pic: New gear failure on 2471

[Bryce2471]

loading photo ...

[mman1506]

And that kids is why keys suck and we should be very grateful for the advent of hex shaft solutions in the last couple of years.

[ThaddeusMaximus]

Originally Posted by mman1506

And that kids is why keys suck and we should be very grateful for the advent of hex shaft solutions in the last couple of years.

Because hex doesn't produce stress concentrations....

And splines aren't used in torque transmission applications...

[Tom Line]

By any chance, was that a recently purchased vex pro pinion? I just bought a couple new ones and had to throw one away because it had a hair-line crack in it. I didn't noticed it until I started running it in the gearbox (very low load) and it was going "clackclackclack".

[mman1506]

Originally Posted by ThaddeusMaximus

Because hex doesn't produce stress concentrations....

And splines aren't used in torque transmission applications...

Of course hex shafts produce stress concentrations. It's just that the induced stress is far lower. They are also far more convenient in a number of ways.

[Bryce2471]

Originally Posted by Tom Line

By any chance, was that a recently purchased vex pro pinion? I just bought a couple new ones and had to throw one away because it had a hair-line crack in it. I didn't noticed it until I started running it in the gearbox (very low load) and it was going "clackclackclack".

Although I don't know how new this pinion was, I can say that it was making a minor "clackclack" sound before the failure. However, this pinion didn't need any more reason to break, given that it was a 12 tooth made 7075 aluminum and was taking the load of two CIMs.

After replacing it with a steel equivalent, the gearbox has been working great so far. (Fingers crossed)

[Munchskull]

Originally Posted by Bryce2471

Although I don't know how new this pinion was, I can say that it was making a minor "clackclack" sound before the failure. However, this pinion didn't need any more reason to break, given that it was a 12 tooth made 7075 aluminum and was taking the load of two CIMs.

After replacing it with a steel equivalent, the gearbox has been working great so far. (Fingers crossed)

Bunnybot?

[SenorZ]

Hey its the open source hardware logo!

http://www.oshwa.org/open-source-hardware-logo/

[Richard Wallace]

Originally Posted by Bryce2471

This was a new one for us. I bet someone can guess what the loading situation was.

Did you get your wires crossed and let two CIMs fight it out to see which way the bull gear would spin?