R/C Tech Forums

Go Back   R/C Tech Forums > General Forums > Rookie Zone

Reply
 
Thread Tools Search this Thread
Old 05-30-2012, 10:35 PM   #1
Tech Apprentice
 
Join Date: May 2012
Posts: 64
Default motor turn amount (8.5 vs 10.5)

can someone explain electric motor terms and how they affect my 2wd buggy

1) What exactly is the difference between how many turns my motor has ... I was looking at the reedy sonic and the 10.5T is the same price as 8.5...is one of them faster?

2) What exactly is KV

3) What are the other important stats I should know about motors?
amali2 is offline   Reply With Quote
Old 05-30-2012, 11:19 PM   #2
Tech Master
 
justpoet's Avatar
 
Join Date: Jan 2012
Location: CA, USA
Posts: 1,440
Trader Rating: 16 (100%+)
Default

Motors will generally all be the same price from the same line, regardless of "turns". Turns is really an "equivalent turn rating", so while it is helpful for "spec" or "stock", one manufacturer's 8.5t may be quite different from another's 8.5t, since there really isn't much of a standard. It is close enough to get a general idea though.

As for your question, a lower turn (10.5) will generally be considered "faster" than a higher turn (17.5). In motors you generally give up efficiency and torque for higher rpm as you drop in turns.

kv rating is a way of equating volts to rpm. The higher the kv, the higher the rpm (and the lower the "turns").
__________________
"We do not act rightly because we have virtue or excellence, but we rather have those because we have acted rightly. We are what we repeatedly do. Excellence, then, is not an act but a habit." -Aristotle
My wallet supports: NorCal Hobbies, Tekno, Kyosho, Tekin, Team Powers, HobbyWing, Spektrum, and several battery/tire/servo companies.
justpoet is offline   Reply With Quote
Old 05-31-2012, 06:42 AM   #3
Tech Elite
 
JFuel11's Avatar
 
Join Date: Oct 2009
Location: Central IL
Posts: 3,021
Trader Rating: 110 (100%+)
Default Hope this helps...

Quote:
Originally Posted by amali2 View Post
can someone explain electric motor terms and how they affect my 2wd buggy

1) What exactly is the difference between how many turns my motor has ... I was looking at the reedy sonic and the 10.5T is the same price as 8.5...is one of them faster?

2) What exactly is KV

3) What are the other important stats I should know about motors?
1. The difference is that inside the motor it has wire wrapped aound what they call the stator. That is the part of the motor that has power runs through in pulses to generate an magnetic field and turn the magnetic rotor that the pinion is mounted to.

The less wire (Less turns) the larger but shorter the wire is creating less resistance. This results in a stronger magnetic field pulling on the rotor thus creating more power.

In short... Less turns = more overall power because it will want to turn more RPMs which is whay the smaller turn the motor the small pinion you typically need to run to keep the motor in an effecent gearing for the applicaiton.

2. KV - This is a rating that is used to measure the RPM (Free Spinning - No Load) of a brushless motor. So when you see a rating such as 3100 KV what that means is for every volt applied to that motor it will product 3100 RPM for that volt.... For example...

3100 KV (Motor) x 7.4 Volt Battery (Lipo) = 22940 Total RPM

Just like with power the lower the turns, the less resistance = more power (Higher KV Rating).

3. Other status you shoudl know about a motor... It really depends on what type of racing/driving you are going to be doing. It would be more helpful for you to let us know what vehicle and type of racing you will be doing as well as class you plan to race so we can advise you on the best motor for your application.

In general 1/10th Scale Classes

2wd Buggy Stock Class - 17.5 Turn
2wd Buggy Mod Class - 10.5 to 7.5 Turn
2wd Stock SCT - 17.5 Turn
2wd Mod SCT - 10.5 - 6.5 Turn
4wd 1/10 Buggy 8.5 - 5.5 Turn
Stock Stadium Truck - 17.5 Turn
Mod Stadium Truck - 10.5 to 6.5 Turn
4x4 SCT (4 pole motors rated by KV Only - 3600KV to 4800KV or 550 Motors 6.5 Turn - 4.0 Turn)

The choice of motor turn is really dependant on driver skill, track size and track conditions (Traction)

Regarding brands most name brand motors are pretty close and you will not go wrong if you stick with brands such as Trinity, Reedy, LRP, Tekin, Novak, Viper and such. There are others that are good I didn't list...

Hope this helps.
__________________
Alan Bachman (AKA - Johnny Rocket Fuel)
Help your fellow racers go faster... You will have more competition!!!
Sponsors:
Team Associated - Hobbywing of North America - FalconSekido - Schelle Racing Innovations - SMC - Pro-Line Racing - DE Racing - FbombGraphix.com
JFuel11 is offline   Reply With Quote
Old 05-31-2012, 11:41 AM   #4
Tech Addict
 
nadan805's Avatar
 
Join Date: Mar 2011
Location: PHX
Posts: 613
Trader Rating: 5 (100%+)
Default

8.5 is faster if you can keep the wheels from spinning. I like running my 8.5 motors because I don't have to mess with the timing.
__________________
HE > I______Back in the day:
-AE RC10T3 Basic
-Tamiya Ford SVT F-150 Lightning
-Traxxas Spirit
nadan805 is offline   Reply With Quote
Sponsored Links
Reply

Tags
buggy, motor, reedy sonic, turns


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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Brushless VS Brushed motor. M03Racer Electric Off-Road 37 04-20-2012 08:45 AM
Z-Car 1/8 Buggy E-conversion GSMnow Electric Off-Road 96 12-14-2010 03:32 PM
TVRCRC vs ROCK Racing Club Cup 2009 Dan Boundy Canadian R/C Scene 110 02-24-2009 06:47 PM


All times are GMT -8. It is currently 05:50 PM.



SEO by vBSEO 3.5.0