the Papertrail – Page 39

Result from Last Weekend’s Casting Run

Posted on 2014/02/15 by kpmartin Posted in Composition Casting, Kevin, Monotype Composition Caster — No Comments ↓

Despite all the difficulties I encountered in last weekend’s attempt to do some composition casting, I still ended up with some type cast, which I proofed on my Challenge MA15 and annotated:

From this it looks like my matcase arrangement isn’t quite what the ribbon expects. In particular there seem to be some characters in positions where the ribbon expects to find low quads. There are also still two re-keyed lines where the original erroneous lines (in this case missing their indent) were not killed. I will splice these two lines out of the ribbon. One lowercase ‘g’ floated into the wrong line because the galley width was set generously to allow for varying line length. There are some other errors that may be due to incorrect compressed air pressure causing the wrong air pins to rise. The parentheses appear to be interchanged in this case as well.

The matrices themselves ended up with a lot of type metal pressed into them. I may be getting a lot of leakage in the seal between the mat and the top of the mould and some of the flash is adhering to the mats.

This weekend I’ll be trying again, and I hope it won’t take all weekend this time!

A Manual Punch for Monotype Ribbons

Posted on 2014/02/14 by kpmartin Posted in Composition Casting, Equipment Acquisition, Repair, and Maintenance, Kevin, Monotype Composition Caster — No Comments ↓

In the process of patching together the only ribbon I have for my Monotype, some of the holes have been blocked and needed to be re-punched. Furthermore, repairing the edges of the ribbon requires re-punching all the tractor holes. Finally, modifying a ribbon for a new set size can be done by altering the punches that set the justification wedges.

To do these jobs I made myself a small punch out of steel. It is just a short piece of steel rod with a hole drilled down the middle and the end tapered to form a cutting edge. I started drilling the hole with a #47 drill since this seemed to be the best compromise between the three different hole sizes encountered on a ribbon, but that drill broke. After removing the shattered pieces of the drill bit, I used the next size up (#46) to deepen the hole a bit, then drilled from the back end with a larger drill that was less likely to break. I tapered the end finishing off the job using a file.

At first I was just using this held in my fingers but that got tiring pretty quickly, so I found a way to fit it to a handle. Using a bit of paper I jammed it into a socket which in turn fits onto a screwdriver handle.

Punching holes is a simple matter of pressing this cutter down with the ribbon sitting on a cutting mat. The chaff pushes up through the central hole and comes out the back of the cutter, so occasionally I have to remove it from the handle to clear it out.

This is not hardened steel, so I expect it to dull quickly, but sharpening it is easily done on the lathe.

Monotype Display Mat Storage

Posted on 2014/02/13 by kpmartin Posted in Kevin, Type Casting — 2 Comments ↓

The question came up recently on the Typecasting mailing list as to the best way of storing American-style display mats. These originally came in boxes with a slotted wood insert and a covering made of heavy cardboard covered with faux-leather cloth. The cloth provided hinges for a flip-over cover which was held closed by a pair of snap fasteners.

With age the cloth and paste have deteriorated and most of these boxes are crumbling, although one occasionally finds a few in good condition. Besides disintegrating with age, these boxes also occupy a lot of space, as each font of mats 3.5 ×8×22cm (about 1½×3¼×9 inches).

The storage system I use is pretty much the same as the one used by Rich Hopkins. Each set of 5 sizes in a single face is stored in one polyethylene box with a hinged lid. This particular box, a Flambeau V501 with home-made partitions, is pretty much the ideal size, as long as the partitions are not too thick. The box outside dimensions are 25.5×10.8×3.8cm (10×4¼×1½ inches), so stored mats only use about one third the volume (assuming you have most of the sizes of most of the faces).

At the time I bought them (early 2009) I paid $3.82 each for 48 of them. With shipping and currency conversion they ended up costing me CAD6.40 each—the Canadian dollar was really in the dumps back then. Now their web site lists them at $4.04 each in unit quantities. They don’t mention any discount for full cases but it probably wouldn’t hurt to ask…

I used sheet aluminum (some 0.025″ and some 0.032″) to make the partitions, cut to size using a shear and notched using a slitting saw. This notching was a tedious process and although the accurate slot widths look pretty they aren’t really very useful. I could have spent a tenth the time just using my bandsaw to cut the slots.

By the way, the double slots at the bottom of the five long piece are a cutting mistake.

Rich used reglets and thin leads for his partitions, cutting the slots on his Hammond saw. I believe he also had a different arrangement of the horizontal partitions.

Assembling this grid is something that would also have gone faster with wider slots. Once the box is full of mats the extra slop would not show anyway.

The tricky part at this point is picking up the assembly without letting any of the pieces drop out.

I tried assembling them in place in the box but that was harder than assembling them outside and lifting the assembled dividers.

I picked this partition layout partly so that there would be horizontal dividers near either end of the long vertical dividers to give them lateral support.

Once the grid of partitions is placed in the box it looks like this.

Because the width is such a tight fit the rightmost vertical strip is actually interrupted to span over the inset area around the cover latch.

Because the leads Rich used were thinner than the aluminum I used he was able to have five full-height vertical dividers.

Once the box is filled it looks like this. A full box of brass mats weighs a little over 4kg (a little under 9 pounds). Naturally, boxes containing aluminum mats or missing sizes will weigh less.

This was one of the boxes I filled early on when I was ambitious enough to write the sizes and line standards inside the cover.

There is also a bit of room along the right side of the box for a few more mats or other stuff.

From top to bottom the compartments contain:

Line standard and/or reference sample cap H
Miscellaneous non-letters
Standard points (plus & and $)
Figures (without $)
Uppercase alphabet
Lowercase alphabet
Miscellaneous letters (ligatures and alternate forms)

There is also room on the inside of the cover for other notes about the face as needed.

I find a couple of minor disadvantages in this storage system:

One is that picking out a particular mat, especially an alphabetic one, requires a lot of counting or good guesstimation. I am strongly tempted to use my mill to engrave the letter on the top edge of each mat.

Another is that I think I made the dividers a bit tall, making it harder than it should be to lift out a mat.

As well, the dividers are loose in the box and if they work up it makes pulling a mat even harder. With a full box of brass mats the dividers can work up quite easily as the box flexes in handling under the weight of the mats.

If I were to make up more of these (and it looks like I’ll have to soon, since I’m out of boxes but still have mats to store) I would make the dividers narrower, and somehow arrange that they bit into the box sides (perhaps heat them so they melt into the plastic a bit?). I would also forego the nice accurate slots and just use my bandsaw to cut them.

The boxes can be stored on shelving or a galley cabinet (although only every second slot can be used because of their height). I happen to have a chest of small drawers where each drawer has room for one of these boxes and several matcases should I be so lucky as to find composition mats for the same faces I have in display sizes. The drawers are unfortunately not large enough to hold two of these boxes so I’m not sure what I will do for faces that have many alternates (e.g. a large set of swash caps) or come in other display sizes (such as 12 point).

Composition Casting Followup: Type Carrier Repair

Posted on 2014/02/12 by kpmartin Posted in Composition Casting, Equipment Acquisition, Repair, and Maintenance, Kevin, Monotype Composition Caster — No Comments ↓

While trying to do some composition casting last weekend I found that an internal part of my type carrier was broken, so I had to give this part a quick servicing.

There aren’t actually that many internal parts to deal with, but they go together in a non-obvious manner and if you were not paying careful attention during disassembly you’ll spend forever putting the carrier back together again.

So here is a step-by-step disassembly of the type clamp and type support spring.

This shows the type carrier with the back facing up and the top towards the camera. The linkage rods are out of view to the left and were not involved in this procedure.

The first part to remove is the cover, officially called the Type Clamp Shoe. It is held on by three small screws, and has a tang which compresses a spring located under its left end. As you remove the cover be careful to allow the spring to extend in a controlled manner so you don’t lose it. This cover is quite a close fit in its recess so you may have to use a thin knife to lift it out. Start lifting at the right-hand end.

With the shoe off, most of the internal parts are at least partly visible. The type clamp is held closed by its spring a26B2 which in turn was compressed by the tang at the left end of the shoe. The Type Support Spring runs mostly under the Type Clamp but there is a small protrusion on the Type Clamp which is behind the Type Support Spring. This protrusion is what the lever presses against to open the clamp.

To remove the Type Clamp, use your left hand to gently hold the Type Support Spring and its associated parts in place while you use your right hand to lift out the Type Clamp. The support spring will start to come up with the clamp, but once the clamp is completely out of its groove it can be pivoted up and twisted to release it from the type support spring. The Type Clamp Spring and its guide rod should be removed if they did not come out with the clamp.

The Type Support Spring and its Bar Yoke are tenuously attached to each other but it should be possible to remove them as a single unit by just lifting them out.

These parts are only held together by a small contact area. If this spot is worn and no longer has nice sharp corners, the pieces will tend to fall apart and, if you are not careful, may shoot across the room. The Type Support Spring is moved back and forth by the lug on the lever engaging in the spot as marked by the dashed arrow.

The Type Support Spring comes apart into the parts shown above. When assembled, the left end of f31B1 snags on the boss on c31B4 and is held against this by pressure from the spring. In use, if something is blocking the support spring from advancing towards the end of the type carrier, the spring compresses and only c31B4 moves.

This shows the two damaged parts in my type carrier, with new (or perhaps like-new) replacements above them.

The prongs on the type clamp are splayed outwards and (although it does not show in the photo) also bent back.

The end of the type support spring is still bent out of shape, despite my attempts to straighten it, and is also missing its tip.

After cleaning all the parts, I reassembled the type carrier with the new type support spring, but I was unable to get the new type clamp to move smoothly so I bent the prongs on the old one back into shape as best I could and re-installed it.

I have two or three other type carriers in my spares so I may try mixing and matching type clamps to see how their fit varies. The parts manual does not contain anything implying that these would need to be specially fitted.

Once I reinstalled the repaired type carrier in my caster all the type started arriving in the type channel oriented correctly—no more sideways spaces! Unfortunately I still don’t know what actually happened to damage the support spring in the first place, and I only have a few more spares.

Composition Casting Followup: Nozzle Problems

Posted on 2014/02/10 by kpmartin Posted in Composition Casting, Kevin, Monotype Composition Caster — No Comments ↓

During this weekend’s attempts at composition casting I had problems with type metal flow, both flowing where I don’t want it, and not flowing where I do want it.

I had many problems with nozzle freeze. On each casting cycle, the nozzle, which is the outlet of the metal pump, rises to seal against the opening on the underside of the mould, the pump stroke occurs, and the nozzle drops down again. The nozzle is heated by conduction from the molten metal in the pot, and also by the molten metal that pumps through it. It is cooled somewhat by radiation and air convection, but primarily by its periodic contact with the mould. The nozzle movement is adjusted to minimize the time it spends seated in the mould while still sealing against any pump pressure that might exist.

A nozzle freeze occurs when the metal in the nozzle solidifies before the mould is full and fails to melt again before the next casting cycle. At that point, there is no metal flow to heat the nozzle and the temperature drops quite a bit. The immediate cure is to turn off the pump so the nozzle can thaw again by heat conduction from the metal in the pot. Needless to say, at this point the cast line has lost some types.

Things that make nozzle freeze more likely are:

Maladjustment of the seating time keeping the nozzle against the mould longer than it needs to
Maladjustment of the pump stroke timing delaying the initial flow of metal
Insufficiently hot metal in the pot
Mould too cold
Casting speed too slow
Casting too many small (narrow) types

Converse problems which can happen include leakage around the nozzle when the pump stroke occurs while the nozzle is not properly seated, deformations of the type body if the metal in the mould cavity had not solidified quickly enough, or mould damage or incorrect type dimensions caused by the mould overheating.

Leakage around the nozzle is caused by:

Maladjustment of the seating time not keeping the nozzle against the mould long enough
Maladjustment of the pump stroke timing making the initial flow of metal too early in the cycle

Deformed type and signs of mould overheating are caused by:

Too high a temperature of metal in the pot
Mould too hot
Casting speed too high
Casting too many wide types (Em quads)

As you can see there is a balancing act between these two limits. Controlling mould temperature in particular requires ongoing monitoring of the cooling water, plus remembering to turn it on and off when the casting is started and stopped. At least the pot temperature and casting speed are regulated…

One thing Monotype did to help with freezing was to introduce nozzles made from stainless steel, which has only about half the thermal conductivity of regular steel. Although this means the nozzle gets less heat from the pot, it also means it loses less heat to the mould. Unfortunately I don’t have one of these, although I have the shop drawings and could make one if I felt I really needed it.

During my casting efforts on Saturday it was clear that the nozzle and pump timing were off because I was getting huge deposits of hardened type metal under the table around the nozzle. The photo shows one of these lumps once I had pried it out. Near the center top of this lump you can sort of see the shape of the cone hole on the underside of the table. At the point I removed this the lump was bulky enough that it hung on to the nozzle as I cranked the pot down to clean up.

On Sunday I got the nozzle and pump timing adjusted so these nozzle leaks did not occur, but then I was confronted with constant nozzle freezes. I eventually got the caster to run without freezes by raising the pot temperature to 690°F (which I think it pretty high for Linotype alloy), running it at 120RPM, and keeping the cooling water off completely.

Although I managed to finish the casting (only about 12 lines), I had several signs that the mould was running very hot. One was that, after ending the casting run I ran some cooling water and the water leaving the mould circuit was steaming hot.

Another is that the air vent added to the mould by Hartzell was filling completely with metal and in fact spurting out a bit of metal.

I mentioned this vent while describing the mould refurbishing, and this photo shows the tomahawk-shaped jets that are formed. The red arrows point to the area where molten metal was spurting out. Normally the metal should harden partway along its flow through this channel.

There is also quite a bit of flash on these, indicating that there is some excess clearance in this part of the mould (where the bottom plates of the crossblock press against the squaring block).

When running the caster I kept thinking I was seeing things, like a little shiny drop squirting from the side of the mould, but could not see it when I looked directly at the area. But when I was done I found that all the squirts were landing on part of the pump supports, as indicated by the red arrow in this photo.

So far, before another casting run, my action items include:

Review recommended metal temperature and casting speed for this alloy and body size
Check mould crossblock for contamination during reassembly

It Speaks! Well, mumbles, anyway…

Posted on 2014/02/09 by kpmartin Posted in Composition Casting, Kevin, Monotype Composition Caster — No Comments ↓

I spent the weekend trying to do some composition casting on my Monotype caster, using the ribbon I had keypunched while I was at Mono U 8 last summer. By Sunday evening I had something I could take a proof of, but there is still plenty to do. I knew I would not have a good forme of type because I was casting the type to a different set size that the ribbon was punched for (I did not have the correct wedge), which guarantees that the line lengths will be all wrong.

Through Saturday afternoon I had the caster reading the ribbon and casting short bits of the text, but I had plenty of problems.

One is that I was getting large amounts of type metal collecting around the nozzle under the caster table. I thought I had adjusted the nozzle seating timing properly but this persisted, forcing me to stop the machine every dozen lines or so, lower the pot, and pry out the lump of hardened metal.

I also had problems with the transfer of the type from the mould to the type channel. While casting low quads, things seemed to be running fine for a dozen casts or so, then I would hear a clunk and a badly damaged quad would appear in the type channel. The type appeared to have been smashed by the type clamp, or perhaps by the type pusher while pushing it into the type channel. Ofter the foot and/or head would be sheared off, and often this would jam the type channel, forcing me to stop casting and clear the type channel.

The type support (which is a spring arm that catches the type as the mould blade ejects it) appeared a bit distorted and seemed to be leaving a mark on the end of the mould blade as well. The problem was more frequent at higher caster speeds. One thing I tried was to disable the type support, and this seemed to make the problem go away but I could not really explain why.

As the afternoon wore on, the casting seemed to start to work better, probably as the machine warmed up overall. Things seemed to be going not too bad, except that narrow spaces were turned sideways in the type channel. A closer look at things revealed that they were sideways in the type clamp as well. As it turns out, I still had the type support disabled, and this allowed narrow types to turn sideways before the type clamp could grab them. Turning the type support on gave back the properly-oriented narrow types.

By this point, though, my ribbon had become damaged enough to jam in the paper tower. Actually, it did a neat trick: it managed to come off the sprocket holes and shift sideways by about 1/8″ but still run straight and advance properly. Because all the punch holes were off by one position this made for some pretty random casting!

By then it was time to call it a day.

Sunday afternoon started with repairing the damaged ribbon. It turns out that the areas that I had repaired using PVA glue were quite brittle and prone to cracking. This time I used Scotch Tape to repair the tractor holes. Where there were few punch holes near the edge of the ribbon I applied the tape half over the edge of the ribbon and folded it over the edge to tape both sides with one piece of tape. If there were many punch holes near the edge I would apply one strip of tape on one side, just clearing the punch holes and hanging over the edge of the ribbon, then apply another piece of tape similarly on the other face of the ribbon. I would then trim the excess tape using a rolling cutter. In either case I would use a small home-made hole punch to re-punch the tractor holes and also any punch holes I might have blocked.

Back at the caster I repeated the nozzle seating adjustment, and also re-checked the nuts on the underside of the swing frame that determine exactly when, in the stroke of the pump cam, the pump actually starts to pump metal.

Once that was done I was back to casting quads. And back to the nozzle freezing after casting only a few quads. Eventually by speeding the caster up to 120RPM, running the pot at 690°F, and running no cooling water, I got the machine to cast quads apparently indefinitely.

So I started the ribbon up again. It seemed to be casting all right, but I was once again getting turned narrow spaces in the type channel. Using a flashlight I had a look at the type carrier action, and saw that the type support was badly bent, preventing it from doing its job. I removed the matcase and bridge so I could verify that the type support was bent, and it was. I removed the type carrier and replaced the type support with a spare I have. I also wanted to replace the type clamp (which was also bent) but the replacement part did not move smoothly, so instead I did as best I could to bend the type clamp back into shape and replaced it in the type carrier.

While the bridge was off I also checked the crossblock on the mould and since it seemed a bit loose, I tightened it up a bit.

I reinstalled the type carrier on the caster, along with the bridge and matcase and gave things a try. I was rewarded with an unusual squirt of type metal. As it turns out, while diagnosing the type carrier problem I had removed the coupling block that connects the type carrier to the mould cross block. When I tried casting the front face of the mould cavity was completely open, hence the squirt. The good news is that the squirt was confined to a small area to clean up. The bad news was that it was the opening that the mould crossblock slides in.

Once that was cleaned up I got back to casting again. While I was fixing the type carrier, the pot was swung out so the mould and caster table had cooled down, and I was back to having nozzle freezes. I just wanted to bulldoze my way through by then so I just kept an eye on things; when the nozzle froze I would stop the ribbon, turn off the pump, and wait a moment. Then I would turn on the pump again and turn on the ribbon feed. Generally casting would resume and I would get the line with a few types missing.

At one point, though, the caster just stopped. I had my hearing protectors on, and the compressor was running, so it took me a while to figure out that the motor was stopped. The overcurrent sensor in the magnetic starter had tripped. The motor itself did not seem hot, so I think I have to adjust the current limit setting.

I finally managed to fight my way through one run of the ribbon. The type was badly pied because the line lengths were all wrong, but I had cast the ribbon and it was time for dinner.

I cast it all. Waddaya mean you want the type in neat lines?

After dinner, I repeated the exercise with better results. I turned off the wrong-line-length detection and cast the ribbon with only one incident. The motor overcurrent tripped again on me, but this time I just waited for it to reset and restarted the caster. After each line was delivered do the galley I used quads to fill it in a bit.

Happy now?

Since this post is already TL;DR I’ll follow up in the next couple of posts.

Monotype Mould Signalling Lever

Posted on 2014/02/06 by kpmartin Posted in Equipment Acquisition, Repair, and Maintenance, Kevin, Monotype Composition Caster — No Comments ↓

The Monotype caster has a small lever which is used to control the opening of the upper mould blade to produce low spaces. This lever is actuated by an arm that descends from the bridge, which in turn is controlled by the presence of a mat with a shallow cone hole.

An alternative version of this lever is straight, and is used with an English bridge and American moulds.

I had been trying for ages to get this lever off my caster (as evidenced by the mangled screw head on its pivot) but with no success.

As I found out on last summer from looking at Rich Hopkins’ casters at Mono U 8 this pivot pin has no head. The lever should just lift off it!

So a few weeks ago when I had a bit of time to spare, I tried once again to remove it. With its spring, spring post, and the mould removed the lever should be clear to lift off. The damage to the top of the pin from by previous removal attempts might cause a bit of trouble, though.

I sprayed some solvent onto the pivot pin, and gradually managed to work it up, first getting a putty knife under it, then a small screwdriver, followed by larger ones. Finally the arm popped off, and it appears that it was just dirt and hardened oil that was holding it on. Once I cleaned the lever and post and re-oiled things it slipped on and off easily, although it is necessary to turn it to just the right position partway up to clear other parts. It also turns easier now.

While I was working on this I also closed up the loops at the ends of the spring so it would not accidentally fall off and end up on the floor. This happened to me once here and also happened to us several times at Mono U.

The pivot pin itself is still seized in the table, but that should not be a moving part anyway.

This puts me one step closer to using my English bridge should I choose to do so.

Cleaning the “Scissors” on a Monotype Display Mould

Posted on 2014/02/02 by kpmartin Posted in Equipment Acquisition, Repair, and Maintenance, Kevin, Monotype Composition Caster — 2 Comments ↓

While waiting for other things to resolve themselves, I set out to clean the display mould that I has last used on my Monotype caster. This particular mould is an English-style display mould, which uses replaceable inserts to change body size.

Both these and the American-style display moulds use a pair of levers which vaguely resemble a pair of scissors to control the upper mould blade. In normal usage, a spring box is positioned between the “handles” of the scissors to push them apart, which forces the upper mould blade to open in unison with the lower blade, for casting normal type. For casting low quads, the spring box is swung around to press against the mould oiler fitting, thus forcing the upper blade closed at all times.

The spring box on this mould had become seized, with the plunger stuck in and no spring action, so I disassembled it to clean and lube it. A rivet holds this together, so I had to carefully file the head and peened end so the rivet could be driven out.

The rivet and arm were now out but the plunger was still stuck. Fortunately there was just enough of the plunger showing through the arm slots that I could grip it gently with a pair of wire end-cutters and work it out. The spring then came out as well, with a cake of oily rust covering about two of its turns.

The plunger, spring, home-made rivet, and tube, all shown below one of the arms.

I cleaned the parts first with solvent, then with a soak in Evapo-Rust. I also felt that it should be possible to oil these properly so I added an oil hole to the tube. Either this is very hard steel or I had the misfortune to try the two dullest drill bits in my shop, but I was unable to drill a hole. Instead I used an abrasive cutting disk on my Dremel to cut a groove that penetrated to the inside of the tube.

I made a replacement rivet on my lathe, reassembled everything, and finished putting the cleaned mould together. The photo of the mould, above, is actually an “after” photo where the oil hole I added can be seen.

The spring box and lever arm ends viewed from the underside of the mould. This shows the peened end of the rivet.

Unclogging Cooling Passages in a Monotype Mould

Posted on 2014/02/01 by kpmartin Posted in Equipment Acquisition, Repair, and Maintenance, Kevin, Monotype Composition Caster, Other people — No Comments ↓

After installing my refurbished 10-point mould on my caster I tested the cooling water flow and found that the flow through the mould itself (rather than just the cooling passages in the table) was inadequate.

I know from when I had the mould in pieces that the water passages had been plugged completely with rust. I managed to clear them at least somewhat using a piece of stiff wire—the end left by the wire cutters proved to be good for drilling through the rust. However, not all the passages in the squaring plate could be cleared this way since they were not straight, and the plugs sealing off each straight section could not be removed.

It turns out there is a tool for clearing these water passages by forcing fluid through them with much more pressure that the cooling piping supplies. This tool is bolted to the underside of the mould and connects the two coolant ports on the mould to the two open brass tubes on the tool.

The piston (at the center of the picture) is a close fit in the brass tubes and can be used to force fluid through the cooling passages of the mould.

This particular version seems to have been mass-produced, as I know Rich Hopkins has several of them (I got mine from him). However, I also have a much cruder one which appears to be someone’s attempt to make their own.

The second photo shows the tool mounted on the mould. The mould itself is upside down on a piece of triple-wall corrugated cardboard to protect its top surface.

The paper towels in the photo show some of the dirt and rust I extracted.

The first fluid I used was some Evapo-Rust, which would to some extent dissolve the rust and loosen more of it. This seemed to flow fairly well, but it was still clearly loosening some rust.

After draining the Evapo-Rust I switched to heavy lubricating oil, which could generate more internal drag to break away more rust.

After a couple of passes with oil, I did two more passes with odourless paint thinner to clear out the rust-laden oil.

I re-installed the mould on the caster and tested the water flow again. I was still having trouble getting flow through the mould. Thinking the piping might be blocked somewhere, I removed one of the plug screws from the water fitting on the side of the table. The screw I removed was the one closest to the front of the machine, which lines up with the outlet of the mould cooling loop. A couple of seconds after removing this screw, water started to flow from its hole, so I put the screw back in place.

I now had water flowing through the mould. Perhaps the narrow oily water passages were sufficiently hydrophobic to prevent the water flow from starting. Essentially the water was being held back by its own surface tension.

So I think I have everything ready to go now. Except that the handle has fallen off the ball valve I installed on the water line…

Tagged with: Rich Hopkins

A Mess Delays Work

Posted on 2014/01/29 by kpmartin Posted in Equipment Acquisition, Repair, and Maintenance, Kevin — No Comments ↓

The snow plow that I use to clear the driveway here stopped working. The winch which raises the blade stopped running, and since it seemed to be related to the cold weather (and heating the unit appeared to fix it temporarily) I figured there must be ice in the gearbox or motor housing. Opening up the gear box revealed nothing suspect, but even with the gears removed I had trouble turning the output shaft of the motor.

I reassembled the gearbox, then took the motor casing apart. This is a permanent magnet motor, and at least one of the magnets had come loose and was clinging to the armature. Every time the motor turned some of the face of this magnet would get ground off. The banging around each time the motor reversed also chipped and cracked the other magnets, so the motor was filled with black dust and crumbs in a whole range of sizes. The real problem, though, was that this was magnetic dust (and probably a good abrasive), and I was using the same workbench area I was using to refurbish a Monotype mould. I was certainly not expecting this sort of mess to come out of this motor.

You can see a crossblock and other mould parts near the back edge of the paper table cover, and some of the magnets coated with a fur of dust just in front of the motor casing.

I spent part of this evening carefully picking up each tool, wiping off most of the dust, using adhesive tape to pull off the rest, and putting the cleaned tool aside. I did the same for the mould parts. I bagged all the parts of the motor in Ziploc bags and put them aside. The paper table cover was carefully folded over with all the dirty towels and tape inside and tossed in the trash. I wiped down the tabletop a couple of times and replaced the paper table cover.

Now, with a clean work area, I went over the mould parts again for any remnants of the dust. The motor can perhaps be repaired by gluing the magnets back in, but that is a summer job, when I can work outside and not have to worry about the dust. For now I am replacing the entire winch on the plow.