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finallyfox075

HELP, melted Speed Passion 3500kv motor in 35 seconds!

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Guys what have I done wrong?

Ok, got the genuine Fox rebuilt with as much premium, alloy quality parts as I could find. Fitted a SP 3500KV and Reventon S speed controller and it literally torched itself in less than a minute after a short run-in.

Ran it initially for about 2 minutes at reduced throttle for a quick check. No heat issues with ESC or motor. loaded it into the car drove 5 mins to the track and honestly 35-40 seconds later, smoke and melted death.

I know it has a narrow gear window. 5.?? to 6.?? and I was about 7.4, is that enough to overload to melt point. Have I got ($50.00 AUD on sale) what I paid for???

I purchased 2 of these combos, as I have an original and a nova. Are they just completely unsuited to a buggy and if so.....

....

...

.. what is the best motor esc combo for these animals??? do I stay brushless or go back to a brushed setup???

really need some solid advice guys, I just want a quick and reliable setup.

specs, Fox + Nova, both identical. alloy wheels, hot trick up and low rear arms and heaps of other retro hop ups. Nano Lipo 2S 5300mah 50-100c's, Flysky GT3C series controllers ...

Whats the answer? P.S this is my 9yr old daughters, she waited months and.... dead.....shes not happy.

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That doesn't sound right, I've ran these setups in a DT-02 and a 4x4 TA-02 (albeit with touring car size wheels on loose surface) and not had an issue. Sounds like you've had a dodgy motor there. Have you tried the other kit yet?

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how long are your motor screws... if they poke in more than 3-4mm max, you're hitting vital gizzards

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how long are your motor screws... if they poke in more than 3-4mm max, you're hitting vital gizzards

Very good point that. For comparison I've run a 4000KV eZRun combo (About £65 worth) in my hotshot on 2S 4000mah LiPo with no heat issues at all, and I'm pretty certain from memory that's running with a 15tooth pinion.

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how long are your motor screws... if they poke in more than 3-4mm max, you're hitting vital gizzards

You've got me worried now, I'm off to check my motors!

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Thanks guys,

So the 3x20mm motor screw protrude about 3.1mm through the motor side housing, then minus the thin motor heat shield / spacer of about 1mm. The gearbox has metal spacer tubes that sleeve the motor screws, I assume this is to stop compression and the motor screws doing just as described above and protruding any further than 3-4 mm.

I will run the second motor, place 3mm washers under the motor screw heads to have absolute confidence there isnt any problem in that department.

Either way I now have to buy a second motor or complete combo. Any suggestions on something more robust, bulletproof would be ideal :)

any thoughts on this. ....

Turnigy TrackStar Waterproof 1/10 Brushless Power System 4000KV/80A

ESC Specs:
Continuous Current: 80A
Burst Current: 95A
Resistance: 0.0009ohm
Battery: 2-3 cells Lipo (5-8 cells NI-xx)
BEC output: 6V/1A
Motor type: Sensorless brushless motors
Running mode: Forward only or forward with reverse (user programmable mode)
Dimension: 43 x 38 x 20mm
Weight: 88g

Motor Specs:
Model: 3650 Sensorless
Kv: 4000
No. of Poles: 2
Cont Current: 45A
Peak Current: 55A
Max Power (15sec): 370W
Winding: 16T
Resistance: 0.0125ohm
Weight: 180g
Diameter: 36mm
Length: 53mm
Shaft Diameter: 3.175mm

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Try and find a 4 pole motor for bags of torque, wheelies on command at anything past half throttle. :D :D,

Pretty sure the one you have listed is a 380 size rotor in a 540 size can, which can be good as you have a large heat sink area, but the bigger rotor, full 540 size will have more torque even with 2 pole motors.

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I have a few of the SP 3500 and they all arrived with lotsa paint obscuring the mount holes.

It's worthwhile running a tap in, or at least a hi tensile screw before mounting.

And vacuum out the metallic dwarf you create... :)

If you peek into the side holes near front, there isn't much depth to allow screws over 3-4mm.

If your RevS ESC is unscathed, I'd buy a SENSORED motor to replace the smoker.

SP, YeahRacing etc probably all work fine... maybe even Turnigy if you're lucky.

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If the Speed Passion is a Sensored system, could the problem have been a wiring issue?

Did you match the A, B & C on the ESC with the A, B & C on the motor connections?

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no the $50 combo gets a 3500 motor which is unsensored

but the RevS ESC is capable of sensored control, just BYO motor & cable.

I think it auto self detects too, no need manual settings like TBLE02S

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No problem Willy..

I figured that there had to be a reason why they were only $50...

I don't know the motor limit of the RevS ESC, but maybe a Hobbyking Trackstar 21.5, 17.5 or 13.5 would be the go in the Fox..

(I don't know that I'd like to go much hotter than a 13.5 in a Fox)

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supposedly they'll handle down to 10.5 I read somewhere

That's good to know as I'm looking at the 10.5 Turnigy Trackstar sensored motors on Hobbyking to replace the unsensored motor that came in the Speedpassion kit. Anyone know why there are two variants of the 10.5, one which is 3250KV and the other which is 3730KV?

3250KV http://www.hobbyking.co.uk/hobbyking/store/__43533__Turnigy_TrackStar_10_5T_Sensored_Brushless_Motor_3250KV_UK_Warehouse_.html

3730KV http://www.hobbyking.co.uk/hobbyking/store/__32391__Turnigy_TrackStar_10_5T_Sensored_Brushless_Motor_3730KV_EU_warehouse_.html

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I suspect they're 2 different models if not totally different factories... the 3730 I think is older & the 3250 is current lot

I'd go the 3250 as its lighter & draws less current haha :)

I've got a Trackstar 8.5 here that's silver & looks like the 3730.

It arrived late 2012 I think; only just gotten around to wiing it up.

Seems to run ok, not a huge fan of all those vent holes in the can though

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Thanks matey, it's going in my TA-02 so I'll go with your suggestion of the 3250

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Be a bit careful with the cars where you fit the pinion blindly before bolting in.

Since Xmas have fixed up several Avante/Egress/Fox/Hotshot/MantaRay

and installed some SP RevS combos or Hobbywing EzRuns.

At least once have managed to mash the pinion against inside wall of gearbox.

When first powered up it runs really coggy and soon enough there's a smell

of hot plastic...

RTFM don't help cos the old cars often measure where pinion should sit

from the protruding front bushing of the 540, which the BL don't have

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Hmm I might check that on my TA first as the only reason I want to change the motor is because of the cogging at low speed, there may actually be no need to upgrade to sensored. Thanks for the tip (and sorry for the major thread hijack).

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And vacuum out the metallic dwarf you create... :)

:huh::D Nearly spat my tea out! Assume you meant "swarf"? I've got a great mental image of a little goblin running around inside the motor now...

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:huh::D Nearly spat my tea out! Assume you meant "swarf"? I've got a great mental image of a little goblin running around inside the motor now...

blame AutoCorrect :( damned newfangled gadget goblins... haven't typed on a real keyboard all week

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Thanks for the advice TC crew.

Fitted the second motor and all seems ok so far. Needless to say I'm a little disappointed in the run time of the first motor.

So its time to grab another motor and quite frankly ill ditch the SR reventon S just in case it played a part in its death. WilllyChang, you can have it if you want if you have a spare motor or two to check its performance / operation. Let me know!

I'm looking at these motors.

http://www.hobbyking.com/hobbyking/store/__49215__Turnigy_TrackStar_13_5T_Sensored_Brushless_Motor_3040KV_AUS_Warehouse_.html

http://www.hobbyking.com/hobbyking/store/__47651__Turnigy_TrackStar_17_5T_Sensored_Brushless_Motor_2270KV_AUS_Warehouse_.html

Mayby I'll back it down a little and run the 17.5 for a little less stress on the driveline. Any advice on a decent ESC with a little service factor up its sleeve for either of these highly welcome.

Thanks all.

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Stupid Question..

But if you bought the Speed passion set in Australia, and it was new, have you considered contacting Walters RC regarding warranty?

OR, do you know that the failure was because of something you did wrong..

Just a thought....

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Hi Backlash

I did buy from WRC and to Daves credit he did tell me to be VEEERY wary of the final ratio. As above i was knowingly outside the window so ill take the hit regardless. On the positive side the second motor was jammed into the nearly 29 yr old fox with original gearbox and it lifts the front wheels on demand, on the run anywhere from 1/4 throttle DOWN HILL! Impressed? only wish I could have had this much fun as a kid. My 8 yr old girl is happy, she got to throw it about, belt a number of gutters and really just whip it. Still alive and ready for a track session. it had a good, hard (20 min) run and the smoke stayed inside. yay!

Any suggestions on a new motor/esc combo for the nova still welcome guys.

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You do realise that a 7.4:1 gear ratio is slower, or easier on the motor than gearing at 6:1...??

Who told you to gear it between 5:1 and 6:1??

Even if you had way over geared it, I would suggest that having the motor smoke in under a minute, the motor would have had to be faulty..

Did you check the windings near the screw holes to see if that was were the issue was?

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Yeah i know the motor ratio should have proved easier on the motor. Im a Hydraulic Engineer and electrical really isnt my field of expertise. Im not overly sure how the motor would or wouldnt use current / absorb power outside its recommended gear ratio. The gear ratio window was first advise by Walter RC and its also outlined in the instructions. The motor screws were rougly 3.1mm then the motor plate of about 0.9mm so shouldnt have been an issue. I did check last night and all looks ok. No indications of contact.

It seems likely that the motor could have been faulty but either way I'm thinking after a bit of reading that a 4 pole motor may be a better option for a variety of off road surfaces.

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A 2 pole motor should be fine for a light 2wd buggy, but a 4 pole motor will have noticeably more torque.

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