Thread Tools
Oct 06, 2015, 10:35 PM
Scratchbuild Aviation
speedactyl's Avatar
Thread OP
Discussion

IC Engine on a foamie Plane


Question how well do they Go? and if Vibration , Vapor ,Heat ,or fuel spillage can affect the foam

EPS Foam
EPP Foam
EPO Foam

I'd Ask cause an RC buddy Plans to load a 26cc on a rather Large Foamy
Sign up now
to remove ads between posts
Oct 06, 2015, 10:50 PM
Registered User
exf3bguy's Avatar
The engine description would suggest a gasoline engine rather then a glow engine. Exactly what fuel source is being used?
Oct 07, 2015, 01:28 AM
Scratchbuild Aviation
speedactyl's Avatar
Thread OP
if its a Gasser or nitro im not so clear yet, but what I do know is both are internal combustion . it doesn matter but what does matter is how well the would work. or any method to make them work.

im mainly fly Electric so I have no idea on the Sort of IC engine he's planing to put in.
Last edited by speedactyl; Oct 07, 2015 at 01:37 AM.
Oct 07, 2015, 02:27 AM
Youtube channel : solentlifeuk
solentlife's Avatar
First ... Gasoline dissolves many foams ... Glow can but usually ends up with a mushy surface.

I had early Foam IC models about 30yrs ago and they were nice out of box ... but flight was poor.

Yes it can be done ... but total fuel-proofing to protect the foam. That's inside and out. Best application is a varnish or non-solvent lacquer.

Engine mount will need serious woodwork buried into the fuselage usually in form of hardwood beams running back into the foam longitudinally. The stress and thrust of an Ic engine needs to be spread back into the fuselage to avoid localised cracking / fracturing of the foam.

The engine quoted ... is a gasoline job I would think and is even more in need of stress / vibration load spread to avoid the model literally falling apart.

It's not a project I would entertain to be honest. Not without significant modification and strengthening of the model overall.

Nigel
Oct 07, 2015, 02:40 AM
Registered User
exf3bguy's Avatar
I agree with everything Nigel says here and will add that the fuel source matters greatly. A 26cc gasoline engine is going to vibrate much more then an average size glow engine would so as Nigel pointed out would require much more structure. Then again the different fuels are better used with specific foams. Personally if I were to take on such a project I would apply a fiberglass skin to the exterior.
Oct 07, 2015, 04:22 AM
Scratchbuild Aviation
speedactyl's Avatar
Thread OP
im looking into that. knowing foam alone wont stand a chance if the fuel drips somewhere.

my next concern is foam isnt gonna last any longer than balsa wood model. maybe I should ask him why the trouble of putting an IC engine on a foamie.

adding fiberglass would end up as heavy as balsa wood model or more

and what about Coroplastic S.P.A.D. how well do they do on IC engines
Oct 07, 2015, 06:36 AM
Registered User
earlwb's Avatar
Yes gasoline dissolves foam or turns it into a gooey sludge like stuff. Glow fuel isn't a problem with foam but the foam will absorb the oil over time like a sponge. So you need to fuel proof the foam around the engine, etc.

Coroplast is gasoline and glow fuel proof. No problems there at all. Check out the "Spad to the Bone" Website. Lots of ideas on how to build and fly coroplast planes.
Latest blog entry: yes I still fly airplanes too
Oct 07, 2015, 09:17 AM
AMA 537620
ChillPhatCat's Avatar
There used to be a line of .25 sized combat warbirds that were made entirely out of pink foam... the kit was a square block of foam in the outline of the fuselage that needed to be shaped and sanded down, and a foam core wing and balsa tail feathers. There were strips of fiberglass tape used to provide strength down the fuselage sides and on both sides of the wing, top and bottom and then the whole thing was to be covered with colored packing tape and sealed with clearcoat... I had a Corsair that I never finished and then sold off, was a pretty cool idea but I didn't have the time or experience to finish it at the time. As long as the foam is completely protected from the fuel it shouldn't be a problem.
Oct 07, 2015, 01:58 PM
Registered User
exf3bguy's Avatar
Adding fiberglass does not need to add a bunch of weight. A glass covered foam airplane done correctly would be way lighter then a coroplast airplane of the same size.
Oct 08, 2015, 02:24 PM
Registered User
earlwb's Avatar
Sureflite for many years made foam model RC planes in several different types. When I last looked they still made them but for electrics now. I still have one setup to fly with a .32 ASP engine on it.
Latest blog entry: yes I still fly airplanes too
Oct 08, 2015, 06:51 PM
Scratchbuild Aviation
speedactyl's Avatar
Thread OP
Thanks guys for some insights oddly im also looking for longevity of airfame . And rare i have seen foamies last 10 years or more. Or risk in flight obliteration. Will be moving to other material options
Oct 15, 2015, 10:06 AM
Scratchbuild Aviation
speedactyl's Avatar
Thread OP
Guys one question what about aluminum foam core boards would they be better?
And how do i go a bout the firewall to protect the foam froam heat.
Nov 12, 2015, 12:41 PM
Registered User
I make blue foam cowls out of 1" sheets from Lowes. Shape it sand it to shape, and fiberglass it. But you must seal it with gas proof finish such as the Z-poxy fiberglass resin.

The obvious approach on a big foamy, is to fiberglass the entire thing. now it's a foam filled fiberglass model.
Nov 13, 2015, 04:00 PM
team sleprock
whiskykid's Avatar
is this what your buddy was thinking?

Scratchbuilt Foam Airplane with a DLE30 - "Bubbles" (2 min 58 sec)
Nov 13, 2015, 11:00 PM
AMA 537620
ChillPhatCat's Avatar
Was poking around and came across this old for sale thread. I am pretty sure this is the Corsair kit I had so many years ago. Obviously they are selling it with electric setup but it was intended for 1/12 scale IC combat.

https://www.rcgroups.com/forums/show....php?t=1656541


Quick Reply
Message:

Thread Tools