Go Back  R/C Tech Forums > General Forums > Electric Off-Road
3S in an 1/8 electric with 1900kv? >

3S in an 1/8 electric with 1900kv?

3S in an 1/8 electric with 1900kv?

Reply

Old 10-08-2013, 09:18 AM
  #1  
Tech Addict
Thread Starter
iTrader: (24)
 
Join Date: Jul 2006
Location: CT
Posts: 561
Trader Rating: 24 (100%+)
Default 3S in an 1/8 electric with 1900kv?

Just wondering your thoughts on this. For the winter our local indoor track is running 1/8 e buggy with a max of 1,950kv motors on 3s lipos. I ordered a few Nano-tech 3S 5100s as well as two SMC 5100 3S. Will have both an 8ight-e 2.0 (RX8 gen 1 w/ T8 1900kv) and a MBX6 ECO (RX8 gen 2 w/ T8 1900kv) to use. I want everything to run well and not get too hot. What would be a good starting point for gearing? I have 12-18t pinions available.

The Losi as it sits has a 15 or 16t pinion on it and on 4S it is insane...perfect for the outdoor track, but way too much for the indoor.

I've forgotten so much since i've been out of RC it's crazy!

This is the track i'll be running on.

http://www.youtube.com/watch?v=dlXTN...ature=youtu.be
jamesbernatchez is offline  
Reply With Quote
Old 10-08-2013, 09:33 AM
  #2  
Tech Master
iTrader: (6)
 
snwchris's Avatar
 
Join Date: Feb 2010
Location: NE Ohio
Posts: 1,531
Trader Rating: 6 (100%+)
Default

Hmm interesting with the 3s ruling.
Well i run a 4s lipo and 1900 Tekin and currently geared at 17T pinion for our medium indoor track that is high bite clay. Depending on layouts I can usually just turn down the throttle on the radio.

Maybe 12T to 15T for pinion gear to have on hand for trying.


Tekin Motor / Lipo chart
http://www.teamtekin.com/t8/index.html
snwchris is offline  
Reply With Quote
Old 10-08-2013, 10:06 AM
  #3  
Tech Addict
 
USMC STONE's Avatar
 
Join Date: May 2012
Posts: 583
Default

I think with the 3s on 1900 you will end up with 16-18 tooth.
USMC STONE is offline  
Reply With Quote
Old 10-08-2013, 11:36 AM
  #4  
Tech Elite
iTrader: (27)
 
BLbound's Avatar
 
Join Date: Feb 2009
Location: In the LE, SoCal
Posts: 2,288
Trader Rating: 27 (100%+)
Default

I'm seeing a little more & more of this class, here in SoCal we call it 1/8 SL or light...some of the guys are running 550 sc motors with 2 cell lipos...the cars are still super fast!
BLbound is offline  
Reply With Quote
Old 10-08-2013, 12:23 PM
  #5  
Tech Master
iTrader: (4)
 
BillyT.'s Avatar
 
Join Date: Nov 2012
Posts: 1,914
Trader Rating: 4 (100%+)
Default

I had my MBX6 running on 2 cell with a HW 4700, and the thing ripped... for 6 minutes... I mean, it drove so so good. But I would start to dump 6 in and a few features got kinda difficult. It would ultimately run for about 10 minutes. I was as fast as anyone with that car though. .4 slower than I ever ran in my nitro car, and as fast as I ever was in my truggy.

Ran the same car on 3s with a 550 2800 SCTE motor. But it was never as good as it was on 2 cell...


Originally Posted by USMC STONE View Post
I think with the 3s on 1900 you will end up with 16-18 tooth.
I think 16-18 is spot on for both cars, also... Leaning more towards 16...
BillyT. is offline  
Reply With Quote
Old 10-08-2013, 12:24 PM
  #6  
Tech Elite
iTrader: (53)
 
Join Date: Feb 2008
Location: Belleville, MI
Posts: 4,517
Trader Rating: 53 (100%+)
Default

Originally Posted by jamesbernatchez View Post
Just wondering your thoughts on this. For the winter our local indoor track is running 1/8 e buggy with a max of 1,950kv motors on 3s lipos. I ordered a few Nano-tech 3S 5100s as well as two SMC 5100 3S. Will have both an 8ight-e 2.0 (RX8 gen 1 w/ T8 1900kv) and a MBX6 ECO (RX8 gen 2 w/ T8 1900kv) to use. I want everything to run well and not get too hot. What would be a good starting point for gearing? I have 12-18t pinions available.

The Losi as it sits has a 15 or 16t pinion on it and on 4S it is insane...perfect for the outdoor track, but way too much for the indoor.

I've forgotten so much since i've been out of RC it's crazy!

This is the track i'll be running on.

http://www.youtube.com/watch?v=dlXTN...ature=youtu.be

Most importantly the dimensions of your track will determine the recommended gearing. At my local indoor track (95' x 60') I run a Tekin 1600kv T8i motor on 4s with "theoretical top speed" of 32mph. My car is near impossible to beat I can use the whole throttle range everywhere and not worry about overshooting jumps or blowing corners. My buddy and I have dubbed it "Stock 1/8th scale" racing.

http://scriptasylum.com/rc_speed/top_speed.html
Use the web link above to calculate gearing/top speed

here are the parameters for my Hotbodies D812e
Front/Rear Differential Gear Ratio: 4.3:1
Transmission Gear Ratio: 1:1
Spur gear: 46T
pinion: 20T
total battery voltage: 14.8v (nominal voltage)
kv rating: 1600kv
tire diameter: 4.5 inches
MPH =32.1


This should get you close to my settings with a losi buggy on 3s
Front/Rear Differential Gear Ratio: 3.31:1
Transmission Gear Ratio: 1:1
Spur gear: 45T (stock losi plastic spur)
pinion: 17
total battery voltage: 11.1v (nominal voltage)
kv rating: 1900
tire diameter: 4.5 inches
MPH = 32.25
nv529 is offline  
Reply With Quote
Old 10-08-2013, 04:41 PM
  #7  
Tech Addict
Thread Starter
iTrader: (24)
 
Join Date: Jul 2006
Location: CT
Posts: 561
Trader Rating: 24 (100%+)
Default

I appreciate the ideas guys. I plan to get up there and test out different pinions and run times with the 3S lipos once the all come in.
jamesbernatchez is offline  
Reply With Quote
Old 10-08-2013, 08:02 PM
  #8  
Tech Addict
iTrader: (12)
 
Speed Freak RC's Avatar
 
Join Date: Jan 2013
Location: Grayling, MI
Posts: 659
Trader Rating: 12 (100%+)
Default

Nick is that the setup you ran at AMS on Friday night?
Speed Freak RC is offline  
Reply With Quote

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


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service