Dogbone Length question pin to pin

[332_RC]

I have mostly Arrma rc's. They list their driveshaft dogbone length in mm from drive pin to pin centerline. So a 135mm Arrma dogbone is 135mm pin to pin center. Do most all other manufacturers do they same? Say, if I found a Mugen or Corally dogbone listed as 110mm, are they also pin to pin centerline measurements? And Arrma dogbones are 5mm shaft, 8mm ball, & 3mm pins. Most others are similar or same in 1/8 scale stuff?

 

[paytonimusrex]

I think tekno does measurements the same, if you need to replace though probably best to just get the arms replacement part

 

[332_RC]

Well, it's not a worn part. I was like figuring if I made a hybrid rc, I need a special length driveshaft. Like this. It would be a driveshaft Arrma doesn't offer, so I'm looking at other manufacturers.

It would be a rear driveshaft from the center diff to the rear bulkhead gearbox.

 

[paytonimusrex]

ah okay, i would like to think at least other manufacturers would follow some kind of standard with the measurements of these parts at least, if you find one in a length you need wouldn’t hurt asking before you buy or just testing your self

 

[332_RC]

I'm thinking so too, & maybe couple members have a few brands & measure one.

 

[paytonimusrex]

the one from my tekno I think is 175mm length, my calipers aren’t big enough, and ball is 8mm

 

[332_RC]

Maybe they are sorta industry standards to them. The pins & balls. Is the shaft diameter 5mm? I bet the pins are 3mm too.

 

[paytonimusrex]

Maybe they are sorta industry standards to them. The pins & balls. Is the shaft diameter 5mm? I bet the pins are 3mm too.

ah I didn’t check either of those but id imagine they are

 

[jimdavis577]

I would think that would be manufacturer specific on how they measure them ..... some may go end to end ... or pin to pin like you said ... but most the time , anything pinned like that on both ends would be for a 4x4 or an old school cv shaft ... either way I would think the 1/10 shafts would be smaller diameter and your set and 1/8 stuff would be the bigger ( thickness wise )

 

[Littlemotor]

Length of the cross pins vary between manufacturers, as well as between center drive shafts, and outers..

Also, I know my Tekno axle shafts aren’t as large diameter wise as say a Kraton, or Talion axle… Tekno definitely uses stronger steel for theirs as I’ve ran both, and it’s a notable difference.. I’ve got some huge M2C CV shafts for one of my Tekno truggs, but retired them as they’re heavy AF, and the factory shafts haven’t bent on me once.. Keep in mind that some manufacturers (like Tekno) also offer center shafts in Aluminum. Of course Xray offers spring steel, so you have a lot of options all the way around. Everything I’ve ever measured has been from pin center to pin center, or bore center for a CVD.. Same with universals-cross pin to closest cross pin in the universal joint assembly.

 

[332_RC]

The one I'm looking at is a rear dogbone driveshaft for a Corally Spark 1/8 6s basher buggy. Just a little digging, it's a 110mm, but haven't found any other specs as far as the ball diameter or pin diameter.

 

[RustyUs]

I went looking for replacement CV bones and ended up using some that were designed for another platform. Some brands will state dimensions being center to center of things in their descriptions.

Mixing and matching different parts from different brands can be a slippery slope. Having a great bunch of people in a forum with a variety of RCs is your best bet at finding measurements needed to get things done on a custom build/project. In the past I've joined a few groups just for purposes of getting measurements from others in the groups. Most places were accommodating.

 

[332_RC]

Yes sir. That's why I started a new post & asked! Just kicking around ideas. And the forum members are always great on adding details of their experiences & getting dimensions or pics. I believe I got my answer tho, over on AF. A fella posted about a Corally rebuild & several responded, & the dogbone question got answered!

 

[332_RC]

Team Corally measures their dogbones center pin to center pin. This is a 110mm dogbone. The measurement shown is outside to outside, subtract 3mm for the pins & it's 110mm. 7.8mm ball. 4mm center shaft.

Fits Arrma diff outdrives, really good.
The only engineering difference, really, is Arrma pins are 90° apart, end to end. Corally are in a line. Anyone know if this is a significant mechanical factor in a RC?

 

[jimdavis577]

well by phasing joints it has some benefits.... to the effects on the joints and shafts.... I don't know all the specific jargon to explain it properly but I do know it's called " driveshaft phasing "

 

[332_RC]

well by phasing joints it has some benefits.... to the effects on the joints and shafts.... I don't know all the specific jargon to explain it properly but I do know it's called " driveshaft phasing "

I know when I built driveshafts for my mud truck, (1:1) I phased the universals 90° apart. But in a pickup truck, the rear driveshaft is at a much more angle to the rear diff. Like a crawler. In a flat chassis RC, rear shaft is basically flat. So idk.

 

[jimdavis577]

I know when I built driveshafts for my mud truck, (1:1) I phased the universals 90° apart. But in a pickup truck, the rear driveshaft is at a much more angle to the rear diff. Like a crawler. In a flat chassis RC, rear shaft is basically flat. So idk.

well it could be something to do with the harmonics / vibration of the shaft in a rc .... i use to race the TC3 which is shaft driven but i can't remember if the shafts were phased or not

 

[CertifiedMike]

Years ago before cvd's dog bones would fly out of your buggy during long extensions, turns, bumps, heavy acceleration or braking. Fronts were worse.
Phasing the pins theoretically leaves the pins "more engaged" with their drive cups than if they are in-phase as they rotate, leading to fewer dogbone loss.

I have a set of offset dogbones from Thorp(?) for tha Optima series.
They def help in my case.

 

[CertifiedMike]

Makes sense. The walking back n forth inside the cups.

This set is 30 years old or so. Hasn't flown out yet!

Its easy to see if you have dogbones in the front of any of your rigs still.
Its because when the pins roll around together, the cups are both at their "loosest" in relation to the dog bone.

The off phase dogbones were a fantastic idea for 4x4 owners.
I think they are still a better design than in phase.

 

[CertifiedMike]

I am not sure if this relates to ujoint phasing in a 1:1. That IS about vibration and harmonics as @jimdavis577 mentioned.