CIM-U-LATORS

[AdamHeard]

Originally Posted by topgun

So if you guys are so great, why did you as a mentor for an 8 year old team order not one, not two, but 20 P60s? Surely you could have built your own gearboxes, probably with one hand behind your back and going uphill both ways.

My point still stands. FIRST distributes four motors, with no gearboxes, no pinions, and the supplier is 10 - 15 days behind. The build season isn't exactly the time to be experimenting at building a gearbox. Many teams will learn to build gearboxes in the future, and many have put forth some great workarounds, but for many younger teams and rookies, the banebot problem is a major headache.

You need to remember that not every team has engineering mentors. Not everyone team has access to lots of cash to experiment with. Even with those, not every team has access to the tools needed to build a gearbox. Even using CAD for many teams is a challenge.

Off the bat, ten are for my the prototype for my senior project, I was taking advantage of the quantity discount.

The other 10 are split between our practice and comp bots, four each, and then two total spares.

We are using 775s in two distinctly different sytems. We are only using 4:1 p60s, and we're using them to interface with our spur gearboxes. We are a fan of a specific style of gearbox we make using COTS AM gears and shafts, to where we just waterjet/laser out plates and have zero fab after that. We can get any ratio from 2:1 to several hundred to one. We easily could have bought 60+tooth 32dp gears and directly interfaced with them, but we wanted to keep commonality between the two systems (the same p60 is a spare for system 1, and for system 2). The p60 option was more expensive, but the interchangeability is nice. We also chose p60 over AndyMark planetary because of the quantity involved and the cost.

Although this is horribly decision making process, the fact that I was already ordering 10 for my project, which meant a discount, did weigh in on the decision somewhat.

What I said still stands however, even with using p60s, every system on our robot has a custom gearbox. This is not because we are a "have" team (I still don't believe that, but because we decided to. The point I was making is that lack of resource is not a permanent affliction, it can be rectified easily. My team went from zero machining sponsors during the 2008 season, to nearly every machine shop in the SLO county sponsoring us in one way or form (that
s A LOT). This wasn't by accident, we made this happen.

I started out as a high school student with minimal knowledge, and I learned to make gearboxes during a season (without engineering mentors; I learned reading posts on this great site). I firmly believe a team of people can do the same thing, even with a hand drill and some material. Well, I am incorrect, not all teams can; only the teams that want it bad enough. 1726 made a hand made gearbox on one of their most dominant robots ever reusing gears from the FP transmission.

I also don't buy that CAD is a challenge for teams, especially for a single system. My students take the basic solidworks tutorials in a few hours, and then are capable of making several part assemblies. Sure it's not a 1000 part robot, but it's something.

FIRST did put these motors in the KOP, but the 395/540/550/775 motors are not banebots specific, they are industry standard which have been around for years, and there are a whole slew of gearboxes to support.



In Summary, boo hoo. The were speedbumps, don't complain, find a solution and move on. Every team that gives a darn is doing so.