Hot Wire Question and Fin Material (US)

I may be the crudest, but I can’t help deleting all possible parts in my mind, and I end up with my car battery or a battery charger sitting on the ground, me holding the clamps and a 26" length of wire tied to a couple bolts held by the clamps.

I keep wondering if by holding either end of the thing in my sensitive surgeon’s hands, I could do away with the springs and lumber and transformers and things.

What sayest thou?

But thanks for all the schematics. I’m sure I’ll end up seeing the erro of my reductivist ways.

Hey Janklow,

I don’t know about you, but my short arms can’t reach all the way around a huge block of eps while walking and cutting the foam. I guess you could wear gloves but the wire gets pretty hot. You also might want to be as far from the foam as possible because it smokes alot.

It might work if you get another pair of hands from a friend. And don’t forget to get another pair of gloves as well :wink:



my favorite way to make a hot wire cutter is this. Take a piece of 1x2 or so hardwood as wide or a little skinnier than you want for your bow, and drill a 1/4 in. hole in each end angled out at about 30 degrees. into these holes, glue in 1/4 music wire from your local hobby shop, about 1 - 1 1/2 feet long, and then file a small slot in the outside of these rods. Now, cut your wire a little shorter than the space between these, and put loops on each end, and hook the loops into the slots you made earlier. It ends up almost like a bow and arrow. To hook up your wires just run the leads down the music wire (Insulated of course) and then hook on to each end of the wire. It ends up looking sorta like a bow and arrow. This system eliminates the need for springs, and is very easy to make. It will also keep your wire plenty tight for cutting.

Hope this helps!



Well, like I say, I’d have the hotwire tied to a couple of small bolts, and I’d have the charging (jumper) cables clamped to those, and there’s usually a rubber handle on each of the clamps, so hands are insulated and away from the wire.

I was kinda envisioning leaning the block (8 foot length) against a wall at a diagonal lean, with the templates affixed in the usual fashion, but me standing facing the thing (like the 2001 boys facing a big white styrofoam monolith), and my arms have a span of about 6 foot, so I was thinking that would cover the 2 foot of width on the blank and the 4 or 5 inches or so of depth,

and I can reach up about 8 foot, so that’s how I found myself thinking of the lowest tech solution physically possible and maybe even advantage myself in terms of the sensitivity of having each end in my hand more or less…

I also like the flex bow solution, although I’d use a screw eye on each end and alligator clips or something, rather than glue the wire in, so I could replace it easier.

Thanks guys!

I doubt you could keep the tension right AND still have enough control by hand.

My favourite way to build one is by using whatever is laying around :slight_smile:

Well I did take the photos that weekend… But I immediately forgot to post them :smiley:

I managed to remember eventually, tho :slight_smile:

Did I mention this was almost entirely made out of bits lying about in the shed :smiley:

Screw. Old shade-sail fitting. Nylon line.

Spring and brass hook.

Sewing bobbin. 20lb fishing leader (the only bit I bought - and I hate stripping off the nylon). Brass “L” hook. 12volt outdoor cable (you can see it’s got the leader looped twice around it).

Oh yeah. The Bow itself is scrap timber. Two screws in the left join and one in the right (to let it hinge). Some staples across the 12 volt cable to hold it in place. Goes onto a car charger.

I’m squinting and I can’t quite make out how you wired the one in your avatar…

This place has a Houston location and sells G10 by the sheet. check out the 25lbs G10 remnants box in the clearance items…

That’s very helpful–thanks! 50 dollars gets me like 4 or 5 sq.ft. of offcuts in the lovely Griffin green—

I realized that FCS composite fins are ridiculously flexy for my 200# and their stiffer fins are ridiculously expensive.

Attached is an updated and corrected drawing of the harp…