Looking for advice on reinforcing the FT Arrow w 3D printed center pod

[Jsteketee]

Hi Everyone! I built an FT arrow using a 3d printed center pod. So far the plane has been a blast both flying LOS as well as FPV. I'm having a big problem though with durability. Whenever I have a minor/moderate crash the glue seam between the upper wing and the 3D-printed center pod completely fails. I'm assuming this has to do with the ability of hot glue to grip the 3D-printed PLA. The rest of the airframe is rock solid in crashes due to the packing tape I have covering it.

Could anyone offer some advice on how to make this seam stronger? I've thought about redoing the build using a foam board center pod but I really like the looks and functionality of the 3D-printed piece.

PS Sorry if this is posted in the wrong place I'm new to the hobby/forums. Appreciate any advice!

 

[Merv]

I'd put a barbeque skewer form wing to wing about here, one on top & one on the bottom.
Imbed the skewer in the foam.

 

[RossFPV]

Hi Everyone! I built an FT arrow using a 3d printed center pod. So far the plane has been a blast both flying LOS as well as FPV. I'm having a big problem though with durability. Whenever I have a minor/moderate crash the glue seam between the upper wing and the 3D-printed center pod completely fails. I'm assuming this has to do with the ability of hot glue to grip the 3D-printed PLA. The rest of the airframe is rock solid in crashes due to the packing tape I have covering it.

Could anyone offer some advice on how to make this seam stronger? I've thought about redoing the build using a foam board center pod but I really like the looks and functionality of the 3D-printed piece.

PS Sorry if this is posted in the wrong place I'm new to the hobby/forums. Appreciate any advice!

next time it breaks you can try sanding the pla with rough sandpaper to give the glue more grip.

 

[Piotrsko]

Obvious observation: don't crash and it won't break.

You are dealing with the surface adhesion problem of the glue. You'll either have to increase the bond area or get a glue with better adhesion. I have some really expensive industrial glue that wont fail before the understructure fails, even if it's steel. The art store stuff while cheap is mostly useless

 

[quorneng]

Jsteketee
As you have discovered foam board and PLA don't stick together well. PLA has a completely non absorbent surface whereas foam board is the exact opposite. Any glue that adheres well to the PLA surface will simply pull out of the foam board.
You may have to consider altering you printed nacelle so the wing is actually supported by it so the glue joint works on the paper rather than the foam. It is after all the paper that is giving the foam its strength.

 

[RossFPV]

I'd put a barbeque skewer form wing to wing about here, one on top & one on the bottom.
Imbed the skewer in the foam.

View attachment 235766

If you were up to the challenge you could try to make it fully 3d printed.

 

[FlyingWithRyan]

Lot of subpar tips here in my opinion, the best option would to be to scuff it with some 80 grit sandpaper and then slice marks in the PLA like we do on our servos on planes. This way you have plenty of rough surface to adhere to.