Mine came in at 30 oz's, using a 2100 3 cell.
J

kahloq

Mine is flying at about 36oz. I balanced her at 60mm (where the gas caps are on top of the wing). Today I took her out for a second flight and had the nerve to fly her inverted (way up mind you) and found I needed a fair amount of "down" to maintain level flight. That means she is a bit nose heavy so I will be moving the CG back a bit. Theory says that a balanced model should fly hands off sunny side up and down.

I did fly with the EagleTree data logger. As you can see from the graph, in my launcher's hand at about 90%, she was drawing 38 amps. Upon release, the load dropped off. (By the way - she took off like a bat outta hell). Instinctively we knew it would unload in flight but not how much. Now I know. I held the throttle steady at 85% or so and as you can see, there were peaks and valleys in the current draw. I'm guessing this was due to aerodynamic loads (turning into the wind, loops, rolls, etc). Bottom line, with the TowerPro 2409-12 and APC 8x4's I was drawing no more than 16amps in flight for brief periods, consistantly in the 13 amp range.

Jim

Originally Posted by jamesdr

kahloq

Mine is flying at about 36oz. I balanced her at 60mm (where the gas caps are on top of the wing). Today I took her out for a second flight and had the nerve to fly her inverted (way up mind you) and found I needed a fair amount of "down" to maintain level flight. That means she is a bit nose heavy so I will be moving the CG back a bit. Theory says that a balanced model should fly hands off sunny side up and down.

I did fly with the EagleTree data logger. As you can see from the graph, in my launcher's hand at about 90%, she was drawing 38 amps. Upon release, the load dropped off. (By the way - she took off like a bat outta hell). Instinctively we knew it would unload in flight but not how much. Now I know. I held the throttle steady at 85% or so and as you can see, there were peaks and valleys in the current draw. I'm guessing this was due to aerodynamic loads (turning into the wind, loops, rolls, etc). Bottom line, with the TowerPro 2409-12 and APC 8x4's I was drawing no more than 16amps in flight for brief periods, consistantly in the 13 amp range.

Jim

Thanks for that great info. This tells me I will be ok at the weight I am at as far as it being able to fly and carry the weight decent. Can you tell me how well it did with landings(like how slow you could get it without it dropping a wing). Does yours stall easy or is pretty tame and is mostly controllable all the time? Do you have to keep the speed up to keep her flying well or can you slow it down for some slower "photo" shot flyby's.
If I remember the stats right, my max amps were in the range of 24 and had 250 watts combined using 9x7x3 MAS props. Think I'm good?

Of course your milage may vary but I find this a very sweet handling plane. The only other war bird that was easier to handle is the eFlite P-47. The -38 slows easily without a lot of dramatic wing wagging. Mine's heavy so I would not say she "slows to a walk" to land but is under control down to landing speeds. Mine is a belly flopper. 250 watts is a bit under my motors but you are lighter. May be a toss up.

One thing I did note, leave altitude for loops. I did a fairly high speed, low level loop and was rapidly running out of airspace as she sagged on through the bottom.

Good luck on the maiden!

Jim

Originally Posted by kahloq

.....but possibly due to weight of the MAS 3-blade props and dubro spinners. I will have to weight an APC 9x7.5E prop and compare that to an MAS 9x7x3 to see the difference.

Yeah, the MAS 3-blade props are heavy...

Originally Posted by jamesdr

The only other war bird that was easier to handle is the eFlite P-47.

LOL -- and I'm retireing my Eflite P-47 because it's too docile...

Well mine is finally ready for the maiden.
AOW is 36oz with the 3s2p 2400mah polyquest 20 and the 2 GBX triple stack motors.

I am getting about 1:1 thrust with the 8*5 scimitar props drawing 10amps per motor. I measured a full 5.5 minutes of full throttle duration before partial cutoff (I disabled the cut-off after the test).

I was also worried about the weight but it sounds like that is about normal (especially with rudders and heavy motors). CG will be back pretty far, probably 80mm range.

Originally Posted by Red 61

Yeah, the MAS 3-blade props are heavy...

LOL -- and I'm retireing my Eflite P-47 because it's too docile...

MAS 9x7x3 weighs 5/8 of an oz or 19 grams.
E-flight 10x7 prop weighs 16 grams
APC 10x7 SF prop weighs 12 grams

So, even if I switched to APC props, I'd only save .5 oz total. Not enough for me to bother.

Jamesdr, mine is actually 1.5oz heavier then yours, but Im using landing gear. I have thought about upping the motors to e-flite park 400's instead of the 370's in there now, but then I'd start to ahve to consider a larger battery too...which adds even more weight so it'd probably be a wash. I will try it as is and hopefully she'll fly decent. If, not I can switch to two blade APC props.

Originally Posted by kahloq

So, even if I switched to APC props, I'd only save .5 oz total. Not enough for me to bother.

Yet, remember that 0.5 ounce is weight about 5.5 inches forward of your CG... It could make a difference!

kahloq

Get rid of thoes Dubro spinners,

Weight of one Dubro spinner ........................25 grams
Weight of one self made foam spinner .............5 grams

Weight saved .............................................40 grams = 1.5 oz

Ken

Originally Posted by kensp

kahloq

Get rid of thoes Dubro spinners,

Weight of one Dubro spinner ........................25 grams
Weight of one self made foam spinner .............5 grams

Weight saved .............................................40 grams = 1.5 oz

Ken

No! Thanks, but I dont care for the foam look regarding spinners. I may switch to the aluminum backplate dubro style if I change to 2 blade props. These weigh about half of the ones with the plastic backplate.

Ok...here is pics of mine.

Well - don't just sit there - FLY her! She looks good!

Jim

The maiden was un-eventfull (which is good ), the day started with some trouble, though. It turns out my transmitter battery toasted, and actually heated up and warped the plastic in the transmitter. thankfully Phillip let me borrow his backup transmitter battery, and I was able to fly some today. It also turned out that the spinners were both a little out of round so they had to be removed.

The 38 tracked well on takeoff, even with the castor nose wheel and had plenty of power with the 8*5 scimitar props (about 1:1). Took some measurements with Chucks E-meter before the flight, they are:
10.29 volts
20.1Amps
206 Watts
10,320 RPM

first flight was mainly for tirmming. It took a few clicks of up and I noticed it was rather twitchy, so after a few rounds I landed it and adjusted the elevator and ailerons throws (changed from 85% to 50%). the second flight was not twitchy at all.

later, I put on some 8*6 APC props and took some more measurements:
10.36 volts
29.6 Amps
307 Watts
9120 RPM

This was over the ESC burst rating of 14 amps each, But I flew it anyway since the Amps should be lower in the air. It took off in about half the distance than before. It had more speed, but not a whole lot. I will try a 7*7 or 7*8 prop next, for more speed. I tried the rudders in-flight and they seemed to work well, but I was mostly flying without them just to feel it out. More flights tomorrow AM.

Chucks Video'ing came out great, he got the first 2 flights. The videos can be found here: http://www.rcgroups.com/forums/showt...42#post6371369

Toby

Originally Posted by kahloq

No! Thanks, but I dont care for the foam look regarding spinners. I may switch to the aluminum backplate dubro style if I change to 2 blade props. These weigh about half of the ones with the plastic backplate.

If you dont like lightweight foam spinners then how about these TYI lightweight electric spinners

My GWS-38 may not look as pretty but at an All Up Weight of 25 1/2 oz it preformance and handeling is very good.

Ken

kahloq, she looks great man! Now get out there and fly her! If you switch to 2-bladers and still use DuBro spinners, get the 2.25", they fit the cowlings much better.

Toby, nice maiden! Looks like you had plenty of power.

Pat