Solved 1/16in balsa firewall cannot take 2300kv motor power

agupt108

Member
In the FT tiny trainer build, I am using a 1/16" firewall of balsa, however, it is splintering on full throttle with a 2300 kv motor and 7x5 prop. The motor flies out with the screws, shattering the balsa. What is alternative firewall material I can use? Basswood?
 
Last edited:

Foamforce

Well-known member
In the mini tiny trainer ft build, I am using a 1/16" firewall of balsa, however, it is splintering on full throttle with a 2300 kv motor and 7x5 prop. The motor flies out with the screws, shattering the balsa. What is alternative firewall material I can use? Basswood?

The recommendation is plywood, which is much stronger than balsa. I buy firewalls from the FT store now since they’re cheap, but before that I just used 1/8” plywood that I bought from HobbyLobby. That’s the thinnest plywood they carry. It adds a little weight vs 1/16, but not enough to notice. Fwiw, in my Mini Scout I used a credit card as the firewall and that worked too.
 

The Fopster

Master member
In the mini tiny trainer ft build, I am using a 1/16" firewall of balsa, however, it is splintering on full throttle with a 2300 kv motor and 7x5 prop. The motor flies out with the screws, shattering the balsa. What is alternative firewall material I can use? Basswood?
If you can’t easily get plywood you could glue three sheets of the balsa in a sandwich to make your own. Put each layer at 90 degrees versus the one before (so the grain is at right angles) and glue with CA or even just PVA. I think that would do fine. Good luck!
 

agupt108

Member
You need to use 3mm plywood.
The recommendation is plywood, which is much stronger than balsa. I buy firewalls from the FT store now since they’re cheap, but before that I just used 1/8” plywood that I bought from HobbyLobby. That’s the thinnest plywood they carry. It adds a little weight vs 1/16, but not enough to notice. Fwiw, in my Mini Scout I used a credit card as the firewall and that worked too.
Yes I see that now thank you so much!
 

agupt108

Member
If you can’t easily get plywood you could glue three sheets of the balsa in a sandwich to make your own. Put each layer at 90 degrees versus the one before (so the grain is at right angles) and glue with CA or even just PVA. I think that would do fine. Good luck!
What is CA? Would wood glue work? Thank you so much for your help!
 

Merv

Site Moderator
Staff member
...What is alternative firewall material I can use? Basswood?
Lots of people 3D print firewalls, just about any thin wood will work. A thicker balsa would work, I’m guessing 3/16 would work.

I use the 5 gal paint stir stick from Walmart for my firewalls. They are longer and thicker than the free paint sticks for the 1 gal can of paint.
 

danskis

Master member
Glue a credit card to the front of the firewall or use hobby plywood. You can buy hobby ply at true value hardware