argggh revo motor heat

i finally run my truck for more than a couple min after stripping 4 spur gears (yeah im an idiot and forgot to tighten ALL motor mount screws )
now my motor seems to get hot hot hot (the bad kind) after running 5 min


revo conversion
mmm
medusa 36 60 2000kv
5s1p zippy 5000mah
rcm motor mount

mmm never hits fan temp
batt cool


am i just over geared or under geared, is this too much truck weight for the medusa and hard driving (the only kind of driving for me)
is anyone running this setup successfully?


Differential Ratio: 2.8461538461538463
Transmission Ratio: 2.5
Other Ratio: 1
Spur Tooth Count: 40
Pinion Tooth Count: 18
Total Voltage: 18.5
Motor KV: 2000
Tire Diameter (inches): 5.75
Tire Ballooning (inches): .3
Motor Current Draw: 0
Motor coil Ω: 0.006
Spur/Pinion Ratio: 2.22 : 1
Total Ratio: 15.81197 : 1
Tire Circumference (inches): 19.95 inches (506.71 mm)
Total Motor Speed: 37000 RPM
Vehicle Speed: 44.21 mph (71.01 km/h)
Estimated Adjusted Speed: 42 mph (67 km/h) - 6% loss
Effective KV Value: 2000
KT constant: 0.68 oz-in/A

so very frustrated

[BrianG]

IMO, a 60mm long motor is a bit too small for a truck geared for over 40mph. The future 70mm Medusa would be a better choice. But since that is what you have right now, I would reduce gearing to about 35mph, 40 tops. Then, add about 60% (or more) punch control in the ESC. That'll ramp up the acceleration instead of instant on. This will also help temps all the way around. Might also try reducing the timing and start power.

damn i had a gut feeling about that being the answer. What is slated to come out first the 70mm Medusa or castle's new neu type motor.
on the bright side this motor will inspire a new project
thanks

[BrianG]

No idea which will be out first. In the meantime, gear down, add punch control, reduce timing, and decrease start power to make things work in the meantime.

awesome thanks for the quick responses

[kostaktinos_mt]

seems that either something is binding through the drivetrain [badly meshed pinion/spur included], or the motor is deffective/damaged.

the very same motor drived my lgt [12lbs+ rtr, heavier than the revo probably, plus 7inch tires accounted] geared for approximatelly 40mph, and i was getting temps in the region of ~140F at the end of the session [15~20minutes]... the batteries that were used were mostly 14nimh cells and a 5s flightpower pack ocassionally... ambient temps were near 90F [typical summer in greece]...


if your battery and esc temps are low, then gear up and set the timing to about 10degrees...

[bruce750i]

Are your motor screws to long and jamming into the windings?

no binding, it rolls pretty easy, good gear mesh. Im pretty sure the screws are not too long, there is no indent or wear marks on the winding inside the screw hole. the total screw length including the hex head is 1/2 inch
so overall length .5" with there being .4" of thread does this sound right for length

[BrianG]

The easiest way to gauge screw length is to screw one in gently by hand until it stops (where it touches the coils), then back off a turn. Measure the depth and that's the max you can go. Be sure to do this for all holes and use the smallest value.

[bruce750i]

For a depth Gage, take a small Allen wrench and gently poke it in the motor holes and mark it. Then check against or screw length coming out of motor mount. Or with the Medusa's open holes you can hold the screw inside one of the holes and check depth. 1/2" seems long. How are you measuring temps? What in Fahrenheit or Celsius does a "Hot" equal? Temp F = X(Hot3) X=?

ok screws are good and im off to buy a temp gun. it just felt way hotter than im used to. yeah i used my hand.

[bruce750i]

Just yesterday I thought my motor felt like 200f+ but only 150f when I measured it.

to beat a dead horse what is my target motor temps. i searched for a thread i saw awhile back about temps but could not find it sorry for the question that has been answered many times

stay under 170 for that motor and you will be golden, medusa says anything under 194 is ok

ok the most i hit before i ripped a wheel hex was 165 with a temp gun. but i recorded temps of 65 over an over how do i get accurate readings i was close enough but got different temps the difference was 100 degrees do i sand the shinny motor or paint it white?

and also how do you stop hex ripping i have talons with aluminum hexes i have smaller bolts than stock to hold on the wheels do larger bolts help

love this hobby i only break stuff when i have friends watching
hard to get them addicted