Thread Tools
Old Jul 24, 2006, 12:52 AM
Cheesehead is offline
Find More Posts by Cheesehead
Ego varius quis.
Cheesehead's Avatar
Discussion

How to make/get really thin foam?


I've been tinkering with indoor flight lately, but I seem to be limited by the fact that all I own is "thin" (3mm+) Zepron, as opposed to something thinner. I've also got 5mm low-density EPP.

What's a good source for large panels of really, really thin foam? Styrofoam plates are too small for most wings, but are just the right thickness. Super-thin (2mm) EPP might work nicely for "skinning" EPS ribs for a flexible wing, but I doubt that a homemade hot-wire cutter would work.

So, what should I do? I've got power transformers and associated parts (incl. rheostats and assorted load resistors), and I can get nichrome. Should I cut my own foam, or try and find bigger plates? Should I stick with EPS, or use EPP?

Thoughts?
Sign up now
to remove ads between posts
Old Jul 24, 2006, 01:07 AM
LOGICAL_PSYCHO is offline
Find More Posts by LOGICAL_PSYCHO
Registered User
LOGICAL_PSYCHO's Avatar
You could check here, might have something you can use.

link here
Old Jul 24, 2006, 01:51 PM
rick.benjamin is offline
Find More Posts by rick.benjamin
Reduce the drama...
rick.benjamin's Avatar
HAH! Beat ya, Brad!
Old Jul 24, 2006, 02:38 PM
RobinBennett is offline
Find More Posts by RobinBennett
Sussex, UK
RobinBennett's Avatar
> I doubt that a homemade hot-wire cutter would work

It does, although it takes more care with adjusting the runners because any taper is more obvious in a thin sheet.

Over here we get 2mm EPS in long rolls for sticking to walls under wall paper.

You can also get 0.5mm, 1mm and 2mm depron
Old Jul 24, 2006, 03:02 PM
arx_n_sparx is offline
Find More Posts by arx_n_sparx
Dismembered Member...
arx_n_sparx's Avatar
Quote:
Originally Posted by Cheesehead
So, what should I do? I've got power transformers and associated parts (incl. rheostats and assorted load resistors), and I can get nichrome. Should I cut my own foam, or try and find bigger plates? Should I stick with EPS, or use EPP?

Thoughts?
Power transformers are good - especially one that will drop wall voltage to 24V. It should put out a few amps minimum - 100VA (~4 amps) is even better.

Forget the load resistors and rheostats; a *good* quality dimmer (Leviton makes one rated for 600W) or ceiling fan speed controller is what you are after. I built my own PS, but if I had to do it again, this is what I'd use.

Forget NiCr - use stainless steel instead; it takes less juice, and (much) more tension. Anything in .015 to .020" thickness is good. Braided or solid doesn't matter.

Thread on home-made foam cutters: https://www.rcgroups.com/forums/showthread.php?t=287621

Wire: http://www.cabelas.com/cabelas/en/te...equestid=49376


Brad (sheesh - I got beat to my own thread I bookmark the good ones too )
Old Jul 24, 2006, 03:13 PM
Cheesehead is offline
Find More Posts by Cheesehead
Ego varius quis.
Cheesehead's Avatar
Quote:
Originally Posted by arx_n_sparx
Power transformers are good - especially one that will drop wall voltage to 24V. It should put out a few amps minimum - 100VA (~4 amps) is even better.

Forget the load resistors and rheostats; a *good* quality dimmer (Leviton makes one rated for 600W) or ceiling fan speed controller is what you are after. I built my own PS, but if I had to do it again, this is what I'd use.

Forget NiCr - use stainless steel instead; it takes less juice, and (much) more tension. Anything in .015 to .020" thickness is good. Braided or solid doesn't matter.

Thread on home-made foam cutters: https://www.rcgroups.com/forums/showthread.php?t=287621

Wire: http://www.cabelas.com/cabelas/en/te...equestid=49376


Brad (sheesh - I got beat to my own thread I bookmark the good ones too )
I think mine's rated to at least 120VA, and I've got an 18v transformer that should do at least 7A. (Huzzah for industrial-grade electronic surplus!)
I'm tempted to try your foam-slicer-thingamajig, but I have no place to put it. I think I'll try hitting the local grocery stores for bigger plates before anything else. (That, or make a polyhedral wing.)
Old Jul 24, 2006, 06:53 PM
flypaper 2 is online now
Find More Posts by flypaper 2
Registered User
flypaper 2's Avatar
I cut pink foam down to 1 MM with a wire cutter, then cover it with Doculam for a tough wing skin. The old EZ OK wings were skinned this way. I just copied it
Old Jul 24, 2006, 11:10 PM
WrongwayII is offline
Find More Posts by WrongwayII
Registered User
Flypaper,

What thickness of Doculam do you use. What width works best
for you. I'm getting up courage to buy some.

WWII
Old Jul 24, 2006, 11:14 PM
foxabilo is offline
Find More Posts by foxabilo
Registered User
foxabilo's Avatar
Warm it gently 75c 30 seconds and then press it with a heavy roller, two thick metal plates and a heavy truck driving over them will do too also makes the foam more dense and heavy so I don't know if that right for your needs
Old Jul 25, 2006, 01:25 AM
Cheesehead is offline
Find More Posts by Cheesehead
Ego varius quis.
Cheesehead's Avatar
Quote:
Originally Posted by foxabilo
Warm it gently 75c 30 seconds and then press it with a heavy roller, two thick metal plates and a heavy truck driving over them will do too also makes the foam more dense and heavy so I don't know if that right for your needs
Tempting, actually.

What, exactly, is Doculam? I'd like to cut my airfoil out of foam, but it's always been too fragile. This sounds like a possible solution.
Old Jul 25, 2006, 06:40 AM
flypaper 2 is online now
Find More Posts by flypaper 2
Registered User
flypaper 2's Avatar
This is .002 thou thick. 13 1/2 in wide. Handles much like monocote inasmuch as it can be heatshrunk and stretched around the tips. Makes a nice stressed skin structure. Can be painted with no prior preparation. I get mine from Staples. Made right here in the best country in the world It's a clear sticky back plastic film made to protect documents among other things.
PS : It's cheap.
Old Jul 25, 2006, 12:22 PM
arx_n_sparx is offline
Find More Posts by arx_n_sparx
Dismembered Member...
arx_n_sparx's Avatar
Doculam Discoveries: https://www.rcgroups.com/forums/showthread.php?t=274520

I haven't tried this stuff. Personally, I have a real hatred for anything iron on (as in I really suck at it ) Doculam comes in various thicknesses - you want the thinnest stuff - I believe 1.5 mils (whatever that actually is ) It comes in a roll of 500 or 1000 ft, and is about a foot wide.

Brad
Old Jul 25, 2006, 01:06 PM
Cheesehead is offline
Find More Posts by Cheesehead
Ego varius quis.
Cheesehead's Avatar
Interesting. Perhaps I should make a foam-and-doculam wing?


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion How do I get really dazzling photos and Laughlin, NV vpatron Aerial Photography 15 Aug 29, 2006 08:36 AM
Discussion How to Make/Get BIG ailerons? Evan Byrne Slope 34 May 26, 2006 05:41 PM
does anyone know how to make a foam cutter im a newbie Flamy Foamies (Kits) 3 Jul 31, 2003 12:22 AM
How do you get warps out of foam ? American Flyer Parkflyers 3 Jul 03, 2003 10:54 AM