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  #11  
Old 10-07-2009, 04:34 AM
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Oh yeah, I went and looked at Bob's pics again.

My upper dies are much flatter, and I take almost all of the clearance out of the lower die. Everything beyond the planishing area dives away at a radius.

Tim D.
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  #12  
Old 10-07-2009, 10:25 PM
Barry Barry is offline
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Originally Posted by tdoty View Post
.......The bright, polished finish, however, plays a big part in keeping the dies from rusting......

Tim D.
I find the automatic tool (and floor) oiling function built into the Nibbler's seals takes care of that.....

Thanks for the explaination Bob.

Barry
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  #13  
Old 10-08-2009, 04:12 PM
JonD JonD is offline
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Here is a Photo of my thumbnail dies I made a couple of years ago. Since the photo was taken all the edges have been blended, the lower die to ease pushing the metal in/out and the upper to reduce coining especially around the thumbnail to smile area.

The only lathe work was to surface the two round blanks. These were tacked together as other did. The hole was drilled at approx 17 degrees. The pin was undersize so that there was less grinding required on the upper die and ease of lower weld cleanup around the pin.

For alignment I welded the lower shank on and loaded it in the pullmax and tacked the upper shank on. Luckly the upper shank was short enough to enable removal of the upper / lower once split.

All shaping / blending was done with a flap wheel or dremmel.

These were adapted from plans on metalmeet.

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  #14  
Old 11-14-2009, 10:23 PM
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I was at George Barnes house today and he helped me drill the pin for a set of thumbnail dies. Thank you George

We drilled the the hole in a 14dg angle.I have heard people mention 17dg and I have also heard people saying that their pitch was to high making it hard to pull the metal back through.

I did some quick markings on it on how I was thinking of grinding them.Could you guys tell me if you see something wrong?The markings are rough I will make them more exact when I am happy with them.

I have read about the sweet spot right behind the pin but I am still not quite sure how to do it.Unless you just cut the clearance out of the top die so it will miss the few thousands you leave behind the pin.

Here are some pictures.I was just going to grind them but I figured I better ask first.Better to be safe then sorry.

test run 6 066.jpg

test run 6 067.jpg

test run 6 068.jpg

test run 6 071.jpg

test run 6 073.jpg

test run 6 069.jpg
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  #15  
Old 11-14-2009, 11:12 PM
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Personally, I would leave the outer edges of the upper alone except for raduising them, no need to remove a lot of material there.

On the lower die, you're almost there. I can't post pics from here, or I would mark up what I mean. Anything forward of where the "thumb" comes up needs to go away as well. The only flat spot on my lower dies is the smil shaped area behind the "thumb".

HTH,

Tim D.
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  #16  
Old 11-14-2009, 11:20 PM
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Thanks Tim

On the top die I was only going to take a little away.If you look at the side you can see how much. I was just thinking it would make it easier to push the metal in.

You think I should do away with that?

test run 6 074.jpg

Like this on the lower?
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  #17  
Old 11-14-2009, 11:28 PM
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Kerry Pinkerton Kerry Pinkerton is offline
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Quote:
Originally Posted by jhnarial View Post
Thanks Tim

On the top die I was only going to take a little away.If you look at the side you can see how much. I was just thinking it would make it easier to push the metal in.

You think I should do away with that?

Attachment 1780

Like this on the lower?
NO! The metal at the side of the pin HOLDS the metal while it is crushed at the base of the thumb.

Johnny, it's easier to remove metal than add it. Clean up the edges and experiment before you start cutting... imo anyway.
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  #18  
Old 11-14-2009, 11:39 PM
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Can I agree with Kerry and disagree at the same time?

I know how my last few sets of dies have been made, but, I have to agree with Kerry - do your basic rounding and clearancing as you marked it up the first time, and then experiment.

On the top die, I wouldn't spend the time to remove that much metal. Just giving the edges a nice smooth radius is enough. The edge of the trough needs to be nice and round and just absolutely kill the open end of the trough (at the outside edge of the die). I used to get "snakebite" marks on the metal, that was from the end of the trough not being smooth enough. That end doesn't do much anyway, so get the excess metal out of there and make yourself plenty of clearance.

I've found you get more out of making sure the lower is clearanced and smoothed properly than from removing a bunch of metal from the upper die. Make sure the planishing areas of the dies are parallel to each other and nice and smooth.

The back edge of the lower die (toward the operator) needs to have a nice radiuis cut into it. If the radius is too too flat, you'll limit yourself on how much the dies will shrink, as metal here will cause you to fight your dies as the shrink puts more curve into the panel than the shape of the die allows. I guess, though, the radius wouldn't matter a whole lot if the metal was just cut away. Never really experimented with that, I just round them off a bunch.

These are lessons I learned the hard way. Hope it helps.

Tim D.
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  #19  
Old 11-14-2009, 11:40 PM
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That is what I was thinking to.Go a little at a time.Then maybe I will be able to see trouble areas and how they work exactly.


I have to fix my hammer first before I can test them,me and Joe talked about the bearing issue and I think we have it resolved.I just have to take the time to fix it.
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  #20  
Old 11-14-2009, 11:42 PM
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Thank you Tim I know you have put a lot of time into studying these dies
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