Looking for (idler?) gear wheel of HP-46 printer unit

[Duane Hess]

After reading through my last post, gee the coffee wasn't strong enough! Its hard to tell what the point is. It's the rambling of how my thoughts went throughout the day. I'm apologize for sounding to schizo. I was trying to be informative.

The point was (somewhere in all that) examining the 3 printers where the drum is aimed directly at its sensor and the motor shaft sensor is directly inbetween the 2 nubs may imply "start here".

Reinstalling the 17/68 gear with the above orientation should produce correct operation. Noted each printer had a minor drum to nub shift between them. Implying each printer may require individual alignment. However it's likely alignment may require repositioning of either drum & motors shafts a single tooth. Although physically accomplishing such may be tedious but eliminates trail and error to find initial alignment.

Presumably after "start point" is done, printing occurs on a time delay basis, i.e. one rotation of the drum. Probably all is reset each time the drum passes its sensor.

Intially trial and error was my thoughts on the F-20P but much other work was required so I didn't try it. Wasn't ready to tear into that.

Well, had to get the car repaired, so haven't left town. Of course the coffee wasn't strong enough!!!!! Naturally, I can't leave things alone either. Subsequently looked at the F-20P. (with the barrowed 17/68 gear from a working F-10P)

Did not remove the printer from the calc; simply removed the top cover. Removed the "housing cover" exposing the drum/motor/surrounding areas. Interestingly, the motor detents did not align with the nub/sensor but was about 12 degrees off. Noticed the drum was nearly 1/2 a row high relative to the nub. Figured this was individual alignment during manufacture because of how other components fell into place or varing component tolerances.

Removed the upper right and lower left screws from the 17/68 mounting plate. Aligned motor shaft (leaving it on its detent) and the drum nub/sensor directly aligned. Its was off. So aligned the drum again. Aligned the motor shaft inbetween the two nub and held the motor as it was not on a detent. Keeping a finger on the motor and drum rotated the mounting plate back, wiggled slightly and it fell into place. (using the paper advance lever to hold the drum didn't work in this case, it actually forced the drum off nearly a whole tooth)

It printed with the correct digits/special symbols exactly aligned for the function performed. Only certain functions work; the calc needs a lot of maintenance. Most functions lock it up immediately.

Say, shorter is better isn't it? So much blah, blah, blah in the last one, wasn't sure where I was going; if anywhere.

Well, ...., ya that's right, more coffee.