On a side note but still related to the issues of teams not having the resources available to do extensive CNC machining or make super accurate gearboxes.
It is not our teams intentions to make master machinists out of students in 6 weeks.
None of the engineers on our team are qualified to be teaching them every in and out of the mills and lathes. When it comes to parts that we feel are too complex to be made in the lab we can either make them at our sponser MG tool or find somewhere to pay to have them done.
In the offseason we wanted to make a super trick chassis that would require extensive CNC work to actually produce. Our sponsor looked at it and said it would be at least $1000 to CNC machine from a 2'X4' 1/4" piece of 6061 aluminum. (About 30 different parts). Troy Athens has a CNC, I actually have a CNC but neither of us had the time to make the parts right now. We looked around at laser and water jet cutting and found it was definately the way to go for FIRST robots. The local place we found in our area
www.copland-gibson.com can take your .dxf file and give a quote within about a day. Total cost for the above parts, $400 for the first sheet of parts, just over $200 for each additional.
ANYONE can use a source like this, turnaround time is usually a week or less. Yes your read this correct, if you live in California, Canada, or Florida, you can use sources like this tom make your parts. If your team wants to start getting more advanced but you have nothing more than hand tools, USE the resources available. If your team doesn't have $400 to spend on the robot, get out and start fundraising now.
No one on any team should feel bad that they had parts made by a CNC instead of some poor student or mentor cranking away on the wheels of a machine. Back when I was at Purdue I took a machining class where we had to make a hammer. It took forever to make this thing by hand. Then on the last day of class we all came over to the CNC mill and lathe and it cranked one out every 45 seconds, each more accurate than the one I could do. The teacher made it clear that there are jobs that should be done by man, and jobs should be done by machine. If you can perfect a CNC based design now, the first day of the season it can be reproduced within the rules by popping the program in the machine and letting it cut the piece out.
Matt,
Supporter of the AM Shifter