Source for suitable template materials?

[rtfm]

Hi again,

 

I'm also looking for suitable material out of which to make hotwire templates. I've tried MDF, but the wire burns right into it. Same with plywood. I read on the web that guys use formica or phenolic impregnated paper. Neither of which I seem able to find a local (to Brisbane) source for.

 

What do you guys use? And where can I get some?

 

Cheers,

 

Duncan

 

 

[Bob Llewellyn]

Hi again,I'm also looking for suitable material out of which to make hotwire templates. I've tried MDF, but the wire burns right into it. Same with plywood. I read on the web that guys use formica or phenolic impregnated paper. Neither of which I seem able to find a local (to Brisbane) source for.

What do you guys use? And where can I get some?

 

Cheers,

 

Duncan

I use commercial aluminium, 2mm... never burned it!

 

 

[Garry Morgan]

If you are burning the wood I think the wire is to hot ,I have always used plywood for many years. The wire is drawn slowly over the foam to allow for the bow in the wire, my wire is only 1.2m long make the templete longer at the end to allow for the bow in the wire to catch up. If the wire gets to hot it melts below the templete. also keep an even speed, or it will leave lines in the job. after a couple of goes you will get the hang of it. I have an adjustable voltage to adjust the wire temp. it is a transformer with tags on it for different currents.

 

 

[Bob Llewellyn]

If you are burning the wood I think the wire is to hot ,I have always used plywood for many years. The wire is drawn slowly over the foam to allow for the bow in the wire, my wire is only 1.2m long make the templete longer at the end to allow for the bow in the wire to catch up. If the wire gets to hot it melts below the templete. also keep an even speed, or it will leave lines in the job. after a couple of goes you will get the hang of it. I have an adjustable voltage to adjust the wire temp. it is a transformer with tags on it for different currents.

Agree - I hotwired a few model aeroplane wings on a 1-m frame, using an old electric blanket transformer (OLDE!), ply templates... I also suggest do not get impatient and saw with the wire, it does cut but because the ends are cooler than the middle you get an hourglass effect - small but irritating.

I'm using al because I want high reproducibility, and it's easy to shape very accurately, and the wire slips along it like a dream.

 

 

[rtfm]

Hi guys,

 

AL sheet might be just the thing. I wonder if my router friend will be able to cut them? Or should I find somewhere to laser cut them?I need about 14 of them.

 

Ideas?

 

Duncan

 

 

[Bob Llewellyn]

Hi guys,AL sheet might be just the thing. I wonder if my router friend will be able to cut them? Or should I find somewhere to laser cut them?I need about 14 of them.

Ideas?

 

Duncan

I've seen a guy hand-carving spar extrusions with a router, so a piddling little template iught to be so easy...

 

 

[rtfm]

Great. I've just received my copy of CompuFoil software, so I'm going to be creating the files for the templates any day now. I also ordered the Feathercut hotwire system, after trying VALIANTLY to get manual hotwiring right. Every hesitation, sneeze or eye-blink puts a little groove in the surface. It's a LOT harder than it looks. But the gravity fed Feathercut looks to be the boss!

 

Duncan

 

 

[Gnarly Gnu]

Al sheet might be just the thing. I wonder if my router friend will be able to cut them? Or should I find somewhere to laser cut them?

If you're going to the expense of having templates cut what not just get the foam itself wire cut automatically, you'll then get a perfect job too.

 

BTW not sure why styrene based foams are so crazy expensive in this country....?

 

 

[rtfm]

What, and spoil all the fun?

 

Actually, one of the guys in the same complex as I am building has a business which makes industrial cases, boxes etc. He'd got a great big router, and is keen to give me a hand with my "crazy airplane". Cost will be very reasonable - materials and a bit of loose change for beers, I think.

 

I'd LOVE to get the whole lot CNC done - but like most of us, it always comes down to money...

 

Duncan

 

 

[Bob Llewellyn]

What, and spoil all the fun? Actually, one of the guys in the same complex as I am building has a business which makes industrial cases, boxes etc. He'd got a great big router, and is keen to give me a hand with my "crazy airplane". Cost will be very reasonable - materials and a bit of loose change for beers, I think.

 

I'd LOVE to get the whole lot CNC done - but like most of us, it always comes down to money...

 

Duncan

Write your MP - Australia needs a "Paid build your own aeroplane leave scheme"...

 

 

[Bob Llewellyn]

Write your MP - Australia needs a "Paid build your own aeroplane leave scheme"...

Tell 'em only Lib voters fly... they don't deserve the truth...

 

 

[Garry Morgan]

You can sand the surface to a fine finish and fill any groves . once you glass over the foam is where the work realy starts. I use a long alloy or plywood strip to bend over the job to drag / pull the filler over the job, the thinner the fill thinner the fill mix. I have seen people with things like a putty knife them sand ,it makes a big job a hole lot harder. Block foam or harder foam / sheet is a lot easier and a close weave cloth stops the shrinkage showing in the finish .

 

 

[Downunder]

You may want to look at water jet cutting (if going mechanised).

 

It can cut things laser or cnc can't.

 

I had some carbon fibre plate cut and the edges were perfectly smooth.