The first parts of my 10-point mould to be cleaned and reassembled are those that form the mould blade. The flat end of this blade forms one side of the cast type, and the caster adjusts the width of the type by the position of this blade. A separate top section of the blade can remain closed to cast a low space rather than the character formed on the mat positioned over the mould. The blade also ejects the finished type from the mould cavity.

The main parts of the blade are the Upper Mould Blade, the Lower Mould Blade, and the Mould Blade Carrier. Below them are a couple of pivot pins, a spring, and the Mould Blade Carrier Latch. On the right is the lever that selects whether the upper blade opens for normal casting or remains closed for a low space.

The caster moves the lower mould blade using the square hole near its right end. The carrier latch normally makes the blade carrier move in unison with the lower blade, and the upper blade always moves with the carrier. Thus the upper and lower blades normally move together.

For low space casting, the lever releases the carrier latch and also pushes the carrier to the closed position, so the lower blade still moves as selected by the caster but the upper blade remains closed.

I suspect that my mould might be made from parts from several other moulds. In particular, the upper blade is wider (by about 0.001″) than the lower blade and also sticks out a bit (I didn’t measure this but it was enough to snag my fingernail). This would imply to me that the upper blade is a newer replacement. The two sides of the mould, between which the blade slides, also show a wear pattern consistent with the upper blade being wider. I’ll have to keep this in mind if there are problems with the cast type. This could also be compensation for differences in thermal expansion when the mould gets hot in use, although the width difference is close to 1% which is quite a bit more than I would expect for any expansion.

I have reassembled the blade, and it is shown on the left with the upper blade projecting beyond the lower blade, as if a very wide low space were to be cast. The lever cannot be installed until the blade is properly set into the mould.

I think this is the last thing to do before trying to cast the ribbon on my Monotype: Cleaning the old 10 point composition mould so it works at top performance.

This particular mould is a 10 point serial number 3E1046H. It is essentially the composition mould design used by Lanston Monotype, but as indicated by the nameplate and the ‘H’ on the serial number it has been reconditioned by Hartzell Machine Works, who for many years repaired Monotype moulds. One visible change Hartzell made was to add an air venting passage to the jet so that at least some of the air could escape the mould cavity rather than having to be compressed into trapped bubbles. This means this mould should eject the tomahawk-shaped jets characteristic of this modification.

The exploded diagram for this mould is shown on page 38 of Plate Book, Monotype Typesetting Machine, the Composition Type-caster. The only difference I could find from what is shown in the manual is that this mould does not have the left mould blade guide 18MC3E1 nor its screw, nor even the hole in the top cover to clear the screw head (so it is not just a case of a missing part). Furthermore, the mould blade latch spring on this mould is a single piece with the end loops formed by bending the spring wire, while the parts manual shows a spring with separate end eyes that the last coil of the spring threads into.

On disassembly I found that all of the cooling water passages were plugged with rust. I would have liked to remove the four plug screws so I would have full access to all the passages to clean them out but these plugs refused to budge, even using an impact screwdriver on them. Although I could drill them out, clean out the scraps, and make replacements, I will first try other means to clean these passages. Perversely, the two plugs in oil passages, which seem perfectly clear, came out easily.

It is not necessary (nor even advisable) to disassemble the mould to this extent for normal cleaning, but I wanted it to be as factory-fresh as it could be. Besides, if I destroy it, Don Black has several other moulds of the same size that I could use. YOLO, as they say.

A 10 point Lanston 3E composition mould, freshly disassembled, dirt and all

As annotated in the photo, a few parts were left to be disassembled when the photo was taken. I have now removed items C and D and two of the plug screws B (the ones in oil ports). The remaining parts are too hard to remove or might be too hard to reinstall.

I was planning on casting the Monotype ribbon I brought home from Monotype University 8 last August, but I just noticed today that the ribbon is punched for 9½-set and I don’t have an S5 wedge for this size. All I have is the wedge for 10-set (and fractions larger).

I can use the 10-set wedge with this ribbon, but the lines will come out with the justification all wrong because the variable space width is specified in the ribbon punches based on the set size being 9½ points. So I will have to baby-sit the machine, with the galley set overly wide (to accommodate the lines that will be about 5% longer than planned), the wrong-line-length trip disabled, and dropping in leads between each line.

There are only about 8 lines of actual text (not counting warm-up lines and such) so this would not be too burdensome.

I have also figured out how I can manually read the justification punches in the ribbon, convert the value to inches, scale it by 20/19 (10/9½), and convert back to punch codes. Then I can paste over the existing justification punches and manually punch new ones, thus giving a ribbon made for 10-set and a line 20/19 times longer than the original line length. Once again this is only feasible because there are so few lines. I had originally thought that to correct the justification punches I would have to count all the unit widths of all the characters in each line. The latter method might be a bit more accurate since it would not suffer from double rounding during the calculations, but that isn’t really worth the trouble.

So for now I’m continuing to plod on, with the next job being to disassemble and clean my 10-point composition mould.

After deciding to replace some of the valves that control the cooling water flow on my caster, I made a visit to a few hardware stores. I came home with a ball valve and a needle valve but as they did not have the correct pipe connections I also bought two adapters.

The valves I purchased. Main row (L-R) are the original supply flare fitting, the ball valve, a ⅜″ compression nut, the body of the needle value, and another ⅜″ compression nut. Above is the valve needle and cap.

The ball valve has ¼″ FPT (Female Pipe Thread) connections, which are fine. The flare fitting that connects to the supply line will attach directly to this valve.

The needle valve was unfortunately only available with ⅜″ compression fittings. In order to fit this to the ball valve and to the line that carries the water to the table and mould, I also bought two adapters from ¼″ MPT (Male Pipe Thread) to ⅜″ compression. I would also have to dig through my supplies for a couple of short lengths of ⅜″ soft copper tubing.

It turned out there were three downsides to this approach. One is that the combination of all these adapters and connections would make the valve unit too long to fit in the original valves’ location. Another is that all these connections are potential points of leakage. Finally, closer measurement revealed that the fitting to on the line to the table does not attach onto ¼″ MPT as the thread pitch is wrong.

The compression ends on the needle valve could not be directly modified to another thread type because there was not enough metal thickness to cut different threads. What I did instead was to modify one of the compression adapters I had bought to slip into one of the compression sockets and to make another adapter from scratch for the exit fitting that also slipped into the compression fitting, and solder both these directly to the needle valve.

Cutting these to fit into the compression fitting was fairly easy, and the solder would fill in plenty of sloppy measurement. The outlet fitting turned out to need 19 threads per inch on an odd diameter. To do this on my lathe I had to replace a 24-tooth gear in the carriage drive with a 60-tooth one, and select 48 threads per inch on the gear box (which had no 19TPI setting). This would make the lathe cut at 19.2 threads per inch (48×24/60) which is close enough. I did test fittings of the matching nut to determine when the threads had the correct diameter.

The needle valve and custom adapters, ready to solder in. The one on the left is the oddball 19TPI straight thread, and on the right is the 1/4″ MPT.

After soldering the adapters onto the needle value, I loosely assembled the two valves and verified that the assembly is about the same length as the original valve pair.

I assembled these using Teflon tape on the pipe thread joints and thread sealing compound where the cone ends screw onto the ends of the copper tube. With everything installed on the caster, the water valves look like this:

The repaired outlet valve is at the upper left and the two new inlet controls on the right. There is no longer any chance of confusing the flow control and the water shutoff. A trial run indicates excellent flow rate and good control using the needle valve.

The next thing to check on my caster was that the cooling system could deliver sufficient water to cool the mould for composition casting. I have a closed-loop system which uses a small fountain pump to force the water up into the cooling system, and cools the drain water in an open coil of copper tubing before emptying it back into the tank.

The fountain pump does not supply much pressure, so the passages in the system must be reasonably clear.

With no mould installed, I turned on the pump and opened all the valves. No water flowed out of the drain pipe. I disconnected the drain fitting on the right side of the caster table near the mould, and no water was coming out there either. Actually, after a few minutes, and small trickle started to appear but nowhere near enough to provide adequate cooling.

I disconnected the inlet to the table cooling port to check if the passages in the table were clogged, but the flow there was just as bad. Finally I disconnected the inlet to the two inflow valves, and got a gusher there. Obviously the valves were barely opening despite having their knobs screwed all the way out.

After shutting off the pump I removed these two valves and their associated piping, disassembled everything and cleaned it. I also removed the cover from the outflow valve whose purpose is to generate controlled back pressure to force cooling water to flow through the mould itself rather than just the caster table.

The three valves and associated piping, in pieces, on the right, and some spares on the left.

The valves are of a type called a weir diaphragm valve. The two valve bodies are at the bottom center of the picture. To their right is the water line which runs from the valves to the table inlet fitting. Above these are the three sets of (top to bottom) knobs with taper pin, stem, lock nut, top cover with screws, piston, and diaphragm. Each piston is split with an internal hole to grab onto the end of the stem and onto a button on the back of the diaphragm. Once the valve is assembled, this piston is contained in the cap, preventing the two halves from separating.

The upper half of this diagram, on the Spirax Sarco web site, shows how these valves work. When closed the diaphragm is pressed against the weir to cut off flow. When open, the valve stem pulls the diaphragm up to provide high flow.

One advantage of this style of valve is that none of the moving parts are exposed to the controlled fluid (cooling water, in this case). They also provide fairly good modulation of the flow rate. Unfortunately on my caster, the diaphragms, which might be 50 to 90 years old, are very hard and set in their closed shape since the casters were generally mothballed with these valves closed. Furthermore, on two of them the button that the stem pulls on to open the valve is breaking off so the valve cannot supply much flow unless the water supply pressure is sufficient to push the diaphragm open.

Torn button on back of diaphragm

In my spares I have two complete valves and one valve cap assembly. On examining the two spare valves, it is clear that the diaphragm button is broken on one of them as well. I feel it is unlikely that I could find any replacements to buy, and although I could make most of a diaphragm from sheet rubber, it is not clear how to make and securely attach the button.

Given the shortage of good diaphragms, I decided to save them for the outflow valve, and replace the inflow valves with something more modern.

The caster is fitted with two identical valves in series, and I have never seen a written explanation of this; I guess this is something one would have learned at Monotype School back in the day. My assumption is that one is supposed to set one of the valves to control the desired water flow, and turn the other valve either shut or wide open. In this way the water can be turned on and off without losing the flow setting. I have been trying to use them this way myself but I could never remember which valve I was using for which purpose so I was always losing the flow setting anyway.

For the replacement valves I will use a ball valve for the on/off control, and a needle valve for the flow control. Time to wander through the plumbing department at the local hardware store…

I made myself a Winding Spool for my Monotype caster, to take up the ribbon as the machine reads it. The internal mechanism is similar but not identical to the standard part. The main difference is that the part know as the Driving Disc 21G7 is closer to the rear of the machine (the open end of the spool) and also does the duty of the Shaft Spring Abutment 21G11, with the spring being held between the Driving Disc and the front end cap (Flange Bush a21G2). The Driving Disc is held in place on the Shaft by a setscrew, and the Shaft Driving Disc Pin 21G8 is threaded directly into the Driving Disc and held by thread locking compound rather than a locknut.

The parts for my home-made Winding Spool, showing the names and numbers of the closest corresponding standard parts.

Most of the parts were scavenged. The Tube was a piece from the photosensitive drum of an old laser toner cartridge, the Flange Spring was a strip cut off some scrap aluminum siding, and the Flange came from some random piece of black anodized aluminum scrap. The spring was hand wound on my lathe. Everything is held together with #2-56 flat head screws in countersunk holes. Getting the spool to work properly required a bit of fine tuning on the lathe adjusting the thickness of the Rear Plug and Flange Bush so the Shaft had the correct range of longitudinal motion.

The Winding Spool all assembled

The Winding Spool installed on the caster with drive engaged

When the spool is off the caster both ends of the Shaft are flush with the ends of the spool. Once on the caster, the big end of the shaft is pushed by the Winding Spool Spring Box Plunger group X25G, causing the small end to project and engage the hole in the center of the drive disk. If the Button 25G2 is turned so its bumps are not in the notches in its housing, this is all that happens, and the spool can rotate freely. If the button is turned so its bumps are in the housing notches, the Shaft is pushed further, causing the Disc Pin to also project from the end of the spool and engage one of the drive holes on the drive disk. In this manner the Winding Spool Driving Ratchet X23G can turn the spool to apply enough tension to the ribbon to cause it to wind onto the spool.

With this spool on the caster, my patched-up ribbon runs flawlessly from start to finish, although I have yet to try this with the air on to see how much leakage there is over the ribbon patches.

I think I’m finally coming to the home stretch to get this sucker working. All that seems to be left is to clean the mould so it operates smoothly and verify that my closed-loop cooling system still works, and then I’m ready to try casting this ribbon.

The one ribbon I have to test out composition casting on my Monotype was in rather sad shape. It had several kill lines which cause casting problems by allowing the mould to chill too much, and it had also been damaged quite a bit during my attempts to adjust the ribbon feed on my air tower.

I used PVA (white glue) for the repairs, but in retrospect this seems to leave very stiff areas in the ribbon so a glue that sets softer (perhaps starch paste) would have been preferable.

The main job I undertook was to cut out the kill lines and splice the remaining ribbon together.

The kill lines removed from the ribbon. Some have been scavenged for repairing torn tractor holes.

The six splices from removing kill lines.

Most of the splices were lap joints, although in the fifth joint I cut the ribbon wrong and had to butt the two ends together then join them with tissue. The gap in the butt joint was air-sealed using correction tape. Because of the width of the tissue this joint has a particularly long stiff section from the glue.

In the third and sixth joints the killed line had an odd length, so I had to keep the line-kill punch to make the tractor holes come out even.

Several of the punch holes should be cleaned up so they pass air properly, and the roughness from the lap joints may cause excessive air leakage around the air bar. I have already re-adjusted the air bar to raise higher than normal to allow the rough joints to pass without snagging.

I also repaired a couple of tears using tissue, and torn tractor holes using edge strips harvested from the removed kill lines:

There were also a pair of small holes torn, probably caused by the metal supports for the two drag bars that provide slight tension for the ribbon passing over the top of the air tower. For these I tried correction tape (a very thin tape for covering over printing on paper to allow for corrections) applied to both sides so there would be no exposed adhesive. This stuff is so thin I wonder if I should have used it to make all butt joints in the ribbon. Although I can experiment this way on the kill lines, because I used PVA on the good ribbon I can’t take the lap joints apart to turn them into butt joints anyway.

Having found that my patched-up ribbon would not run through my caster’s air tower because of the low clearance under the raised air bar, I tried a different adjustment procedure to maximize the clearance available for ribbons in poor condition.

The Bar Length and Air Valve adjustments are the same as in the normal procedure.

Bar Sleeve Adjustment

This adjustment differs from the normal procedure in that it sets the length of the rod stroke to the longest possible amount which still ensuring that the ribbon stops moving before the air bar starts clamping.

The rod end 4G1 should still be clipped onto the pin 3G1 on the pressure lever. Turn the caster handwheel until the air tower lever is in its downwards stroke and the pawl ring lug has just stopped its counterclockwise motion against its stop screw.

Loosen the Bar Sleeve locknut, and screw both the locknut and sleeve clockwise (down) until the sleeve and its washer are no longer against the underside of the lug on the air tower side cover. Now carefully turn the sleeve counterclockwise (up) until the sleeve and washer just contact the underside of the lug, then give them one more turn. Tighten the locknut.

Verify that the pin on the end of the paper tower lever still has some downward travel before hitting the end of the slot in the lower end 4G3 of the rod by carefully watching it while the handwheel is advanced a few degrees. There should be about 1/32″ travel (from the one turn of the sleeve).

Air Bar Pressure Spring Length Adjustment

This differs from the normal procedure in that the spring length is adjusted to ensure a particular amount of spring compression, leaving the rest of the pressure lever movement for raising the air bar.

With a ribbon loaded in the air tower, rotate the caster handwheel until the pin jaws are closing.

Use a pair of wrenches to loosen the two locknuts 2G7 without loosening the studs 2G4. Turn the adjustment screws 2G6 clockwise by hand until they contact the pressure bar. Turn them back counterclockwise ⅓ turn. Turn the locknuts until they contact the adjustment nuts, then hold the locknuts steady while you turn the adjustment nuts counterclockwise against them to lock them.

Having done the adjustments this way, my lumpy ribbon seems to run through the air tower without jamming, at least when done by turning the ribbon feed wheel by hand.

I only have one punched ribbon to test out the composition casting on my Monotype, and this ribbon is wanting in more than one way.

For one, it was my first (and I hope only) attempt at punching a ribbon on the Monotype keyboard. About a quarter of the ribbon is kill lines (when you make a punching mistake on the keyboard, there is no backspace or delete, so the best you can do is kill the entire line and start over). Although the caster will not cast any type for such lines, it still cycles through the ribbon at the same speed as if it were casting, and while it is doing this the mould is still being chilled by its cooling water supply. As a result, when the end of the killed line is reached and the machine starts casting again, there is a good chance of miscast types or even a nozzle freeze (and nothing casting) until the mould warms up again.

The other problem is that I was using this ribbon while I was testing and adjusting the air tower on my caster, so it has a large collection of torn sprocket holes and other tears as well.

I spent some time in the past few days trying to repair the ribbon. I cut out the kill lines and spliced the cut ends together, repaired tears with tissue, and used some of the cut-out kill lines as a supply of sprocket-hole repair strips.

The end result is a ribbon that is entire, but because of the thickness of the splices and patches, will not run smoothly through the air tower because it is set for minimal lift of the air bar. When the bar is raised, there is only enough clearance beneath it for 2 or 3 thicknesses of paper, and a lap joint is a minimum of two thicknesses, plus any roughness and glue thickness.

To enable this ribbon to be read, I have readjusted my air tower to provide more clearance for rough or damaged ribbons. Details on this procedure in another post.