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Old 07-05-2011, 12:10 PM   #1
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Default TC3 with 17T brushed motor gearing help!!!

I have got a TC3 with a modded 17 turn motor. I need to know what gearing i should use. I'm running a traxxas XL-1 esc and it getting hot within a minute. Should I go lower pinion larger spur? or vise versa? Any help would be great. Thanks
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Old 07-05-2011, 12:15 PM   #2
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Not knowing the condition of the car, or the motor, can't give you an exact answer (these things need to be in good shape and spin freely)... but basically, yes going down some teeth on the pinion should help it run cooler. Also more run time. If it's so hot you can barely touch it after a minute, it's geared too tall...
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Old 07-05-2011, 01:21 PM   #3
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A tc3 with a 17t motor should start gearing around 6.666fdr(72t spur/27t pinion), if the tranny is free and the motor tuned right !
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Old 07-05-2011, 02:00 PM   #4
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It is about 122 degrees after about a minute of full throttle up and down the driveway, a ESC shouldn't get that hot I am sure its gear totally wrong. I have no clue the stock spur that came on it it has No numbers on it. i put on I think is a 17 or 19 tooth pinion is 48P should I change it to 64P

This is just something to play with until I can buy the brushless system to go into it.

The car seemed to roll well w/o a motor hooked up of course being brushed its coggy feeling.
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Old 07-05-2011, 02:12 PM   #5
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Quote:
Originally Posted by epoweredrc View Post
I have no clue the stock spur that came on it it has No numbers on it. i put on I think is a 17 or 19 tooth pinion is 48P should I change it to 64P
One,two,three,four,five,six..... you get the point

I kid, but maybe you could use a sharpie to mark a spot and count your way around it.
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Old 07-05-2011, 03:43 PM   #6
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Originally Posted by nf_ekt View Post
One,two,three,four,five,six..... you get the point

I kid, but maybe you could use a sharpie to mark a spot and count your way around it.
its black so black on black doesn't do well. i understand what ur saying but lot of teeth not sure why they thought was a good idea not to make the teeth with the number. maybe I will take off off and try match it up to spurs at work.
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Old 07-05-2011, 03:59 PM   #7
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Quote:
Originally Posted by bertrandsv87 View Post
A tc3 with a 17t motor should start gearing around 6.666fdr(72t spur/27t pinion), if the tranny is free and the motor tuned right !
+1 !

Epowered : look for the TC3 manual on the Associated website. It's all explained there. Your 17 turn is very likely burnt.

The formula to get your fdr : ( spur/pinion) x Internal ratio

In the case of the TC3 you get :

(72/27) x 2.5 = 6,66

The higher the number you get, the easier it will be for your motor to make the car move, but the less top speed you'll have. You'll have to find the best compromise.
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Old 07-05-2011, 04:50 PM   #8
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Originally Posted by heretic View Post
+1 !

Epowered : look for the TC3 manual on the Associated website. It's all explained there. Your 17 turn is very likely burnt.

The formula to get your fdr : ( spur/pinion) x Internal ratio

In the case of the TC3 you get :

(72/27) x 2.5 = 6,66

The higher the number you get, the easier it will be for your motor to make the car move, but the less top speed you'll have. You'll have to find the best compromise.
Thanks I will try to find the manual as got it used and no manual for it, was justing trying to get someone to tell me they had same size motor and gearing they used that worked I guess. i dropped to a 17 tooth pinion try a 15 but not enough motor movement to get it tight on the spur. we are using these cars for VTA at the shop i work at but there all brushless and were running from 390-4.0 or so on FDR.

just trying to get something that I can play with on the track for around 5 minutes. but right now getting to hot. Maybe my esc is the issue its a old one but nothing wrong with it that I know but it was ment for a rustler not a on road car
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Old 07-06-2011, 09:40 PM   #9
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Well I took the rear diff apart today it was all messed up melted together. I had another got in the deal i changed it out and now seems to roll lot better drove for about 2 minutes at WOT and it was cool enough I could touch and hold my finger on esc and motor, one was about 120 other about 96.

So guess fixed my issue guess i could go back to a larger pinion now for more speed right?
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