Hot, hot, hot, - need a bit of advice please

[BrabusBen]

Running this at the moment:



Hobbywing WP-SC8 - with Stock 3500kV Traxxas Brushless

Initially I couldn't get the esc or motor above about 80F running 12/52 slipper so geared up (but changed to differential at same time) got a bit hot (esc 100F but motor approaching 175F) so geared back down to 12/52 but the motor is still hot (esc running at 107F - motor approaching 200F) ambient is hot for uk but not for the rest of the world. So really, only thing that's changed it the diff. My runs are long - approx 1hr from 3x 2s back to back on mown grass in the dry - same conditions as before problems ;0)

I think (pretty sure) that I put 70K diff oil in the center diff (got confused between MERV and Slash 4x4) and should have used nearer to 5K

My question is - could the thick diff oil heat the motor up? Thinking it through I don't think it can but what do you think. I'm sure the gearing is ok - was running taller with stock esc, but if I've made a schoolboy error please feel free to chastise lol

The esc is a 1:8 unit well up to the job but could it be the motor is not up to it? In which case I need some advice for new motors to run on 2-3s - sensor less only (I'm not buying a new esc - I like the WP-SC8)

I'm going to back to slipper to see if things cool down but advice on both above would be appreciated

Many thanks

[El Sob]

My advice is to go back to where it was running cool. Use baby steps to get more out of her. As for motors, Castle has a few that will work well. The 3800, 2400, 2650, 2200 will all work great in the Slash.

[SlashandBurn]

throw a fan on your motor that should drop your temp about 20 degrees

[BrabusBen]

My advice is to go back to where it was running cool. Use baby steps to get more out of her. As for motors, Castle has a few that will work well. The 3800, 2400, 2650, 2200 will all work great in the Slash.

Gone back to the slipper with 12/54 (where i was originally getting 80/80F) and STILL getting motor temps in excess of 180! - less than before and gets there slower but still much hotter than experienced before - Me thinks the motor may be on its way out. Esc is back to about 90F. Been looking at the 3800 castle as I think the 2200 and 2400 probably won't be fast enough on 2s (don't want to run 3s all the time as most of my batts are 2s - 4s would be a bit extreme for the general bashing I do) not sure about the 2650 - might be a nice compromise.

The stock motor is a 3500 right? Doesn't that mean that the 3800 would need even lower gearing - or does castles magic keep it cooler.

Anyone tried other motors on 2s? Castle are WAY expensive to get in, or to get to, the uk

I've tried fans before and TBH not been that impressed by any of them. My bashing tends to be muddy and wet (see "Low Maintenance Thread") the fans get clogged up or wet and break - I've also not found any way near as much as 20F drop - more like 5F - prob just my driving style but they don't tend to have much of an effect on mine, beside, at anything other than lowest gearing at the moment my motor is running so hot even a 20F drop would mean it was still too hot :0(, heat sinks generally work better on mine.

Was thinking about a ssc chassis, mainly for cooling, it's one big heat sink (the fact that it looks real nice and is proving to be very strong helps lol) my "bashing" is not extreme (no 15ft air jumps etc) most of it is just mucking around at the local parks with a few small jumps, quiet a lot of flat, and a bit of mud/dust (might have to cover that exposed gearing tho). Most people reckon to get a good 10-20F drop in temps - costs about the same as a new motor tho (not far off a new rolling chassis I've got my eye on either)

[BrabusBen]

Been doing a little looking around and the TenShock SC401 looks like a good buy for the money (great reviews) not sure which Kv to go for tho - running mostly on 2s, heavy(ish) truck, sometimes 3s. My thoughts are that the 4600 might get a bit warm and the 4000 may be a bit better for general bashing - I want the un-achievable highish speed (faster than stock on 2s) low temp on 2s, plus the ability to go to 3s for the occasional show off - without risking the esc or motor (noting worse than someone admiring your work for it then to go up in smoke in front of them lol). I'm using the SC8 esc which can run at 120A with 720A bursts - so that should be ok and my batteries are more than up to it. Advice on Kv greatly appreciated

[The VXL]

It does sound like your motor is on it's way out I'm afraid.
As for alternatives I would discourage you from getting a tenshock motor because they draw a lot of amps and don't run the coolest. For your needs I think a castle 3800 is much better because it has crazy torque while being light and yes castle do work their magic and the thing runs super cool. Those motors are much cheaper on ebay btw

[BrabusBen]

Thanks, I know castle is good, but in uk not cheap - up to £250 ($320+) in many shops, £144 incl. taxes, import etc, via eBay uk. Compared with £45 for a toro (tenshock) with free postage - that's a couple of good lipos cheaper! Thanks for the heat warnings of the tenshock, knew about amp draw but wasn't aware of heat problems - so thanks, the search continues (got eye on 2nd hand castle but 4d to go)

[crusey]

A Tenshock / Toro 4 pole 550 offers great bang for buck

If geared correctly with a decent 5000mah 40c battery you wont have any heat issues

Cheers

[BrabusBen]

VXL - just noticed you're in the uk - seen any cheaper castles?

[BrabusBen]

A Tenshock / Toro 4 pole 550 offers great bang for buck

If geared correctly with a decent 5000mah 40c battery you wont have any heat issues

Cheers

Thanks Crusey, was waiting for your input as I know you run one and are v.knowledgeable about then. You run quiet a low Kv don't you? What Kv do you reckon is a good 2/3s all rounder (2s mostly)?

[crusey]

I like to bash at 50 mph or so on 3s

I run the 3500kv version of the Tenshock, works well for switching between 2s and 3s

Cheers

[BrabusBen]

Thanks again Crusey - thinking 3500-4000kv would be ideal for me - do you have to gear it (the 3500) really high to get any speed on 2s? - don't mind this but just trying to work out gearing etc so I can pre-order a few ;0)

EDIT: was on another forum I found out that apparently the tenshock has a new bigger shaft bearing (like to toro) so there really is no difference between the two.

[crusey]

With stock sized tires 15/54 is good for 35 mph on 2s with the 3500kv version, 50 mph on 3s

Cheers

[BrabusBen]

Gone with the Tenshock 3500 Kv - cant go wrong really for £39 lol. It's got great reviews, got 10-20 days to wait now. The real thing that swayed me was Crusey using this size and my ESC states in its specs for 2-3s use less than or equal to 4000kv - figure would be running toward the hotter end on 4000kv, and other forums have said they also run the 3500kv nicely on the slash 4x4 - so DONE.

Feedback will follow ;0)

Crusey - thanks for your advice on this ;0)

[BrabusBen]

Now.........let's have a look at that scclcg ;0)

[BrabusBen]

Turns out I was under geared - running 14/52 still on stock - 165 motor 100 esc - must have had binding somewhere, new motor not here yet but can't wait anyway - keep stock as spare ;0)

[FASTMAXX86]

Just a thought and not 100 percent on this..but if your center diff oil is to heavy(as you mentioned as a possiblility) you may be putting to much strain on the motor and ESC as they spin the diff through the heavier oil. Once again I am not 100 percent sure but it seems logical to me. Maybe someone else can shed some light if this is correct or not.

[naturalstrike]

FASTMAXX86 if you see this, empty your inbox

[BrabusBen]

Here it is:



Love the English:



But nicely packed, only took 1 week from china:



Useful tip: place bullet in the hole of an old spur to hold when soldering - they don't melt and hold it nice and still:



Old motor:



New motor mounted:



It's a tad longer:



And....... Even with only 13/54 - it flies - this is the first time on 2s I've ever seen this truck wheelie! - ruined my mini spikes in 1/4 of a pack!

I'll give it a real try out when the 14 & 15 tooth pinions arrive - its under geared at the moment (motor temp only got to 73F, esc 71F)