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-   -   GP Rimfire motors? (https://www.rcuniverse.com/forum/brushed-brushless-motors-speed-controls-gear-drives-123/8492272-gp-rimfire-motors.html)

badazzbusa 02-18-2009 07:37 PM

GP Rimfire motors?
 
Is anyone flying a Rimfire GPMG4595 in a aerobatic plane? If so, are you doing any 3-d and not cooking the motor?
I have a GP Edge 540 with a 4595 Rimfire, 35a ESC and flying on 3cell 2100mah packs.
The first motor lasted 3 flights and burnt up. They replaced it. The second one lasted 1 flight. Sent that back with the ESC and they replaced the motor with the GPMG4600 and said the ESC was fine. The 4600 lasted 3 flights and burt up also. I was running a 10x7 prop on the 4595's and a 12x6 on the 4600. Now I'm waiting for my 4th motor. I'm starting to think a Rimfire isn't very good, lol.
I've never had a problem like this with any other electrics.
This is the set-up I'm running.
http://www3.towerhobbies.com/cgi-bin...?&I=LXRYN9&P=V

Dr Kiwi 02-19-2009 11:43 PM

RE: GP Rimfire motors?
 
Rimfire motors have ridiculously optimistic specs for max. amps and max. watts!

I tested the 35-30-1250 and found that it had no hope of surviving a 10x7 APC E on 3s - my test motor (sent to me by Great Planes for test purposes) drew almost 30A/330W and got HOT (65C) very fast...even a 10x5 APC E was too much for it. The most I would use would be a 9x5 or 10x6 GWS HD ... no more than 250W.

Hopefully, after they've replaced lots of motors Great Planes will finally realize that their motors CANNOT sustain the amp/watts loads they recommend. I tried to tell them this after testing several different Rimfire outrunners for them, but they've obviously paid no heed.

But you are seriously at fault with the 4600 (35-30-1450) - it is HIGHER Kv yet you are running an even bigger prop... what on earth do you think this will do to the motor??? Even GP recommends no more than a 9x6... and that is probably optimistic!

badazzbusa 02-20-2009 09:03 AM

RE: GP Rimfire motors?
 
Dr Kiwi, Thanks for your response. As for me being at fault on the 4600, I don't think so. GP recommends the 9x6 on 4 cells and the 12x6 on 3 cells. Here is the link: http://www.electrifly.com/motors/mot...ire-35-30.html
That is also what they told me to run on the phone when I called and questioned them about changing it over to a 4600 from the 4595. The 4600 should run on a 45amp ESC. They told me to go ahead and run it on the 35 amp esc and 12x6 prop and if it damaged the ESC they would take care of it. I'll be the first to admit I know nothing about elec. flight but I have 2 Trex 450se v-2's and a E-flight 3 cell Extra flying on E-flight gear with no problems at all using the gear they recommend. Thanks again for the info. I guess I will keep being a pain to them until they fix their motors or they run down the street to Horizon and get me a good motor, LOL.

jdetray 02-21-2009 02:30 AM

RE: GP Rimfire motors?
 
1 Attachment(s)
You'd better have another look at that Rimfire chart!

For the GPMG4600, they recommend the 12x6 on 2 cells and the 9x6 on 3 cells.

- Jeff

badazzbusa 02-21-2009 07:12 PM

RE: GP Rimfire motors?
 
Ya'll are correct. Sorry about that but I didn't look up the chart until after Dr Kiwi told me it was the wrong prop. I just misread the chart. Hobby services was the ones that told me to run that prop when I questioned them on that motor with the 35amp ESC. Bottom line is I've still burnt up 3 rimfires in 7 flights and I'm trying to find out if anyone else is going through this with Great Planes.

BigTb17 02-22-2009 09:06 AM

RE: GP Rimfire motors?
 
That's a shame about your Rimfires. I haven't done any serious testing like Dr Kiwi has done, but I do have three Rimfire motors and have never had a problem with any of them.

I have a 28-26-1000, and a 28-30-950 that have both seen countless flights and I've never had an issue with either. I also have a 35-30-950 that only has maybe 4-6 flights on it so far, but no problems yet. I hope you get something worked out, good luck.

badazzbusa 02-22-2009 10:36 AM

RE: GP Rimfire motors?
 
Thanks!!!!!

Dr Kiwi 02-22-2009 10:43 AM

RE: GP Rimfire motors?
 

ORIGINAL: BigTb17

That's a shame about your Rimfires. I haven't done any serious testing like Dr Kiwi has done, but I do have three Rimfire motors and have never had a problem with any of them.

I have a 28-26-1000, and a 28-30-950 that have both seen countless flights and I've never had an issue with either. I also have a 35-30-950 that only has maybe 4-6 flights on it so far, but no problems yet. I hope you get something worked out, good luck.

I'm glad you have success with your Rimfires - just to clarify........I have never said that Rimfire motors were poor... only that the suggested amp/watts limits are ridiculous - run 'em at modest amp draw and they ARE good motors.

jimmyjames213 02-25-2009 09:27 PM

RE: GP Rimfire motors?
 


ORIGINAL: Dr Kiwi

Rimfire motors have ridiculously optimistic specs for max. amps and max. watts!

I tested the 35-30-1250 and found that it had no hope of surviving a 10x7 APC E on 3s - my test motor (sent to me by Great Planes for test purposes) drew almost 30A/330W and got HOT (65C) very fast...even a 10x5 APC E was too much for it. The most I would use would be a 9x5 or 10x6 GWS HD ... no more than 250W.

Hopefully, after they've replaced lots of motors Great Planes will finally realize that their motors CANNOT sustain the amp/watts loads they recommend. I tried to tell them this after testing several different Rimfire outrunners for them, but they've obviously paid no heed.

But you are seriously at fault with the 4600 (35-30-1450) - it is HIGHER Kv yet you are running an even bigger prop... what on earth do you think this will do to the motor??? Even GP recommends no more than a 9x6... and that is probably optimistic!
well....................i have the same motor and use the apc 10x7 e and it works great, i have even used top flight and MAS 10x7 props (fpr glow) and they have worked great
i just got a 11x4 im going to try w/ the motor (topflight power point, wood prop) to get more torque
i only have a 25 amp esc so maybe thats why it aint frying, but since im useing it on gws foamies i could care less if i dont have full power since i fly on 5-6 clicks of throttle most of the time, even when i WOT it the esc is still cool after flight so......

the rimfire motors are durable in crashes, i have put one through a tree that landed motor first on a asphalt road (the wing ripped off in the tree, got it back the next day) and it only had a scratch (needed shaft replacement). a few nose dives into the ground have required shaft changes but i was amazed the motor still worked when it hit the asphalt.

Dr Kiwi 02-26-2009 03:02 PM

RE: GP Rimfire motors?
 
If you don't use WOT very much, then you can get away with over-propping somewhat. Just to clarify a common myth - the fact that you have a 25A ESC doesn't mean a thing - the ESC does NOT control the amount of current the motor/prop demands. If the motor/prop wanted 40A at WOT it would surely try to draw them... and the 25A ESC would simply fry trying to allow them through. The fact that your 25A ESC has survived unscathed indicates that you are not drawing 25A. The other factor could be your pack... if it cannot deliver what the motor really wants, it won't, and the voltage will be pulled down low... so the amp draw will be lower than it would be if you had a fully capable pack.

badazzbusa 02-26-2009 06:11 PM

RE: GP Rimfire motors?
 
That is why I questioned the replacement motor they sent me. I thought the 35-30-1450 would be hard on the 35amp ESC. For the GP Edge I would perfer the 1250 motor and the bigger prop (10x7). After double checking the specs after your post, I agree, I probably helped cook the 1450 motor. The strange thing is I've owned some off the wall, cheap motors before but have never had one fail so soon. I would expect alot better quality from Great Planes and for their equipment to be able to perform within their specs (or exceed) or just say "not for aerobatic or 3-D aircraft". Having people see their brand new equipment fail at the two flying fields I have been at is not the greatest advertising.

jimmyjames213 02-26-2009 09:24 PM

RE: GP Rimfire motors?
 

ORIGINAL: Dr Kiwi

If you don't use WOT very much, then you can get away with over-propping somewhat. Just to clarify a common myth - the fact that you have a 25A ESC doesn't mean a thing - the ESC does NOT control the amount of current the motor/prop demands. If the motor/prop wanted 40A at WOT it would surely try to draw them... and the 25A ESC would simply fry trying to allow them through. The fact that your 25A ESC has survived unscathed indicates that you are not drawing 25A. The other factor could be your pack... if it cannot deliver what the motor really wants, it won't, and the voltage will be pulled down low... so the amp draw will be lower than it would be if you had a fully capable pack.
yep, i just have one question. say i were to throw a insanly large prop on the motor, say a 12x6. would it fry the motor that is rated for 27 amps, since my esc is only 25 amps, my guess would be yes.

also i have a 3's 2100 15c that i use all the time
i used to have a 2200 25c but it broke
both worked fine couldnt tell a dif between the two

btw wouldnt a 11x4 be underproping it?



jdetray 02-26-2009 09:36 PM

RE: GP Rimfire motors?
 


ORIGINAL: jimmyjames213
yep, i just have one question. say i were to throw a insanly large prop on the motor, say a 12x6. would it fry the motor that is rated for 27 amps, since my esc is only 25 amps, my guess would be yes.
It would be a race to see which component failed first: the motor or the ESC. Each one would be operating well past its limits. With a little luck, BOTH could fry at the same moment!

- Jeff

jimmyjames213 02-26-2009 09:54 PM

RE: GP Rimfire motors?
 
This is the ElectriFly Silver Series 25 amp Brushless Electronic Speed Control.

FEATURES: Compatible with NiCd, NiMH and LiPo batteries
Auto-detects input volts and sets Low-Voltage cutoff
8.5kHz switching frequency, for good run-time and cool operation
Pre-installed Universal radio connector* (see Comments below)
Pre-installed WS Deans Ultra male connector for battery (see
comments below)
Pre-installed gold plated 3.5mm female bullet connectors for motor
High powered BEC (Battery Eliminator Circuit) which handles 3 or 4
standard servos
Full proportional forward and smooth throttle response with ON/OFF
brake
Safe Start System** (see details in Comments below)
Thermal Protection stops motor when maximum temperature 230°F
is reached


^^^ the thermal protection would kick in and i wouldnt fry any of them? or is that just for show, does it really work?
i have the gp silver series 25 amp esc

badazzbusa 02-27-2009 07:41 AM

RE: GP Rimfire motors?
 
I promise you it's easy to fry the motor, even if you don't exceed the specs.

jdetray 02-27-2009 12:05 PM

RE: GP Rimfire motors?
 

ORIGINAL: jimmyjames213
^^^ the thermal protection would kick in and i wouldnt fry any of them? or is that just for show, does it really work?
Assuming the thermal protection works, it protects only the ESC, not the motor. If the motor overheats before the ESC overheats, the motor could still be fried.

- Jeff

Dr Kiwi 02-28-2009 10:38 AM

RE: GP Rimfire motors?
 
And if the motor fries and shorts out, it may well take out the ESC too! I've had two motors on the test stand burn their windings and short out - in each case the ESC was destroyed too (one was a PH45... not a cheap one)!


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