paper tape punch isnt punching

From: Lawrence LeMay <lemay_at_cs.umn.edu>
Date: Mon Jul 3 17:20:54 2000

> >
> > I bought a paper tape reader/punch on ebay, a DSI NC2400.
> >
> > unfortunately, 2 of the holes arent punching through the mylar tape that
> > came with the unit. does anyone have experience with this unit, or know
> > what might be causing the problem?
>
> I don't know this unit at all, but I can make some guesses. There are
> basically 2 types of electrically driven punch -- those where the
> solenoids operate the punch pins directly (like the Facit 4070) and those
> where the solenoid operates a linkage which enables a drive from the
> motor/camshaft to operate the punch pin, like the Teletype BRPE, the GNT
> 34, etc.
>
> Firstly, is there any mark on the tape at all? If not, try operating the
> solenoid armature by hand (with the motor turning if necessary). If it
> punches now, then suspect that either the solenoid is defective, wildly
> out of adjustment, or that (hopefully) the drive electronics is
> malfunctioning. I say hopefully to the last one because electronic parts
> are easier to get and cheaper than mechanical ones! If it still doesn't
> work, look for damaged, misadjusted, or sticking linkages.

Forgot to mention that the 2 holes that arent punching are adjacent
to one another. Also, the guy I bought it from mentioned it hadnt been
used in 10 years. There is a slight partial hole punched for one of the
holes. Also, there was one time when it did punch on all 8 hole, but only
once, ie, for one character only, and after that those 2 didnt punch
properly since.

>
> If there is a mark on the tape then either the punch pin is _very_ worn
> (unlikely if the others are fine) or the solenoid or drive link needs
> adjusting. Or maybe the solenoid is mechanically defective -- the rotary
> solenoids used in Facit 4070s suffer from this. Often they can be
> repaired once you understand how they should work.
>
> Don't overlook the possibility of old lubricant gumming things up (!). In
> fact you probably should clean and lubricate the machine right now.
>
>
> >
> > I know western numerical controls sells refurbished units, but I expect they
> > would charge quite a bit just to replace the punching mechanism. their
> > web page mentions something about "The precision die blocks are interchangeable
> > and field-replaceable in just minutes, no adjustments necessary". so,
> > I'm hoping that means I can buy a new set of punch parts and replace
> > them easily. and hopefully inexpensively.
>
> The punch pins are normally machined to fit in one hole in a particular
> die block and shouldn't be moved around. So a new die will come with new
> punch pins. Expect to pay a few hundred dollars for a block+pins -- at
> least that's the sort of price I've been quoted.
>
> If it is that easy to take the die out, do so. Take out the pins, keeping
> them in order (9 jam jar lids :-)). See if the 'defective' pins are
> noticeably shorter than the rest -- if not, the problem is likely to be
> elsewhere.
>
> -tony
>
Received on Mon Jul 03 2000 - 17:20:54 BST