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Old Aug 30, 2004, 10:17 PM
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Talontsi96's Avatar
Edmonton, Alberta, Canada
Joined Jun 2004
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Why does the 370 give more thrust than the 400?

I burned out my stock slow stick 300 motor with the "D" gearbox after about 10 flights. I'm using 1500mah lipos and the 1180 prop. I decided to get another unit and got the 370 with the 5.33 gear box. I used the same prop. I never went more than 3/4 and mostly 1/2 on the throttle the motor lasted 2 flights and on the third one it crapped out. The slow stick had excelllent power with this motor/gearbox.

Finally I decided that I should get the 400 because people say it has more power and I figured it would last longer. Well it may last longer but with this setup the SS is a dog and can barely lift the SS and camera. I got the 400 with the 5.28 "H" ger box and was using a 11X7 prop. Tommorow I'll try the 1180 prop on it but I'm really disapointed with the performance of the 400. After the flight I checked the 400 and the lipo and they were not even warm. So I don't thik I'll burn it up but I need more power.

Why does the 350 with the same gearing have so much more power than the 400?

How do I get the same power as the 370 with the 5.33 gearbox and 1180 prop on the 400 "H" gearbox (5.28 ratio)?
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Last edited by Talontsi96; Aug 30, 2004 at 10:28 PM.
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Old Aug 30, 2004, 10:37 PM
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umrk's Avatar
Paducah Barkley, Kentucky, United States
Joined Sep 2003
783 Posts
How many cells?
What cells?
Is it reversed timed?
Did you break in the motor?

DeanInMilwalkee reports that a reverse timed 400, "I" gearing (6.3), 13x9, on 10 cells will put out 20-25oz thrust and draw 9a. It sounds to me like your not loading it hard enough (needs a larger prop), or running too few cells (6-7?), or its not timed, or a bad solder joint, or... ?

At abt 60% efficency for a speed 400, if its not getting rather warm, its not putting out anywhere near its capibilities.

mike
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Old Aug 30, 2004, 11:44 PM
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Talontsi96's Avatar
Edmonton, Alberta, Canada
Joined Jun 2004
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Its running on 3 cell lipos. Koham 3 cell 1500 lipo.

I'm running it the way it came (I guess that would be reverse timed). I'm not sure what you mean by reverse timed. I know that I read somewhere that the motors are actuallty running in reverse from the factory and if you mod the gearbox such that the motor spins the right way it will be properly timed. Is that what you mean? What youre saying is that I mod the gearbox so that it runs in the proper direction and use a bigger prop? How big can I go with the 5.28 gearing?
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Old Aug 30, 2004, 11:59 PM
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eBird's Avatar
Grand Junction, Colorado
Joined Jul 2002
4,636 Posts
I'd try a 12 inch prop before you go messing with the gearbox. Put a 12x6 or 12x8 on there and let 'er rip.

It is a 6v motor or 7.2v?

That 11v lipo pack should run that motor pretty good...
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Old Aug 31, 2004, 12:27 AM
Abundantly deficient.......
CptMike's Avatar
Orange County, CA
Joined May 2004
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Looks like you made a prop change somewhere in there. Check your prop, could be on backwards. That setup with 3 cells should be smokin'.

Mike
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Old Aug 31, 2004, 01:54 AM
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Talontsi96's Avatar
Edmonton, Alberta, Canada
Joined Jun 2004
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I'm not sure what voltage the motor is rated for, I dont see any ratings on the packaging. As far as the prop, I did not have it on backwards. So I sould just go to a bigger prop? like a12 by 6 or 12 by 8?
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Old Aug 31, 2004, 02:28 AM
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Jim Mackay's Avatar
Ελλάς, Αττική, Αθήνα
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My 400G with 9.6 KAN 1050 turns the 1206 pretty good. Your 11.1 Lipo should be a lot better I guess.
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Old Aug 31, 2004, 07:33 PM
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Talontsi96's Avatar
Edmonton, Alberta, Canada
Joined Jun 2004
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I got the 12X8 prop and although its better its no wehre near the thrust I was getting with the 370 and the 1180 prop. Both motors had the same gearbox. At least not the motor (400) is warm (not hot) when I run it at full throttle. Why is it that with the same gearing the 370 feels so much more powerfull?
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Old Aug 31, 2004, 09:10 PM
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Kyle G.'s Avatar
Wheeling, Illinois
Joined Dec 2003
5,240 Posts
how heavy is your setup? ive heard many good things about speed 400's and 3s li-pos. should work pretty well. breaking it in isnt a bad idea either. just take some C sized alkaline batteries (1 battery) and hook it up to the motor. put the motor in water and let it run for 5 minutes. (the water should start turning black) then siwtch the polarities so the motor spins the other way. repeat the process. after its all done, spray some oil or WD-40? inside the can to get rid of the water and lubricate the motor. once youve done that i think you should be set. also, like others said, try the next prop size up.
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Old Aug 31, 2004, 09:40 PM
Been There! Done That!
boomerace's Avatar
Eugene, Oregon, United States
Joined Sep 2001
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It's no wonder the 350 crapped out! Good god man you shouldn't have been running it at over 9.6 V and you were using over 11 V and it shouldn't had a prop bigger than 9 X 5 or 8 X 6! Crap you were running it way over specs... no wonder it had insane power!!! Try looking at the GWS tables before you do that to a motor!!! You are lucky the 300 lasted that long on the way over spec voltage you were using!
boomer
www.boomerseflight.com
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Last edited by boomerace; Aug 31, 2004 at 09:43 PM.
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Old Aug 31, 2004, 10:19 PM
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Talontsi96's Avatar
Edmonton, Alberta, Canada
Joined Jun 2004
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Well I mentioned that the 370 I bought lasted only 2 flights. But I alos mentioned that I never went to full throttle. The most I went was 3/4 spurts. Otherwise it had great power at half or slightly above half power. I don't think it was getting full 11.1V to burn out that quickly. I did look at the GWS prop specs. Right on the box of the motor it said that I could use a 1180 prop. So I did. Great power but not for too long. T

he 400 with the same prop and gear ratio does not have the same poop. But I am experimenting now with different gear ratios and different props to make the 400 work.
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Old Aug 31, 2004, 10:25 PM
Been There! Done That!
boomerace's Avatar
Eugene, Oregon, United States
Joined Sep 2001
19,187 Posts
Quote:
Originally Posted by Talontsi96
Well I mentioned that the 370 I bought lasted only 2 flights. But I alos mentioned that I never went to full throttle. The most I went was 3/4 spurts. Otherwise it had great power at half or slightly above half power. I don't think it was getting full 11.1V to burn out that quickly. I did look at the GWS prop specs. Right on the box of the motor it said that I could use a 1180 prop. So I did. Great power but not for too long. T

he 400 with the same prop and gear ratio does not have the same poop. But I am experimenting now with different gear ratios and different props to make the 400 work.
Forget the box as the figures I gave you are right from the GWS motor charts on their website! Surely you didn't think you could safely use over 11 V with your stock 300 as max recommended voltage is 7.2V or 2S lipos!
boomer
www.boomerseflight.com
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Old Sep 01, 2004, 10:52 AM
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Gardena, California, United States
Joined Feb 2004
736 Posts
It might be more in the gearing. I went to a 400-4200 e-flite and picked up a C gearbox 5.33 and was disappointed. I changed it to a 6.6 gearing and running a 12x8 apc prop with 3s 1500's and the plane really moves. Good luck.
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