What type of motor to use for a worm/gear box

[awagenhurst]

Hello,
I'm trying to figure out which motor that cane move a 7 foot poll that weighs 15 lbs, that has a weight on the top that weights about 5-8 lbs. The weight on the top can be as long as 7 to 9 feet wide. The poll will be attached to a half gear at the bottom. So the motor will need to be able to move the poll 90 degrees in both directions and to hold it in any position. I attached a paint drawing of the best way to visualize what it would look like. Please let me know if you have any questions. Any help would be appreciated.

Thank you
Awagenhurst

 

[BrianE22]

Are you looking for just the motor or a motor/gearbox? AC motors are generally bigger but less expensive than DC motors. DC motors are usually cheaper to control the speed.

Looks like you are driving a self locking worm gear. Make sure to include the friction of the gear set in your torque calculations. Probably count on no better than 60% efficient if it's self-locking.

 

[awagenhurst]

BrianE22,
As of right now I am looking just for the DC motor. I'm sure I'll have to get a custom gear but the one thing I cannot figure out is the size of motor that could drive this gear. As for the calculations I'm not that savvy, I wouldn't know where to begin on the math or to find the information you need. I do know that with the weight the motor would need to push and pull would be at max 162 ft lbs.

Thank you
AWagenhurst

 

[drawoh]

awagenhurst,

What is it you don't know? Everything?

You need a motor that puts out adequate torque. Do you need to move thing accurately? You need even more torque, plus some position indicator. You need a connection to your worm drive that can handle the torque. You need a worm drive that can handle the torque. You need a connection out of your worm drive that can handle the torque. You need a pole that can handle the torque. You need to connect adequate power to the motor.

Are people going to be in the vicinity of that weight swinging up and down?

What you really need is a design engineer.

--
JHG

 

[3DDave]

At this point on Shark Tank, all the investors would say "I'm out," for lack of clarity.

I think there are websites you can put up problem statements and have people bid on providing design services.

 

[awagenhurst]

Drawoh/3DDave,
Sorry for the "lack of clarity", however almost everything you mentioned about the pole, the power, people, and the position indicator is not what I'm looking for. All I asked is "what type of MOTOR" would I need to push and hold 162 ft lbs. I'm not worried about anything but the motor. For the motor aspect, what information would be needed?

 

[MikeHalloran]

You are not acting appreciative.

In order to answer your question about the motor, ALL of the information requested so far, and then some, must be used to 'run the numbers'.

The 'then some' includes some idea of how fast or slow you want the machine to move.

I'm not clear about how the width of the weight on the end of the pole is measured, which affects how it affects the numbers.
Did the person who came up with the 162 ft-lb torque have more knowledge of the system geometry than we do?



Mike Halloran
Pembroke Pines, FL, USA

 

[gruntguru]

"what type of MOTOR" would I need to push and hold 162 ft lbs?

Any electric motor can push 162 ft lbs. All it takes is the right gearing.

je suis charlie

 

[drawoh]

awagenhurst,

I missed an important detail. How efficient will your worm drive be? Lots of worm drives are way below 50% efficiency. Typically, these are self locking, so there is no need for the motor to hold anything in place, unless there is vibration. Do you understand that the gear ratio affects motor torque, even without accounting for efficiency?

--
JHG