TOPIC:

Think it'll be alright with a Traxxas pinion. Mind the volume.



TRF limited slip diff :

Edou wrote:

Think it'll be alright with a Traxxas pinion. Mind the volume.

...

Sounds dreadful - something's bent, not round, broken, or partially seized there ... from the frequency I'd say it's not the pinion, but everything else is suspect ... 1st thing I'd check is for a broken tooth on the small side of the spur gear.

Sounds a lot better if you press mute.
I wasn't all that worried since it turned smoothly by hand...

Thought it was the diff rings I added but apparently I stumbled upon a pair of MkI Grasshopper axles.
Guess they have a 3mm hole for the smooth 3mm diff pin. While I'm using a stepped one with 2mm ends.

MkI... or maybe not. I'm not sure. There's another deviation :



Besides the diameter of the hole when the diff pin goes :



Anybody recognise the top/left axle?
I switched them at the last moment for the ones I had already selected because they looked prettier.

I'm thinking possibly Grasshopper 2. There's a straight 3mm pin depicted in the manual.
They go back to a stepped version on the Super Hornet...
Longer threading also seems to match :

I'll be leaving out the additional diff rings...



Making an LSD that way was an interesting idea but in practice it is putting to much strain on the transmission.
And creating unnecessary friction in the drive train altogether...
I've tried thinner ones as well - up to a point where they become abundant in themselves.

Sounds a little better (once more reminding of the volume) :

a little

Indeed it is... can't seem to get it much more silent.
Sounds about the same as my other Hopper's gearbox. Unmatched pinion would be a higher pitch, I think...
Not overly concerned about it though. There isn't much inner resistance (hand test).
That gearbox's far from a precision mechanism. Sloppy.

Edit - but probably purposely sloppy, which is why adding those diff rings actually kinda goes against the design.

I've actually driven my first Grasshopper for many years with the spur not being straight.
Built it with a friend of mine - he did the gearbox...
Even though he eventually became an aerospace engineer, I think the 3mm straight pin depicted in the manual messed him up a bit so he pushed the stepped diff pin way inside the axle. Making for the spur to not be straight.
Guess even that can't hurt that little gearbox much 'cause I drove it for miles and miles like that...
Always wondered why it wouldn't turn smoothly by hand though (now I know).