R/C Tech Forums

Go Back   R/C Tech Forums > International Forums > Australian Racing

Reply
 
Thread Tools Search this Thread
Old 05-02-2009, 05:08 PM   #1
Tech Fanatic
 
J-T9959's Avatar
 
Join Date: Oct 2007
Location: On some mud track
Posts: 913
Trader Rating: 17 (100%+)
Default Help with gearing 17.5

Hi guys
I've just changed to LI-PO brushless 17.5 on my Bj4 and need some
help with the gearing as im not sure where to start.

Ive heard that you need a large pinion and small spur i already
have a 72 and a 75 spur and the largest pinion i have is 26.

Can some one help me out with the ratio.
J-T9959 is offline   Reply With Quote
Old 05-03-2009, 12:47 AM   #2
Tech Elite
 
spawn's Avatar
 
Join Date: Oct 2001
Location: SydNeeeeY
Posts: 4,559
Trader Rating: 6 (100%+)
Default

I am running my B44 with FDR 5.7 for the 17.5. I think it depends on the motor brand you are using as some can be geared as low as 5.0. Temp is your guide, never let is cross 80 degrees C.
spawn is offline   Reply With Quote
Old 05-03-2009, 01:38 AM   #3
Tech Elite
 
lookieaefanboi's Avatar
 
Join Date: Jan 2009
Location: Rc Heaven
Posts: 3,165
Trader Rating: 37 (100%+)
Default

Yup 72t spur 36t pinion here. Some ppl advance timing on motor/esc and run a taller fdr.
lookieaefanboi is offline   Reply With Quote
Old 05-03-2009, 01:53 AM   #4
Tech Fanatic
 
J-T9959's Avatar
 
Join Date: Oct 2007
Location: On some mud track
Posts: 913
Trader Rating: 17 (100%+)
Default

Thanks for the replys

At least now i know where start.

So if i keep the motor about as hot as i had my
brushed motor witch i could still hold after a run
would be good start.

Im running the tekin ecs and 17.5 motor.
Cheers Jay
J-T9959 is offline   Reply With Quote
Old 05-05-2009, 03:08 AM   #5
Tech Elite
 
Join Date: Aug 2008
Posts: 2,138
Trader Rating: 26 (100%+)
Default

check out this topic, there is also input from one of the Tekin guys, great info on gearing for those using the new tekin RS and PRO ESC's with the hotwire unit http://www.rctech.net/forum/electric...s-offroad.html
__________________
Kyosho RB5 SP2 WC Limited Edition, Tekin
muzza_t is offline   Reply With Quote
Old 05-05-2009, 05:29 PM   #6
Tech Fanatic
 
J-T9959's Avatar
 
Join Date: Oct 2007
Location: On some mud track
Posts: 913
Trader Rating: 17 (100%+)
Default

Thanks for that link Muzza ill check it out.
J-T9959 is offline   Reply With Quote
Old 05-06-2009, 02:50 AM   #7
Tech Elite
 
spawn's Avatar
 
Join Date: Oct 2001
Location: SydNeeeeY
Posts: 4,559
Trader Rating: 6 (100%+)
Default

I am using rspro too, my settings are sensored with boost timing of 5. Motor is about 70C. ESC software is 194. This setting allowed me to obtain my fastest timing with a 17.5t since I bought my B44 6 months ago.....Just 8s shy from the track record (driver was using a 13.5t).

Last edited by spawn; 05-06-2009 at 04:06 AM.
spawn is offline   Reply With Quote
Old 05-06-2009, 06:50 AM   #8
Tech Regular
 
ryan_c's Avatar
 
Join Date: Dec 2007
Location: Australia
Posts: 250
Trader Rating: 1 (100%+)
Default

hay,

In my b44 I run 78/35 at 0 degree timing. This is a bit over geared but it does not get too hot and is quite a good setup for me. I am using the Tekin/Fantom by the way so same motor you are using.

I think I worked out the gearing should be about 78/33 also, if this is the case I would probably go 10 degree timing.

Ryan
ryan_c is offline   Reply With Quote
Old 05-07-2009, 12:18 AM   #9
Tech Elite
 
spawn's Avatar
 
Join Date: Oct 2001
Location: SydNeeeeY
Posts: 4,559
Trader Rating: 6 (100%+)
Default

Quote:
Originally Posted by ryan_c View Post
hay,

In my b44 I run 78/35 at 0 degree timing. This is a bit over geared but it does not get too hot and is quite a good setup for me. I am using the Tekin/Fantom by the way so same motor you are using.

I think I worked out the gearing should be about 78/33 also, if this is the case I would probably go 10 degree timing.

Ryan
I am using Team Orion 17.5t. I have tried 81/36 and its overgeared. I guess different motor requires different gearing.
spawn is offline   Reply With Quote
Old 05-07-2009, 03:25 AM   #10
Tech Fanatic
 
J-T9959's Avatar
 
Join Date: Oct 2007
Location: On some mud track
Posts: 913
Trader Rating: 17 (100%+)
Default

I have not run the car yet.
Hoping to get up to Maitland for Sunday racing
to do testing in a feild going to start with 5.80 72/31
running the tekin 17.5.
J-T9959 is offline   Reply With Quote
Old 05-07-2009, 03:54 AM   #11
Tech Elite
 
old_skoolie's Avatar
 
Join Date: Mar 2007
Location: Sydney
Posts: 3,154
Trader Rating: 7 (100%+)
Default

Are you running the Tekin 17.5 combo, if so do you have the hotwire, if you don't you'll be in dual mode and you'll have to gear it to up to get speed, if you've got the hotwire, run in sensored only mode, maximum of 35 degrees split between you ESC and motor, ESC gives power higher up the rev range, motor timing gives you more bottom end grunt, Start at about 26 t pinion with a 72t spur and see what temps you're achieving, gear up or down accordingly, motor should not go over 80 degrees centigrade,
The problem with the BJ4(and b44) is no circulation around the motor, you'll probably have to get a heatsink and fan combo but be warned there is not much space in the car (as I've found out) best to take you car to the hobbyshop and try out various cooling methods
Hope this helps you
Steve
old_skoolie is offline   Reply With Quote
Old 05-07-2009, 05:09 AM   #12
Tech Fanatic
 
J-T9959's Avatar
 
Join Date: Oct 2007
Location: On some mud track
Posts: 913
Trader Rating: 17 (100%+)
Default

Yes the i got the combo Tekin rs pro with 17.5.

Ive only just put it in the car last week end have not
conected the hotwire yet so the speedy is still set at
factory setting.
Also have sensore conected.
Jay
J-T9959 is offline   Reply With Quote
Old 05-07-2009, 05:20 AM   #13
Tech Fanatic
 
J-T9959's Avatar
 
Join Date: Oct 2007
Location: On some mud track
Posts: 913
Trader Rating: 17 (100%+)
Default

Ye the bJ4 dose not have much room i do have a small
heat sink that i ran on the brushed motor that worked ok.

Where is the timing mark on the end bell got timing on the
can ( for the tekin 17.5)
J-T9959 is offline   Reply With Quote
Old 05-07-2009, 05:34 AM   #14
Tech Elite
 
Join Date: Aug 2008
Posts: 2,138
Trader Rating: 26 (100%+)
Default

Quote:
Originally Posted by J-T9959 View Post
Where is the timing mark on the end bell got timing on the
can ( for the tekin 17.5)

There should be a little mark on the edge of the end bell , probably around the 10 to 12 degree mark if you havent already adjusted the motor timing.
You really should get a hotwire and the latest software, its amazing what it can do to a 17.5!
__________________
Kyosho RB5 SP2 WC Limited Edition, Tekin
muzza_t is offline   Reply With Quote
Old 05-07-2009, 05:36 AM   #15
Tech Regular
 
ryan_c's Avatar
 
Join Date: Dec 2007
Location: Australia
Posts: 250
Trader Rating: 1 (100%+)
Default

Quote:
Originally Posted by J-T9959 View Post
Ye the bJ4 dose not have much room i do have a small
heat sink that i ran on the brushed motor that worked ok.

Where is the timing mark on the end bell got timing on the
can ( for the tekin 17.5)

Is it the Fantom tekin 17.5 or the Tekin brand itself? It should be on the top of the end bell near where the screws go in. it will say 10 20 then 30.

Cheers

Ryan
ryan_c is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Team Associated B44. Race, Tune and Modify Shadows Electric Off-Road 6171 08-09-2015 08:32 AM
Atria Car Park Speedway tIANcI Malaysian R/C Racers 26519 12-07-2013 07:04 PM
YOKOMO MR4-BX stegger Electric Off-Road 592 05-04-2012 11:10 AM
B44 gearing issues scrappydoo Electric Off-Road 19 06-27-2010 11:38 PM
SMC 4000/25C/3.7V single cell Hardcase pack. Danny/SMC Electric On-Road 1022 03-10-2010 08:56 AM
Losi Constant Velocity Drive (LCD) vs MIP CVD John Stranahan Electric On-Road 263 01-24-2010 12:51 PM



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 05:55 AM.


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