Machine arm powered by a motor and chain

[Erik O]

Hey Guys,
I was wondering if you could help me with a machine issue I have a work. The machine uses an arm powered by a motor and chain to raise and lower powder for welding. The chain broke the other day and I need to come up with a fail-safe. First, I need to come up with the force required to stop the arm from falling. The arm is usually held at an angle of 105 degrees. I also attached a picture.

Thank you!

 

[MikeHalloran]

The force required to support the 100 lb load is 100 lb, at the load.

You haven't given nearly enough information to determine how much tension that produces in the chain, if indeed it produces any.

The simple answer, absent any other useful input, is, use a bigger chain.

Have you got an actual engineer there on site, who can help you?



Mike Halloran
Pembroke Pines, FL, USA

 

[Erik O]

What other information do you need? It would only take 100 lbs to stop the arm from falling?

 

[BrianE22]

I assume the sprocket is attached to the shaft holding the arm? Calculate the torque on that shaft. Knowing the torque you can calculate the force on the chain. Throw in some safety factors.

 

[Erik O]

Thank you. So t=(36" x 135lbs) + (36" x 135lbs x sin(105))??

 

[Erik O]

Is tension=(61.235 kg)(9.8m/s)+(61.235kg)(9.8m/s)=600.103+600.103= 1200.206 N?