Results 1 to 5 of 5
  1. #1
    RC poster
    Join Date
    Jul 2012
    Posts
    1

    More gearing questions

    Dear all,

    just upgraded my slash 2wd brushed to the turn igy ********* 8.5t from HK;

    Can Size: 540
    Turns: 8.5
    RPM/v: 3983kv
    Poles: 2
    Sensored: Yes (Standard 6 pin harness)
    Max voltage: 7.4~11.1V (2~3S)
    Max Current: 33A
    Max Watts: 365w
    Resistance: 0.0141ohm
    No Load Current: 5.8A
    Shaft Size: 3.175mm
    Can Diameter: 36mm
    Can Length: 51.5mm
    Weight: 158g


    and this ********* ESC on a 3s lipo

    Specification:
    Cont. Current: 100A
    Burst Current: 200A
    Car Size: 1/10th
    Battery: 2-3 Cell Lipo
    L-BEC: 5.0V / 2A Output
    Motor Type: Sensored or Sensorless Brushless
    Size: 40.5 x 37.5 x 24mm
    Weight: 45g
    Battery Plug: Required
    On/Off Switch: Yes
    Reverse: Yes
    Thermal Overload Protection: Yes
    Battery Terminals: 12AWG size
    Motor Terminals: 12AWG size

    Problem is that it's running pretyy hot with the stock gearing (19t pinion 90t spur). I went down 1 tooth on de pinion (18t) and it seems to get even hotter (could be me, don't have a temp gun).

    I have now ordered a 16t pinion and a 92t spur which will hopefully make things better. But will it? I noticed that in some cases a larger pinion (let's say 20t) made the motor and esc cooler. I guess this would have to do with less rpm's? Then again it will also increase the load on the motor so I think I'm not understanding it fully.

    I was running it (as a test) on the street and on some gravel but it should work offroad (there's a small track close to my house). After 10 minutes or so the thermal protection kicks in (which kind of s*cks as it also cuts power to the steering servo, not very nice when this happes while going pretty fast).

    Anybody willing to shine a light on this? Am I turning into the wrong direction?

    Thanks guys!
    Last edited by Insane; 07-27-2012 at 04:11 AM.

  2. #2
    RC Turnbuckle Jr. O.G.'s Avatar
    Join Date
    Nov 2010
    Location
    South of St Louis
    Posts
    5,986
    The motor would be a lot cooler if you ran it on 2s lipo. 3s is fast and powerful, but also adds a lot of heat.

    Regardless, you need to add an aluminum transmission case to help keep your temps down. At the very least, a heatsink on the motor will help. The motor looks pretty good on paper but I think the 3s is too much for it without gearing down and adding aluminum to cool.
    My Black & Blue Rally is faster than your color...

  3. #3
    RC Champion
    Join Date
    Nov 2011
    Location
    North Central OH
    Posts
    1,047
    A temp gun is a must to know how hot is too hot. I had the same feeling with a setup I was running, borrowed a good temp gun from an auto tech and learned that 135-165 can feel pretty darn hot. That temp gun will help a lot with gearing and also make you feel comfortable you are not about to harm your suped up motor!

  4. #4
    RC Turnbuckle Jr. O.G.'s Avatar
    Join Date
    Nov 2010
    Location
    South of St Louis
    Posts
    5,986
    Quote Originally Posted by kwitty View Post
    A temp gun is a must to know how hot is too hot. I had the same feeling with a setup I was running, borrowed a good temp gun from an auto tech and learned that 135-165 can feel pretty darn hot. That temp gun will help a lot with gearing and also make you feel comfortable you are not about to harm your suped up motor!
    This is very true. I thought my motor was running WAY hot until I put a gun on it. 130F feels pretty dang hot to the finger test, but is right in the sweet spot for the motor operating temps.
    My Black & Blue Rally is faster than your color...

  5. #5
    RC Qualifier
    Join Date
    Apr 2012
    Location
    Pomona CA.
    Posts
    327
    20 tooth pinion 90 tooth spur. Use a 2 cell with high discharge rate like 35 c , something descent. You'll do good on the track. I use my 3 cell battery only to do speedd runs once in a great while , and to not damage it just being kept stored. I don't use my 3 cell on the track because every time i do , i break something , or strip my wheel hexes'.
    Traxxas Slash 2wd and Thunder Tiger Tomahawk Vx

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •