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Old Sep 03, 2009, 04:01 PM
Crazy, that's how it goes
CRAZYDAVE's Avatar
Calgary, Alberta CANADA
Joined Aug 2008
397 Posts
Question
Attention GWS Spitfire owners, a question please...

Hey ya'll

Been thinking about buying a GWS spitfire, brushless powered, dual Aileron servos for flaperons, and possibly retracts.

My issue is, unless I purchase new batteries, the only batteries I have available to me are Hextronic 2200mAh 3cells.

Are those big batteries and the modifications I have planned going to make the model unflyable?
I really don't want a tip stalling monster, but a good every day (including the odd windy one) warbird.

Any experiences including (but not limited to):
Setup, AUW, Battery size would be GREATLY Appreciated!

Thanks in advance!
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Old Sep 03, 2009, 04:16 PM
Oh no, not again!
jhspring's Avatar
United States, LA, Carencro
Joined Dec 2005
5,437 Posts
Dave, I have built a couple of these now. The first one was my goto plane for years. I used carbon fiber tape instead of the bamboo spar, and glassed it with 0.5 oz glass and WBPU. It even crashed in flames (literally) one time when the esc burned up. Anyway, I have never used smaller than a 2200, you'll need the weight for balance. I had to hollow out the fuse to get the batt as far forward as possible. On the second one I converted it to a Mk.IX by making the front fuse an inch longer. Some no-name 4200 kv 20-40 inrunner in a GWS gearbox driving an FSK 9 x 7 x 3 prop.

The Spit was one of GWS first planes. It's crude by the current standards and not really all that scale. However it has an undercambered aerofoil that makes it very forgiving and easy to fly. Not a speed demon by any means. Retracts are doable, see D-Rock's blog. Never found the need for flaperons on this one.

HTH, Jeff
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Old Sep 03, 2009, 05:51 PM
Glenn
wellington53's Avatar
United States, WI, Oconto Falls
Joined Jan 2004
2,751 Posts
Build the plane as instructions and you won't be dissapointed and like Jeff say's make the battery hatch to fit before you glue the two halve together. The flaperon idea I'm afraid is not a good idea on a GWS warbird or whatever, the plane floats in nicely anyways. Retracts are doable, Type in GWS Spitfire Retracts on You Tube and you will see. Let us know if you want to know more!
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Old Sep 03, 2009, 09:33 PM
Crazy, that's how it goes
CRAZYDAVE's Avatar
Calgary, Alberta CANADA
Joined Aug 2008
397 Posts
Thanks guys, I'm glad to hear the 2200 isn't too much weight.

Jeff, it sounds like (I'm guessing here) you're flying with aproximately a 19-20oz AUW with glassing and the big battery... no bad tip stalling tendencies?

Wellington, so no flaperons huh? Good, saves me installing an extra servo.

I've read up on all the retract stuff before I started this thread, so I am looking forward to this project.

An idea i've had is to make my spit a Mk V, with clipped wings, and am hoping that clipping the tips won't increase wing loading too much.

Appreciate all the advise so far..Please keep it coming, always looking for good/bad experiences before starting a project!
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Old Sep 03, 2009, 10:49 PM
Oh no, not again!
jhspring's Avatar
United States, LA, Carencro
Joined Dec 2005
5,437 Posts
Dave, I never weighed the first one but it might have been heavier than that. It was a belly flopper and my transition machine from Zagis. I could still be flying it, but it finally was just so beat up I got tired of looking at it, so I stripped the electronics for another plane. Very stable. The day it caught fire, losing the esc froze the controls, and it just gently spiraled in pouring smoke from the vent holes in the fuse, like a scene from the Battle of Britain. Melted a lot of foam, always smelled bad after that, and flew for a couple more years. I have nothing but good things to say about this airframe.

Jeff
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Old Sep 04, 2009, 03:54 PM
Crazy, that's how it goes
CRAZYDAVE's Avatar
Calgary, Alberta CANADA
Joined Aug 2008
397 Posts
Ohh, a question:
I'm not a big fan of the foam GWS spinners...What diameter at the cowl is the spinner?

There are a few dubro ones at the LHS that I might pick up, but I'm lookin for the right size... thx!
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Old Sep 04, 2009, 05:38 PM
Glenn
wellington53's Avatar
United States, WI, Oconto Falls
Joined Jan 2004
2,751 Posts
I don't know the diameter but the Spitfire does come with a plastic spinner and it's OK.
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Old Sep 04, 2009, 11:07 PM
Your Pilot Ryan
ryramZ's Avatar
United States, IN, South Bend
Joined Nov 2008
3,343 Posts
Quote:
Originally Posted by CRAZYDAVE
Ohh, a question:
I'm not a big fan of the foam GWS spinners...What diameter at the cowl is the spinner?

There are a few dubro ones at the LHS that I might pick up, but I'm lookin for the right size... thx!
I think it is an inch and a half, not positive though wait till you get it and check it out. i also used a big lipo in mine tp 2100 it barely fit i should have hollowed it out some before i glued the fuse together. Once you see what you have to work with you'll realize that there really is no room for servos out on the wing, the wing is not very thick. people have done retracts. I definitely would not use the stock LG, also i cut trenches and embedded extra spars in the wing. I used a 400 brushless motor from heads up rc great price, flight times were forever. As far as the tip stall goes. You have to be careful not to let it slow down to much. The eliptical wing shape lends itself to the tip stall, i noticed that you really have to keep your speed up in a loop and do it big, fly through it. Rolls are a non issue it does them great, it's a plane that keeps you on your toes. The clipped wing version might be more forgiving, although i am not sure. Let us know what you decide, of course all the mods you mentioned could be engineered if you wanted to do them bad enough. Keep us posted..
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Old Sep 05, 2009, 12:15 AM
Doing it in the Lateral Axis
modfly's Avatar
USA, OH, Akron
Joined Dec 2006
15,360 Posts
Well, I have been flying the GWS Spitfire for 3 years or so and it is one of my fastest planes. It is the fastest of the GWS 1st Gen warbirds IMO. The one in this video has a 1320mah 3cell @ 3oz with a 400 motor. Yes its hard to balance. I flew this same plane today with a 400 and a 1800 mah lipo. Its a very durable plane and easy to repair. Seems to be a little tricky to fly compared with the Corsair, Zero, 109, Mustang IMO. I have mine balanced 10mm forward of what the spec calls for. That eliminates Tip stall. Forgot stallerons I mean Flapperons. Try spoilerons.
The plane in this video is 17oz.

GWS Spitfire Landing (0 min 19 sec)


windy flight..
GWS Spitfire @ 120 watts #2 (2 min 47 sec)
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Old Sep 05, 2009, 12:44 AM
Crazy, that's how it goes
CRAZYDAVE's Avatar
Calgary, Alberta CANADA
Joined Aug 2008
397 Posts
Excellent video thanks!

I've decided that I will be getting the GWS Spitfire, and anticipate recieveing it in the next couple of weeks.

My order to HC will be sent on Monday.

Here is what I have planned in regards to components:

Motor: http://www.hobbycity.com/hobbycity/s...idProduct=7992

Prop:http://www.hobby-lobby.com/scale_3_b...18580_prd1.htm

Retracts: http://www.hobbycity.com/hobbycity/s...idProduct=4310

Any opinions would be greatly appreciated, and I'll post build pics either in this thread or a seperate one!

Thanks again!
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Old Sep 05, 2009, 01:22 AM
Doing it in the Lateral Axis
modfly's Avatar
USA, OH, Akron
Joined Dec 2006
15,360 Posts
wow! 340 watt motor. How many amps is that thing going to draw? That style motor will take a bit of effort to mount in this plane.
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Old Sep 05, 2009, 05:51 AM
Dr. John
Sudbury, Canada
Joined Mar 2004
498 Posts
RE Motor

Agree with Modfly that motor is overkill, a 57gram or 45 gram motor would be fine here, you could use that motor but the airframe will need some stiffing up a carbon fiber rod for the wing as a minium. Copy cat outrunners are so inexpensive($15-20) its no longer an issue, I purchases a 20-20L hacker knock off for $20 that has 80-90% the quality of the original hacker I bought for $80 5 years ago. A 77 gram motor is probably the biggest I would consider here.

TR 35-30C 1100kv Brushless Outrunner (Eq AXi 2808)
http://www.hobbycity.com/hobbycity/s...r_(Eq_AXi_2808)

TR 28-30B 14A 1050Kv Brushless Outrunner
http://www.hobbycity.com/hobbycity/s...less_Outrunner
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Old Sep 05, 2009, 07:01 AM
Confused? Who, me?
Roger Lombard's Avatar
United Kingdom, England, North York
Joined Jan 2005
4,790 Posts
I'd agree with thosewho are saying 340w is way overkill - it won't give you as much fun as a lesser power output. THe Spitfire (and any of the other first generation GWS warbirds will do unlimited vertical on anything over 120-150W and even then you'll find yourself at less than 50% WOT most of the time.

If you go with johnprov's second recommendation I think you'll be fine and get much better flying time. You'll need a motor mount to adapt the outrunner to the mounting stick - this is it:

http://www.hobbycity.com/hobbycity/s...otor_Twin_Pack

The other thing to note is that the Spit is very pitch sensitive - set your elevator movement for maybe 1/8" either way, and you may find even that is more than you need.

Lastly the problem with the Spit is not tip stall (unless you go seriously overweight) but the fact that it floats forever. More likely to overshoot on landing than undershoot.

FWIW I use a geared inrunner which draws about 15 amps with a GWS 0975HD (NOT SF) prop on 3 cells. It accelerates hard even going vertical.

The kit supplied spinner is fine but is designed to push onto the 3mm threaded propshaft of the GWS gearbox. Using the outrunner with a prop adaptor you are going to need to use your thinking cap to get a correct size spinner to fit.
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Old Sep 05, 2009, 08:25 PM
Crazy, that's how it goes
CRAZYDAVE's Avatar
Calgary, Alberta CANADA
Joined Aug 2008
397 Posts
I think HC's numbers for motor I was looking at are a little outta whack.

Looking at a few reviews for that motor, I'm guessing it probably produces around 270watts.

Regardless, for the 1/2 oz weight difference, wouldnt more power be better?

Mind you, for the whopping 11USD, I might just buy one to try out.

Thanks for all the input!
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Old Sep 06, 2009, 04:05 AM
Confused? Who, me?
Roger Lombard's Avatar
United Kingdom, England, North York
Joined Jan 2005
4,790 Posts
Power you don't need is a liability because the efficiency of the power train is reduced so actually running the more powerful motor/prop to give the same power output as a lesser power train will require a greater power input. Let's say for argument's sake that you're happy spending at least part of the flight cruising round the sky at about 35 mph (which would be a scale speed of about 420 mph - pretty good for a Spit.) On a 7.5" pitch prop the motor is going to be doing about 5000 rpm (assuming it's direct drive, not a geared set-up). Assuming the same battery pack and prop for both motors that will require more current on the bigger motor than on the smaller motor. I think I'm right in saying that speed controllers, never mind motors, don't like having to run in a "throttled" condition, so they get hot and chew amps.

If you can put in four minutes of safe flight on 340w in the Spit flying all the time at WOT you should be entering competitions, and you can certainly think faster/ concentrate better than me!

I have a GWS Formosa I with a 220w motor. Bear in mind the Formosa is a decent bit bigger than the Spit. It's good for getting "wow's" from the crowd when it jumps out of your hand and heads for the moon at warp 9 but truth to tell, for me, - and that's for me, not for you, - for me, it's not as much fun or as satisfying to fly as it was on 120 watts. Don't take this amiss but any silly can fly an overpowered plane, you'll learn more about the plane and your own skills with a balanced set-up. And even more with an underpowered set-up!

Now having said all that, you can fly with whatever the hell motor you like and if you want to try the more powerful motor - and it will fit? - you go right ahead and do it and good luck to you, but be safe.

Anyway - keep us posted
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Last edited by Roger Lombard; Sep 06, 2009 at 04:11 AM.
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