gravityrules

I'm putting the finishing touches on a new GWS Spitfire, all glassed and painted. From my last unfortunate experience with a GWS P-51, I want to make sure that I get the CG right on this. Is the setting stated in the directions correct? Where is the best spot to measure from (leading edge right next to fuselage?). Is the supplied clay good to use for balance? Where is the best spot to put it?

Specs:
Motor - HiMaxx 2015-4100 geared 5.3-1 (aluminum HiMaxx gearbox)
Prop - GWS 9070 (I have some 1080's laying around)
Battery - 8 cell 730mA 9.6v NiMH (yeah, I know - I should go LiPoly)

I'll be flying this at about 6000ft elevation. Any advice to avoid destruction on maiden would be MOST appreciated

BuzzBomber

My Feedback: (4)

My spitfire flies best balanced somwhere between 55-60mm from the leading edge at the wing root; this is just behind the bamboo spar, I think. Use lead stick on weights from the hobby shop to get it to balance, they're available in 1/4 oz (7gram) increments. Put them as far forward as possible (perhaps the inside front of the plastic cowling) so that less total weight is needed. Most importantly, DO NOT use more than the recommended throw on the elevator. I use about 6mm up and down on low rates, and 9mm on high rates--I haven't needed high rates yet.

gravityrules

Thanks, Matt. Just so I'm clear - what do you define as the "wing root". Is this where the wing mates to the fuselage? I'm not sure my LHS has those cool stick on weights. Maybe I'll tape some rocks on the nose :-)

BuzzBomber

My Feedback: (4)

Chance are, if your LHS has anything for pinecar derby or even boats, they should have the weights. If not, no biggie, just use what you've got on hand. When I say wing root, I mean the radiused fillet where the wing joins the fuse--it's not too critical exactly where. Say, 1/2 inch out from the fuselage should be good. You just don't want to measure 60mm back 4 inches out on the wing, since the wing is elliptical.

gravityrules

Cool! Thanks! I should be able to have it airborne by Sunday. I've read on threads that it's not so quirky as the stang, but livelier than the ME-109 and Corsair. I'm getting a bit bored with my E-starter. Would you suggest the 9070 or 1080 prop to start? I'm almost thinking the 1080 for a bit more thrust and less speed and then using the 9070 once I get it dialed in.

BuzzBomber

My Feedback: (4)

At my elevation (drop a zero off the end of yours) those AAA cells would be seriously overtaxed with the 1080 prop. However, in your case, it may be okay. You may also want to try out the 1060HD prop, but I'm not sure it would have enough pitchspeed to make the spit happy. Might be worth a shot. If you're not ready to go li-ppoly just yet but are willing to spend a few $$$, the CBP 650 packs available from www.cheapbatterypacks.com are worth every penny. I think they're about $15 a pop for 8-cell plus shipping.

mrstingray

Does your plane not have the round areas under the wing where the center of gravity is supposed to be checked? My e-starter has a round "crossshatched" area where it is supposed to be checked.

I have a 2 cell lipo battery and can almost complete an outside loop with a fresh battery. Am going to go brushless before I get my GWS Corsair!! Good luck and let me know how it flies compared to the e-starter.

gravityrules

mrstingray,
No, the GWS warbirds don't have that nice CG marks on the wing that the E-starter has. You have to measure from the leading edge of the wing. My Spitfire was pretty tail heavy and I had to put almost a whole stick of clay in the nose to balance it out. I hated to add the weight, but I've heard that proper CG on the warbirds is critical.

The E-starter is a great plane to have before moving to the warbirds. I put a brushess Himaxx in mine. I maidened the Spitfire this weekend and it is much more challenging to fly than the E-starter. Very sensitive to controls and will "snap" into a spin on stalls (altitude is your friend when that happens!). I've heard the Corsair and Messerschmidt are more forgiving than the P-51 or Spitfire. I would suggest doing some research on how to beef up plane with fiberglass. I had some rough landings this weekend that only cause minor damage that would have been much more severe had I not made the mods.

I was never able to finish an outside loop with my E-starter. Just as I would try to bring it up out of the bottom inverted part of the loop it would roll out of inverted to normal flight. I'd me interested to know if anyone has mastered that maneuver with an E-starter.