I use 3 different 'oversized' battery packs (200 -220Mah) in my Scrappee.

I found three problems with this:-
(1) The packs don't fit in the cowling.
(2) The packs were resting on top of the servos
(3) the packs move around and upset the C of G.

This tray fixes these issues.
(1) It lifts the pack up so that it doesn't foul the servos.
(2) Each pack is taped to its own tray in the right place to attain the correct C of G.

Now all I do is drop a tray into the plane knowing that the servos will work and the C of G is perfect :-)

If printed in PETG, the trays weigh 0.9G each.

Prusa

I3 MK3S

No

No

0.2

If printed in PETG, the trays weigh 0.9G each (and don't snap!)