So we were lucky enough to get some FP 0673 and some pinions for them to interface them with an AM Planetary Gearbox. However when we tried to pressfit them on they were really tight and we ended up bending a shaft of a motor…
For these are we supposed to heat them up or is there something we are missing?
We had this happen recently as well. Our older sun gears press right on; I wonder if the bore is ever so slightly too small on this batch.
The ones we are using were just ordered.
Would order new gears now help? This is part of our withholding.
We had a CIM-sim pinion pressed halfway onto the shaft when it just stopped moving as it reached the knurled part of the shaft. Since I didn’t want to bend the shaft on our precious 0673’s, we pulled the gear off and lightly sanded some of the knurling off of the shaft. After that, pressing the pinion on went smoothly.
We had precisely the opposite problem: We had to get a 19 tooth gear off of one of our FP’s, and in the process managed to pull the shaft out. We then let the team have their wrath upon the motor with the arbor press. We fixed it up good.
You do realize you’ve probably just brought tears to the eyes of a large number of people who couldn’t get their hands on any 0673’s?
Include 1296 on that long list!
Why I am being wary about how to get the pinon’s on…
A good arbor press, right-sized tooling, good alignment and a deft touch are required. We took pinion gears (as delivered in 2011 KOP) off 2 673s and replaced them with something else (since we thought we going to be able to order them sans gears and had already built a matching transmission).
Just so the sad people don’t get too sad, this was a 9013, not a 0673. We’ll be bringing all of our 1 0673’s to competition to give to whomever asks.
Our team will pay your team for it!
For those pressing gears on or off, make sure you only have forces acting on the gear and the shaft. So when you want to take a gear off, use a piece of steel with a slot and slip the shaft into it. Then press down on the shaft, so the motor itself takes no load.
If you have trouble pressing gears on, pop the gear into a lathe with soft jaws or a correct-sized collet and run a 1/8" bit through a few times. Make sure the gear is spinning true!
This worked for our aluminum inserts, but if the steel gear is still resisting, follow Kevin’s suggestion and sand the knurls down a tad.
Do be kind to the most sought after motors in FRC right now. Best of luck!