Springs not bouncing back

We stamp lots of thin strip materials, no drawing jobs. We build our dies with 4 of 3/4” diameter OD 3/8” ID Green die springs 1 1/2” long with a collapsed height of 1 1/4” for the stripper plate and use ejector pins usually 4 to push the knock out to push the part out.

Industrial Supply Equipment from MSC Industrial Supply

www.mscdirect.com www.mscdirect.com
 
Took me a bit to understand the pieces here, but I think I have it figured out.

OK, I think see the problem. You need to add shoulder bolts through the springs. So they would go through the punch holder, through the springs, and be screwed into the top stripper plate.

1641174124605.png
 
Are you using wood dowels for leader pins? If so that would allow parts of the die assembly to move all over.
 
JimDawson said:
Took me a bit to understand the pieces here, but I think I have it figured out.

OK, I think see the problem. You need to add shoulder bolts through the springs. So they would go through the punch holder, through the springs, and be screwed into the top stripper plate.

View attachment 390671
Click to expand...
I'm not understanding the bolts within the springs. How do I compress the plates together if there's something rigid there inbetween them?
Right now the top and bottom ends of the springs sit in 1/4" deep holes in the upper and lower plates.
 
Nutfarmer said:
Are you using wood dowels for leader pins? If so that would allow parts of the die assembly to move all over.
Click to expand...
Yup, the metal rods helped keep the plates stuck together after pressing so I moved to wood. There doesn't seem to be any issues with the wood guide rods.
 
The shoulder bolts will allow for the spring to compress. I will have to find a diagram.CDE2AF90-E2A4-4785-AA0C-5D359607835B.jpeg
 
This is closer to what you would have in an industrial situation. Complex build.
Pierre0A1EBFDF-05EF-4E15-9EBB-D3692D00ABB6.jpeg
 
Maplehead said:
Yup, the metal rods helped keep the plates stuck together after pressing so I moved to wood. There doesn't seem to be any issues with the wood guide rods.
Click to expand...
Odd, were you using hardened pins, or soft rods? Hardened pins would have been the way to go.
 
Maplehead said:
I'm not understanding the bolts within the springs. How do I compress the plates together if there's something rigid there inbetween them?
Right now the top and bottom ends of the springs sit in 1/4" deep holes in the upper and lower plates.
Click to expand...

I drew this up real quick. Maybe it will make more sense.
1641227312967.png

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1641227700186.png

1641227352980.png
 
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