How long did it take for you to build your drivetrain?

[Veselin Kolev]

Originally Posted by Steve W

Arguing is never a good idea. Challenging and discussing is OK but arguing doesn't do anything but cause hard feelings.

A strategy we're using this year is to incorporate drive train discussions into our trainings with rookies. For example, most people that start to go to trainings have no clue about what’s going on with FIRST robotics, never really read CD, and must be taught everything. That lets us teach them from ground zero, and a little thing we do is give them mock brainstorming sessions, where we "reveal" to them old FIRST games, and they use their knowledge of drive trains (that we gave them) to determine not only the ways a drive train could go about doing the tasks of the game, but which drive train could do it best. In simple words, we let them decide what the best drive train would have been. Of course, as a veteran member, I have to sometimes step in and remind the rookies about our limited money and machining capabilities. It really helps the brainstorming process if you've done it before, but not for real. It's real enough to make a lasting impression on rookies on how to go about making rational decisions during build. And keeping the brainstorming process short.

Anyway, back to the real question. Last year my team did swivel drive, and I was managing that system. The decision process was rather quick, and the design took three days to finalize. Took another three days to distribute parts amongst our two machinists, and then took two weeks to machine. Then... the horrible week of assembly... So in the end it was mounted on our chassis by end of week 5. Well, our school has finals the first week, so we never do anything then. So it took a good 4 weeks to do it all.


The main reason why it took so long to machine and assemble was that it was not an efficient design. It was good and strong, but could have been a lot easier to make. You gotta remember that you can design anything, and build anything, but the building part will always take the most time. It helps to know how to use a mill and lathe so you can design something that is easy to make.

I have a lot to say about this actually... just because there have been too many bad experiences. A few more things that will help cut time: once you finish your design, get accurate quotes for everything you will have to buy. For example, if your design needs four bearings that cost $150 each, don't do it. Redesign your butt off. Also, once you finally do finish the design, order the parts immediately. Who knows how long it will take to ship, and its nice for the machinist to have bearings while he machines the part they go into.

Also, once you finish a design, print out all the parts drawings and give them to a machinist. Don’t worry that the machinist will be discouraged with a big pile of parts to make. They like it when they don’t have to call you and ask if there’s any more. Giving them drawings every few days seems like a good idea, but it just keeps the machinist in the dark and kinda ticked off at you… well at least for me. Anyway… enough blab. Hope that helped.