Foam Board

[Nelson]

I have ordered the electronics for my first scratch build, being in the UK I am unable to source Dollar Tree Foam Board cheaply so I was wondering are there any good substitutes and what are there disadvantages/advantages compared to DTFB.

Plus could someone post the weight of a A1 5mm sheet of dollar tree foam board so I can compare.

I found these two companies:

http://www.foam-board.co.uk/a1-5mm-white-foamboard/

http://www.depron.co.uk/

Thanks,

Nelson


Oh and where can one find a similar firewall motor mount for the FT Spit which doesn't have $44 shipping?

 

[rcspaceflight]

http://www.flitetest.com/articles/comparing-foam-board

Adams brand

Bought at Dollar Tree

Price: $1.00 (not including tax)

Sheet size: 20" x 30" x 3/16" measurements were double checked and are true.

Total weight of sheet: 115grams

Weight per one square inch: 0.191666grams

----------------

Not sure on the first link, but Dollar Tree foam board is very, very similar to Depron except DTFB has paper on both sides. You can use depron, a lot of people do, you just need to cover it with something to get it as stiff/rigid as DTFB. Packing tape works, so does newspaper with white glue and water mixed together and use that like a paper mache.

 

[Flat4]

Dollar tree foam board weighs about 115 grams per sheet. Being that it's dimensions are 20"x30" that gives 600 sq. inches of foam so that gives us 0.1916 grams per sq. inch. A1 is 23.4" x 33.1", which is 774.5 sq. inches. Multiply that by the weight per square inch and you get 148.5 grams for an A1 size sheet of Dollar Tree Foam Board.

As far as what's available across the pond, I'm not to sure. I know I've read posts from others from the UK stating what they had available. The big advantage of DTFB over other foam boards is it's generally considerably lighter, but at the cost of weight you lose strength. So it's really a give or take with all types of foam board.

I found it nearly impossible to source motor mounts for our application, I'm sure there are others out there like FT that cut their own and sell them, but I never ran across any for decent prices. I believe most people just make their own, that's what I've been doing at least. Just source some hobby plywood, cut a square, and drill some holes.

Hopes this helps a little, and good luck in your search.

 

[Flat4]

Bah, rcspaceflight beat me to it.

 

[rcspaceflight]

Oh and where can one find a similar firewall motor mount for the FT Spit which doesn't have $44 shipping?

Flite Test uses a hobby grade plywood. I want to say 4mm but I don't remember for sure. I think you could use a plastic card like a gift card. Anything that can hold a screw would work. The real strength is the packing tape that goes around the power pod and in front of the firewall.

 

[rcspaceflight]

Bah, rcspaceflight beat me to it.

I'm tricky like that.

But two answers saying the exact same thing is usually reassuring. Chiming in with a similar response is always good. At least I hope so because I do that all the time.

 

[Flat4]

Flite Test uses a hobby grade plywood. I want to say 4mm but I don't remember for sure. I think you could use a plastic card like a gift card. Anything that can hold a screw would work. The real strength is the packing tape that goes around the power pod and in front of the firewall.

Yea I want to say they use 3/32 hobby ply, I snagged 1/8 and it's slightly thicker. At least from what I can remember, I'll chime back in later when I get home and can measure them.

Edit found this on their FT Flyer plans:

Firewall
2” X 1 3/4“ Inch
(50mm X 45mm)
1/16“ Inch thick(1.5mm)
Hobby Plywood

 

[rcspaceflight]

I was way off. lol.

 

[Flat4]

I was way off. lol.

Or just making sure he built nice strong firewalls, it's all in the perspective.

 

[Nelson]

Okay so I put some numbers in and came out with these figures.

Foam Board UK

Dimensions: 59.4cm x 84.1cm

Area: 4995.54cm^2

Mass: 320g

Density: 0.064 gcm^-1

Dollar Tree Foam

Dimensions: 50.8cm x 76.2cm

Area: 3870.96cm^2

Mass: 115g

Density: 0.030gcm^-1

It turns out the UK Foam Board stuff is twice as dense (consequentially twice as heavy) as the dollar tree foam board, would this be a problem with the FT Spitfire, I have seen reviews of this foam board and apparently they are similar.

 

[Flat4]

I can't see it being to big of an issue. My spitfire from DTFB just floats, so I can't see the addition 200 grams of foam or so should be a deal breaker. It will penetrate wind easier with the more weight that's for sure, the only downside is your stall speed will be a bit faster than a lighter plane, but again my spitfire flies super slow, so you should be fine.

 

[rcspaceflight]

I started off building with Flip-Side foam board which is about twice the weight of Dollar Tree. It doesn't work well with the FT Flyer or FT Delta, but the FT Spitfire should be fine. Warbirds like weight. You'll fly faster, but that's not always a bad thing.

If you want a more basic plane, then a square tube with a true airfoil wing is always a classic design. It uses as little foam as possible so the weight of the foam isn't much of an issue.

 

[pastrychefin]

i have yet to buy any dollar tree foam board i source my foam board my local grocery store they use it as advertisement and its free 4 foot by 8 foot

 

[rcspaceflight]

i have yet to buy any dollar tree foam board i source my foam board my local grocery store they use it as advertisement and its free 4 foot by 8 foot

Now you're just showing off.

 

[Nelson]

How many sheets of a1 does the spit need?

Also could someone who owns an FT spit tell me how much it weighs with everything (but the battery) in it.

I saw some other people have a spit which weight from 750-950 grams is this too much for the spitfire?

 

[Nelson]

I can't see it being to big of an issue. My spitfire from DTFB just floats, so I can't see the addition 200 grams of foam or so should be a deal breaker. It will penetrate wind easier with the more weight that's for sure, the only downside is your stall speed will be a bit faster than a lighter plane, but again my spitfire flies super slow, so you should be fine.

How much does your spit weigh?

Other people (using the heavier foam) have spit's that weight from 750g to 950g.

 

[epp static]

I have ordered the electronics for my first scratch build, being in the UK I am unable to source Dollar Tree Foam Board cheaply so I was wondering are there any good substitutes and what are there disadvantages/advantages compared to DTFB.

Plus could someone post the weight of a A1 5mm sheet of dollar tree foam board so I can compare.

I found these two companies:

http://www.foam-board.co.uk/a1-5mm-white-foamboard/

http://www.depron.co.uk/

Thanks,

Nelson


Oh and where can one find a similar firewall motor mount for the FT Spit which doesn't have $44 shipping?

Hobbycraft sell 5mm foamboard at £4 per A1 sheet, often with buy 2 get 3rd free or 2 for £7 offers.
Make you own firewall with 2 pieces of 1/8th ply hot glued together, strong and excepts self tap screws well.

 

[Ace2317]

I have used Elmer's brand foamboard once. It works, but it is much more dense. It's heavier, so the plane flies heavier, and is more prone to stall. Cutting it out was a pain too. It was somewhat stronger, but if it comes down to it, I think it would just break rather than crumpling. Overall, DTFB is better, but if it's all you have, you could definitely make do.

 

[gowen]

I bought some of this black foamboard in the UK (http://www.foam-board.co.uk/a1-5mm-black-foamboard/) about a year ago. Hopefully they are still selling the same stuff.

It's about 490 g/m², but if you run an iron or heatgun over it you can peel the paper off one side reducing the weight to 340 g/m² to use for wrapped parts like wings and fuselage.