GW sport cg.. anyone?

[mtorcyclst]

I've just upped the power in my gw sport to a 270 mah 7 cell pack.. the thing really moves out now, but seems a bit tail heavy.. Sadly, I didnt make a backup copy of the plans before i hacked them to bits in the building process. Can anyone give me an approximate cg location for this plane?

[Dave Robelen]

Hi,
The front edge of the spar is a good place to start. It can be fun making the distinction between tailheavy, and a trim problem. If you can set the model up in a smooth glide without excessive control sensitivity, your CG may be pretty close. When you added power, it may have introduced a tendency to nose up more at full throttle. I have only flwn mine on a seven cell ni-cd, so it is difficult to make a comparison.
Regards, Dave

[mtorcyclst]

Thanks much, Dave! I couldn't have asked for a better source for the answer to my gw sport questions.. I'll try that c.g. and let you know.. Here's another quick one.. I initially covered it with tissue .. it was very very light, but the tissue would wrinkle whenever the humidity changed, which is often in SE wisconsin.. I re-covered the wing with Coverlite, which is fine, but even with balsarite on the plane, doesn't have very good adhesion. DO you have any suggestions for a light, durable covering material that's easy to apply?

Thanks again!
Rob

[Dave Robelen]

Hi, The Coverlite is a good choice. I have found that Balsarite (especially film formula) comes up short in the adhesion department. Sig makes a decent paint on adhesive Stix-it? You could do worse than applying it with Elmer's White glue much like the tissue, then shrink it. That worked for me. Also, the Elmer's glue will get tacky once it is dry with heat, much like the paint on adhesives.
Regards, Dave