12-22-2016 07:35 PM

mman1506

Re: pic: New gear failure on 2471

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.

12-23-2016 12:35 AM

ThaddeusMaximus

Re: pic: New gear failure on 2471

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

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

12-23-2016 12:38 AM

Tom Line

Re: pic: New gear failure on 2471

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".

12-23-2016 01:55 AM

mman1506

Re: pic: New gear failure on 2471

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.

12-23-2016 02:03 AM

Bryce2471

Re: pic: New gear failure on 2471

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)

12-23-2016 02:21 AM

Munchskull

Re: pic: New gear failure on 2471

Bunnybot?

12-23-2016 11:36 AM

SenorZ

Re: pic: New gear failure on 2471

Hey its the open source hardware logo!

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

12-24-2016 05:47 AM

Richard Wallace

Re: pic: New gear failure on 2471

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