R/C Tech Forums

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

Reply
 
Thread Tools Search this Thread
Old 04-07-2012, 07:16 PM   #1441
Tech Master
 
bronc4now's Avatar
 
Join Date: May 2011
Location: Hoffman Estates,IL
Posts: 1,378
Trader Rating: 40 (100%+)
Default

Quote:
Originally Posted by squarehead View Post
In case anyone is trying to get to the proper gearing on this car for a USVTA car using a 25.5 it's not an easy process on this car. I figure I would save everyone else from making the same mistakes I did to get it to work.

First, if you want to use a 21.5 or 25.5 motor, you are going to need the vertical motor mount (SAK-66/PK). Don't even bother with the stock setup. I haven't found any small enough spur gears that had holes for the horizontal motor mount.

The 3racing website and a few people here expressed that it is mandatory that you use SAK-38/WO Soft upper deck with this, which is true, however, the car comes with the soft upper deck, so you do NOT need to buy another upper deck. I don't know why I assumed the "soft" upper deck was aftermarket and not stock, but I was wrong, and I ordered that part with the vertical motor mount. You don't need to at all, as it is the same one you already have. Unfortunately, I found out the hard way.

Anyway, I am used to having small spurs and large pinions for VTA spec racing, and the small spurs would not come close to the pinions when the motor was in the closest position to the spur. Everything I had in my box was either too large or too small to work. I wound up in a trial by error experimentation with expensive spur gears to get the right mesh and alignment.

So the absolute smallest 64p sour you should even try is an 83t gear. With that and a 25.5t spec motor, I can get a 40t pinion on and meshed properly to get a 4.040 FDR on the car with a 37t pulley on the diffs and a 19t pulley on the spur (not stock). I could probably get a 39t to work, but it would be REALLY close. Anything larger should work fine.

I would recommend at least a 85t spur for proper mesh and alignment on a spec car using anything 21.5 or 25.5. The 37t/19t pulley setup helps a lot in getting the FDR in the right window.


Hope this helps someone else avoid the expense and time wasted that finally got me to the right solution.



doug
so i should get a 83t spur and a 40t pinion 64pitch for vta 25,5t.
I ordered the 19t center but not a 37 , next order..

just ordered 84t spur and 39-40-41t pinions 64pitch hope that works
__________________
RACE-BASH-CRAWL
Two many toys not enough time..

Last edited by bronc4now; 04-07-2012 at 11:34 PM.
bronc4now is offline   Reply With Quote
Old 04-08-2012, 05:45 AM   #1442
Tech Fanatic
 
mingnon's Avatar
 
Join Date: Jun 2011
Location: Sutherland Shire
Posts: 962
Trader Rating: 12 (100%+)
Default

am running sakura zero with a few hop ups, and a couple of relatively simple mods allows me to run 21.5 blinky, VTA down here in Aust

- 60 tooth (48 pitch) RW Sur gear - file off two of the lugs on the spur gear holder (plastic or aluminium)

- Filed the top of the vertical motor mount - can now fit a 43 tooth (48 pitch) pinion gear

- Using the 20 centre gear and a tamiya 37 pulley (solid front), and 37 on the rear have got the gearing to 1.85

Only problem is wearing out front hpi tyres in vta, going to go back to gear diff and then run lighter springs and oil.
__________________
---------------------------SMA The Home of GREAT Racing------------------------------
mingnon is offline   Reply With Quote
Old 04-08-2012, 06:18 AM   #1443
Tech Master
 
Join Date: Jun 2011
Location: Northeast GA
Posts: 1,685
Default

88 spur in 64 pitch will give you plenty of room for a 4.0 FDR. Use the 38 tooth and 19 tooth pulleys. I have run 3.7 to 4.2 on this set up.

I don't know who said the soft deck was needed for the vertical mount. it is the carbon upper deck that fits better although it is not completely necessary if you are willing to grind the stock deck.

Although I'm happy your mod filing the spur gear holder worked I would not recommend this. It will produce a weak point in holding the gear. With only two contact points you will increase the wear on the parts. Also it is unnecessary work with the right gears.
__________________
3Racing Sakura XI 17.5 TC
Formula Rabbit (FGX conversion) 21.5
STRC LCG 2WD Slash 17.5
Serpent S120 13.5
6376vette is offline   Reply With Quote
Old 04-08-2012, 07:38 AM   #1444
Tech Master
 
pejota's Avatar
 
Join Date: Apr 2008
Location: Vero Beach, FL
Posts: 1,018
Trader Rating: 11 (100%+)
Default

I'm the oddball here with my gearing...

I picked up the optional 37 tooth front and rear diffs. Combine that with the stock 20 tooth center pulley and i run a 1.85 internal ratio. Belt tension is not an issue with the smaller front/rear diffs.

For a spur, i run 3racing's 92 tooth, 64 pitch gear. I am also running the stock motor mount. No issues with adjustments and i'm running a 47 tooth pinion for a 3.62 FDR. I'm still working on gearing/motor timing since i'm on a new track. Tightening motor screws is a pain with the stock mount, so i'm thinking of getting the vertical mount. From what i hear, the issue with that is flipping the belts and that causes issues with the battery mounting system. I think 3racing's battery system is the best i've ever seen, and i'm reluctant to get away from it.
pejota is offline   Reply With Quote
Old 04-08-2012, 09:39 AM   #1445
Tech Champion
 
SteveM's Avatar
 
Join Date: Aug 2001
Location: Ottawa, Ontario, CANADA
Posts: 5,622
Trader Rating: 125 (100%+)
Default

Quote:
Originally Posted by pejota View Post
For a spur, i run 3racing's 92 tooth, 64 pitch gear. I am also running the stock motor mount. No issues with adjustments and i'm running a 47 tooth pinion for a 3.62 FDR. I'm still working on gearing/motor timing since i'm on a new track. Tightening motor screws is a pain with the stock mount, so i'm thinking of getting the vertical mount. From what i hear, the issue with that is flipping the belts and that causes issues with the battery mounting system. I think 3racing's battery system is the best i've ever seen, and i'm reluctant to get away from it.
With the vertical motor mount you must flip the belts to the other side of the chassis. The upper deck must also be modified to clear the motor mount, but this is relatively simple to do and takes only a few minutes with a Dremel and a small sanding drum bit. The effort is worth it in my opinion as you gain much better access to the two motor bolts.
SteveM is offline   Reply With Quote
Old 04-08-2012, 10:17 AM   #1446
Tech Master
 
pejota's Avatar
 
Join Date: Apr 2008
Location: Vero Beach, FL
Posts: 1,018
Trader Rating: 11 (100%+)
Default

What about belt interference with the battery mounts?

Any pics you can post?



Quote:
Originally Posted by SteveM View Post
With the vertical motor mount you must flip the belts to the other side of the chassis. The upper deck must also be modified to clear the motor mount, but this is relatively simple to do and takes only a few minutes with a Dremel and a small sanding drum bit. The effort is worth it in my opinion as you gain much better access to the two motor bolts.
pejota is offline   Reply With Quote
Old 04-08-2012, 11:13 AM   #1447
Tech Champion
 
SteveM's Avatar
 
Join Date: Aug 2001
Location: Ottawa, Ontario, CANADA
Posts: 5,622
Trader Rating: 125 (100%+)
Default

Quote:
Originally Posted by pejota View Post
What about belt interference with the battery mounts?

Any pics you can post?
The reversed belts also interfere with the plastic battery tray guides and they will also need to be modified.

Last edited by SteveM; 12-24-2015 at 08:58 AM.
SteveM is offline   Reply With Quote
Old 04-08-2012, 04:11 PM   #1448
Tech Fanatic
 
mingnon's Avatar
 
Join Date: Jun 2011
Location: Sutherland Shire
Posts: 962
Trader Rating: 12 (100%+)
Default

Quote:
Originally Posted by 6376vette View Post
88 spur in 64 pitch will give you plenty of room for a 4.0 FDR. Use the 38 tooth and 19 tooth pulleys. I have run 3.7 to 4.2 on this set up.

Although I'm happy your mod filing the spur gear holder worked I would not recommend this. It will produce a weak point in holding the gear. With only two contact points you will increase the wear on the parts. Also it is unnecessary work with the right gears.

Have been running this mod in 2 chassis for 3 months with no wear on any of the drive train (one a drift setup -9 turn motor, other a carpet runner 13 turn). Have also seen same setup in 1 other car, has been running for 2 months with no wear issues. Cars are stripped down bi weekly for maintenance.

Down here we need a fdr of 3 - 3.2 to be competitive in the local VTA.
__________________
---------------------------SMA The Home of GREAT Racing------------------------------
mingnon is offline   Reply With Quote
Old 04-08-2012, 07:55 PM   #1449
Tech Master
 
Join Date: Jun 2011
Location: Northeast GA
Posts: 1,685
Default

Glad it seems to be working thus far.
__________________
3Racing Sakura XI 17.5 TC
Formula Rabbit (FGX conversion) 21.5
STRC LCG 2WD Slash 17.5
Serpent S120 13.5
6376vette is offline   Reply With Quote
Old 04-09-2012, 04:06 PM   #1450
Tech Adept
 
redbarton's Avatar
 
Join Date: Jan 2006
Posts: 230
Trader Rating: 3 (100%+)
Default

I am liking my Zero S so much that I bought a second used chassis to replace my TC4 for Vintage. Unfortunately, our outdoor on-road season now seems to be in jeopardy about whether or not it will happen at all. Grrr! I just put a bunch of upgrades on the original, too!
redbarton is offline   Reply With Quote
Old 04-11-2012, 07:24 PM   #1451
Tech Apprentice
 
ChrisNRG's Avatar
 
Join Date: Mar 2012
Location: NJ
Posts: 57
Trader Rating: 3 (100%+)
Default

A box stock Zero S would require the 44mm Universals to replace the rear swing shafts, correct?
ChrisNRG is offline   Reply With Quote
Old 04-11-2012, 09:15 PM   #1452
Tech Master
 
malcnz's Avatar
 
Join Date: Sep 2006
Location: DUNEDIN, NewZealand
Posts: 1,296
Default

Quote:
Originally Posted by ChrisNRG View Post
A box stock Zero S would require the 44mm Universals to replace the rear swing shafts, correct?
yes correct.
__________________
SCHUMACHER MI5 EVO/TEAM POWERS/SANWA/DX4R PRO.

SERPENT F110/TEAMPOWERS 21.5.

LOSI 22 2.0/TEAM POWERS 8.5
malcnz is offline   Reply With Quote
Old 04-12-2012, 08:16 PM   #1453
Tech Regular
 
rsawyers9's Avatar
 
Join Date: Jan 2011
Location: Knoxville, TN
Posts: 361
Trader Rating: 7 (100%+)
Default

I snapped a front arm this evening. Glanced off a pipe on the straight and broke the RF arm through the outer hinge pin holes. After looking at the remaining bit of the arm it looks like there was a significant amount of air bubbles in the plastic along the break. Was this just a bad molding or are the arms really this fragile. I was running a 25.5t and the hit was not at all hard.

Also, which arms should I order. The Hard sak-25h or the sak-x02?
__________________
Mugen MBX6R US | Novarossi P5 | 2058 | Savox |
rsawyers9 is offline   Reply With Quote
Old 04-12-2012, 08:35 PM   #1454
Tech Fanatic
 
Madulla's Avatar
 
Join Date: Aug 2010
Location: Calgary
Posts: 982
Default

Get the hard ones. Do you have the X-ray hard bumper?
__________________
Hobbywing North America Team Driver
hobbywingdirect.com

CARCAR VP carcar.ca
Madulla is offline   Reply With Quote
Old 04-12-2012, 08:41 PM   #1455
Tech Regular
 
rsawyers9's Avatar
 
Join Date: Jan 2011
Location: Knoxville, TN
Posts: 361
Trader Rating: 7 (100%+)
Default

Quote:
Originally Posted by Madulla View Post
Get the hard ones. Do you have the X-ray hard bumper?
Thanks. No i have the stock bumper but I actually didn't even hit the bumper in this impact.
__________________
Mugen MBX6R US | Novarossi P5 | 2058 | Savox |
rsawyers9 is offline   Reply With Quote
Reply

Similar Threads
Thread Thread Starter Forum Replies Last Post
Sakura Zero - New Touring Car! InZane Electric On-Road 1355 02-14-2014 05:14 PM
New to the RC scene...need some help! Jmoney12 Rookie Zone 13 06-15-2010 10:21 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 01:21 AM.


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

SEO by vBSEO 3.5.0