HobbyKing.com New Products Flash Sale
Reply
Thread Tools
This thread is privately moderated by RAY GWS, who may elect to delete unwanted replies.
Old Nov 10, 2006, 06:45 PM
I fly for Beer
Jagzilla's Avatar
Chilliwack, B.C. Canada
Joined Sep 2004
2,730 Posts
Mine came in at 30 oz's, using a 2100 3 cell.
J
Jagzilla is offline Find More Posts by Jagzilla
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 10, 2006, 07:02 PM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
Now I know!

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
jamesdr is offline Find More Posts by jamesdr
Reply With Quote
Old Nov 10, 2006, 07:46 PM
Registered User
kahloq's Avatar
Fort Collins, Colorado, USA
Joined Dec 2005
7,821 Posts
Quote:
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?
kahloq is offline Find More Posts by kahloq
Reply With Quote
Old Nov 10, 2006, 08:13 PM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
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
jamesdr is offline Find More Posts by jamesdr
Reply With Quote
Old Nov 10, 2006, 09:58 PM
Outcast outlaw
As far away from RCGroups and the AMA as possible!
Joined Aug 2004
6,601 Posts
Quote:
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...

Quote:
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...
Red 61 is offline Find More Posts by Red 61
Reply With Quote
Old Nov 10, 2006, 10:00 PM
Watts Rule, Glows Drool
dogon1013's Avatar
orlando, FL
Joined Mar 2003
3,197 Posts
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.
dogon1013 is offline Find More Posts by dogon1013
Reply With Quote
Old Nov 10, 2006, 11:11 PM
Registered User
kahloq's Avatar
Fort Collins, Colorado, USA
Joined Dec 2005
7,821 Posts
Quote:
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.
kahloq is offline Find More Posts by kahloq
Reply With Quote
Old Nov 11, 2006, 09:06 AM
Outcast outlaw
As far away from RCGroups and the AMA as possible!
Joined Aug 2004
6,601 Posts
Quote:
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!
Red 61 is offline Find More Posts by Red 61
Reply With Quote
Old Nov 11, 2006, 02:23 PM
Registered User
kensp's Avatar
Darwin Australia
Joined May 2002
6,960 Posts
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
kensp is offline Find More Posts by kensp
Reply With Quote
Old Nov 11, 2006, 04:00 PM
Registered User
kahloq's Avatar
Fort Collins, Colorado, USA
Joined Dec 2005
7,821 Posts
Quote:
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.
kahloq is offline Find More Posts by kahloq
Reply With Quote
Old Nov 11, 2006, 04:08 PM
Unrepentant Carnivore
jamesdr's Avatar
Brandon, Fl
Joined Mar 2005
2,499 Posts
Well - don't just sit there - FLY her! She looks good!

Jim
jamesdr is offline Find More Posts by jamesdr
Reply With Quote
Old Nov 11, 2006, 04:21 PM
Watts Rule, Glows Drool
dogon1013's Avatar
orlando, FL
Joined Mar 2003
3,197 Posts
Maidened the 38 today.

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
dogon1013 is offline Find More Posts by dogon1013
Last edited by dogon1013; Nov 11, 2006 at 04:39 PM.
Reply With Quote
Old Nov 11, 2006, 05:10 PM
Registered User
kensp's Avatar
Darwin Australia
Joined May 2002
6,960 Posts
Quote:
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
kensp is offline Find More Posts by kensp
Last edited by kensp; Nov 11, 2006 at 05:25 PM. Reason: Add photo and text
Reply With Quote
Old Nov 11, 2006, 08:21 PM
Pusher jets rule!
crxmanpat's Avatar
Mesa, AZ
Joined Jan 2006
17,109 Posts
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
crxmanpat is offline Find More Posts by crxmanpat
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Gws 二次大戰 名機 Gws-38 GWS CHEN Japan 6 Jan 01, 2007 10:36 AM
GWS-38 Twin Fighter Randori GWS (Grand Wing Servo) 154 Dec 13, 2006 02:35 PM
Discussion GWS-38 soon 廣營新的戰鬥機即將上市. GWS CHEN Taiwan 15 Dec 11, 2006 11:35 PM
New Product ****Must check GWS New Airplane GWS-38**** RAY GWS Product Announcements 24 Oct 25, 2006 11:21 PM
New Product GWS-38 (P-38 Lightning)... its here. Blaze.45 Hot Online Deals 18 Oct 05, 2006 12:39 PM