Ball Differential upgrade

[ajdragon]

Hi

I was woundering if anyone has ever put a ball differential in there Arrma RC's? I have been doing some looking around and I just might be able to put a all metal ball differential in my Raider XL. Once I get all the parts I will see about posting some pictures and part numbers if it works out.

 

[Kregger]

I actually use the ball diff from an sc10 and shim it so it doesn't slide side to side in the gear case.

 

[poombah]

Are these really and upgrade over a geared diff?

I was looking at this in my fury but looking at some other brands in got the impression a metal geared diff was seen as superior to a ball diff?

 

[ajdragon]

Hi

Who says you cant get an all metal ball diff. Now that I know that the SC10 ball diff will work in the 1/10 scale Arrma's. I have done my research and I know for a fact that you can get an all metal ball diff for the SC10. The RC10GT uses the same ball diff gear as the SC10. RRP still makes a aluminum ball diff gear for the RC10GT, this is a fact that a lot of the SC10 owners do not know about.

 

[ajdragon]

Hi

Here are some shots of the Ball Diff. Unfortunately I don't have any 10mm shims to center it yet. And as you can see it is 4mm narrower then the stock diff.

 

[Unusual RC]

For track racing this is very interesting! I am curious if this will line up perfectly with 2x2mm of shimms...

 

[Blxer]

Hi

Here are some shots of the Ball Diff. Unfortunately I don't have any 10mm shims to center it yet. And as you can see it is 4mm narrower then the stock diff.

How's this working out for you?

 

[ajdragon]

Hi

I still need to get the shim kits so I can center it and I'm also building another tranny just for that ball diff.

 

[ajdragon]

Hi

I need some help in finding some shims for the out side of the bears so that I can move the bearing closer to the Ball Differential. I'm looking for shims that have a outer diameter of 15mm and a inner diameter of 13mm. I'm trying to make my own by hand but it is slow going, so if any one can help please let me know.

 

[WoodiE]

@ajdragon I don't know if this company sells shim kits for the Arrma line but I do know that fasteddybearings.com has a large number of shim sizes and might be able to get what you're looking for. Could be worth sending him an email!

 

[ajdragon]

Hi

Well I got the tranny part all together, I had to make the shims for moving the bearing inwards 1mm on each side.

Also the idler gear with the yellow bearing in it is the HPI Blitz Idler Gear.

As you can see these are the 1mm home made shims, there not pretty but they work. If you are going to make these shims I recommend that you get Toggle Switch Nuts like the one in the link below.
http://boutique.rickenbacker.com/NUT-KNURLED-TOGGLE-SWITCH-CHRO_p_663.html

I had to use 3 of the .3's and 1 of the .1's on each side to center the diff gear.

 

[Unusual RC]

How does it run?

 

[LunchBox]

Kind of wondering that my self!

 

[ajdragon]

Hi

Other then a weird clicking sound it seems to work really good..

 

[ajdragon]

Hi

Well bad news, the ball diff is not a posible option any more. I did not realize that the gear in the ball diff could move from side to side, basically free floating on the ball bearings. There is about 1/16 of an inch of movement, I can literally put the gear at a slight angle to the rest of the diff assembly. This little bit of movement combined with the 1/3 thinner Arrma gears, and the extra space in the tranny case, means that the gear gets to move around a lot. I came across a video on YouTube showing how to properly setup the ball diff, I followed it step by step and got the gears moving nice and smoothly. You couldn't even tell that there were gears in the tranny, it was that smooth. But as soon as I started driving it started grinding again, it felt like the tranny was fool of sand when I turned it by hand. So I'm going back to the stock diff gear.

 

[uberfinity]

Hi

Well bad news, the ball diff is not a posible option any more. I did not realize that the gear in the ball diff could move from side to side, basically free floating on the ball bearings. There is about 1/16 of an inch of movement, I can literally put the gear at a slight angle to the rest of the diff assembly. This little bit of movement combined with the 1/3 thinner Arrma gears, and the extra space in the tranny case, means that the gear gets to move around a lot. I came across a video on YouTube showing how to properly setup the ball diff, I followed it step by step and got the gears moving nice and smoothly. You couldn't even tell that there were gears in the tranny, it was that smooth. But as soon as I started driving it started grinding again, it felt like the tranny was fool of sand when I turned it by hand. So I'm going back to the stock diff gear.

Well, that sucks. Thanks for traversing the unknown and sharing your results.

 

[mrbelloso]

Hi aj, are you going back to the arrma or the hpi diff?

 

[ajdragon]

Hi

I'll be going back to the Arrma diff.