Springs not bouncing back

[Maplehead]

Hi All
I have to buy lots of these 10mm x 30mm medium load springs because after pressing just one pickup cover the springs lose their original shape and don't bounce back, (as you can see in the pic). Do I need to go to a heavier load spring or is there a better alternative? I don't want to have to re-make all my die plates as they took forever to mill.
Any and all help and advice is greatly appreciated.
(Picture showing just the top two plates of my die jig.)

 

[Aukai]

Are they coil binding?

 

[Maplehead]

Are they coil binding?

Are you asking if the coils are catching to each other? If so then I would say no.
Here's a before and after pic.

 

[markba633csi]

I think you need a much heavier spring with fewer turns

 

[Aukai]

Coil bind I'm thinking about is too long of a spring, and coils getting compressed before the halves come together.

 

[DAT510]

Looks like you are exceeding the elastic range (in compression) of the springs and ending up with binding (Plastic Deformation), too long.

If you look here at the McMaster Carr site, you can see the compressed length of the springs at "Max" load. (Max load is the the load they can see before binding.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[JimDawson]

OK, that's a new one. In 45 years of building dies I have never seen that before.

Best guess is that the springs are too short (or too long) for the job, and you are pressing them down hard to complete collapse. There is a max compression spec on the spring, expressed as a percentage of the spring length. It could be that your spring pockets are not deep enough. I assume you are using shoulder bolts to keep them aligned?

 

[Maplehead]

OK, that's a new one. In 45 years of building dies I have never seen that before.

Best guess is that the springs are too short (or too long) for the job, and you are pressing them down hard to complete collapse. There is a max compression spec on the spring, expressed as a percentage of the spring length. It could be that your spring pockets are not deep enough. I assume you are using shoulder bolts to keep them aligned?

Here are pics of my set up. Don't know if it helps or not. The purple sticky is pretending to be the .020" nickel-silver blank.

 

[RJSakowski]

I've not worked with die springs but any compression springs that I have worked with are able to be compressed to solid height without deforming. However, if the the tooling setup would allow compression past that point, telescoping one coil within another, the elastic limit would be exceeded and the type of deformation you are seeing would occur. The press is capable of supplying enough force to do that.

 

[woodchucker]

Couldn't you redo it without springs, and make it use pins, and the pins become ejection pins.