midnight
04-20-2014, 07:58 AM
A member here asked me about punches I was making & I took some pics. He wanted to know how I was doing it. I found I needed many core seat punches. When you swage for many calibers and use cartridge case jackets, straight wall jackets, tapered wall jackets, copper tubing jackets, and all of the above drawn down to a smaller caliber jackets, you need a lot of core seat punches. I decided to make my own.
I only have a milling machine (Grizzly 1006) so I used it as a lathe. The punch stock is 3/4 in. W1 drill rod cut into about 2¾ in. lengths & chucked in the R8 spindle. I face off both ends with a carbide end mill. Then I put the blank in a ¾ in. 5C collet with a collet stop in it and put the 5C collet in a collet closer. Find the center & drill and tap ¼-28. Then put it back in the spindle. I put a ½ square toolholder with a TCMT 32.52 carbide insert on parallels in the milling vise & turn 5/8 in down to 0.570 taking cuts of 0.005 until I am almost there, then 0.002 until I am within 0.001. Then use 400 grit emory strip to polish down the last 0.001. Then turn it over & turn the punch end to the desired diameter. Leave about a 0.125 in collar between the two turnings. I make up several at a time & turn the punch to about 0.450 & keep them to turn down further as I need them. A few pics should make it more understandable. 102743102744102745102746102747102748
I only have a milling machine (Grizzly 1006) so I used it as a lathe. The punch stock is 3/4 in. W1 drill rod cut into about 2¾ in. lengths & chucked in the R8 spindle. I face off both ends with a carbide end mill. Then I put the blank in a ¾ in. 5C collet with a collet stop in it and put the 5C collet in a collet closer. Find the center & drill and tap ¼-28. Then put it back in the spindle. I put a ½ square toolholder with a TCMT 32.52 carbide insert on parallels in the milling vise & turn 5/8 in down to 0.570 taking cuts of 0.005 until I am almost there, then 0.002 until I am within 0.001. Then use 400 grit emory strip to polish down the last 0.001. Then turn it over & turn the punch end to the desired diameter. Leave about a 0.125 in collar between the two turnings. I make up several at a time & turn the punch to about 0.450 & keep them to turn down further as I need them. A few pics should make it more understandable. 102743102744102745102746102747102748