actuator

[bigTomHanks]

I need to perform a life cycle test on a pin spring combination. I need to stroke the pin about 0.030''. The force that will need to be applied to the pin to move it is around 30 lbs.. Please give me any suggestions you may have on how to do this without making expensive tooling.
Thanks
bigTomHanks

 

[desertfox]

Hi bigTomHanks

How about a motor and cam arrangement,the cam could be designed to impart the desired deflection and load and the motor the power source which would provide continous cyclic movement the the pin and spring.

regards

desertfox

 

[Barry1961]

With the light load you could probably make a cam plate with one or more cam followers on a bolt circle. The cam followers would reduce the side load if that is a concern.

If you really need to get ugly cheap you could slightly round the corners on the head of a hex bolt and chuck it in a hand drill. Have the bolt long enough where you can have some type of bearing, plastic or wood, running on the shank. A few vice grips, cut up coke cans for shims and duct tape and you should be ready.

Barry1961

 

[bigTomHanks]

I like the cheap idea. I'll persue that.
Thanks

 

[Barry1961]

Make sure the test is a true simulation. If in actual operation the pin will be struck at a certain angle try to match it. Actuating the pin without any side load when in operation there will be side load will be a waste of time.

Side load is a big factor in most spring pins. Many things can effect the amount of side load such as lubrication, material type, material finish, chamfer on striker, angle of contact, corrosion, dirt and temperature.

If you need to have the striker come in from the side you could drill holes in a circular pattern in a plate and spin the plate. You might need a support bearing near the spring pin which could be made with a borrowed caster off an office chair.

Barry1961

 

[tlee123]

Do you need to stroke .030" or apply 30 lbs? It's not clear which way you need to test from the original post.

If you need a certain amount of stroke, the cam arrangements will work.

If you need a certain amount of force, use the cam to drive a low rate spring or just use an air cylinder. Air cylinders are cheap if you have the supporting equipment avaliable (compressed air, valve, pressure regulator).

Tom