R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 04-04-2012, 10:15 AM   #1
Tech Champion
 
touringdriver's Avatar
R/C Tech Elite Subscriber
 
Join Date: Mar 2007
Location: RICKY RACERVILLE
Posts: 5,203
Trader Rating: 15 (100%+)
Default Large or Small spur for brushless

looking for some input on what to expect by running larger or smaller spur gears of a touring car with a brushless motor mod or stock? i have no issue with gearing a car but i do hear a lot of racers telling others you gear a brushless the opposite of a brushed motor???????????????????
__________________
Proudly Sponsored by: Mr. Crash Racing, RickyRacer lidz & Ebay..
Rock Chalk Jayhawks
2014 Subway Cup & Dee and Mees On-road Race Schedule:
http://www.rctech.net/forum/kansas-m...l#post11891510
touringdriver is offline   Reply With Quote
Old 04-04-2012, 11:07 AM   #2
Regional Moderator
 
CarbonJoe's Avatar
 
Join Date: Jul 2006
Posts: 2,661
Default

No, with brushless you still put the pinion on the motor shaft.

By running larger or smaller spur gears, you decrease or increase the FDR.

Not sure what you're really asking here?
__________________
*** The Gate - Celebrating 8 years at the same location ***
The difference between genius and stupidity is that genius has its limits. - Albert Einstein
Understeer is when you hit the wall with the front of the car and oversteer is when you hit the wall with the rear of the car
CarbonJoe is offline   Reply With Quote
Old 04-04-2012, 11:14 AM   #3
Tech Champion
 
touringdriver's Avatar
R/C Tech Elite Subscriber
 
Join Date: Mar 2007
Location: RICKY RACERVILLE
Posts: 5,203
Trader Rating: 15 (100%+)
Default

what are the results to low end and top end quickness by going large/small on spur.
__________________
Proudly Sponsored by: Mr. Crash Racing, RickyRacer lidz & Ebay..
Rock Chalk Jayhawks
2014 Subway Cup & Dee and Mees On-road Race Schedule:
http://www.rctech.net/forum/kansas-m...l#post11891510
touringdriver is offline   Reply With Quote
Old 04-04-2012, 11:16 AM   #4
Tech Master
 
Mr RCTech's Avatar
 
Join Date: Dec 2005
Posts: 1,291
Trader Rating: 2 (100%+)
Default

Quote:
Originally Posted by touringdriver View Post
looking for some input on what to expect by running larger or smaller spur gears of a touring car with a brushless motor mod or stock? i have no issue with gearing a car but i do hear a lot of racers telling others you gear a brushless the opposite of a brushed motor???????????????????
Need more information.
Is this for blinking mode (zero timing)?
Mr RCTech is offline   Reply With Quote
Old 04-04-2012, 11:18 AM   #5
Tech Champion
 
touringdriver's Avatar
R/C Tech Elite Subscriber
 
Join Date: Mar 2007
Location: RICKY RACERVILLE
Posts: 5,203
Trader Rating: 15 (100%+)
Default

in my t3 12 i run 48 pitch gears with a 69 tooth spur with final drive at 3.7, another racer runs same car except with 64 pitch gears and same final drive. the reason i ask is his car is a lot quicker/snappier than mine so he really works me over on the infield of our tracks. so my point is his spur is larger in dia. that mine so is that the benefit of running a larger dia. spur? we also run the same 17.5 locked endbell motors as well.
__________________
Proudly Sponsored by: Mr. Crash Racing, RickyRacer lidz & Ebay..
Rock Chalk Jayhawks
2014 Subway Cup & Dee and Mees On-road Race Schedule:
http://www.rctech.net/forum/kansas-m...l#post11891510
touringdriver is offline   Reply With Quote
Old 04-04-2012, 11:19 AM   #6
Tech Champion
 
touringdriver's Avatar
R/C Tech Elite Subscriber
 
Join Date: Mar 2007
Location: RICKY RACERVILLE
Posts: 5,203
Trader Rating: 15 (100%+)
Default

Quote:
Originally Posted by Mr RCTech View Post
Need more information.
Is this for blinking mode (zero timing)?
yes blinky mode and this class requires all the same trinity spec locked endbell 17.5 motors.
__________________
Proudly Sponsored by: Mr. Crash Racing, RickyRacer lidz & Ebay..
Rock Chalk Jayhawks
2014 Subway Cup & Dee and Mees On-road Race Schedule:
http://www.rctech.net/forum/kansas-m...l#post11891510
touringdriver is offline   Reply With Quote
Old 04-04-2012, 12:14 PM   #7
Regional Moderator
 
CarbonJoe's Avatar
 
Join Date: Jul 2006
Posts: 2,661
Default

If the FDR is the same, there shouldn't be much (if any) of a difference either way. There are manufacturing tolerances for everything, so his motor might be a little better than your motor (better rotor, etc.). You might have a bad bearing somewhere in your drivetrain. Do the motors come off the track about the same temp?

What if you guys switch motors? Is your car now faster? Maybe his setup or driving is a little better, giving him more corner speed, so he loses less? Are the ESCs identical? Batteries could also play a role.

Have him drive your car, and you drive his. Same end result?
__________________
*** The Gate - Celebrating 8 years at the same location ***
The difference between genius and stupidity is that genius has its limits. - Albert Einstein
Understeer is when you hit the wall with the front of the car and oversteer is when you hit the wall with the rear of the car
CarbonJoe is offline   Reply With Quote
Old 04-04-2012, 02:16 PM   #8
Tech Addict
 
Join Date: Nov 2009
Location: Denmark
Posts: 562
Default

I don't know if it is actually true or not (but it has been confirmed by several of drivers at my track), but it seems like a bigger spur (while maintaining the same FDR) gives more bottom end power, where as a smaller spur (still same FDR) seems to give more top-end.
__________________
Niklas Hansen
Team TCHobby / Team Upgrade-RC
Tamiya TRF417 / Speed Passion GT2.0 / Speed Passion V3 motors.
Nilks is offline   Reply With Quote
Old 04-04-2012, 02:36 PM   #9
Tech Champion
 
touringdriver's Avatar
R/C Tech Elite Subscriber
 
Join Date: Mar 2007
Location: RICKY RACERVILLE
Posts: 5,203
Trader Rating: 15 (100%+)
Cool

Thanks Nilks, I've been hearing that as well. A 69t 48p spur is a lot smaller in dia. Than say a 100t 64p spur. However with the correct pinions equal the same FDR. Which makes we wonder and ask the benifits of larger/smaller spur.
__________________
Proudly Sponsored by: Mr. Crash Racing, RickyRacer lidz & Ebay..
Rock Chalk Jayhawks
2014 Subway Cup & Dee and Mees On-road Race Schedule:
http://www.rctech.net/forum/kansas-m...l#post11891510
touringdriver is offline   Reply With Quote
Old 04-04-2012, 02:38 PM   #10
Tech Addict
 
djnsayne's Avatar
 
Join Date: Nov 2008
Location: As you can see....My hands are full
Posts: 543
Trader Rating: 11 (100%+)
Send a message via Yahoo to djnsayne
Default

If the FDR stays the same, the size of the gears shouldn't matter at all...... I would bet that the guy smoking you has a much better battery then you do, or he is just much smoother amd carries his speed better..... how about a video?
__________________
Yes.... That WAS my EVADER that just passed you!!!
Evader BX PRO/Xray T206/ 3Racing F109
DJ Nsayne/Hitt Breaka Dj's/Sexy B Racing
djnsayne is offline   Reply With Quote
Old 04-04-2012, 04:16 PM   #11
Tech Master
 
Mr RCTech's Avatar
 
Join Date: Dec 2005
Posts: 1,291
Trader Rating: 2 (100%+)
Default

Quote:
Originally Posted by djnsayne View Post
If the FDR stays the same, the size of the gears shouldn't matter at all...... I would bet that the guy smoking you has a much better battery then you do, or he is just much smoother amd carries his speed better..... how about a video?
RIGHT!

A free car can carry more forward bite off the turns,to produce faster lap times.

Try running the smallest spur gear you can without sacrificing low-end torque of the corners.
Mr RCTech is offline   Reply With Quote
Old 04-04-2012, 04:19 PM   #12
Tech Regular
 
Join Date: Oct 2011
Posts: 345
Default

Always run the biggest spur gear that you can to get the ratio you want. There is a difference, do your own experimentation with smaller spurs then try the largest spur that gives you the ratio you want. It affects both bottom end and braking.
HawaiiBob is offline   Reply With Quote
Old 04-04-2012, 04:23 PM   #13
Tech Elite
 
wwddww34's Avatar
 
Join Date: Feb 2011
Location: Dallas Texas
Posts: 2,560
Trader Rating: 9 (91%+)
Default

It also depends on how powerful your brushless motor is. For example if you are running a 25.5T motor (like those in VTA class) you probably have to find the smallest spur gear and biggest pinion gear that you can fit into your car.
__________________________________________________ _________________

--------------------------------->http://www.rctech.net/forum/texas-ra...obby-shop.html
wwddww34 is offline   Reply With Quote
Old 04-04-2012, 05:01 PM   #14
lee
Tech Adept
 
Join Date: Mar 2002
Posts: 216
Trader Rating: 1 (100%+)
Default

Spur gear size does not matter if the FDR is the same.
A larger spur will gives you bottom end but the large pinion that would be needed to get to the same FDR will give you top end. Balancing the power out. I would go over the car to make sure everything is free and I would also try differant gearing since not all motors like the same geraing.
lee is offline   Reply With Quote
Old 04-04-2012, 06:48 PM   #15
Tech Elite
 
Join Date: Nov 2002
Location: NY/FL
Posts: 3,376
Trader Rating: 24 (100%+)
Default

I agree that spur size makes no difference. It's all about FDR and car setup. Is the drivetrain free ? Is the diff set up with more slip ? Spool or diff up front ? Belt tension ? All these things will have an effect.
That said, If our spur gears had any real weight to them then the argument would be different. A larger,heavier spur would have less torque effect but greater inertia effect therfore it would be better for higher speed and worse for acceleration. A smaller, lighter spur would be the opposite.
So...because we spur gears that have very little mass (weight), the effects are extremely minimal. Look for other factors between the 2 cars.
Evoracer is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
CRC Battle Axe, GenXPro 10, 1/10th pan, Brushless, Lipo,4c, Road, Oval,TipsandTricks John Stranahan Electric On-Road 1776 03-01-2016 01:18 PM
Lots of stuff for sale Squidward R/C Items: For Sale/Trade 58 06-27-2010 09:20 PM
TeamNovak Brushless Stock Motors NovakTwo Radio and Electronics 15 02-26-2009 10:15 AM



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 07:54 PM.


Powered By: vBulletin v3.9.2.1
Privacy Policy | Terms of Use | Advertise Content © 2001-2011 RCTech.net