rigging a monkey.

[havieman]

i work for a put, put golf course. there is a t-rex that has a monkey attached to a cable..the arm goes up and down making your shot a timed one..well inside the t-rex there is a long metal arm about 7 or 8 feet long..at the front right where the arm comes in is a pivot point..it has a shaft inbetween two greased bearing, making it a great spot for a pivot point..the arm is pretty well balanced..on the arm sticking out on the left hit a weird shapped heavy cam bout 40 lbs..mounted to a 5hp a.c. motor, i think..it is a really big motor..this cam looks to be crudely made and will not stay on the motor, it keeps shearing the kotter key..i could just weld the pulley slash cam because the cam was welded on to a steel pulley, not sure what to do?? rip motor out and start over?? anyone out there with any suggestions i would appreciate it..

 

[Joe G]

How about a bigger cotter pin (it does look like a "hair clip" correct") or even drill the cam and motor shaft for a nicely fitting solid pin are preferably a "shear pin" for safety reasons. I would'nt weld it JIC, harder to remove and repair.

 

[dr pepper]

If you weld it you'll not be able to do any repairs in the future without hardship.
If you have the cash pull out the motor/cam and take it turn a machine 'shop and ask them to make it right, if your broke then yep I spose weld it on, just put a few tacks on so you can undo it if req.

 

[unclejed613]

if it's breaking the shear pin, then something is causing a lot of resistance. the cam surface may be worn and pitted, or something else in the mechanism is pushing back with an unusual amount of force.

i would put some white paint marks on the cam, shaft and the arm that contacts the cam, and use a strobe light to "slow-motion" the action. this way you can see if something is happening during operation that shouldn't be.

the slow motion effect happens when the strobe light and motor shaft are operating at slightly different speeds. you can make a strobe with white LEDs and a 555 if you can't get a xenon strobe.

 

[cowboybob]

Although I have a mental picture (if a bit vague) of the mechanism, some real, well focused pictures of each item (plus the whole thing) that you have described would be very useful.

 

[Joe G]

also, is the cam just rotating on the arm? is it greased on the wear/contact points? a picture of it is worth a thousand words
and yes a "strobe" works great in isolating "glitches" and trouble shooting, JUST BE CAREFUL, people have been known to reach and adjust moving
items when "strobing" not thinking that its moving.......not good