Quote:
Originally Posted by mattr
When you get to higher angles, the balls on the outside/inside of the bend come out of their groove, or at least, don't engage enough to transmit any torque with out damaging the balls/grooves. You end up transmitting the torque thro the balls to the left and right of the bend. Concentrating the load.
Also, all the shuttling in and out wears the balls/grooves very quickly. We have to use special, modified CVDs for XC type vehicles, at huge expense. Not sure exactly what the threshold is, but 18 degrees is sounding alarm bells.
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Wow, that sounds really troublesome!
I really thought they could handle more than those 18 degrees and were more consistent (though I did read about raised wear levels).
Still, I'm interested to give them a shot later on in the project - in fact, I'm open to a lot of suggestions on this one. Jimmy mentioned he seemed to have a bit more traction with his Tamiya DB01 using dogbones rather than universal shafts. I find it surprising (I'd say upgraded parts should enhance handling), but I don't doubt his judgement. It's worth trying
The same counts for Rzeppa joints (if possible), CVDs (both the type with the cup on the axle and the type with the cup on the dogbone), and something I'd fancy to investigate further is rubber driveshaft couplings like the Lotus Elan have from the factory. A simple mechanical solution, I believe it's a constant velocity solution, it offers some give in the drivetrain (VERY desirable on a front wheel driven car I'd say, even if this makes the feel of the throttle a bit more vague and slingshot-like).