Quote:
Originally Posted by Sam Skoglund
Can anyone speak about the strength difference between the VersaPlanetary gearboxes and the PG gearboxes?
Our team had issues with PG gearboxes shredding last year. We had one driving an arm that sometimes was hit and therefore put shock on the gearbox. We are looking for a more robust solution. We are wondering if the Versaplanetary gearboxes can withstand higher shock loading. I have also heard of teams "protecting" all brands of planetary gearboxes from damage through one or two external reductions of gears or chain. Another option I am considering is ditching planetary gearboxes entirely and moving towards custom gearboxes with full size gears.
What experience do others have with this? And what method mentioned above do you think would be the best to solve our problem? Thanks to all in advance! |
It's very easy to fall into a trap of sorts with custom gearboxes, where things feel safer and stronger than they are. If you aren't experienced in high reduction custom gearboxes, I would avoid replacing a VP with a custom gearbox to solve a strength issue. Figure out why the VP is breaking first, and what the custom gearbox solves.
The VPs are pretty durable, but it's good practice for any high reduction gearbox to use a chain reduction afterwards to isolate the gearbox. This helps reduce shock load in addition to total load (the gearbox only sees the pre-reduction load). Feeding a VP into a spur reduction isn't necessarily a bad idea, but for something like a long arm you can still have problems if you don't design carefully. (There's probably going to be some sarcastic comment replying to my post referencing early attempts at gear driven arms that my old team has attempted...)
I think for most long robot arms you can do VP -> spur reduction -> chain reduction if you are careful, keep the chain tensioned, and keep everything within safe specs.