My Old Tools
Well-known member
I saw these on Practical Machinist awhile back. I break punches periodically, so I decided to make some I can replace easily.
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Lathe time
- Thread starter My Old Tools
- Start date
AndrewDouglasBird
Well-known member
Did you harden them or at least make them from a hard material? Otherwise they will bend and the tip will mushroom.
http://www.mscdirect.com/product/details/75007377
The above link is to some good core or ejector pins for molding dies. They are good material, and precision sized. Core pins have a head on them and if you modified your handle with a bore for the pin head and a nut to capture it then you would have something you could pull on and easily replace the pin. If you didn't want to use the head end then you could cut off a piece that is to the length you need and save the rest till you need it.
lg
no neat sigline
The above link is to some good core or ejector pins for molding dies. They are good material, and precision sized. Core pins have a head on them and if you modified your handle with a bore for the pin head and a nut to capture it then you would have something you could pull on and easily replace the pin. If you didn't want to use the head end then you could cut off a piece that is to the length you need and save the rest till you need it.
lg
no neat sigline
OP
My Old Tools
Well-known member
I started with semi hardeded drill rod. I'll see if it needs further hardening. I have seen the ejector pins before and also hard music wire. Lot's of options once you have the holders done. Even brass for non-marring punches.
MBfreak
MEMBER EMERITUS
My $0,02s input
Punches used to drive out reamed in conical pins, like used in a coupling collar that connects a sleeve with a shaft, need to be short and as hard as practically possible.
The conical pin is hard to drive out and with a non hardened punch, the energy applied by the hammer to the punch is absorbed and converted to heat in the "soft" punch. The conical pin won´t budge.
With a short and sturdy hardened punch the conical pin jumps out directly .
Ola
Punches used to drive out reamed in conical pins, like used in a coupling collar that connects a sleeve with a shaft, need to be short and as hard as practically possible.
The conical pin is hard to drive out and with a non hardened punch, the energy applied by the hammer to the punch is absorbed and converted to heat in the "soft" punch. The conical pin won´t budge.
With a short and sturdy hardened punch the conical pin jumps out directly .
Ola
OP
My Old Tools
Well-known member
That's the nice part about these, need a short hard punch, put one in. Need a long alignment punch, no problem. Break one, put in another one.
HoosierBuddy
Well-known member
I like em!
Care to post a link to the plans?
Phil
Care to post a link to the plans?
Phil
OP
My Old Tools
Well-known member
Oh Phil, I eyeballed them on the lathe. Once I got one that looked and felt ok I used it as a pattern.
I drilled the hole for the rod first. Then I turned the nose section as a straight turning. The only trick at all was the curved section. I took a plain square tool bit and ground a round nose on it with about a 7 degree relief so it would cut. It worked better than I expected. The base material is just 1/2" rod stock from Enco, O1 I think. Any machineable steel will work. I went through my drill bit drawer with my dial caliper and found bits as close as possible to the rod stock I was using for the inserts. Mine are finger fit and I will probably add a small set screw in the side to retain them. That was my first attempt at knurling ever and it went better than I expected. I hand fed the first one then used the longitudinal feed on the others. Both worked. Then I parted them off. All in all it is a good excuse to use the lathe for a few different operations on something where tolerances are not critical.
I drilled the hole for the rod first. Then I turned the nose section as a straight turning. The only trick at all was the curved section. I took a plain square tool bit and ground a round nose on it with about a 7 degree relief so it would cut. It worked better than I expected. The base material is just 1/2" rod stock from Enco, O1 I think. Any machineable steel will work. I went through my drill bit drawer with my dial caliper and found bits as close as possible to the rod stock I was using for the inserts. Mine are finger fit and I will probably add a small set screw in the side to retain them. That was my first attempt at knurling ever and it went better than I expected. I hand fed the first one then used the longitudinal feed on the others. Both worked. Then I parted them off. All in all it is a good excuse to use the lathe for a few different operations on something where tolerances are not critical.