Problems with FD Zoomie

[J Blatz]

So I build a Zoomie a few years back. Everything is as directed, no mods, no paint, just marker finish. The first flight, again a few years back, was a powered loop followed by the ejection 50' off the deck and a flutter to the ground.

So today, I added some trim to the very front of the wing/body joint, popped in a 1/2A3-2T, and it did the same thing.

I did a few trial glides in the backyard prior to powered flight....most were OK.

Advice?

 

[kjohnson]

It's been a while since I've flown anythign like the Zoomie, but as I recall from the original balsa version, getting the CG right was the key.
For that version the CG was supposed to be about 1/8" ahead of the trailing edge of the wing root.

Based on your flight report it sounds like your foam Zoomie needs more weight forward to a) counteract the looping on boost and b) stop the flutter to the ground.

If you end up adding enough weight to fix the boost that the glide suffers, consider adding small trim tabs made of manilia folder material or thin plastic (like from a blister pack) on the trailing edges.

kj