somewhat bullet proof jato tranny.... - RC-Monster Forums

whitrzac · **somewhat bullet proof jato tranny.... -** 06.29.2009, 01:26 PM

the pinions are 28/18...

you MUST use the stock lower shaft and file off the raised part, or drill the correct hole in the 1 speed shaft to use the 2speed diff idler gear gear...

the mod takes ~ an hour, most of the time is spent fine tuning the endplay in the bottom shaft...

make sure to use the corect pin for the plastic gear

Metallover · 07.09.2009, 04:38 PM

So are those two metal gears you put in the gears that strip? Which one in particular?

whitrzac · 07.09.2009, 05:20 PM

Quote:

Originally Posted by Metallover

So are those two metal gears you put in the gears that strip? Which one in particular?

the lower plastic one that drives the diff, it striped out the pin...

I didn't have the right pinions, but if you find one the size of the top gear in the 1 speed(15t??), it will be alot stronger...

you cant use a modified 1 speed lower because it moves the pinion too close to the diff when you flip it...

Metallover · 07.09.2009, 05:47 PM

So we have gear A, gear B, and Gear C. We also have pinhole 1 and 2.

By my understanding pinhole 2 is the first to go? And gear A and B strip too?

Gear A is in fact 15t, I have a 16t pinion that was just too big and fit real tight. Gear b is something around 20-22 teeth, didn't take too much time to count.

whitrzac · 07.09.2009, 06:38 PM

Quote:

Originally Posted by Metallover

So we have gear A, gear B, and Gear C. We also have pinhole 1 and 2.

By my understanding pinhole 2 is the first to go? And gear A and B strip too?

Gear A is in fact 15t, I have a 16t pinion that was just too big and fit real tight. Gear b is something around 20-22 teeth, didn't take too much time to count.

gear A is the first to go, and usualy takes part of B with it,

I filed the shaft from the origanl 2 speed down to 5mm all the way accross to be able to flip the pinion the other way

you could use the 1 speed gear if you cut the larger portion off, and bore out half of it so the setscrew of the pinion will fit inside

Metallover · 07.09.2009, 09:40 PM

Awesome! Thanks for the info... I think if I blow A or B I'll get a 15t pinion to use for gear A and see how long that holds up.

Are the diffs/output yokes good stock? I have to assume...

whitrzac · 07.09.2009, 09:47 PM

Quote:

Originally Posted by Metallover

Awesome! Thanks for the info... I think WHEN I blow A or B I'll get a 15t pinion to use for gear A and see how long that holds up.

Are the diffs/output yokes good stock? I have to assume...

do it now, cus when A goes it takes B with it...

J57ltr · 07.12.2009, 12:37 PM

So does this keep the 2 speed function? I am thinking of putting a Jato tranny into my HB lightning 10 specifically for the 2 speed. Are their any other problems with the Jato trans? I know I will need to have the mechanical brakes.

Jeff

whitrzac · 07.13.2009, 08:28 PM

Quote:

Originally Posted by J57ltr

So does this keep the 2 speed function? I am thinking of putting a Jato tranny into my HB lightning 10 specifically for the 2 speed. Are their any other problems with the Jato trans? I know I will need to have the mechanical brakes.

Jeff

no...

there is a alloy 2 speed gearset on ebay for ~$70

J57ltr · 07.19.2009, 02:42 PM

Is that Jato trans that weak? My Rustler trans seems to take a ton of abuse without any problems (after you use a VXL diff and Steel idler), and I don't use a slipper at all.

Thanks

Jeff

Unsullied_Spy · 09.09.2009, 05:47 AM

Jato trannies are very weak. The Rustler tranny is tougher because it has steel gears (even though they are smaller pitch). I've seen people putting an 18T pinion in the tranny in place of the stock 17T and they said it meshed better and held up to a ton of power.

J57ltr · 09.13.2009, 09:07 PM

I guess I'll look into this. I bought a JAto tranny a while back and thought about removing the center dif in my Lightning 10 and mounting the trans sideways. I want to keep the 2 speed but will have to use the mechanical brake and won't have reverse, but I want to set it up for top speed runs. I am not going to lock it into just second. Some people think that a 2 speed is useless for electric but I think it will keep the current draw down and allow me to keep the motor rpm's down.

What is the pitch on the Jato trans.

Jeff

whitrzac · 09.13.2009, 09:17 PM

Quote:

Originally Posted by J57ltr

I guess I'll look into this. I bought a JAto tranny a while back and thought about removing the center dif in my Lightning 10 and mounting the trans sideways. I want to keep the 2 speed but will have to use the mechanical brake and won't have reverse, but I want to set it up for top speed runs. I am not going to lock it into just second. Some people think that a 2 speed is useless for electric but I think it will keep the current draw down and allow me to keep the motor rpm's down.

What is the pitch on the Jato trans.

Jeff

I thought that too, but the stock tranny WILL blow when it locks into 2nd...

J57ltr · 09:35 PM

Care to splain? As I see it by the time the trans is going tro shift the power is going to be down as opposed to a nitro, so when second hits the motor will peak again, but then power will start dropping again as rpm's increase.

I do understand that the lower the overall ratio the weaker it is.

I don't know, I'm just asking.

Jeff

Unsullied_Spy · 06:34 AM

I believe they are 32p gears.

A few reasons why 2 speeds don't work well with electrics:

1) BL motors work best with a certain amount of load on them, this varies between motors and setups but you ideally want to find the sweet spot and run it there. If your 1st gear is the gear where it is setup ideally and it only kicks into 2nd when you nearly max it out in 1st I suppose it would be good for a speed gear, but there are a few other issues.

2) A 2 speed will not reduce amp draw, it could actually make it worse. Amp draw of a BL motor is proportional to the load placed on it, when you shift into 2nd there is suddenly a lot more load on it and nothing to absorb the shock (part of reason #3) and the amp draw spikes because the RPM at the input shaft (being driven by your motor) suddenly drops but the ESC is still working the motor at the speed of 1st. The ESC can compensate for this quickly, but the increase in gearing will still require more amps to provide the power needed to get moving.

3) Drivetrain shock. Unless your slipper clutch is adjusted so loose that it slips quite a bit unless you're very gentle on the throttle as soon as it kicks into 2nd gear the sudden RPM change WILL tear things up. Think 2 speed clutches, one-way bearings, output yokes, U-Joints, stub axles, and tranny gears (possibly spur gear if your mesh is too loose).

4) When it shifts into second you will either spin the tires or wheelie, depending on how much traction you get (some nitros experience this same condition when shifting into second). Either way it is very possible you will lose control. This happens because when more load is placed on a BL motor the power output actually goes up unless you can't supply enough amps to feed the motor (in which case things start getting hot, fast). The sudden increase in power and RPM change causes your control problems.

That's about the best I can put into words, but I really think you're best off going with a properly setup single speed.