Brewer- Felix Prop Give numbers!!! If you can handle an E-MAil attachment of an EXcel97 file, I'll send you a test flight form that will for your airframe allow accurate comparison. Really good, or such words don't tell us much. "Facts, just the Facts", the reader can make judgements. From: "DeFord, Brian" Subject: COZY: Chapter 23 - Sensenich Props Date: Mon, 16 Aug 1999 09:05:29 -0700 I just ordered my prop from Don Rowell at Sensenich. This is the prop that Nat recently reported on. The prop is a W70EM8L-89. It's 70" diameter, 89" pitch which they recommend for standard operations on a 200hp O-360. Delivery is about 4 weeks and the price less shipping is $840. When I flew with Nat a couple of months ago in his MK-IV, he had the Sensenich prop on and I was impressed. Based on Nat's data (and Carl Denk's as well) I decideed to go with this prop. Can you tell I'm getting excited??? Regards, Brian DeFord brian@deford.com Date: Thu, 26 Aug 1999 12:17:15 -0700 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: COZY: MT Props >FLYING JULY 1998 >COLBY FARMER Cozy MkIV converted to AeroCanard 502-729-2076 >5731 TIMBERLANE PHILPOT,KY. 42366 > >Colby started a MKIV and used most of our AeroCanard FG parts >less the tub and main spar he built. He has a MT prop and 200 hp >and loves to give rides. I have flown his airplane and it's a rocket >at takeoff with the MT pushing it. I wish I had constant speed in the >rear. It makes takeoffs from 1500 to 2000 ft rolls to 500 to 700ft >takeoff rolls. Down side can be the aft CG from the prop weight. > >Give him a call to set up a demo. >-- >Jeff Russell/AeroCad Inc. E-mail: Jeff@aerocad.com Jeff, I enjoyed hearing the comments about the MT prop. I have a friend, out here in Northern California (John McAvoy, Chech Jets) who is now running an MT on his 0-320 powered Long EZ. He said it adds nearly 1000 fpm to his climb rate, but I never got to hear what it did for his top speed. I am curious about two things (and cost almost doesn't come into this). How MUCH extra weight does this add, over a wooden prop? How much experience is there on running times and reliability with these props on pushers? It sort of sounds like a prayer answered, but I am always very cautious in this particular area, considering how unfriendly these pushers are in the prop environment. Have you run accross many other MT's in Canard service? I'm sure we'd all love to hear more details about something so potentially dramatic to our performance envelope. Howard Rogers From: "Nat Puffer" Subject: Re: COZY: MT Props Date: Thu, 26 Aug 1999 16:37:04 -0500 ---------- > From: Howard Rogers > To: cozy_builders@canard.com > Subject: COZY: MT Props > Date: Thursday, August 26, 1999 2:17 PM > > > > > > Jeff, . Have you run accross many other MT's in > Canard service? I'm sure we'd all love to hear more details about > something so potentially dramatic to our performance envelope. > > Howard Rogers > > Dear Howard, We have had two Cozy builders who installed MT or Hoffman props. The first was Mike Marshall, an orthopedic surgeon who lived in Los Alamos, which had a very high density airport. His Cozy performed very well, but after 2 years he had to send the MT back to Germany for an overhaul which was very expensive. When he gave up his practice and took a teaching position in Kansas (or Nebraska), he elected to go with a fixed pitch prop. The second builder was Tim Merrill, who won the Grand Champion award at Oshkosh with his Cozy Mark IV in 1996 or 1997. He installed an MT (or Hoffman?) prop because he was able to get a used one at a very low price (they cost about $8,000 new). He used it on an 0-320, and got better take off performance than we do with our 0-360, because he was able to develop the full 160 hp for takeoff, whereas with an 0-360 and fixed pitch cruise prop, we only develop about 135 or 140 hp for take off. When we designed the Cozy Mark IV, we recognized that the best takeoff performance would be with an 0-320 and an MT or Hoffman prop, but the cost and maintenance of that combination would be much greater than the 0-360 with a fixed pitch prop. Since most of our builders are cost conscious, we decided to recommend the least expensive combination. To answer your other question, the I0-360 weighs about 30 lbs or so more than the 0-360, and the MT or Hoffman props also add a little weight, so you do need more weight up front, and together, that increases the empty weight. Although the constant speed prop helps you to lift more weight off the ground, the down side is that it increases your rotation and landing speed, as well as the complexity of the airplane, so we believe our recommendations are safer for the average builder/pilot. Off field landings can be dangerous. Kitplanes recently stated that over 60 mph, anything over a smooth touchdown on a smooth surface, survival chances decrease rapidly. That is why we preach building the airplane as light as possible. Regards, Nat From: N11TE@aol.com Date: Fri, 27 Aug 1999 00:54:02 EDT Subject: Fwd: COZY: MT Props Return-path: N11TE@aol.com From: N11TE@aol.com Full-name: N11TE Message-ID: <47e2e292.24f773a1@aol.com> Date: Fri, 27 Aug 1999 00:52:49 EDT Subject: Re: COZY: MT Props To: hrogers@slac.stanford.edu MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: AOL 4.0 for Windows 95 sub 21 In a message dated 8/26/99 2:21:20 PM Central Daylight Time, hrogers@slac.stanford.edu writes: > Jeff, > I enjoyed hearing the comments about the MT prop. I have a friend, > out here in Northern California (John McAvoy, Chech Jets) who is now > running an MT on his 0-320 powered Long EZ. He said it adds nearly 1000 > fpm to his climb rate, but I never got to hear what it did for his top > speed. I am curious about two things (and cost almost doesn't come into > this). How MUCH extra weight does this add, over a wooden prop? How much > experience is there on running times and reliability with these props on > pushers? Other than the two examples mentioned (Colby Farmer's AeroCanard with LIO-360 and 3-blade MT prop and Tim Merrill's Cozy MKIV with O-320 and Hoffmann 2-blade prop) I personally know of 3 other 4-place canards under final construction with constant-speed props. I'm sure there are others I'm not aware of. I have personally talked with both Colby and Tim and both told me that they were very happy with going to the CS prop. My previous spam can had a constant-speed prop which I thoroughly enjoyed. It offered more flexibility and much more power on takeoff. Therefore, this was one option I really wanted on my plane. I calculated the additional weight at a little more than 15 lb. extra which I balanced by moving weight forward as I built. I originally priced an MT prop ... very well proven on many Velocity airframes (pushers). When the original quote was substantial, I began to look for other alternatives. I ran across Hoffmann Propellers and contacted the factory in Germany and became a dealer for them. They have developed a special model for me for the 4-place pusher plane with a built-in 8 inch extension. I received my own propeller last December. I have also helped two other AeroCanard builders to order Hoffmann Propellers ... one with a LIO-360 and one with a Franklin. To date, none have flown, although one has had engine start. I think the reliability of canard CS props has been shown to be good, although all CS props will be more expensive to operate than wood props. I've been told not to expect top end to be quite as high as a cruise fixed pitch prop. However, with my plane having an IO-540, I'm not too concerned with this. I do look forward to being able to run full manifold pressure at and above 7,500 ft and be able to reduce prop RPM to more comfortable levels. Colby also told me it makes a great landing brake when you pull the power back. If I'd known or thought about it I might have considered not installing the landing brake. Although, one could make a case for keeping it for rock protection. Tom Ellis AeroCanard 540 s/n 11 From ???@??? Sun Aug 29 01:43:19 1999 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id TAA29265 for ; Fri, 27 Aug 1999 19:41:09 -0400 (EDT) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id OAA12004 for cozy_builders-list; Fri, 27 Aug 1999 14:41:45 -0400 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from dfw-ix11.ix.netcom.com (dfw-ix11.ix.netcom.com [206.214.98.11]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id OAA11999 for ; Fri, 27 Aug 1999 14:41:38 -0400 From: cdenk@ix.netcom.com Received: (from smap@localhost) by dfw-ix11.ix.netcom.com (8.8.4/8.8.4) id SAA20509; Fri, 27 Aug 1999 18:12:52 -0500 (CDT) Date: Fri, 27 Aug 1999 18:12:52 -0500 (CDT) Received: from ely-oh4-20.ix.netcom.com(206.216.59.148) by dfw-ix11.ix.netcom.com via smap (V1.3) id rma020407; Fri Aug 27 18:12:20 1999 To: N11TE@aol.com To: cozy_builders@canard.com Message-Id: <199982719919641@ix.netcom.com> Subject: Re: Fwd: COZY: MT Props X-Mailer: Netcomplete v4.0, from NETCOM On-Line Communications, Inc. MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: cdenk@ix.netcom.com X-UIDL: 335865de6bee27b4f118636c457b4e03 A concern of rear propellers is debris damage, 2 issues 1: In the event of a hit, what is the mode of failure. With wood prop blades, I highly recommend fiberglass wrapping of the tips to prevent zipper action of a split tip. 2: Rear props are much more prone to damage than tractor props. With the high initial cost, one should anticipate some damage, have a spare prop readily available and be prepared to spend $$$ to be flying again. Date: Fri, 27 Aug 1999 19:19:25 -0700 From: "LCDR James D. Newman" Subject: Re: Fwd: COZY: MT Props Hi All, > Carl Denk wrote: > A concern of rear propellers is debris damage, . . . > 2: Rear props are much more prone to damage than tractor props. If you widen your main gear, prop damage will not be any worse than with tractor props :-) . Infinity's Forever, JD From: "Nat Puffer" Subject: COZY: Sensenich props Date: Sat, 28 Aug 1999 13:33:39 -0500 Builders, We have approved the Sensenich prop for Cozy Mark IV builders. We just haven't zeroed in on the best specs for a 180 hp Lycoming. We tried 70" dia x 87" pitch, and 69" dia x 87" pitch, and still couldn't squeeze out 2700 rpm at best power setting at altitude. 2640 rpm was the best we could do. So we suggested Sensenich let us try a 70" dia x 85" pitch. We think this will give us best climb and best cruise. Will let you know what results we get. Best regards, Nat From: cdenk@ix.netcom.com Date: Sat, 28 Aug 1999 07:37:49 -0500 (CDT) Subject: Re: Fwd: COZY: MT Props J.D. wrote Not terribly scientific, but after I removed most of the thread from the nose tire, the light damage to the prop seemed to be reduced, I'm talking more the heavy sandblast type nicks. Also have on my to do list, new main wheel pants that shield the prop better. Big bucks and time are not available to install a retractable. First would be to build a Super Cyclone (Cessna 185 clone), since our flying requirements are changing. Date: Sun, 29 Aug 1999 14:43:50 -0700 From: "LCDR James D. Newman" Subject: COZY: Re: MT Props Hi Carl and All, > J.D. wrote :-)> > Cark Denk wrote: > Not terribly scientific, but after I removed most of the thread from the nose tire, the light > damage to the prop seemed to be reduced, I'm talking more the heavy sandblast type nicks. Interesting. Installing a nose tire fender (Wes Gardner used to have a mold of this) would stop FOD from the nose tire hitting the prop too. Obviously, leaving the belly board out at all times, even on take-off (for real dirty runways) if the runway is long enough and only until airborne (already been done), would help stop FOD from the nose tire hitting the prop. > Big bucks and time are not available to install a retractable. Just let me know when you are ready ;-) . > First would be to build a Super Cyclone (Cessna 185 > clone), since our flying requirements are changing. I'll have to look up what that is. Infinity's Forever, JD Date: Sun, 26 Sep 1999 11:01:43 +0200 From: Rego and Noleen Burger Subject: COZY: Prop Specs I would like all operators of two bladed props to please let me know what dia and pitch you are running on Cozy 3 or 4 placers please. Data gathereing to help me decide on prop. State engine type and cruise @ 75% pwoer please. Send direct to me if you feel it not of interest to the group. -- Rego Burger CZ4#139 South Africa Web:http://home.intekom.com/glen/rnb.htm Work e-mail, mailto:burgerr@telkom.co.za From: cdenk@ix.netcom.com Date: Sun, 26 Sep 1999 10:17:11 -0500 (CDT) Subject: Re: COZY: Prop Specs Prop diameter and pitch by itself doesn't say much. Each design family (manufacturer, airfoil crossection, and other items) can be compared within that family. But to say a 80x84 of a Sensenich, Performance, Cato, or whatever will have the same performance range doesn't work. In replying to Rego, include manufacturer, prop model, engine, airframe, and performance comments. Here;s mine Cosy Classic, IO-320, 160 hp. Performance below is operating at 1831 lbs. takeoff weight. Sensenich W67CML-84 Too flat pitch, Can't use full trottle till over 12,000' and not exceed 2700 RPM, 175K cruise 2000'- 12,000' Sensenich W67CML-86 Full trottle, 2700 rpm, 25.5" manifold @ 5000' 186 Knots cruise. Higher and lower altitudes, 175K+ cruise. Date: Mon, 27 Sep 1999 12:41:20 -0700 From: "LCDR James D. Newman" Subject: COZY: Re: Whirlwind Props (was: "Runway Lengths") > > WhirlWind's 20 lb. 3 blade constant speed prop is $6500. > Howard Rogers wrote: > JD, can you tell us where to get more info on the WhirlWind props? Do they have a website? Yeap. http://whirlwindpropellers.com POC: Jim Rust (619) 562-3725 From: "Steve Campbell" Subject: Re: COZY: Whirlwind Props (was: "Runway Lengths") Date: Mon, 27 Sep 1999 15:35:02 -0500 Just thought that you might like to know, I spoke to WW today. They have no products that they recommend for a canard pusher unless you are putting in a O-540. Steve Campbell From ???@??? Mon Sep 27 06:43:34 1999 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id SAA16565 for ; Mon, 27 Sep 1999 18:27:13 -0400 (EDT) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id RAA17488 for cozy_builders-list; Mon, 27 Sep 1999 17:34:45 -0400 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from chupacabras.flash.net (chupacabras.flash.net [209.30.6.16]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id RAA17481 for ; Mon, 27 Sep 1999 17:34:40 -0400 Received: from flash.net (p117.sas5.dialup.san1.flash.net [209.30.93.117]) by chupacabras.flash.net (8.9.3/Pro-8.9.3) with ESMTP id QAA07608 for ; Mon, 27 Sep 1999 16:33:04 -0500 (CDT) Message-ID: <37EFE28F.5ED4EAA3@flash.net> Date: Mon, 27 Sep 1999 14:33:03 -0700 From: "LCDR James D. Newman" Organization: INFINITY Aerospace (http://www.flash.net/~infaero) X-Mailer: Mozilla 4.61 [en] (Win95; I) X-Accept-Language: en MIME-Version: 1.0 To: "Canards - 'R' - Us" Subject: COZY: Re: Whirlwind Props (was: "Runway Lengths") References: <19990927185745.BTXC617@localHost> <003b01bf0927$c7cc6920$4d956580@umn.edu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: "LCDR James D. Newman" X-UIDL: 3f89ae9c5589347620a3b65bd02b66e1 Hi Steve and All, > Just thought that you might like to know, I spoke to WW today. They have no products that they > recommend for a canard pusher unless you are putting in a > O-540. While the above is basically correct, I just talked to Jim Rust of WhirlWind to clarify - they will *eventually* be making pusher propellors. But as of *today*, they have nothing to ship you except a prop for the 0-540. They are 5 hangar rows over from me. And like I've said before, I plan on using their prop. So I needed to know for myself their plans :-) . Infinity's Forever, JD Date: Sun, 31 Oct 1999 09:00:54 -0600 From: Curt Smith Subject: Re: COZY: Performance Prop performance Dave, I lost 50-75 rpm on the finished prop vs. the unfinished. Clark told me to expect this. In my case, it was desired as I wanted to reduce cruise rpm by just that amount. My experience with engines is that even though they may be "broken in" (rings seated so that oil consumption is nil and temps stable), they are still "tight" for a long time. Mine now has about 150 SMOH and is running better (faster, smoother) all the time. Knowing how thorough you are, you've probably already done this, but you might check mag/ign timing. Curt LE N86CS At 08:17 AM 10/31/99 -0600, David Domeier wrote: > > Something weird is going on with my 3 blade Performance Prop. > > Yesterday on take off, and this is not new, its been going on for >some time, the rpm was 2400 most of the roll. As soon as the airplane >was airborne, rpm dropped to 2380. The rpm usually hits peak as full >throttle is reached but does not increase as speed is increased as one >would expect with a fixed pitch prop. > > I've done a number of full throttle runs 8500 pressure altitude >recently and the engine numbers are about the same each time. Max rpm >is 2560. A year ago the engine would turn at 2690. TAS is off also. > > Two things have changed in that time. > > 1. The prop was new and unfinished. It's been refinished by Clark >Lydick. > > 2. The engine has been overhauled with new cylinders. > > Has anyone noticed a degradation in performance with a smooth finish >as opposed to running an unfinished prop? > > The engine has about 70 SOH. I would think he cylinders would begin >to be untight by now. Maybe not. > > What has been sitting in the back of my mind is the possibility of >the blades flexing in some manner the is new as the prop ages. They are >mighty skinny. > > What do you-all think? > >dd > ***************************************************************** Curtis A. Smith, Ph.D. Professor Southern Illinois University at Edwardsville Box 1125 Edwardsville, IL 62026-1125 Phone: 618/650-3970 Fax: 618/650-3359 From: cdenk@ix.netcom.com Date: Sun, 31 Oct 1999 12:41:53 -0500 (EST) Subject: Re: COZY: Performance Prop performance On 10/31/99 08:17:42 you wrote: > > > As soon as the airplane was airborne, rpm dropped to 2380. Common, the coarse pitch props needed for a Cozy's high speed cruise usually is partially stalled (a prop blade is an airfoil), and gets out of the stall during the takeoff run. To steck static RPM, do a second time at 180 degree heading change, average results. > 1. The prop was new and unfinished. It's been refinished by Clark >Lydick. Also the urethane leading edges were installed, the leading edge profile may have changed slightly > > 2. The engine has been overhauled with new cylinders. Lots of items here, tight rings, ignition timing changed, a cylinder is bad performance (can happen anytime). > > Has anyone noticed a degradation in performance with a smooth finish >as opposed to running an unfinished prop? Take a prop sand the blades with 600 grit sandpaper, loose 3 knots. With a paint thickness offset from masking ot end of urethane leading edge, loose 6 Knots. > > The engine has about 70 SOH. I would think he cylinders would begin >to be untight by now. Maybe not. Should loosen within hours. > > flexing in some manner the is new as the prop ages Shouldn't. How about the airframe, any changes there that could affect drag? What about temperatures, and barometric pressure, use 29.92 for all data runs. Date: Mon, 01 Nov 1999 08:28:44 -0600 From: Michael Pollock Subject: RE: COZY: Performance Prop performance David Domeier wrote: >Something weird is going on with my 3 blade Performance Prop. My performance prop does exactly the same thing. However, I have had two of them and both do the same thing. They both go down in RPM as soon as I lift-off or just a little before. However, I can turn 2750 RPM at full throttle at 8500 feet. I believe this to be the quasi-constant speed nature of the design. What is your manifold pressure doing at climb, cruise, etc? You also may not be delivering the same power as you were before due to the cylinder change. Michael.Pollock@wcom.com Flying Velocity N173DT Building Cozy MKIV #643 From: Militch@aol.com Date: Mon, 1 Nov 1999 09:29:52 EST Subject: Re: COZY: Performance Prop performance In a message dated 10/31/99 2:20:33 PM, david010@earthlink.net wrote: > Yesterday on take off, and this is not new, its been going on for >some time, the rpm was 2400 most of the roll. As soon as the airplan Funny you should ask. This response was explained to me at the Salisbury fly-in on Saturday. If I understood it correctly, before take-off, there is a lot of turbulence and cavitation behind the cowling area. After take-off, with faster flow over the canopy, things clean up a bit, the prop loads up and you see a slow down. Regards Date: Tue, 02 Nov 1999 15:24:59 -0500 From: David A Froble Subject: Re: [c-a] Re: COZY: Performance Prop performance While props are very complex things, you can apply some principals to events at times to determine what's going on. When a prop is working, moving air, it requires energy to do this work. This energy is supplied by the engine. Now consider a prop that is not doing work, or is doing less work than usual, as in the case of a partially stalled prop. Since less work is done, less energy is required, and there is more energy available to spin the prop faster. I know it sounds wierd, but it's good solid physics. For an easy demonstration, take a common window box fan. notice the amount of air moved and the speed of the fan. Now cover the intake side of the fan to prevent air from being drawn in. Again note the air being moved by the fan (work) and the speed of the fan. Dave Militch@aol.com wrote: > > [The Canard Aviators's Mailing list] > > In a message dated 10/31/99 2:20:33 PM, david010@earthlink.net wrote: > > > Yesterday on take off, and this is not new, its been going on for > >some time, the rpm was 2400 most of the roll. As soon as the airplan > > > Funny you should ask. This response was explained to me at the Salisbury > fly-in on Saturday. > > If I understood it correctly, before take-off, there is a lot of > turbulence and cavitation behind the cowling area. After take-off, with > faster flow over the canopy, things clean up a bit, the prop loads up > and you see a slow down. > > Regards > > \ > ->>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>-|- > / > -For details on sponsors of this list, copyrights, and how to remove > -yourself from this list, please visit: > > http://www.canard.com/canard-aviator-sponsors.html > > (c) 1997,1998, 1999 Canard Aviators. support@canard.com > / > -|-<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<< > \ -- David Froble Tel: 724-529-0450 Dave Froble Enterprises, Inc. Fax: 724-529-0596 170 Grimplin Road E-Mail: davef@tsoft-inc.com Vanderbilt, PA 15486 Date: Sun, 31 Oct 1999 16:22:00 -0600 From: David Domeier Subject: COZY: Re: [c-a] Performance Prop performance Lynn, I had a Bruce Tift prop on my LEZ and wish he were still around. I liked that big beefy prop alot and if he were still around, I'd order one for the Cozy just to have a spare and to compare numbers. dd From: "Lynn Crawford" Subject: COZY: Re: [c-a] Performance Prop performance Date: Sun, 31 Oct 1999 09:59:46 -0800 I have a 2 bladed Performance prop and see characteristics similar to what you describe except that I saw these differences when I replaced my Great American with the Performance prop. My Performance prop is still in the as built configuration (not finished yet) but it also acts like the prop changes pitch for different conditions. I can get the same static rpm as with the Great American but at altitude full power, the RPM is about 150 maybe 200 RPM hundred lower. My top speed is down from what it was but I cruise at the same or slightly higher speed at at least 100 rpm slower. I think you are correct in assuming the blades flex and changes pitch with airspeed and power. Lastly my climb rpm is also slower than my ground static RPM much as you describe. The prop almost seems to have semi constant speed prop characteristics. From: "Nat Puffer" Subject: Re: COZY: Re: [c-a] Performance Prop performance Date: Sun, 31 Oct 1999 14:26:45 -0600 David, Featherlite took over all the tooling from Bruce Tift's estate, and still makes the same prop. Nat