Spring Selection

[Finglas]

I need to select springs for a die press. Not sure what needs to be taken into consideration though. I have springs for the stripper plate selected. Force required to press through the workpiece is approx 144N. There are 3 punches so that equals 432N. Read stripper springs are about 20& of press force so that would mean 108N. Put in a FOS of 3 to be sure and I've selected springs to strip up to 300N.

But for the springs that go on the guide posts in the pic, I'm not sure. Presume it has something to do with weight of material acting on them? Reason want to put them in is because I don't want to connect the ram on the arbor press to the long pucn mounting plate.Just want the ram to push this down. When punches go through part and ram is released, the springs on the post will move the stripper assembly back up and leave space to insert the next workpiece.

 

[drawoh]

Finglas,

I believe I took this stuff in college about thirty years ago.

This is where you ask your experienced co-worker how he does it. He then answers your question, and points out the one or two other mistakes you are in the process of making.

Your other choice is to advise your boss that this is a prototype, and that it will likely need modifications after the first test. You, of course, will make detailed notes so that you or the next person who gets to do this again, will not have to repeat the trial and error process.

JHG

 

[Finglas]

haha. will go with the modifications or just leave out the spring altogether and join the ram to the mechanism hence eliminating the need for springs.