Mounting the arm

How do you mount an arm on the robot?

connect it to the shoulder?! (is this a trick question?)

remember that you are allowed to make your bot 5 feet tall - I would guess that for most teams, you will want an ‘elbow’ that attaches to framework just below that height, so your arm pivots from the top of the robot.

for what we need to do this year, you might not want an arm like a human arm, you might want something that looks more like a ladder, that attaches on both sides of the bot and pivots up and down - just a suggestion.

maybe something like the drawing I posted in this thread?

possibly weld it…bolt it…oh i know…DUCT TAPE!! :stuck_out_tongue:

Actually the best way is to bolt it, that way next year when you want to use that bot as a prototype, you dont have to grind off the weld. makes it alot easier too if something goes wrong and you need to change somethign quickly. Its easier to fix something that is laying down rather that fix something that is 4ft high.

Can’t use ducktape. Mounting brackets and an axel, a turret style, etc. would work. Chances are you questions would get better answers if you posted them in the right forums too.

To mount an arm:

Build your robot so you have a plate about 4.5’ in the air. Put a brass plain bearing in it. Also put a bearing directly below, around where your motors are. Buy a 5’ section of thinwalled steel 1" pipe, put it through the bearings, weld a segment of 5/8" shaft to the top, put bearings on that, and your arm on the bearings. Put a sprocket on the lower part of the steel pipe, drive it with a motor to give yourselves a turret. Fix a sporcket to the welded 5/8" shaft on top, put a gearbox on the arm, chain it to the sprocket.

And your done. Maybe add another segment or two after the first one for a really cool arm.

I was being “cute” with the word duct tape :mad:

anyways i dont think ducttape would be able to hold the amout of torque anyways.

I didn’t break it!

We welded ours to our frame, not the best idea now that I think about it, but not much we can do about it now. Basically we have one centeral column going up our robot, at the top there is a notched out area, and a hole going throught the side walls. Then we put a bearing and axel in there. The area with the notch is for a movible arm. We just drilled a hole thought that, and placed it on the axel going throught the centeral column. Finally we just hooked up a motor to the base of the centeral column, put cable around it, and attached the other end to the moviable part. And “waaa la”, an arm.

I would highly suggest bolting it, just becasue welds are not fun to break.

oh, come on! welds are lots of fun to break, they’re just not that much fun to fix.

Who needs arms when you’ve got a… forklift! Our monster drawer sliders are mounted with two reinforced, shelf, L-brackets that are bolted to the frame and the lift.

Now that i think about it, Our robot may have an additional function as an organizer :slight_smile:

and the survey says…


that’s right, we’ve locked the entire team in the basement for the past 4 weeks so that they can dilligently chew up enough bubblegum to not only attach the arm but to make on the spot repairs at the competitions.

Mount it 3 ways!
A) Very carefully and acurately - so you don’t extend the profile.
B) Very securely - so when you extend it somehow, your robot doesn’t break.
C) Very center of gravity-ish - so you don’t tip as you retract and/or pivot it!!

That’s all I got!