I offer the following not as a complaint, but as a recommendation for future product success and reliability.
I have a few comments about the AM planetaries. First of all, the product for the price is extremely fair. You cannot get or make that thing for the same price, and you definitely cannot have it in the same amount of time. That is great. However, I believe there have been some quality and reliability issues. When I first took a look at it in the 2005 season, there were some burrs on the planet gears and the backplate bolts had to be torqued just right in order to avoid binding up the whole thing. After a while, it ran in and became smoother.
After one regional, an offseason, and a demonstration, one of them completely bound up. It bound up so bad that the whole side of our our drivetrain would not move no matter what we did. After pulling it out and disassembling it, I noticed that one of the planets had siezed onto it's pin, and the pin had lost its press fit with the carrier plate. Pressing the pin out of the gear and back into the plate and hand reaming out the gear a bit seemed to solve the problem. Cleaned it out, greased it up, and ran smooth as butter. I have heard of one other team with the same problem though.
Throughout use of the planetary I experienced the planet gears rubbing on the backplate causing a nice aluminum powder to mix itself in with the grease. However, it is possible that this mix may actually have some lapping properties and it may not be an entirely bad thing. A fix would be to put nylon spacers/washers between the gear and planetary much like what is done with the CIMs in the KOP gearbox.
Also, throughout use of the planetaries I have witnessed increasing play in the output shaft. You can take ahold of it and wiggle it. There seemed to have been some issues with the output shaft diameter and surface finish and the fit in the roller bearing.
One team I saw replaced the roller bearing setup with two standard ball bearings and you could load it very hard and it would not bind or wiggle or anything. It looked like a very good improvement.
Perhaps the binding and wiggling issues were isolated cases. I haven't talked to too many people who use them. But I offer my feedback based on what I have seen.
Let me put one thing on the record though:
AndyMark planetary gearboxes have never let us down in a competition And you won't find a similar unit at that price anywhere, even if you made it yourself. You cannot mach the light weight, small size, and low price of the AndyMark planetary, not with a Dewalt, not with your own gearbox.
I do not intend for the above to make anyone think twice about buying it. It is a very good product. You can't go wrong purchasing an AM planetary. But, I just wanted to give feedback, because that is how we all improve.
I look forward to seeing this company grow and continue to supply FIRST with even more new and exciting products!
