USA-1 Nitro counter gear and shaft, dimensions

Hiya all

Is there someone out there who can measure a counter gear shaft for me?
I know it's 5mm dia., but would like to know
  • the distance from the flange face to the E clip groove
  • the distance from the E clip groove to end of shaft
  • the thickness of the flange itself
  • the width of each gear
these dimensions should enable me to fab a shaft.
From some image googling I managed to count the counter gear teeth, is it 14/28 ?

Awaiting some parts to modify into a steel counter gear, will post more info once I figure out the process and get some results.

Cheers
Dave
 

Dominick Shauntee

Well-Known Member
Busy with the start of school right now give me a few days to get measurements for you ... and like to thank you for working on a solutions for other USA-1 fans ...
 

Bryonfunderburg

Well-Known Member
Hiya all

Is there someone out there who can measure a counter gear shaft for me?
I know it's 5mm dia., but would like to know
  • the distance from the flange face to the E clip groove
  • the distance from the E clip groove to end of shaft
  • the thickness of the flange itself
  • the width of each gear
these dimensions should enable me to fab a shaft.
From some image googling I managed to count the counter gear teeth, is it 14/28 ?

Awaiting some parts to modify into a steel counter gear, will post more info once I figure out the process and get some results.

Cheers
Dave

well here we go.

distance from face to e clip groove.aprox 1\16 of an inch
from e clip groove to end is 1'' 5\16
the groove itself is 1/8 of an inch
looks like the taller gear for the for clutch bell is 1/4 while the center diff gear is 5/16.


BTW u can buy a hardened steel version with both main gear and counter on ebay.pricy tho

hope this helps

and u can bypass all this with bs-11 or bsw-19 main gear .and adjustable diff housing carrier bsw-34.and eliminate the counter gear.
 
Thanks guys

I got the teeth count from pictures of those all steel gears on ebay ;)

Basically what I'm attempting is mating a 14T mod 1 pinion gear to a 29T mod 1 pinion gear (was closest I found on ebay, to suit that Traxxas XO-1 thing).

Thankfully, a 14T clutch bell was easy to find (stock is 13 I believe), and in guessing that the main diff gear is 54T, the overall ratio will be 7.99:1, compared to stock 8.30:1.

Regarding the steel Burns gears, I wasn't able to find any as yet, and for about $15 (half was postage!) this is worth a try.
Have lathe, will modify :cool
Dominick, know what ya mean about skool stuff, only over here it's getting towards the end of the year when everything is due..
(Yes I'm 36 and still completing my degree)
 
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Bryonfunderburg

Well-Known Member
bsw 19 and bs 11 are pretty hard to find.bsw 19 is 53 T and is very expensive at minimum 50 bucks .yes the original clutch bell was 13 t.the main gear was 53 t also.
 
got the gears in the mail, both Traxxas items.

First impressions - these things are bloody hard!
Not just a simple job of drilling them out, the drill bits didn't want to cut into them.
May be some kind of self lubricating alloy as well?

Had to use a grinder to remove one boss, hacksaw went nowhere.

Awaiting a carbide rod in the mail, will fashion into a boring tool, need to make bearing recesses in both ends of the smaller pinion.

Turns out this job ain't as simple as first thought, but that's kinda normal I guess :rolleyes
 
if only my truck had come with dual engines

got the carbide rod in the mail, did some machining out in the shed, got a working gear :D

Didn't get any build pics, but will get some when I install the 2 bearings.

Now to find out if this engine runs...



 
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atrc

Well-Known Member
if only my truck had come with dual engines

got the carbide rod in the mail, did some machining out in the shed, got a working gear :D

Didn't get any build pics, but will get some when I install the 2 bearings.

Now to find out if this engine runs...



The stock counter shaft is prone to fail over tine due to the rpm from the motor. I have lots of them and have been making inproved ones with out useing the e-clips. I have lots of main gears for the Usa-1 nitro and all the parts from the burns are intercangeable. Don't use just the main gear alone with one motor. Your just wasting your time looking for those parts and you will loose all the power needed to turn the big tires. The truck was designed to use the counter gear to lower the gearing for the big tires. I have lots of usa-1 and Burns parts. the biggest problem I had with the Usa-1 was breaking the wheels. So I machined my own wheels. The shocks are junk so I upgrade to large bore shock from the burns and I made new shock tower to accept them. I also replace the radio tray with a aluminum one to handle the 200oz servo. The truck isn't built for speed.
 
The pics show the counter gear I already made, from 2 hard steel pinion gears.
The shaft is also a machined item.

When you say the shafts fail, do you mean the nut works loose, or you end up with cracked shafts?

Since the motor is the original GS21 (not even the R version), the counter gear is a necessity, hopefully it lasts a while.
 

atrc

Well-Known Member
The pics show the counter gear I already made, from 2 hard steel pinion gears.
The shaft is also a machined item.

When you say the shafts fail, do you mean the nut works loose, or you end up with cracked shafts?

Since the motor is the original GS21 (not even the R version), the counter gear is a necessity, hopefully it lasts a while.
The side with the gear. The e-clip groove will fail every time. I modified that by drilling a metric hole and used a metric cap screw. I only have melted the counter gear 3 times useing a 1.2 hp motor puts alot of stress on the counter gear with a 13 tooth clutch bell. I lowered it to a 12 tooth. I have the 11 tooth and that's when I melted the counter gear. I am now trying a 1.7 hp motor and a 13 tooth clutch. I only run Os motors.
 

Bryonfunderburg

Well-Known Member
is that a gs 21 r or gs 21.could not tell from the pic.but by the carb it looks like a gs 21, the filter nozzle is longer.i only have one usa 1 with a counter gear out of 6,and is will prob have a modified rx on it at one point.but i have prob the largest usa 1 twin info site on the web.started about 4months ago and i almost got 7000 hits.check it out and it may help.burn are great to have for the front and rear diff since bsw-1 and bsw-2 are 30 bucks each if u can find them

http://www.ultimaterc.com/forums/showthread.php?t=149399
 
It's a GS 21, in the pic you can see the main needle/fuel line ****** has snapped off, thankfully I have the piece and I'm now waiting for the JB Weld to cure ;)

I also took note of atrc's post, and end drilled the counter shaft for an m3 screw.
Unfortunately I don't have much (any) time to keep the project going right now, I'm in the middle of finishing up my University degree and it's very hectic.. but come November I'm gonna make it happen ;)

Thanks for the help btw
 

atrc

Well-Known Member
is that a gs 21 r or gs 21.could not tell from the pic.but by the carb it looks like a gs 21, the filter nozzle is longer.i only have one usa 1 with a counter gear out of 6,and is will prob have a modified rx on it at one point.but i have prob the largest usa 1 twin info site on the web.started about 4months ago and i almost got 7000 hits.check it out and it may help.burn are great to have for the front and rear diff since bsw-1 and bsw-2 are 30 bucks each if u can find them

http://www.ultimaterc.com/forums/showthread.php?t=149399
You can use more than just the diffs? The Burns is the platform for the USA-1 nitro. I pick up the any kyosho Burns series buggies just for for parts. I just picked up a Turbo Burns cheap. All it needed was a new motor,body and bumper. It had a motor but it was junk. I don't care for Ofna engines. I had a Os .21 Exb that I picked up cheap. It only needed a new pistion/sleve and o-rings in the carb. total spent $150 US. They are selling now for $300-800 now US.
 

william g

Retired
Moderator
you should covert these to brushless and you don't need the counter gear assembly.

This is the 1 I did for Artie

[video=vimeo;20286461]https://vimeo.com/20286461[/video]
 

Bryonfunderburg

Well-Known Member
none of my usa 1's came with dual engines,i made new frames and all the parts to go with it! has been lots of work.only ones i have with twin engines from the factory are the twin titan ,and the giga crusher DF
 
The engine runs!!
Only until the main needle assembly falls off :(
Seems JB Weld aint as fuel proof as I thought.
On to other solutions...

On the bright side, the counter gear assembly worked and stayed in place :D
 
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