R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Electric Off-Road

Reply
 
Thread Tools Search this Thread
Old 01-14-2014, 02:19 PM   #1
Tech Apprentice
R/C Tech Elite Subscriber
 
Join Date: Dec 2013
Posts: 83
Trader Rating: 1 (100%+)
Default Trinity D3.5 17.5 Gearing/Timing Help

For those of you that have this motor, I run tight indoor carpet racing with one 50-75' straight away and my truck is one of the fastest, but my motor temps get up to 180-200 degrees after 5-6min races...Originally I had a 27t pinion with 78t spur and I swapped that down to a 23p and 78s still gets hot, still fast...Timing was where it was when I got the motor, at -8 then plus the built in timing...Wondering if I should put timing to 0 on the endbell, and try a smaller pinion like a 20T or what...Im happy with how fast my truck is, just need to run cooler...Im wondering if the temps are causing the fade toward the end of my races or if its because my maxamps are dropping off so fast...I run the Gen2 rspro with maxamps 6500mah dual core 150c batteries...

Any help would be great...


I run a proline pro 2.
FinishLineSport is offline   Reply With Quote
Old 01-14-2014, 03:13 PM   #2
Tech Elite
 
Join Date: May 2010
Posts: 3,844
Trader Rating: 19 (100%+)
Default

Quote:
Originally Posted by FinishLineSport View Post
For those of you that have this motor, I run tight indoor carpet racing with one 50-75' straight away and my truck is one of the fastest, but my motor temps get up to 180-200 degrees after 5-6min races...Originally I had a 27t pinion with 78t spur and I swapped that down to a 23p and 78s still gets hot, still fast...Timing was where it was when I got the motor, at -8 then plus the built in timing...Wondering if I should put timing to 0 on the endbell, and try a smaller pinion like a 20T or what...Im happy with how fast my truck is, just need to run cooler...Im wondering if the temps are causing the fade toward the end of my races or if its because my maxamps are dropping off so fast...I run the Gen2 rspro with maxamps 6500mah dual core 150c batteries...

Any help would be great...


I run a proline pro 2.
That has a 2.72 gear ratio like the Slash correct? You might be under geared, causing heat. When that motor is in its "sweet spot" for gearing it will run between 110-120 and be ballistic. The temp you're running it at will degrade rotor strength quickly and eventually burn up the stator as well.

I plugged your gearing into a gear chart and that's what I would start at for a shorter track, which makes me wonder if you have a bind in the drive train somewhere. Was the motor new when you got it? Does it have the 12.5 HT rotor?
__________________
XRAY, RC America, MOTIV, Sanwa, Arrowmax, Neverlift Racing Apparel
Jonny5ive Designs- by racers, for racers!
Jonny5 is offline   Reply With Quote
Old 01-14-2014, 07:04 PM   #3
Tech Apprentice
R/C Tech Elite Subscriber
 
Join Date: Dec 2013
Posts: 83
Trader Rating: 1 (100%+)
Default

Yeah it has the 2.72 and just like a slash. What would you suggest for gearing for a right track?

It is the d3.5 17.5 the certified hand built with that stator you mentioned...it was brand new a month ago, only few races on it.
FinishLineSport is offline   Reply With Quote
Old 01-14-2014, 07:41 PM   #4
Tech Apprentice
R/C Tech Elite Subscriber
 
Join Date: Dec 2013
Posts: 83
Trader Rating: 1 (100%+)
Default

Sorry it was also the maxzilla...the $150 one...would having a lot of drag brake cause excessive heat? I turned up the drag brake high thinking it's be more controlled braking thN me slamming brakes...I picked up a 20T today as that was next size down my hobby shop had.
FinishLineSport is offline   Reply With Quote
Old 01-14-2014, 07:49 PM   #5
Tech Initiate
 
Lead-Lobber's Avatar
 
Join Date: Apr 2013
Location: Currently live in southern AZ, or closer to northern Mexico if your a realist.
Posts: 37
Trader Rating: 1 (100%+)
Default

In my understanding of gearing, dropping pinion would increase speed, and increase motor temps. To decrease temp, increase pinion size, getting the ratio closer to 1:1. This decreases speed (and temps) and increases torque. Am I correct? Again, that is what I'm being told. I'm new to the "go fasts", coming from the crawling world.
Cheers!
__________________
Jeff R.
Tucson AZ
DEX210
SC10
Lead-Lobber is offline   Reply With Quote
Old 01-14-2014, 07:56 PM   #6
Tech Apprentice
R/C Tech Elite Subscriber
 
Join Date: Dec 2013
Posts: 83
Trader Rating: 1 (100%+)
Default

Idk trinity told me bigger pinion equals more heat = bad
FinishLineSport is offline   Reply With Quote
Old 01-14-2014, 08:03 PM   #7
Tech Initiate
 
Lead-Lobber's Avatar
 
Join Date: Apr 2013
Location: Currently live in southern AZ, or closer to northern Mexico if your a realist.
Posts: 37
Trader Rating: 1 (100%+)
Default

Hmmm. Interesting. Maybe I misunderstood what I was told too. I'll have to verify. Good Luck!
__________________
Jeff R.
Tucson AZ
DEX210
SC10
Lead-Lobber is offline   Reply With Quote
Old 01-14-2014, 10:54 PM   #8
JsK
Tech Master
 
JsK's Avatar
R/C Tech Elite Subscriber
 
Join Date: Aug 2009
Location: S.Oregon
Posts: 1,631
Trader Rating: 10 (100%+)
Default

78/23=3.39 x 2.72 transmission ratio comes out to 9.22. Thats pretty low geared for a 17.5
especially a D3.5 with a 12.5 rotor. There has to be a problem
somewhere else in your system. Check for drag. Could be a bad bearing or your
gear mesh might be to tight. Could also be problems with the settings in your ESC.
Lower tooth count on your pinion spins the motor faster, Higher tooth
count spins it slower. 17.5 motors make a ton of torque but very little RPMs
hence the need to be geared much higher than a mod motor.

Your undergeared, excess drag or the ESC settings are off.

Lead-Lobber, maybe if you spent less time being a grammar nazi and calling people stupid you would learn something.
JsK is offline   Reply With Quote
Old 01-14-2014, 11:11 PM   #9
Tech Adept
 
Join Date: Mar 2013
Location: Lancaster, ca
Posts: 118
Default

Quote:
Originally Posted by FinishLineSport View Post
Sorry it was also the maxzilla...the $150 one...would having a lot of drag brake cause excessive heat? I turned up the drag brake high thinking it's be more controlled braking thN me slamming brakes...I picked up a 20T today as that was next size down my hobby shop had.
YESS!!! Drag brake to high will cause to to run high I had the drag set high in mine before and it ran up 180-190 I turned the drag brake down a bit and wow motor temps dropped to 140-145 after 7 mins on a 75/24 and was able to turn the motor trimming up and it's way faster had to turn down the EPA on my remote
__________________
B5M- schuur speed 17.5 sig series- orion vortex r10 stock spec- MT4
SC10.2- Schuur speed extreme spec 17.5 - novak gtb- MT4
Home Track: SCVRC
Bkautz is offline   Reply With Quote
Old 01-15-2014, 05:40 AM   #10
Tech Apprentice
R/C Tech Elite Subscriber
 
Join Date: Dec 2013
Posts: 83
Trader Rating: 1 (100%+)
Default

I'll have to check my esc but the drag brake is very high I know....anybody else think this may be the problem? My wheels spin freely, gear mesh is def not too tight and my motor timing on end bell is set to 0, but from my understanding puts the timing really at +20. I wonder if I should also Turn that down to produce more torque?
FinishLineSport is offline   Reply With Quote
Old 01-15-2014, 06:57 AM   #11
Tech Master
 
liquid g's Avatar
 
Join Date: Dec 2011
Location: streamwood
Posts: 1,133
Trader Rating: 46 (100%+)
Default

On my blinky sc10 I was geared from 22-24/75 on a tight indoor dirt track temps were usually 140-160
__________________
associated sc-10 tekin rs blinky 17.5 murfdogg
associated b4.1 wc tekin rs blinky 17.5 murfdogg
associated t4.2 tekin rs 10.5 murfdogg
dex410 2010 spec rspro boosted murfdogg
liquid g is offline   Reply With Quote
Old 01-15-2014, 07:35 AM   #12
JsK
Tech Master
 
JsK's Avatar
R/C Tech Elite Subscriber
 
Join Date: Aug 2009
Location: S.Oregon
Posts: 1,631
Trader Rating: 10 (100%+)
Default

Quote:
Originally Posted by liquid g View Post
On my blinky sc10 I was geared from 22-24/75 on a tight indoor dirt track temps were usually 140-160
Thats really low for a D3.5,I ran 28/75 on the same style track and with a Tekin
RS in blinky.
JsK is offline   Reply With Quote
Old 01-15-2014, 07:45 AM   #13
Tech Apprentice
R/C Tech Elite Subscriber
 
Join Date: Dec 2013
Posts: 83
Trader Rating: 1 (100%+)
Default

Do you think my drag brake set very high could be the problem?
FinishLineSport is offline   Reply With Quote
Old 01-15-2014, 07:53 AM   #14
JsK
Tech Master
 
JsK's Avatar
R/C Tech Elite Subscriber
 
Join Date: Aug 2009
Location: S.Oregon
Posts: 1,631
Trader Rating: 10 (100%+)
Default

Quote:
Originally Posted by FinishLineSport View Post
Do you think my drag brake set very high could be the problem?
Yes, or you are undergeared. Try running without any drag brake. If that gets
you back down to 100 or so you can start adding it back a little at a time.
JsK is offline   Reply With Quote
Old 01-15-2014, 07:58 AM   #15
Tech Apprentice
R/C Tech Elite Subscriber
 
Join Date: Dec 2013
Posts: 83
Trader Rating: 1 (100%+)
Default

Ok...when you say under geared, do you mean too small of a pinion?
FinishLineSport is offline   Reply With Quote
Reply



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



All times are GMT -7. It is currently 11:25 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net