R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 08-02-2012, 07:44 PM   #1
Tech Fanatic
 
Join Date: Jan 2009
Location: northern california
Posts: 908
Trader Rating: 77 (100%+)
Default motor cogs in only three positions

what does it mean when a brushless motor only cogs in three positions? What I mean is, you take the motor and turn the shaft. almost all brushless motors seem to cog in one of six positions; but I ran across a motor that only cogs in three, each being one third of a rotation apart.

motor seems to run fine otherwise and the rotor checks out ok on a gauss meter, almost balanced + to - too.
__________________
I race at:
SpeedWorld Raceway
Roseville / Sacramento, California
VTA, 1/10 nitro, touring, USGT, F1, and more!
www.speedworldraceway.com
slashdriver is offline   Reply With Quote
Old 08-03-2012, 06:09 PM   #2
Tech Fanatic
 
Hyde's Avatar
 
Join Date: Aug 2007
Location: Los Angeles, CA
Posts: 945
Trader Rating: 1 (100%+)
Default

What esc? What motor? Are you running a sensored brushless motor with a sensor-less esc? What batteries are you using? Gearing? What Model RC?
__________________
MyForum> www.uncovertruth.forumotion.com
Hyde is offline   Reply With Quote
Old 08-03-2012, 06:23 PM   #3
Tech Master
 
samnelso's Avatar
 
Join Date: Aug 2011
Location: Fitchburg, MA
Posts: 1,751
Trader Rating: 1 (100%+)
Default

3 pole stator versus 6 pole?
__________________
Team Associated | Reedy | Airtronics

RC Excitement: Fitchburg, MA | RC Madness: Enfield, CT | Horsham RC
samnelso is offline   Reply With Quote
Old 08-03-2012, 06:26 PM   #4
Tech Fanatic
 
Join Date: Jan 2009
Location: northern california
Posts: 908
Trader Rating: 77 (100%+)
Default

I'm not talking about when it's wired to an ESC/battery etc., i'm talking about when you are holding the bare motor in your hands not hooked to anything, and just turning the shaft by hand.

Interesting thought on the stator. it's an older novak motor, I wonder if they made them that way in the past.
__________________
I race at:
SpeedWorld Raceway
Roseville / Sacramento, California
VTA, 1/10 nitro, touring, USGT, F1, and more!
www.speedworldraceway.com
slashdriver is offline   Reply With Quote
Old 08-03-2012, 10:28 PM   #5
Tech Lord
 
syndr0me's Avatar
 
Join Date: Dec 2004
Location: 5280 Raceway
Posts: 13,140
Trader Rating: 32 (100%+)
Default

You can make any motor feel this way by shorting out two of the poles. Jumper some solder between two of your tabs and see what I mean.

I've come across some DUO motors in the past that felt this way without being shorted. They always ran fine.
syndr0me is offline   Reply With Quote
Old 08-04-2012, 12:47 AM   #6
Tech Elite
 
andrewdoherty's Avatar
 
Join Date: Jan 2005
Location: ★Wylie, TX★
Posts: 3,776
Trader Rating: 47 (100%+)
Default

Quote:
Originally Posted by syndr0me View Post
You can make any motor feel this way by shorting out two of the poles. Jumper some solder between two of your tabs and see what I mean.

I've come across some DUO motors in the past that felt this way without being shorted. They always ran fine.
Interesting. When I bridge the tabs on motors, I usually get high resistance, but not the loss of cogging.
__________________
"Whether you think you can, or think you can't, you're right." -Henry Ford
"[Driving] Genius is 1% inspiration, and 99% perspiration" -T.A. Edison
|◤Hobbywing◢|◤SpeedzoneUSA.com◢|◤Pro-One◢|
|◤ReflexRacing.net◢|◤Protoform◢|◤AVID R/C◢|
andrewdoherty is offline   Reply With Quote
Old 08-04-2012, 03:57 AM   #7
Tech Regular
 
Join Date: Jul 2009
Posts: 436
Default

I believe its less rpm on higher pole count usually.

I have not heard about 540 size motors with 6 poles. More info is needed.
MatsNorway is offline   Reply With Quote
Old 08-04-2012, 08:30 AM   #8
Tech Lord
 
syndr0me's Avatar
 
Join Date: Dec 2004
Location: 5280 Raceway
Posts: 13,140
Trader Rating: 32 (100%+)
Default

Quote:
Originally Posted by andrewdoherty View Post
Interesting. When I bridge the tabs on motors, I usually get high resistance, but not the loss of cogging.
I guess I should have said jumper them and spin it by hand. Applying power would be bad. It makes one of the poles feel soft.
syndr0me is offline   Reply With Quote
Old 08-04-2012, 10:42 AM   #9
Tech Elite
 
Join Date: Sep 2009
Location: Central Wisconsin USA
Posts: 3,339
Trader Rating: 217 (100%+)
Default

Quote:
Originally Posted by syndr0me View Post
I guess I should have said jumper them and spin it by hand. Applying power would be bad. It makes one of the poles feel soft.
I tested 5 of my motors and all have 3 cogs.
Andy Koback is online now   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 06:39 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