[GreenKeys] Model 33 punch depth adjustment.

[Jones, Douglas W]

After going through all the adjustments of the paper-tape punch on my Model 33, I punched the whole ASCII alphabet (or as much as possible, given that my keyboard doesn't have the square bracket or backslash characters).  All was well until there were 6 or more holes to punch.  At that point, the punches failed to fully penetrate the tape.

Obviously, the punch depth was just at the margin, so back to the manual to see what was going on.

The relevant manual page is in part 2 of the adjustments manual:
 -- ISS 2, SECTION 574-125-700TC page 9
 -- http://tinyurl.com/TTY22punchDepthAdjustment

Measuring the clearances, indeed, it was just over the allowed clearance of .037 inch, so I had to follow the "to adjust" procedure.

This is a very frustrating adjustment because the paper tape punch must be mounted on the Teletype in order to set up to measure the adjustment "set up an all marking code combination, manually rotate the main shaft ..."

And then, you have to loosen the code lever post mounting screw, which is only accessible from the back side of the punch, where there is about an inch of clearance between the punch frame and the typing unit frame.  All access to that screw is blocked except from the sides.

Eventually, I found I had this in my tool box:
-- http://www.alumigogo.com/product_detail.php?id=SKUB011W8KOOA

(Well, I bought mine from a junk bin at Ace hardware, and I see you can get them off Ebay for under $7 with free shipping.)

With a screwdriver bit in the ratchet driver, it's no go.  But, the screwdriver has a hex socket that fits the screw head, and with that, you can ratchet it to turn the screw, but only from the front with the paper-tape reader removed.  Ugh, but it only takes minutes do do that, and then the adjustment itself wasn't difficult, and the paper tape punch now does a good job.

		Doug Jones
		jones at cs.uiowa.edu