Wade C
Stainless
- Joined
- Jul 21, 2004
- Location
- Wiggins CO. USA
Not sure where I should have put this post, so figured best to aim here, and then go to a different topic if needed.
Im working on a "simple" punch that I use for punching a thin laminated plastic (.009 - .016" thick - similar to Mylar). Ive built a few over the years, and most have worked well - but I recently decided to try using D2 instead of A2 for the punch and die (top guide plate and bottom cutting plate) - both materials were 58HRc range. I am fighting delamination of the material when punched suddenly and it has me baffled.
I guess Im getting smart enough these days to know when there must be something going on that I dont know about... and realize that sometimes you can get lucky for a while then it runs out.
The design is just a punch cut out with the wire edm, with a handle to smack with a hammer, and then the top and bottom die plates are ground flat, then grind a step on the top of the bottom plate and bottom of the top plate to make the gap for the material to slide in, dowel pinned, and bolted together with a base plate with a hole to give clearance below the die plates for the part to fall out.
I wire out the punch, leaving a good tab to hold it by, and run 4 skim passes. Then cut off the part and take it to the surface grinder to dial in on the surfaces on both sides of the tab, so I can grind the tab off as accurately as I can. Then, the plates that have already been ground, step ground in, doweled and bolted together go in the wire. I cut out the shape, and run about 3 skim passes and then start testing fit after each skim pass. Run the following skim by changing the wire offset by .0001" until the punch will just start in the wired hole (Id guess by time its cleaned up and any recast layer rubbed/worn off that I have around .0003-.0005" clearance per side). Take it out, take it apart, dry, oil and put back together - and usually Im good to go. But not these latest ones Ive tried to do. I thought maybe it was the change from A2 to D2, but I have A2 and D2 versions doing the same exact thing - so Im starting to think its me. Ive made punches before that were looser (on my older wire thats not as accurate as the newer FX10)- and didnt delaminate, so Im a little perplexed.
So Im starting to wonder if Im missing something in the operational theory, or some trick or secret about punching laminated material, or maybe just not holding my mouth right? Im wondering if Im getting a couple tenths worth of misalignment from when the die plates are assembled and then cut to when they are taken apart, dried, oiled and then blown off, and put back together?
Any one willing to share any expertise or thoughts on punch making for thin laminated material where one of the requirements is that the material does NOT delaminate? Feeling dumber and dumber the more I try things to cure it, and it either gets worse, or at least not any better.
Thanks
Im working on a "simple" punch that I use for punching a thin laminated plastic (.009 - .016" thick - similar to Mylar). Ive built a few over the years, and most have worked well - but I recently decided to try using D2 instead of A2 for the punch and die (top guide plate and bottom cutting plate) - both materials were 58HRc range. I am fighting delamination of the material when punched suddenly and it has me baffled.
I guess Im getting smart enough these days to know when there must be something going on that I dont know about... and realize that sometimes you can get lucky for a while then it runs out.
The design is just a punch cut out with the wire edm, with a handle to smack with a hammer, and then the top and bottom die plates are ground flat, then grind a step on the top of the bottom plate and bottom of the top plate to make the gap for the material to slide in, dowel pinned, and bolted together with a base plate with a hole to give clearance below the die plates for the part to fall out.
I wire out the punch, leaving a good tab to hold it by, and run 4 skim passes. Then cut off the part and take it to the surface grinder to dial in on the surfaces on both sides of the tab, so I can grind the tab off as accurately as I can. Then, the plates that have already been ground, step ground in, doweled and bolted together go in the wire. I cut out the shape, and run about 3 skim passes and then start testing fit after each skim pass. Run the following skim by changing the wire offset by .0001" until the punch will just start in the wired hole (Id guess by time its cleaned up and any recast layer rubbed/worn off that I have around .0003-.0005" clearance per side). Take it out, take it apart, dry, oil and put back together - and usually Im good to go. But not these latest ones Ive tried to do. I thought maybe it was the change from A2 to D2, but I have A2 and D2 versions doing the same exact thing - so Im starting to think its me. Ive made punches before that were looser (on my older wire thats not as accurate as the newer FX10)- and didnt delaminate, so Im a little perplexed.
So Im starting to wonder if Im missing something in the operational theory, or some trick or secret about punching laminated material, or maybe just not holding my mouth right? Im wondering if Im getting a couple tenths worth of misalignment from when the die plates are assembled and then cut to when they are taken apart, dried, oiled and then blown off, and put back together?
Any one willing to share any expertise or thoughts on punch making for thin laminated material where one of the requirements is that the material does NOT delaminate? Feeling dumber and dumber the more I try things to cure it, and it either gets worse, or at least not any better.
Thanks