Mechanical tips for rookies

[SpaceOsc]

you forgot about BATTERYS and keeping someone on them at all times, check before matches, keep them charged during build for testing moments or when that Powered rolling skate board you come up with first is ready for moving.

its STUPID for the team to send a robot on the field without at lease someone knowing its voltage... then see it CHOKE and die

hmms heres another, when you mark something for cutting dont do it with a WIDE print dry erase marker... hmms use a flat head screw driver or dark .5mm pencil or ball point pen.

[JVN]

Originally Posted by Billfred

Oh, and remember that while it is important to keep your batteries juiced, you may not have to charge them every match...

BAD ADVICE!
DANGER!

Bill,
I'm gonna come right out and say you're wrong.
You ALWAYS want to put the freshest battery you have on the robot. Brownouts/lowvoltage can KILL you at a critical moment in a match.

Every team should implement some kind of battery management system (ours is a senior named "Aaron"). Trust me, you don't want to die at that critical moment because your battery died.

Charge every match.
Charge constantly.
Keep multiple batteries on charge.

Also, be familiar with your chargers. The ones that take 8 hours to fully trickle charge a battery are NOT going to cut it during the heat of competition.

John

[JVN]

Anne,
This is AWESOME. You're selling yourself short though...

Rookie teams? I bet there are lots of veteran teams who could probably use a reminder of some of these principles from time to time as well.

This is just good advice for ALL teams to take to heart.

Thanks for posting!

John

[Anne Shade]

Very true John, this is advice for all. I'll keep that in mind when I put the final list together.

As for the batteries, I didn't put them on this list since it is the mechanical list. Look at the electrical list and you will see it on there. Please keep the suggestions coming, the more info on this list the better.

[Doug G]

After a bit of chaos last year, our team was / is determined to have a full-functional prototype robot for the 2005 season. Maybe have it completed by the Third or Fourth week. It could be made from 80-20 or Bosch extrusion or even wood. There are some obvious increase in costs associated with this - but hopefully will allow for a more functional and tested robot in the end. Any idea how many teams are out there that already do this? Maybe 10%?

[SpaceOsc]

how about a tip on loctie and whats shouldnt be and what should be

always cut long , but never short (as in extra materail vs making short and useless)


(One of Ours mentors really stress this)
Tight Means Tight , Not how tight you could get it , and not striping and destroying parts, and not leaving it loose


PVC Can be your friend


ALWAYS Clamp it Down


Right tool for the right job


more to come... maybe

[greencactus3]

weeelll, remeber, bungee is your friend, but always do the math to figure out if the cylinder you wanna use has enuf force to lift w/e. even if it works at 100psi, it doesnt matter if it doesnt at 60.

[Al Skierkiewicz]

All,
The top of my list is to get a working/driving base finished first. It is needed for electrical to work on part placement, drive team needs practice and autonomous team needs something to mount prototypes on.
Open gear transmissions produce metal flakes (grindage) so protect electrical circuits from fallout.
Be aware of robot systems when drilling or machining parts on the bot. A square tube makes as good an electrical conduit as it does a support member. Your electrical team may have passed motor wiring through the tube you are drilling!
NO GRINDING IN THE PITS! Besides it causing incredible noise, the flying hot bits are a real fire hazard.
When a motor or other shaft does not have enough bearing (most do not) you must add bearings that can take the stress. You cannot hang a sprocket or wheel on the end of the chalupa motor shaft and expect it (the motor) to survive.
Motors do draw "stall current" when you stop them. Avoid stalling motors or running them in near stall in your designs. The currents are extreme and the motors will run very hot. Stall current on the drill motor is 129 Amps or over 1500 watts.
Grindage and flakes from ferrous metals are attracted to the magnets inside motors. This is a big concern for open frame motors like the drill and FP motors and fans, where the flakes will jamb between magnet and armature or short out the brush assembly or armature windings. Compressed air will not dislodge these flakes. The speed controllers are not sealed and many have died from metal flakes falling into them.

[Anne Shade]

I've posted the updated list in the white paper section. If anyone has any other suggestions, let me know and I'll update the document. Feel free to use it as a handout for your team and for new rookie teams. Hope it helps.