building my own relay computer

[Dave G4UGM]

> >
> >   I think it's the punch that's harder. You would need to harden the
> > punch pins, and the would need to have a very exact fit. I guess a CNC
> > router could be used to make these...
> >
> 
> I think that needs real machine work. Strange what you could do 100 years
> ago you can not do today.
> Computer controlled stuff is good for may things but not that.
> Ben.
> 

I suspect it is not "real machine work, but more likely honing and lapping.
I see from the CREED-25 High Speed punch maintenance manual that  the punch
pins could need honing:-


SHARPENING Of PUNCHES
====================

4. 1 Remove the punches from the punch block as described in Section 7 of
the Dismantling and Assembling Instructions.
4. 2 Insert the punches,  individually,  into a lapping block (TA.1301,
supplied with the tool kit)  so that the chamfered cutting edges of the
punches are parallel with
the chamfered side of the block.

So perhaps it is not as hard to make these things in say a model engineering
workshop.

Dave