1058 built our two robots on a budget this year. The electronics are the toughest part to get around. Many of the design decisions we made in certain sub-systems were to keep our costs down and deliver two competition "shells" and one electronics board we could swap between the two.
Our
main board was a small sheet of 3/16" or so lexan that we mounted the primary electronics to excluding things like the RSL, radio, and pneumatics items. We duplicated those on each machine so we didn't over complicate the system and the team had a large inventory of pneumatics. The board was attached with 8 or 10 screws that went to riv-nuts on both frames so a screwdriver was all we needed to swap boards and all the connectors were easily accessible and Andersons labelled for plugging motors in.
We believe it worked out well for us even though this isn't a normal way of making two machines. It kept our budget for two machines just around $5000 which included a lot of COTS items we used as our machining team was making more framing than a normal season plus spare parts knowing it was a tough game. Throughout our season we swapped the board between our shells which looked something like our practice robot
here in late July just without a climber. For Week Zero our practice robot went to a scrimmage then we held back the board (12lbs) as part of our withholding and tested our climber for Reading. During unbag the board went back on for our first event then taken off at the event before we left. We repeated this for Rhode Island and then after Boston it stayed on our robot except for a few occasions where we removed it to debug some electrical issues which was a big plus in a game where the robot was so compact. The obvious downside was as the season progressed and our to-do list boiled down to software improvements the board was sitting in the robot bag or on the way to St. Louis and the knowledge that our weight budget for improvement or spares was only 18lbs because swapping the board was a 12lb hit on the allowance.
The biggest expense will be your motor controllers. For our needs we went with Talons but the
Spark controller by Rev Robotics is one of the more cost effective ways to maximize your budget. Even though teams already submitted their lists, using FIRST Choice is an easy way to get some large ticket items off of your list. Last year and going into 2017 we've used FC to get some of our control system needs taken care of either full or partially.
Building on a budget isn't easy, but as a Business major its a fun aspect of FRC by learning ways to stretch your budget and maximize what you are getting out of your machine(s). Our system wasn't a perfect solution however it worked really well for our needs. Something we considered was that we didn't have access to more than our hallway for consistent practice so a full functioning machine wasn't our most cost effective solution. We haven't fully discussed what we'll do this year but we might try to squeeze more drive practice in between events.
Our second robot did end up with its own board by the Fall using smorgasbord of motor controllers taken off older machines.