Standard Motor Driver Schematic for FRC

[Kevin Sevcik]

Originally Posted by ProfessorAlekM

I was looking up the encoders on AndyMark. The encoders they sell are only $20 each when you buy them in bulk (50), and they sell them for less if buy more (it says I have to ask for a quote if more then 50), but they sell them for $40 each.

And I'm sure shipping +$5-10 in profit is not $20.

They also sold every team a base kit that can't even clear any of the obstacles, so that you would then have to buy another base kit or upgrades (Making them more money).

On top of that they knew what this years competition was, and they couldn't even keep Rhino Treads in stock during build. Some supply and demand could be going on.

I know that I'm getting off-track on my own thread, but I'm trying to conserve money for our school.

Andymark doesn't get specific game information ahead of time any more than any team does. I believe Andy said they were told there would be obstacles in this game or something like that, which inspired the rhino tracks. Makes it hard to design for specific obstacles. It also makes it hard to pre-buy enough stock to satisfy the demand of 3000 teams. It's obvious after kickoff that there will be a run on pneumatic tires, or banebot wheels, or whatever the hot item is. It's never obvious before kickoff.

On the cable, I suspect you didn't actually specify the encoder correctly on US-Digital. When you specify one spacer and centering tool per encoder, the price per 50 is $28. And then you add a $5 cable on top. Andymark and Vex don't have a huge markup. They can't because if they did, they couldn't compete with other suppliers like Robot Marketplace, Robotshop, Mouser, Digikey, various industrial supply houses, or any random Joe that sets up an EBay or Amazon shop. It's called capitalism.


Honestly, the best way to save money for your school is to not break things so you can save what's salvageable from year-to-year. After about 3-4 years of not exploding motor controllers or melting motors, you'll have plenty for whatever robot you're going to build. A few more years and you'll have plenty for two robots. The best way to save money in a particular season is to CAD and actually design your robot so you can minimize buying the wrong thing or express shipping something you need in 2 days before competition or bag.