In need of high torque motor

Technobots FAQ » Motors » In need of high torque motor « Previous Next »
Author Message
Darren Karp (Darrenkarp)
Member
Username: Darrenkarp

Post Number: 2
Registered: 11-2007
Posted on Tuesday, November 27, 2007 - 7:25 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hi,
I need a 24vdc motor with approx. 12 rpm final output speed and at least 100Nm torque. Can anyone help?
Cheers
Darren
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 633
Registered: 10-2004
Posted on Tuesday, November 27, 2007 - 8:43 pm:    Edit Post    Move Post (Moderator/Admin Only)

Darren,

Have you seen the reply to your similar previous post in which you did not leave an Email address so we could not send you a personal reply? See here

Regards

Paul
Darren Karp (Darrenkarp)
Member
Username: Darrenkarp

Post Number: 3
Registered: 11-2007
Posted on Wednesday, November 28, 2007 - 8:41 am:    Edit Post    Move Post (Moderator/Admin Only)

I assumed by signing in that you would have my email address for a reply. My mistake. My email address is [email protected]

I will reply to the original thread.

Thanks
Darren
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 634
Registered: 10-2004
Posted on Wednesday, November 28, 2007 - 8:25 pm:    Edit Post    Move Post (Moderator/Admin Only)

Darren,

When you first posted, you posted as a guest and without an Email address (it's optional). To register to post in the public area, you do need an Email address. No problem though as we got there in the end.
David Edward Weston (Razerdave)
Member
Username: Razerdave

Post Number: 1
Registered: 1-2008
Posted on Wednesday, January 2, 2008 - 10:31 pm:    Edit Post    Move Post (Moderator/Admin Only)

Hi

I am after a small but powerful motor for my featherweight lifter, but its odd in the way it would operate. The lifter arm would go from the back of the robot (from the motor) to the top of the wedge (distance 14cm), then down the wedge front (10cm). the forks would be attachd to the side of the arm and extend 5cm from the wedge. It doesn't need to operate very quickly, certinatly the motor doesn't need to go over 1000rpm @18v, and throught this arm it needs to shift 13.6kg

Is any of that useful ?
Admin (Admin)
Board Administrator
Username: Admin

Post Number: 655
Registered: 10-2004
Posted on Thursday, January 3, 2008 - 7:54 pm:    Edit Post    Move Post (Moderator/Admin Only)

David,

I am unable to tell how far the load is from the point at which the torque is applied with the information quoted, what is needed is the straight line distance but let's assume 15cm. Also lifting 13.6kg will only happen when the other robot is fully on your lifter arm unless the speed of action is very very quick i.e a flipper.

Speed of operation is key to the motor power as well, linear actuators typically take many seconds to stroke so again for an assumption let's assume 5 seconds. Angle of rotation is also needed but again let's assume 45 degrees.

So you need the motor to rotate 45 degrees in 5 seconds which is one rev in 40 seconds or 1.5 rpm.

Torque needed would be say 7 kg at 15cm as you will only be turning over the other robot. This is 1.05kg/m or 10.3N/m. Our RE975D 504:1 motor has a torque of 3Nm at 28 rpm. If you were to use further gearing of say 10:1, you should get a torque of 30Nm which is plenty and a 45 degree speed of about 2.6 seconds.

Hopefully these sums are correct but you shuld also be aware that the motor may be damage if a force greater than the momentary maximum is applied to the lifter. The max momentary torque is 8.83Nm but allowing for the 10:1 extra gearing, you could handle a torque of 88Nm or 90kg/m. The reason for mentioning this is if your robot is flipped up in the air and you land on the lifter while it is open, it could damage the motor. Maybe a shear pin just in case would protect the motor. Hopefully we have got the above sums correct but do check them yourself.