300% FT Commuter


Elite member
Hello! I used to be very active here on the FT forums, and I recently have been working on making my own autonomous aircraft software from the ground up, but in order to do any fine tuning I want to have a nice testing bed for it.

About 2 years ago I built a 170% Commuter IIRC and it was barely structurally sound enough for flights, I eventually ended up crashing it and obliterating it, but I want to make a 300% one now, I have the majority of the plans printed and taped together, I just need some help with how to reinforce it, I'd appreciate any tips you all may have.



Elite member
I don’t know how big that’ll end up, but carbon fibre tubes are pretty standard.

But with a big wing comes the accommodation for more weight. And with a wide wingspan comes the incentive to make the wings detachable in two halves. I like to use aluminium tube for this. A wider tube in each wing, sliding onto a narrower tube that runs through the both of them. It shouldn’t be hard to find two gauges of tube that will fit snug.



For the joins, I like to use 3mm plywood with hexagonal cuts to house nylon Hexnuts that you can run a nylon screw into. I’ve used this to hold the wings together and pin the vertical stabiliser in place (the vertical stab served as the pin to hold the horizontal stab) on a Sig Cadet. You might find this handy for attaching the supporting struts that the FT Commuter has running from the wings to the fuselage.


For the fuselage itself, the standard fuselage design should be pretty strong as it is. But you can always stick in an extra board of foam or two if you wanna be extra sure.


Elite member
All good tips! In the past I’ve used very strong neodymium magnets for holding wings on, but in this case I don’t want to trust it to that since the plane has a 7 and a half foot wingspan, so I’ll definitely look into what you do, thanks!