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Does anyone have an HP-46 printer for parts? - Printable Version

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Does anyone have an HP-46 printer for parts? - Pcip - 01-11-2017 02:16 PM

I recently got an HP-46. The seller said it wasn't working, but indeed it was, and although filthy, it is like new, with a new manual, cover and literature. All for 30 euro. Of course, the infamous printer double gear disintegrated after a few seconds of use, but thanks to member Sadsilence (thanks again, Werner!) I was able to put the printer up and running again.
Anyway I got very unlucky this time. After a while I heard something like a metallic small "bang". The printer was stuck. After disassembling more I found that two little internal "hammers" had broken up in three pieces. The hard part was to take them out of the mechanism. I spent more than two hours doing that.
Anyhow now the printer works flawlessly, but with two positions missing (I can choose which ones to leave out).

I was wondering if any member here has one of those hammers.
I learned the hard way that these printers should not be put to work without a thorough cleaning.
Hardened grease, useless old oil together with dust and dirt accumulated in 40 years and more will make the bomb tick.


RE: Does anyone have an HP-46 printer for parts? - BobVA - 01-15-2017 10:19 PM

Did you see this thread?

Quote:I also have a bunch of parts (case, PC boards, etc.), still in original boxes, for most of a HP 46.

RE: Does anyone have an HP-46 printer for parts? - Duane Hess - 01-15-2017 11:54 PM

One point you might consider is the model number inside the HP-46.

It is a Shinshu Seiki (Epson) model EP-102 (or just model 102). Various calculator manufacturers used this printer; of couse the drum would have a different character set, but that won't make any difference.

A follow-on printer was the model EP-104 in later model calculators (esp. Canon). Many of the parts are interchangeable.

I have various calculators and have both printers, but am not in a place to determine if the print hammers are the same. By simply lifting the covers they sure to look identical.

Before recent postings mentioned in the previous reply about constructing your own gear I almost purchased a calc from TAS which had the same printer model.

Search the Internet for the EP-102 and EP-104 to find other calcs using those models. Specifically (if you read German) you might consider:


Reading German isn't necessary as the needed info is readily interpretable at the bottom of the page. (I used Google translate) Both pages list various calculator models which use the same printer.


RE: Does anyone have an HP-46 printer for parts? - Duane Hess - 01-16-2017 12:07 AM

OOPS! Had an anurysm! The previous post was about parts for sale.

You might look at the following:


both threads mention different people fabricating their own gear from pre-made, readily orderable parts.

RE: Does anyone have an HP-46 printer for parts? - Pcip - 01-17-2017 10:01 AM

Thanks for your replies.

BobVa: no, thanks, I hadn't seen the thread, I'll contact member guswinfield to see if he can help me.
Duane Hess: I have read all those threads, even contacted member Sadsilence who sent me a new double gear (for free!) and that solved the first issue.
I am also aware of Shinshu Seiki printer model 102 (or 103R, stripped down version of model 102) being present on several calculators of the time.
By the way, I missed a Monroe 1330 lately. It was sold locally in the beginning of october. I am constantly looking, though.

Those little hammers are internal, and I am pretty sure all model 102 (or 103R) printers have exactly those hammers.

RE: Does anyone have an HP-46 printer for parts? - Pcip - 05-15-2017 09:36 AM

After a while I took the time to deal with my 46 again, after receiving a complete printer (but not from another 46) from member Ignacio Sanchez.

I thought of simply exchanging the drums, but I wasn't able to take them out and was afraid of doing any damage.

I directly hooked the new printer to my 46 and, besides printing different (but not wong!) things, it was working perfectly.

So, first thing I discovered, there are at least two flavours of the infamous double gear. The one installed in Ignacio's printer apparently doesn't break, and it is fully functional. The color is darker than the one installed in my printer, so it's definitely another material.

So I took out the metal support and simply thought to mount it on my printer but, as it turned out, I was thinking wrong.

Discovery #2: there is a way to supposedly align the entire thing.
There is a raised mark on the white plastic gear;
there is a hole in the double gear, as well as a small arrow.
There is a hole in the metal support. You can align everything.
There is also a tiny dot on the motor gear that you can align with the arrow printed on the double gear.

Only one problem: once everything is aligned perfectly, it doesn't work.

I'm quite tired of this stuff and almost planning to throw everything away. There must be something not so obvious I am missing, but I am stuck now.
I thought I had found a way to do it, but something is still missing.

RE: Does anyone have an HP-46 printer for parts? - Katie Wasserman - 05-15-2017 01:52 PM

(05-15-2017 09:36 AM)Pcip Wrote:  Only one problem: once everything is aligned perfectly, it doesn't work.

I'm quite tired of this stuff and almost planning to throw everything away. There must be something not so obvious I am missing, but I am stuck now.
I thought I had found a way to do it, but something is still missing.

Did you change the main (large) filter capacitor? Any ripple on the DC supply line to the printer will make it act as if it's not aligned. This is a common problem.

RE: Does anyone have an HP-46 printer for parts? - Pcip - 05-16-2017 07:26 AM

Thanks Katie, but I was aware of the problem you mention. In my post, however, I mentioned I had tried the newly acquired printer on my 46 and, besides printing stuff related to the donor calc, it was working perfectly.

RE: Does anyone have an HP-46 printer for parts? - Duane Hess - 05-19-2017 09:25 AM

From the statement "it doesn't work" I assume you mean the printed output is incorrect or misaligned. My assumption anyways.

From latter posts one assumes you are referring to the original printer, now cleaned & parts substituted. If I understand correctly, after earlier repairs it was printing correctly, minus the 2 columns. Might the drum subsequently have rotated on its shaft? Ask as you mentioned being unable to take them out; don't know which printer you meant or both. If you did loosen the 46 drum could it have rotated out of alignment?

I ask due to my experiences/observation with 4 printers:

- all 4: The drum shaft magnet aligns "somewhere" between the 1's & 2's row. Although no precisely centered between the rows. Noticed the striking surface of the print hammers is approx. 1/3 larger than the largest symbol on the drum. Presumably this allows finer adjustment plus compensation for slight variance from exact alignment of other components.

- all 4: When the drum shaft magnet is aligned with its sensor (or close as possible), the motor shaft sensor was exactly inbetween the 2 magnets on the brass motor shaft collar. (acute angle side)

- after cleaning, greasing, reassembling one of my printers, very recently noticed the 46,81,9805 printer service manual. it states the drum magnet should align between the 2's & 3's rows. ... that simply does not match the 4 printers I checked.

- The manual corresponds with the marking alignments you pointed out. Always wondered what that triangle on the original gear was for. Never noticed the mark on the end of the motor shaft until looking at the 46,81,9805 service manual. Aligning the motor shaft mark with the triangle symbol on the gear points the shaft-mark towards the center of double gear rotation. Since the mark is missing from my new gear, verified the aiming of the motor shaft.

- checked 2 of the 4 printers: With the alignment you stated, happened to notice the "jaw" or flat part of the wedge on the motor shaft that strikes the actuating hammers points directly to the right, when viewed from the side. i.e. the jaw would strike or nearly strike the actuating hammers were they pushed forward. Figured there was no need to check the other 2 printers.
--- seems sensible, as on my printers, when the jaw is 90 degrees to the right it is inbetween the 2 magnets on the brass motor shaft collar. I always thought there is a reason the magnets were not 180 degrees apart. i.e. some reason to sense "where" (or reasonable close to where) during the rotation of the motor shaft things happens to be. The "jaw's going to bite" would be a pertinent thing to know; so one would think.

Barring electronic signalling issues/electronics etc. possibly the drum or brass collar may have slipped on their respective shafts? Hopefully that helps.

RE: Does anyone have an HP-46 printer for parts? - Pcip - 05-21-2017 06:29 AM

Duane, thanks for your contribution.

I restore as a hobby high quality tape decks, so I am quite familiar with precision mechanics.
However I seldom had difficulty like in this case.

I did unscrew the two drum screws, but since the whole thing did not move one single micron, I thought it would be better to leave things alone. Of course I took several pictures before attempting to do anything. My observations regarding the drum alignment in respect to the magnet right now are exactly the same as yours.

I tried to align the double gear assembly countless times now and, although I seem to get pretty close (CLEAR printing, but not anything else, some other symbols printing OK), I still haven't made it yet.

I checked the 15v test point and it is OK. A little more than 15v while the printer is idle (but running), close to no alteration during printing.

What I am beginning to think is that the standard alignment is only a "rough" alignment and it must be refined in some way. I am trying to understand how.

A scan of the pages of the manual regarding the printer would be great, and greatly appreciated. Of course, when I restore my Naks to original specs, I start from there.


RE: Does anyone have an HP-46 printer for parts? - Duane Hess - 05-23-2017 01:18 PM

Sometimes I'm slow. (maybe all the time!)

What do you mean by "CLEAR printing"? Originally when I read it, I thought the hammers try to strike but don't hit the drum, i.e. print but no image, hence "clear."

You mean printing the word CLEAR after power on? Once running does CLEAR print with each press of the clear key? If CLEAR prints then all other symbols in those columns should print, if you have a large enough number. Are the other symbols in the rightmost 2 columns or where?

I would think if any symbol consistently prints correctly then the alignment of the drum, gear train and motor shaft is correct. Any column that prints should verify intact wiring, magnets work, springs work, correct signal timing, etc. i.e. if the word CLEAR prints but no numbers print in those columns, .... ya, I get the perplexment.

I may have an interpretation problem. Been taking finer adjustment as mechanical adjustment. Maybe I'm misinterpreting what you mean.

RE: Does anyone have an HP-46 printer for parts? - Duane Hess - 05-23-2017 03:27 PM

I babble too much for my own good.

Any manual I've seen on the printer was here on the museum, the 46 service manual and another service manual:
HP-46 HP-81 HP 9805 Updating Revision Repair of Printer Assembly
I'm sure you know of them.

You have a point on finer adjustment. i.e. what is it? adjustment or repair. A portion of items from the 2nd manual which refer to some non-mechanical adjustments/settings are:

- motor speed bad
- On page 68 of the latter manual indicates to replace the magnet detector if a timing signal is out of bounds.
- Elsewhere in the manual it refers to input trigger pulses, which I take it, refers to the signal to fire a hammer (engage magnent). If those are bad it suggests to "adjust the driving control circuit". Ya, what does that mean? The driving circuit, in my poor understanding, is on the motherboard. What is there to adjust other than replacing parts?

I'm also interested in how all this works. Generally, my previous posts were to see how people react to them as opposed to suggesting a solution. i.e. people have/do not have similar observations to my own.

I have close to no background in electronics. So let me make something up:
Suppose the word CLEAR prints consistently each time you press the clear key. However, you have a number where '1' is in the 'E' column, but '1' does not print. What would that mean?
- certainly the mechanical mechanism is not bound up in that column
- electronic signals get to the magnet or the 'E' would not print
Suppose all symbols in that column print except '1'. Seems that would be another issue. Maybe my imaginary situations are not possible to exist. Don't know if they are anywheres close to your printer's behavior or not.

RE: Does anyone have an HP-46 printer for parts? - Pcip - 05-26-2017 10:28 AM

I've got all sorted out, at last.

The printouts I have now are far superior for consistency to those I see as examples on the user manual and better than those that the printer had done in the past (there was some old printer paper in the box I received). The functioning is nice, smooth and silent, and I haven't yet properly lubricated the thing.

The easy part was actually the drum gear positioning. Actually, it would have been highly unlikely that an alignment designed for a drum whose magnet was aligned between 2's and 3's could be fit for a drum whose magnet was aligned between 1's and 2's. I tried turning the drum clockwise (don't ask why not counterclockwise) a few degrees and it did the trick. I can confirm that (at least on the two printers I have here) the motor sensor head should sit exactly between the two motor magnets.

The fact however was that I had three variables working against me, and not only a single one.

I had disassembled also the two solenoid banks to get better understanding of the internal working of the printer, and to thoroughly clean it. The reassembly required a lot of patience, because position calibration accuracy regarding depth and tilt is essential for correct printing. The four screws were in fact locked with paint.

Anyhow, a little bit more testing and the printer will go back in the 46.