Date: Thu, 25 Jan 96 09:28:18 EST From: "Wilhelmson, Jack" Subject: Re: Getting Started Opinion on cutting versus buying foam cores: I cut all my cores myself and did what I considered to be a good job, however; when I started the finishing process I found that my cutting job was not as good as I thought. Hot wire drag back causes low places that are not detectable (by a inexperienced builder) until the contouring step of the finishing process starts. Since then I have used precut cores (from Featherlite) on a new canard and found them to be true and they did not require filling to correct low areas. If you decide to cut your own, be critical about what you accept as good, it will payoff later. Date: Thu, 01 Feb 96 14:15:15 EST From: MISTER@neesnet.com Subject: Re[2]: Hot-wire saw ______________________________ Reply Separator _________________________________ Subject: Re: Hot-wire saw Author: Marc J. Zeitlin at INTERNET Date: 1/31/96 4:54 PM The hot wire saw I made seemed to work fine. I took a 2X3 of the desired length and drilled a hole at each end along the 3" dimension. The hole was sized to be a real tight fit for some pieces( maybe 18") of steel tubing (about 1/2" diameter as I recall). I drilled a small hole on the end of each steel tube and threaded safety wire between the pieces of tubing. I wrapped a few turns of the safety wire on one end. My electrical connections were made to the steel tubing using standard worm gear type clamps. I used two 12 volt battery chargers in series with a lamp dimmer control on the 115v input to control the current. Just before starting to use the saw I would take a set of vise grips to one of the steel tubes ( the one with the several turns of safety wire)and tightened to increase the tension on the wire. Pluck the wire as you tighten it until the frequency (pitch) of the tone stops increasing. At that point you've reached the yield tension of the wire. The springiness of the steel tubing keeps the wire tight. Check the tension periodically as you use the cutter. I think this pretty much corresponds to what is recommended in the plans and it seemed to work fine for me. My $.02 Bob Misterka N342RM Date: Sat, 4 May 1996 13:20:02 -0400 (EDT) From: Randy Crutfield Subject: COZY: Nichrome wire Has anyone used nichrome instead of safety wiring for hot wire foam cutting? While researching the thermocouple info., I discovered that Omega lists Nichrome wire as well. I purchased 20 gauge (0.032") safety wire for this. Would one use the same diameter nichrome, or smaller for a better cut? Omega list 20 gauge nichrome for $16 for 50 feet, $48 for 200. Randy Date: Sun, 5 May 1996 19:16:04 -0400 (EDT) From: Bill Walsh Subject: Re: COZY: Nichrome wire On Sat, 4 May 1996, Randy Crutfield wrote: > > Has anyone used nichrome instead of safety wiring for hot wire foam > cutting? While researching the thermocouple info., I discovered that > Omega lists Nichrome wire as well. I purchased 20 gauge (0.032") safety > wire for this. Would one use the same diameter nichrome, or smaller for > a better cut? Omega list 20 gauge nichrome for $16 for 50 feet, $48 for 200. > Randy > It works better than the safety wire in that it takes the heat better and won't streach as easily. I believe that it becomes brittle though,..... Maybe not but it had some quality I didn't like. I found some stuff in the old Alexander catalog. Can't remember the name of it but I haven't been able to find any after Alexander was bought out. I went back to safety wire and just use the old vise grips to tighten before cuts. Ask Jeff Russell he would remember the stuff that Alexander had. I'm done with all of my cuts so I haven't had a need to search for it Bill W From: Rafael Bello Subject: COZY: hot wiring sources Date: Fri, 5 Jul 1996 16:26:00 +0200 (MET DST) Hi Cozy builders, I have been reading the last weeks the stuff related to hot wiring, and the different solutions suggested. I don't know if you have considered the possibility of using the battery of the car as current source. Here in Europe we use a 12 V d.c. battery in the cars and usually 24 V in the trucks. I suppose there in the USA will be the same. They assure in the cars a current of at least 50 A for an hour, what is more than required for hot wiring. I use this source for hot-wiring and works superb. I find it relatively safe enough too. Just only take care in not to short-circuit the battery, as it can source more than 200 A. Or just use a fuse. To regulate the current I attach one of the cables from the battery to a grip, which I move forwards and backwards in the nicrom wire. Hope this helps, Rafa rafa@asterix.cps.unizar.es From: michael.amick@nashville.com Subject: COZY: ACAD hotwired wingcores Date: Thu, 3 Oct 96 19:14:02 Organization: The Nashville Exchange-http://WWW.NASHVILLE.COM I had a neat tour yesterday of a plant that produces stryofoam insulation. They use Acad type equiptment to hot wire huge blocks of styrofoam into small shipping and packing pieces-Cool Stuff!!! Guess What!?! The system is large enough to do Cozy parts per plans (i.e. three sections per wing & canard). Does anybody out there have AutoCAD drawings (on Disks) of the hot wired parts? Michael.Amick@Nashville.com MkIV #317 Chapter 5