Shrink Die Plans

[Richard K]

I have developed a plan for shrink dies that yield consistent results. They shrink aggressively. Some marking of the work still occurs. When the dieset is relieved more to reduce marking the shrinking ability also diminishes slightly.

Important points in fabrication
1. The bottom side of the top die is flat.
2. The area on both sides of the thumb needs the 4 degree relief. This allows the metal to "gathered by the thumb, not stretched.
3. The clearance between the thumb and the upper die hollow is important. Too tight... the die stretches. Too loose... the die stretches. When setup properly the gap should be about 1 1/2 times material thickness. The dies will still work for a range of material gauges. Adjust this clearance by moving the bottom die forward or backward ( to or away from the operator.)
4. Clearance between top and bottom die. Set to a bit more than material thickness.
5. The flat faces of the die set must be paralell.



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If you make a set.. Please post your results.

[Tony Sanchez]

---Richard, thanks for the great information on your shrinking dies. What material do you suggest for making the dies? Also should the die be hardned?
---Tony.

[Dutch Comstock]

Hi Tony, The correct steel would be S5 as it is made for hammers and then most people go to S7 which is for hot hammering. For the amount you might use the shrink die there are a lot of other materials that you might use with out hardening or just case harden that would work for you. What have you been building Lately? Dutch

[CCWKen]

Thanks Richard for the plans. I wish they were larger.

I just started making some dies for my plannishing hammer and decided to tackle the shrinking dies. It's hard to believe these things work until you actually try it and see the principle. I see now!

These are the ROUGH cut version. I know they need a lot more finishing but I thought I'd post a pic and get a response. I do have a concern too but I'm not sure the ripples are caused by the "Unfinished" state or the smile needs to be deeper. The test sheet has a lot of trials but you can see the progress in the smoother areas. (The really bad area is due to not having the lower die locked in place.) It seems the tuck is jaming at the bottom of the smile (on the way back out) rather than rolling and produces a kink that isn't being hammered out.

Whatcha think? Close?

[Gene_Olson]

Originally Posted by CCWKen

Thanks Richard for the plans. I wish they were larger.

try this link in Richard's gallery

http://www.metalmeet.com/photopost/s...1&cat=3086

[Richard K]

Ken,

smooth and polish all working surfaces. All the corners must be transitioned. I use various abrasive disks on a 2" dia air grinder (3M Roloc products).

Persistance and Patience Pay Off

[customotorsinc]

is it possible to make those dies without a milling machine or lathe?
could i do it with a die grinder and drill press?

thanks
Parker

Yes is it possible. Start with two blocks, clamp them together. Place in your drill press vice and the angle you want your thumb to have. Us a drill bit appropriate for the size of the thumb you want. Drill your center punched hole about one inch deep. Now one die will have the "dimple" in it (upper) and one will have a small grove. Weld a piece of round stock (tool steel) into the grove. Use spotting blue to match the die halves

[Boogiemanz1]

Welcome to MetalMeet Matt. If you are a new member or just making your first post, we encourage your participation.

MetalMeet is a great source for metalshaping information, please check out the gallery also. There is a forum for introductions http://www.metalmeet.com/forum/forumdisplay.php?f=129 if you would like to tell us about yourself, your projects, or what you would like to learn...............john

[Marty Comstock]

What i have found when making shrinking dies is that they (mostly the lower die) need a pile of hand work after machining. i used a surface plate and a height gague fitted with a besttest indicator to locate the sweet spot. the metal falls away very slowly after this spot, it can be very difficult to see. coat the lower die with dykem, measure the surface, then polish away untill you have the desired spot. at first, this will be a slow process, but after a feel is attained, it begins to make sence. i admit, it is very difficult to explain this with the written word, but i have had great sucess making dies for pullmax and yoder machines in the past.