I've never seen it discussed, so there must be a reason why you shouldn't, but I'll show my ignorance and ask.... Is there any way you can use a car type battery charger (2/6/8 amp selectable) to power a hot wire for cutting foam? TIA.
On Tue, 3 Jul 2007 16:37:45 -0400, I said, "Pick a card, any card" and "BCRandy" instead replied:
There have been numerous discussions here and in other places on the web regarding this. The answer is yes, to be curt. Do a Google search using the terms 'hot wire foam cutter battery charger' without the quotes and see what you get.
The RCM plans service foam cutter uses one.
-- Ray
Yes, but its not very controllable.
\ Yes, and you will want to make a coil of wire from the same wire you are using for cutting, and use an alligator clip to attach it anywhere along the length of the extra wire, so you get the temperature you want. The coil is like a big adjustable resistor.
Thanks for the helpful responses. Not only will I be trying it out today without worries, but I learned something about RCM and Google, along the way.
One problem with all of those online foam cutter & power supply build i
yourself sites is they are years old and you can't find a lot of th supplies from the places that are suggested any more. It is difficul to substitute suppliers as the parts descriptions are limited t Radioshack part numbers that no longer exist.
I can't get aluminum channel from the local hardware store, I can?t ge ni-chrome, Rene wire, or stainless leader fishing wire anywhere local After pricing all it would take to build a power supply from Radi Shack parts you would be better off buying a power supply from the Ho Wire Foam Factory, it is nearly the same thing, a dimmer switch with fuse connected to a dc transformer except they use a stereo plug $74.90, no build, no fuss
-- sar
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I have been using an auto battery charger from Sears for over 10 years and have cut over 100 wings for combat planes mostly. Temperature control is a bit of an issue. I used 7 strand control line model wire and settled on .012 wire after turning some .008 into a flash bulb and not getting .018 hot enough. Most hobby shops can get the wire from Sig or you can order direct from either Sig or Brodak. I do have a few copies left of a video done by a local hobby shop on cutting foam. It is a primer with all the info needed to get started. If you are interested cost is $15 and that includes postage and handling. It is not professionally done but the info is all there. There is currently a copy listed on Ebay if you are interested. Bob Furr
"sar1" wrote
On the other hand, if you have most of the stuff around, (you probably do) $75 sounds like an awful lot of money.
There are all kinds of ways to build a bow without channel aluminum. You can use wood, with music wire for the ends to control the tension, or wood arms, with a pivot and a twisted up light rope on the back side to make the tension. You can use a stiff spring on the end of the cutting wire where it attaches to the bow.
There are all kinds of ways to make a good cutter, without buying the commercial ones. You can order the cutting wire, or you can substitute something else for the cutting wire. I have even unwound stranded steel cables, and used the individual steel strands, in a pinch.
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Just for your information, all transformers are AC devices. There is no such thing as a DC transformer.
The nichrome cutting wire doesn't care if the electricity being provided is AC or DC, so a light dimmer, which works buying changing the phase relationship of AC electricty's voltage and current components, should work fine. Just be sure to run one of those safety devices - ah, now I remember - a ground fault interrupter circuit - so no one gets electrocuted.
Why not create your own page that shows folks how to build a foam cutter using modern components? You should get quite a few hits, maybe enough to attract a sponsor or two. Then start building a database on the dimensions of various engines, along with their exhaust bolt spacing and you may even get to be able to make a profit.
I would do it, except I don't see well enough/long enough any longer. I hope you do not have the same problems.
Ed Cregger
I have deceided to post my research on hot wire power in the builder
workshop section look her
-- sar
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