WHich motor to lift and for arm

[thoughtful]

hey,

how powerful is the Denso-Window motor, and which motor do you guys think of the most strong one. Can a single Window Motor lift the whole robot up(130 lbs), if no than which one can. I know this is a lat to be asking this.

We had a mechasim that uses a single window motor to move an pivoted arm, with a light grabber, but when we hold on the ball the thing wont go up. But it works pretty good when not holding on ball. Also the arm is about 56 inch, but if we put the ball at about 30 inch it work okay. THe arm is mounted on a 60 teeth sprocket(drilled through and bolted) the window motor has a 20 sprocket so basically a 3:1 ratio. Any comments to help us on this, fast replies will be appreciated.

[Matt Adams]

Out of the box, the van door motor has the most torque. I'd recommend trying to get a smaller sprocket, such as a 10 tooth, so you can get even more torque for your arm.

Matt

[J Flex 188]

van door to lift, denso/window the manipulate the grabber.

rest of it = drivetrain

[edomus]

Originally Posted by J Flex 188

van door to lift, denso/window the manipulate the grabber.

rest of it = drivetrain

will we need a ratchet on the van door?

[jonathan lall]

Yes you will. Or some other device to stop it from backdriving and blowing its worm gear.

[ngreen]

Our will stop without the ratchet. We will probably add one anyways though. Our winch diameter is <5/8" though. Small diameter helps.

[Joe Ross]

Originally Posted by ngreen

Our will stop without the ratchet. We will probably add one anyways though. Our winch diameter is <5/8" though. Small diameter helps.

Ours is exactly 5/8" and a combination of that and the adjustment screw and the van door motor doesn't back drive. It all depends on how fast you want to go, how much energy you want to use, and how complex you want your system to be.

[Solace]

our winch is directly connected to the drive train, so we have 2 drills and 2 fischer prices running it. those have more power than the van door, but stealing power from the wheels requires a lot of planning and is probably not something you can add on at this point

[Andy Brockway]

I would suggest that you look in the White Papers technical section for the papers on motor selection. Ken Leung has done a nice job of compiling info from Joe Johnson and others that will let you select a motor and gear ratios to keep from smoking motors. The key is determinig the Power you need first and then adjusting the motors to get the required torque.

The examples can be used as 'recipes' for lifting balls and robots. We used these notes this past year to select dual Fisher Price gearboxes to lift twice the weight of our robot straight up in under 10 seconds. We have not tested the twice the weight yet but it gives us a good safety factor.