From: "Boykin, Ed (C)" Subject: COZY: Hypothetical idea Date: Tue, 20 Jan 1998 12:17:24 -0500 This is a hypothetical idea and not something I would every try to implement unless I was Bill Gates... Could a laser be used to cut foam for wing and canard cores? A simple device could be built that moved the laser so that it cut the block in alignment with the core templates. A properly set beam would be needed so that there wasn't too much heat much the same the hot wire must be set. A laser cutter on this sort of device would have several adavntages. There would be practically no irregularities in the cut, no wavyness etc. There would be consistent cutting allowing for multiple cores that are identical to be cut. Tolerances could be set alot closer. Cost of a laser to do this would be prohibitive for the average homebuilder although I think the device to align and move the laser wouldn't be to bad. (Although, it would still be pricey compared to two people and a hot-wire saw) Just rambling through a "Gee I wonder what I could do if I hit the lottery" phase... Ed Boykin aviator@mindspring.com Date: Tue, 20 Jan 1998 11:55:27 -0600 From: Chris Anderson Subject: Re: COZY: Hypothetical idea At 12:17 PM 1/20/1998 -0500, you wrote: >This is a hypothetical idea and not something I would every try to >implement unless I was Bill Gates... > >Could a laser be used to cut foam for wing and canard cores? I'd think that water-jet would work better. it is just foam after all, and since the jet can cut steel, I'd think foam would be a little easyer. Some sort of automated core cutter wouldn't be hard to make, but it'd be more expensive. It'd make more sense to make molds of the wings. IMHO =-=-=-=-=-=-=-=- Chris Anderson andersoc@idcnet.com You can't save everyone folks, just try not to be living next door when they go off... Dennis Miller Date: Tue, 20 Jan 98 13:07:54 EST From: "KEN SARGENT" Subject: Re: COZY: Hypothetical idea Lasers will "diverge" for deep cuts. I have seen this even for cutting 3/4" foam, even metal for that mater. What happens is heat absorbs off the cut edge and keeps melting nearest the tip. Waterjets diverge when cutting foam also by bouncing the jet of water off the cut edge. I have had the same thought, so that is why I know. Treadway Idustries in Leesburg, Florida has a three axis CNC hot wire machine. Disney has one as well with a 16x36x8 gantry. Disney routinely holds 0.001" tolerance with this machine. They produce a wonderful part, because the wire adjusts for heat, and you set the feeds and speeds and go. There is now waviness at all. When I get that far, I was going to Autocad up the wing profiles and have Treadway CNC it. I do not know if the premade cores others are selling are done this way. Anybody know? Ken Sargent #555 ken_sargent@wda.disney.com ______________________________ Reply Separator _________________________________ Subject: COZY: Hypothetical idea Author: "Boykin, Ed (C)" at DISNEY-WDW-INTERNET Date: 1/20/98 1:00 PM This is a hypothetical idea and not something I would every try to implement unless I was Bill Gates... From: lschuler@cellular.uscc.com Date: Tue, 20 Jan 98 11:53:09 -0600 Subject: Re: COZY: Hypothetical idea Ed Boykin wrote: >snip >...I think the device to align and move the laser wouldn't be to bad. >snip If that's true, then why not move the hot-wire via such a device and save the cost of laser? I saw one at Oshkosh a couple years back. Neat setup. Computer controlled servo motors. Cost more than a laser; musta been for airplanes. I'm waiting for the lottery too... Course If I win, I'll buy a Lancair IV-P. :-) Larry From: Cozy7971 Date: Tue, 20 Jan 1998 14:35:04 EST Subject: Re: COZY: Hypothetical idea In a message dated 98-01-20 12:22:27 EST, Ed.Boykin@pcs.bls.com writes: << Could a laser be used to cut foam for wing and canard cores? >> I suspect that the answer is yes but for the average homebuilder (or even small business) it would be prohibitively expensive. Two years ago a fellow at Oshkosh demonstrated an automated hot wire tool. It worked on the principle of two parallel x-y plotters with a hot wire stretched between. A PC drove the whole system. It worked quite nicely but would only handle blocks of foam that were two foot square. Date: Tue, 20 Jan 1998 19:27:23 -0600 From: Paul Comte Subject: Re: COZY: Hypothetical idea Boykin, Ed (C) wrote: > > > Could a laser be used to cut foam for wing and canard cores? > > A simple device could be built that moved the laser so that it cut the > block in alignment with the core templates. A properly set beam would be > needed so that there wasn't too much heat much the same the hot wire > must be set. > A laser cutter on this sort of device would have several adavntages. snip > > Ed Boykin > aviator@mindspring.com Three alternates come to mind. First used the laser to "burn back" the foam. The beam is perpendicular to the foam in this process. Place a rough cut block in a jig and have a cnc type of system burn off the excess in the pulse mode used for carving. Big set up cost... Second thought was to put the core in a spit and rotate it while a laser at one end fires down the length. Less setup and now you just have to move the beam ( pitch & yaw ?) while the foam turns. There is a company in Plymouth Wisconsin (so there must be others) that has big, make that really big, production foam cutters. They chop up pallet sized blocks into complex shapes using the hot wire method. They have frames holding multiple wires which are monitored by the control system. Neat huh? If it was practical, a gang order from them would be a nice option to each of us fab'ing our own. All together now, "Ready? begin, on the nail, moving into the foam..." -- Best Regards, Paul Comte PS. Plymouth Foam Products. I have the rep's card somewhere... A Plus Computer Service, LLC. 5100 West Blue Mound Road Milwaukee, WI 53208-3654 (414) 456-9700 Voice (414) 456-9701 Fax Date: Tue, 20 Jan 1998 11:21:19 -0800 From: "LCDR James D. Newman" Subject: COZY: Re: Hypothetical idea Hi Ed and All, >Ed Boykin wrote: >Could a laser be used to cut foam for wing and canard cores?< Yes, there are companies that already do this. If you get a chance to go to the SAMPE convention in June at the Anaheim Convention Center, there should be companies there that do this. Infinity's Forever, JD Subject: Re: COZY: Hypothetical idea Date: Mon, 26 Jan 1998 11:47:56 -0500 (EST) From: "Randy Smith" What I would like to see is the foam actually made in the proper shapes (ie no cutting at all). Simply order the cores and they come premade. What process is involved in making the foam and would it be feasible to make it in the shape of a wing core? This really sounds dumb, but I saw this done on a Mr. Wizard episode where he had some styrofoam(tm) beads that he placed in a cookie mold (fish shaped with scaled texture). He then placed a small quantity of water in it and clamped the mold together with rubber bands and put the whole thing in the microwave. A few minutes later, out popped the expanded styrofoam(tm) fish complete with scales. Could something similar to this be done for a wing core at home? -Randy --* --- -* **-* *-** -*-- -* Table finished, epoxy scale next |Cozy MkIV| NCR General Purpose Computing Randy.Smith@ColumbiaSC.NCR.COM |---( )---| Global Support Center Voice 803-939-7648, V+ 633-7648 ___o/o\o___ West Columbia, SC 29170 "I am the way, the truth, and the life..." -JC > This is a hypothetical idea and not something I would every try to > implement unless I was Bill Gates... > > Could a laser be used to cut foam for wing and canard cores? > > A simple device could be built that moved the laser so that it cut the > block in alignment with the core templates. A properly set beam would be > needed so that there wasn't too much heat much the same the hot wire > must be set. > A laser cutter on this sort of device would have several adavntages. > There would be practically no irregularities in the cut, no wavyness > etc. There would be consistent cutting allowing for multiple cores that > are identical to be cut. Tolerances could be set alot closer. > > Cost of a laser to do this would be prohibitive for the average > homebuilder although I think the device to align and move the laser > wouldn't be to bad. (Although, it would still be pricey compared to two > people and a hot-wire saw) > > Just rambling through a "Gee I wonder what I could do if I hit the > lottery" phase... > > > Ed Boykin > aviator@mindspring.com > From: "Rick Roberts" Subject: Re: COZY: Hypothetical idea Date: Mon, 26 Jan 1998 20:48:19 -0800 The problem is probably the tooling involved. The people who make the foam for our airplanes make about 2 million lbs a year of which maybe a couple of tons go to the airplane builders. The foam expansion process is pretty easy but the tooling to make net shapes would probably kill you. I once make some cruise missile parts from a polyurethane foam injection system (The RIM process) where you inject foam into a mold and mix it on the way. When it contacts the mold it leaves a very hard smooth surface and keeps a foam back side. (Squeeze your dashboard in the car for an example.) With this process we could have made fins for very little but the mold was big (big) bucks. (A production of 2000 missiles would have paid for it, but the US Government only ordered them 100 at a time, so no one would commit tooling money). Rick Roberts -----Original Message----- From: Randy Smith To: Cozy_Builders@hpwarhw.an.hp.com Date: Monday, January 26, 1998 8:59 AM Subject: Re: COZY: Hypothetical idea > >What I would like to see is the foam actually made in the proper shapes >(ie no cutting at all). Simply order the cores and they come premade. From: GeneKnapp2@aol.com Date: Mon, 23 Feb 1998 15:51:16 EST Subject: COZY: Hot Wire Template material Guys So if one is going to cut the foam himself what material should he use for the best results. I have heard 1/16" tin sheet and formica. Of the 1/16" tin, I was told the metal template will cool the wire and cause problems. Fm another source I was told that formica was the ticket. Easy to work with, can be sanded smooth, easy to write on for the talking no's and level Lines. I bought a 26" x 48" sheet. It sure looks flexable. So what advice do yall have. Gene GeneKnapp2@aol.com P.S. I hope I don't pull this stunt but who knows ... The tale : When his neighbor agreed to help cut the foam cores he was very attentive. After explaining the tecnique, they put the hot wire saw to the foam and made a beautifull upper surface cut. The builder feeling better about their work was ready to cut the bottoms. Well then he says something of the order of "Ok, lets make another cut". Finishing the cut the builder was horrified! he didn't mention they were going to make the cut using the BOTTOM of the airfoil template. Being ignorant, his helper had again followed the top of the template. OOPS! Now the core was cut in HALF! ... I'll try to do better : Gene From: Marc J. Zeitlin Subject: COZY: Hot Wire Template material (fwd) Date: Mon, 23 Feb 98 16:09:56 EST Gene Knapp writes: >So if one is going to cut the foam himself what material should >he use for the best results. > >I have heard 1/16" tin sheet and formica. > >Of the 1/16" tin, I was told the metal template will cool the wire and cause >problems. Tin? I doubt it. I used 1/16" aluminum. Glue the paper templates to the aluminum, band sawed it to the template shape + 1/64", then filed it to the final shape. You get a clean edge and it's durable. I had no problems with the templates taking heat out of the wire. Lag in the center of the cut is a much larger issue than a minuscule heat loss at the edges. Some people use formica, some use masonite. Basically, anything will work if you get a smooth edge. This has all been covered in the archives, yadda, yadda, yadda. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 23 Feb 1998 15:11:01 -0600 (CST) From: "Tom G. Brusehaver" Subject: Re: COZY: Hot Wire Template material >Of the 1/16" tin, I was told the metal template will cool the wire and cause >problems. I havn't used tin, so I cant say this is true, but: I could see this cooling the wire near the ends, which would be a good thing, maybe, in that it would keep you slower, and potentially minimize sags. >Fm another source I was told that formica was the ticket. Easy to work with, >can be sanded smooth, easy to write on for the talking no's and level Lines. >I bought a 26" x 48" sheet. It sure looks flexable. I use Formica for most of the templates. It cuts easy, but may chip. I usually cut waay wide of the line and sand/file to the line. I have had a couple peices start to curl, but otherwise in small templates, it is really stiff. From: cdenk@ix.netcom.com Date: Mon, 23 Feb 1998 20:25:58 -0600 (CST) Subject: Re: COZY: Hot Wire Template material (fwd) I have had metal templates short out when accidentally completing circuit with bar clamps, nails touching on short pieces of foam. CAUTION! YOu power source should have fuses or circuit breakers on both low and high voltage side. From: lschuler@cellular.uscc.com Date: Tue, 24 Feb 98 09:54:59 -0600 Subject: COZY: Hot Wire Template material (fwd) Marc wrote: >snip >I used 1/16" aluminum... >I had no problems with the templates taking heat out of the wire. Lag >in the center of the cut is a much larger issue than a minuscule heat >loss at the edges. >snip Just FYI: I tried 1/8" alum (cause I got a bunch for free from a local factory junk barrel). Too thick and does draw noticable heat at the edges. Larry Schuler Cozy plans #500 lachuler@cellular.uscc.com From: Cozy7971@aol.com Date: Tue, 24 Feb 1998 12:33:35 EST Subject: Re: COZY: Hot Wire Template material In a message dated 98-02-23 15:56:42 EST, GeneKnapp2@aol.com writes: << Fm another source I was told that formica was the ticket. Easy to work with, can be sanded smooth, easy to write on for the talking no's and level Lines. I bought a 26" x 48" sheet. It sure looks flexable. >> I used formica and it worked fine. If I was going into production (planing to make hundreds of wings and canards) I'd probably use metal. The formica was cheap and easy to work with. After one use they are still in great shape and could be used again. I suspect that their life will be significantly longer then necessary. Dick Finn From: "L. Wayne Hicks" Subject: COZY: Is template sharing allowed?? Date: Tue, 24 Feb 1998 14:45:35 -0500 There's been alot of talk about templates. Have any of you that have completed building and are flying considered passing your templates and jigs along to new builders? It seems to me to be an excellent way to pass on the heritage and get a few more Cozy's in the air sooner. I understand that the "trust" factor is very important and I do understand that pilots who build can't resist trying to tweak things. A set of primo templates and jigs might fetch a good rental fee. Of course there are a few of you out there with kind hearts that would loan them out for free? __________________________________________ L. Wayne Hicks SpaceTec, Inc. Program Manager 3221 North Armistead Ave. 757-865-0900 voice Hampton, VA 23666 757-865-8960 fax http://www.spacetec-inc.com From: Marc J. Zeitlin Subject: COZY: Is template sharing allowed?? (fwd) Date: Tue, 24 Feb 98 15:22:03 EST Wayne Hicks wrote: While the subject of this message is: Is template sharing allowed?? You don't specifically address this issue. I'll do so. In my view (not a lawyer) as long as I don't charge for the use, I can loan my templates to whomever I choose. Books are copyrighted, and I can loan them to friends as long as I don't charge for them. >........ Have any of you that have >completed building and are flying considered passing your templates and >jigs along to new builders? A number of builders have used my canard templates - Lee Devlin and Marty Kansky among them. I still don't know where they are....... I want them back! :-). It's not a major effort to make the templates, however. >.............. A set of primo >templates and jigs might fetch a good rental fee. Here's where you MIGHT be in legal limbo. I wouldn't charge for them. >........ Of course there are a >few of you out there with kind hearts that would loan them out for free? If I can get my canard templates back, you're welcome to borrow them (and my winglet templates, as well). -- Marc J. Zeitlin Email: marcz@an.hp.com From: SMilesCozy@aol.com Date: Tue, 24 Feb 1998 19:26:00 EST Subject: Re: COZY: Hot Wire Template material and electrical shock In a message dated 98-02-24 04:07:15 EST, cdenk wrote: > CAUTION! YOu power source should have fuses or circuit breakers on > both low and high voltage side. It's in the archives but . . . a GFCI (ground fault circuit interupter) is the most effective way to protect yourself from electrical shock. If YOU become part of the current path, it shuts off instantly, even if you're using a two pronged, non-grounded plug. A fuse or circuit breaker, on the other hand, MIGHT not blow until you're a little crispy around the edges. This is because YOUR body would have to carry the full rated ampacity of the fuse/breaker (15-20 amps in most 120V branch circuits) until it failed, shutting off the power. Of course the circuit still needs the properly rated overcurrent protection device. (fuse or breaker) I'm not sure if you would need a GFCI on the load/low voltage side of a transformer, or even if it would work on the load/low voltage side . . . hmmm . . . more food for thought. I'll check into it and report back. HTH, Steve Miles Cozy MkIV 272 From: cdenk@ix.netcom.com Date: Tue, 24 Feb 1998 20:31:02 -0600 (CST) Subject: Re: COZY: Hot Wire Template material and electrical shock On 02/24/98 19:26:00 you wrote: > >In a message dated 98-02-24 04:07:15 EST, cdenk wrote: > >> CAUTION! YOu power source should have fuses or circuit breakers on >> both low and high voltage side. > >It's in the archives but . . . a GFCI (ground fault circuit interupter) is the >most effective way to protect yourself from electrical shock. If YOU become >part of the current path, it shuts off instantly, even if you're using a two >pronged, non-grounded plug. A fuse or circuit breaker, on the other hand, >MIGHT not blow until you're a little crispy around the edges. This is because >YOUR body would have to carry the full rated ampacity of the fuse/breaker >(15-20 amps in most 120V branch circuits) until it failed, shutting off the >power. Of course the circuit still needs the properly rated overcurrent >protection device. (fuse or breaker) > >I'm not sure if you would need a GFCI on the load/low voltage side of a >transformer, or even if it would work on the load/low voltage side . . . hmmm >. . . more food for thought. I'll check into it and report back. > >HTH, > >Steve Miles >Cozy MkIV 272 > > Agree with the GFCI, only on the high voltage side. It watches current flow through the normal hot and neutral (black and white)(not ground although most of the time the neutral and ground are tied together at the breaker (fuse) panel), when the slightest imbalance is sensed, it trips. I am not impressed with one device being adequate. The low side fuse is when you bump the hot wire into a pipe, duct or something thats ground in you basement, to minimize the arc damage. The low side fuse should be barely adequate. From: Cozy7971@aol.com Date: Wed, 25 Feb 1998 17:14:35 EST Subject: Re: COZY: Hot Wire Template material (fwd) In a message dated 98-02-24 12:37:50 EST, lschuler@cellular.uscc.com writes: << Just FYI: I tried 1/8" alum (cause I got a bunch for free from a local factory junk barrel). >> As an additional thought, the thicker the material the more likely that you will induce errors by failing to file the edges square with the surface. The wie will run along the high edge even if the low edge is the one that matches the template. I started with 1/4" Masonite and ended up with 1/16" formica. Dick Finn