wefalck

The blank on its arbor was then transfered to the dividing apparatus on the milling machine for engraving the dial. For this a 15° engraving bit was used. in the same set-up the hole for the friction brake of the dial was pre-drilled. Set-up for engraving the dial Engraving the dial The numbers were stamped in a make-shift set-up in a vice. In order to ensure that the number-stamps were applied exactly radially a purpuse-made guide-block was used. Set-up for stamping the dial Finally, the dial was mounted back on the arbor and the burrs from engraving and stamping cleaned up with a couple of light cuts in the lathe. Cleaning up the engraved and stamped dial The two parts were separated on the lathe with a jewelers saw substituting for a parting tool. The dial then was degreased and the engravings laid out in black enamel paint. After the generously applied paint had dried, the dial was cleaned up with very fine wet-and-dry sanding paper. Painting the dial To be continued ...

Thanks, Pat. I was actually surprised myself, that it turned out so well

Per, as it never was, the mill doesn't have a price-tag ... unless you were indeed prepared to pay me at my commercial rates, which means that you would have to trade-in a decent car, may not quite an Aston Martin (but I would gladly exchange it for the mill, BTW) *********************************** For the dial on the y-slide I had a piece of 21 mm diameter brass to hand. This was faced in the 3-jaw-chuck, drilled and reamed for the 5 mm spindle, and then bored out to fit over the spindle bearing-plate. Preparing the blank for the dial The blank was the mounted on an arbor with a 5 mm stem so that I could turn the outside shape. At one end there is the notorious convex knurled ring. For this, a ring of 1.2 mm width and 1 mm height was left standing with edges slightly chamfered. Turning the blank for the dial For the next machining step the knurling tool with the concave knurl was mounted to the cross-slide. The knurling tool was fed slowly into the slowly rotating blank. It catches quite quickly at the edges and the pattern evolves fast. As expected, the processes is both, a cutting as well as a shaping one – the relatively soft being squeezed into the indentations of the knurling wheel. While generously lubricating with WD40 the knurl was fed into the faster rotating blank until the pattern had developed fully. Knurling the dial To be continued ...

What lathe do you have ? It may be worthwhile to invest into collets, if your lathe spindle has a taper for them, or into a collet chuck. This gives a much better and concentric grip on thin material - and is also safer, because you are not bothered by the jaws and can work closer to the chuck, which eliminates chatter. Of course, the tailstock needs to be checked for alignment. Why do you use a file to make the groove ? A tool in the slide rest would be safer and more efficient - or are you using a wood lathe ?

Thanks Pat and I hope you have enough Kleenex around ***************************************************************************** After some disruptions due to travelling (spent inter alia a couple of days in Pisa for work ) I tackled a job I had never done before: Digression: making a concave knurling wheel Today, concave knurls to produce the convex knurling seen on many older high-end precision machines are obtainable only at prohibitive costs. Therefore, I embarked on making my own knurl, encouraged by a few examples on the Internet. Knurling wheels normally have to have a certain diameter in order to prevent their bore from being distorted under the stress of the knurling process. I choose a blank of only 10 mm diameter for a bore of 6 mm in order to reduce the mass to be heated, when attempting to harden the knurl with my rather limited heating capabilities. I also had a cut-off from a Schaublin collet-blank available, which I assumed would harden nicely. Hobbing the knurl on the milling machine The proposed process of creating the knurling wheel employs an ordinary threading tap as an improvised hob. This, stricly speaking, would result in a 'rope' knurl, but the helical angle of a, say, 0.4 mm pitch tap is barely perceptible. The easiest way to hold the blank for cutting seemed to hold it in the knurling-holder for the watchmakers lathe that I made a few years ago. This means, however, that the process could not be done on the lathe, because it would have been not so easy to mount the holder on its side. Cutting the knurl on the lathe would have been better, as the end of the tap could have been supported in the tailstock in order to eliminate flexing. Unfortunaly, the DIXI horizontal mill does not have an overarm, which then would make it the ideal machine for the job. So the job was done on the vertical mill. Hobbing process in detail The blank was drilled and reamed for the arbor of the knurling tool holder. Some polishing ensured that it spun freely. A M2 tap was chucked in a collet as short as possible and offered to the blank with its uppermost end in order to keep flexing to a minimum. Initially, the mill was run at slow speed and with a small feed. After each incremental feed, the blank was allowed to make several revolutions until no chips were produced anymore. Once the pattern was created, the mill was run at a somewhat higher speed and the amount of incremental feed increased from around 0.03 mm to 0.05 mm. Every time blank and tap were flooded with WD40 in order to wash out the chips that then were wiped off. A first failed trial showed, how important it is to wash-out chips. The second attempt was successful. The finished concave knurl After the machining, the knurl was hardened by heating it to a cherry-red colour and quenching it in ice-cold water. As I don't have a very strong torch, the knurl was pre-heated to 450°C using the hot-air soldering gun and then brought to temperature with the gas-torch. The knurl was also rubbed in soap to prevent scaling. After some cleaning, the hardened knurl was tempered to a straw-yellow colour using the the hot-air gun. A test with a file showed that the hardening was successful. The knurl in the tool-holder for the watchmakers’ lathe ... well, it actually worked as you will see in the next contribution To be continued ...

Indeed, the bull's eye-glass (or 'Butzen' in German) has been very common and is used in 'romantic' reconstructions of medieval windows. However, considering that there only two bull's eyes coming out of each cylinder and only one from each disc, there must have been a considerable production of plate glass to give sufficient numbers of them for a window. I guess, from the mid-19th century on, they were not only 'waste' products anymore, but made specifically to meet medieval-revival demands. Also, in Germany the 'Butzen' often are 'bottle-green', indicating that inferior quality raw materials with a lot of metal contaminants were used - so the associated flat glass must have also been green. Here is an image from Wikipedia that shows the production of disc-glass in the 'forest' ('en bois', because they needed the wood for fuel): If I am not mistaken, sometime in the last quarter of the 19th century the float-glass was inventend in France, whereby the the near-liquid glass was poured onto a bassin with mercury. Indeed, France seems to have been technologically ahead in glass production for quite some time.

Wasn't this blown into a long cylinder, the bottom and top disc (with the blow-pipe attachment) cut off, the cylinder split lengthwise and then rolled flat while still hot ? Cheaper and smaller panes were cut from the discs, which accounts for the streaks often seen in old window panes.

Actually, I don't mind people adopting ideas - but as you said, it's nasty to take someone elses pictures etc. and then post them at another place without due credit. I have whole pages from my own Web-site being 'mirrored' on Web-sites of certain Eastern European individuals and Russian fora - and they just don't care when you just ask for proper credit to be given. Still, I like to share ideas, tips, information, because somehow it will be repaid by others sharing their ideas, tips, and information ... give and you will be given, as the Romans said.

Thanasis, my post was made in a hurry before going off to work and should have been worded more carefully. My apologies. As a matter of fact, when I used the word 'exactly' I was referring to creating a flat, to drill it and then to shape it. I used a flat-nosed punch to flatten the wire, a sharp punch to mark the hole and to prevent the drill from slipping. I did not use a haemostat or similar to guide the drill. It is always interesting to see that other people come up with the same or similar ideas for solving certain manufacturing problems. The smallest shackles I produced this way were about 1.5 mm long. The size was also limited downwards by the fact that the smallest drill I had was 0.3 mm, so the wire had to be at least 0.3 mm diameter to stay within the proportions.

Thanasis, I tried to be 'tongue-in-the-cheek'. Quite busy at the moment, but will take the time a bit later to put a translation of the PDF onto my Web-site ... have to go and catch a plane now ...

Thanasis, I don't want to accuse you of being a 'copy-cat' as you probably don't read German - and therefore didn't see the article I published in 1980 in a modelling magazine that describes exactly the same technique http://www.maritima-et-mechanika.org/maritime/tips/FALCK-SM-5-80.pdf

The green Chinese stuff in general is not so bad, just got another batch for my lathes/millers. However, if you can find a source for the original 'Polycord', which is a Swiss product, you will be probably happier, as it streches less and has a better grip. Polycord and its clones are available from 2 mm diameter up. ... still trying to find a source that will sell me few meters of Polycord without a surcharge of 70€ for minimum orders. There used to be a shop specialising in transmission belts in Vienna that sold it off the reel at the real price, but they threw the towel a few years ago (like so many small speciality shops).

I have used the cow-hitch in smaller scales, as it represents the sewing without really having to do it - not that I am lazy, but it can be near-impossible to find a thin enough thread for the sewing.

Make sure that all photo-resist has been removed before trying to blacken etched parts. A solvent, such as acetone, should do the work. On the topic of 'beefing up': I am only moderately fond of etched parts, when it comes to represent someting that in reality would have been cast or forged, particularly at larger scales. The parts just look to flat, even though their outline might be correct and quite detailed. In your case I would perhaps tin them thickly with a soldering iron. However, then you will have problems with the blackening and may have to resort to painting.

The original bronze spindle-nut seems to have had a left-hand thread of 4 mm x 1 mm, so it was drilled out 3.7 mm for the 4.5 mm x 1 mm thread and the thread re-cut with the appropriate tap. The odd digs and dents were removed by a light cut on both ends in the lathe. Parts of the spindle and its bearings A test assembly showed that everything worked as planned. The ball-handle crank has been bought-in and is fixed by set-screws, rather than being pinned as was the Lorch-practice. Spindle in place, but micro-meter sleeve still to be made To be continued ...

The long hole for the spindle in the cross-slide was opened up to 5 mm using the Dixi horizontal miller as a boring mill. Drilling out the the spindle hole in the old top-slide However, the travel of the slide was too small, so an extension was made to give the slide a travel of around 50 mm, allowing the milling spindle to reach across a face-plate mounted in the dividing attachment on the mill. The extension is a fairly complex piece, fashioned out of a block of aluminium. This is jointed to the existing top-slide with two location pins and two countersunk screws (the holes used were already made by a previous owner). Top-slide extension (under side) Top-slide extension (upper side) To it screws the housing for the y-spindle bearing. Watchmakers lathes usually have simple sliding bearings there, the end-play of which is controlled by a nut with a very fine thread. The elements of this arrangement would have been ground to give a smooth sliding. I decided instead to use miniature thrust-bearings with I.D. of 5 mm and an O.D. of just 10 mm. Two are needed, with the thrust-collar on the spindle in between. This gives an arrangement of 12 mm in length. Centering the future y-slide spindle bearing-plate in large 4-jaw-chuck Turning stub for spindle bearing-plate The bearing-housing was made from a piece of 15 mm x 15 mm aluminium bar. The section was centred in the large 4-jaw-chuck on the lathe and the stub turned on. The piece then was reversed and taken into a 3-jaw-chuck so that the face that screws down onto the slide extension could be turned flat and perpendicular to the axis. The through-hole was drilled and reamed for the spindle. In the next step the seat for the bearings was bored out to exactly 10 mm diameter and a tad unter 12 mm depth. Reaming bearing for y- spindle Boring-out seats for thrust ball-bearings Finally some cosmetic milling operations gave the bearing housing a more elegant shape. Shape milling of the spindle bearing-plate To be continued ...

While sorting out the replacement motor for the mill, I turned my attention to making the spindle for the y-axis. Most WW-lathes seem to have the odd thread of 4.5 mm x 1 mm pitch. The spindles from the old cross-slide I am using were missing, but must have been thinner, probably 4 mm. As I have both, a die and a tap for the usual left-hand thread, I decided to adapt the cross-slide for this. Set-up for cutting the thread on the y-axis spindle First the spindle was made. Unlike the original desing on watchmakers’ lathes, it will have two ball-races as thrust bearings, but otherwise the design will be similar. The ball-handle crank is a commercial product. I started out with a 5 mm rod and turned it down to 4.5 mm and then set-up the lathe for cutting the left-hand thread. The first pass Almost finished spindle This means cutting proceeds towards the tailstock. As the torque on the WW-lathe transmission system is too low, the thread was cut by hand-cranking. For this purpose I had made an adapter for a ball-handle crank already a long time ago. The thread was cut with full cuts until it was about 90% complete. Calibrating the thread using a 4.5 mm x 1 mm die in the tailstock The final cut then was made with a die in the tailstock die-holder to calibrate the diameter, which might have been a bit bigger in the middle due to the flexing of the long spindle. In order to eliminate the effect of flexing, the cutting bit was run along the thread several times without adavancing it into the work, until no material was taken off anymore. The finished spindle thread To be continued ...

Thanks for the 'likes' ! ************************* ... these day I really became angry – some time ago the nice Sherline-motor (https://www.sherlinedirect.com/index.cfm?fuseaction=product.display&Product_ID=405]) for my Wolf, Jahn & Co. milling machine (http://www.maritima-et-mechanika.org/tools/horologicalmillers.html) that I had imported from the USA some 15 years ago began to make strange noises. Sherline-motor, as used on my lathe and milling machine Upon investigating, I disovered the the brushes were completely run down, in fact the motor was running on the copper contact-plates. I contacted the Sherline and they quoted my 25$ plus shipping for a new pair of carbon brushes – the German/Austrian distributor near Vienna just shrugged the shoulders. I trailed the well-known bight up and down and finally found some of about the right size in China. Three weeks of milling-break. Once arrived, I ground the carbon the the right size and inserted them. The motor was running again, but somewhat noisily. I suspected problems with the ball-bearings. A week later, suddenly during the work loud noises and bang – rien ne va plus. I opened the holder for the brushes and found that they had already worked down by half and the contact-wire ripped off. I dismantled the motor-holder and idle-shaft in order to be able to take the motor out for further investigations. With a doctor’s eye-mirror I tried to look down at the commutator, but couldn’t see much. The only solution was to dismantle the motor. Of course all the nuts and bolts are imperial and had no suitable spanner. Had to go into town and get for some good money a 3/8” spanner for the nut, the screw-head had a 5/16” head, which is almost equal to 8 mm – learned some interesting this way: in the USA screw-heads and matching nuts don’t have the same size, as is the case in the metric system. The motor turned out to be completely filled with carbon-dust, which then spread around my workshop. After having cleaned the rotor a bit (whereby a good deal of the carbon settled on me) the problem became apparent: several lamellae of the commutator had been ripped out and the end of it was that some of the connectors to the coils had been cut – a total write-off ... Ripped commutator of the Sherline-motor In my ‘scrap’-collection I found an old capacitor-motor that originally came with one of my milling machine. I did not use it, because controlling the speed is difficult and one looses torque (unless one buys an expensive inverter). However, as I had acquired a good idle-shaft since, controlling speed on the motor-side is not so important anymore, as the belts can be shifted to various-sized pulleys. I now had to adapt the motor-mount to the new motor and I was back in business. The good thing about this kind of motor is that it is much quieter than a mechanically commutated motor. Motor running-capacitator (bottom) So, milling began again – but not for very long. After two hours rien ne va plus encore. The motor only hummed with the 50 Hz, but didn’t want to turn. Touched the motor and and shrieked back, it was really hot. Perhaps not enough ventilation in the motor housing of wood to protect the open motor from flying swarf. The heat killed the capacitor that must have been several decades old already. Measured the motor through, but the coils were ok. Back to the bight and trying to find a new 7µF-capacitator. Found one, this time in Ireland, which meant only a few days, rather than weeks break ... got it yesterday and I am back in business again ...

Until the adoption of the metric system throughout (continental) Europe in the last quarter of the 19th century, every major city had its own 'foot'. One has to pay attention when using old books and drawings to verify which 'foot' was actually used. The location of publishing or the nationality of the writer does not necessariyl mean that the respective foot was used. I remember preparing a drawing for a model from an 1860s book published in Hamburg and naively assuming that Hamburg Feet were used - when everything was ready, I discovered the small-print saying, that the author used Imperial measures (probably to be make things easier for international readers).

For cutting/milling wood also really sharp tools are essential. I would use carbide, rather than HSS, milling bits, particularly on harder woods. Otherwise, for our purposes one doesn't really need to be to pre-occupied with cutting speeds and feeds. In professional and production context this is different, where you want to remove as much metal as possible in the shortest time, arriving at the desired surface quality. With time one gets a feeling how much feed you can have for a given cutter size on a certain material. In many cases you would not be able to feed fast enough by hand for the RPMs recommended for a certain cutter diameter. One should also keep in mind, that higher spindle speeds will reduce the life of ball-bearings. Not sure how long the Sherline-headstock will last at 10,000 RPM. Most small machine tools in the pre-CNC age only went up to around 4000-5000 RPM.

You may not be able to afford Vallorbe files, but their information is free: http://www.vallorbe.com/ Just to sort out the different types of files: Needle files - fine, general purpose files that typically come in a couple of size classes, one is about 15 to 18 cm long and the other about 10 to 12 cm. Riffler files - designed for die- and tool-makers; they are usually about 18 cm long, but have two different heads at each end; they come in a wide variety of shapes (one even looking like a pig's tail) in order to be able to work on the most impossibly shaped object. Riffler rasps - these are designed for wood-work and in consequence have single teeth, rather than rows, as for a file; otherwise, they are similar to riffler files. Echappement files - the name indicates that they are meant to work on 'echappements' or 'escapements' in English, i.e. the part that times a clock-work (https://en.wikipedia.org/wiki/Escapement); some of them may look like riffler files, but their heads are smaller and in consequence their cut is finer. Then there is a wide variety of specialist files, such as the already mentioned screw-slot files, which are thin strips of steel with a cut at the thin end, machine files, which are straight along the whole length and not tapered, as most hand-files, etc. etc. BTW, the absolute fineness or coarseness of a file depends on its size, meaning that the same 'number' of a cut actually has more teeth per length unit in a smaller file than in a bigger one. Numbers also vary from manufacturer to manufacturer.

Having moved hither and thither between the 'Continent' and the Uk for the past thirty years, I am reasonably familiar with both systems (I even remember the six pence, thre'pence, and shilling coins from my first visit to England and the confusion it caused, when new and old coins were used in parallel ...). However, values such as 5/32 get me - I can cope, though, with quarters, eighths, sixteens ... and pints of course. What few people realise: the Imperial system has gone metric a long time ago ! In fact it is defined, using the metric system as a reference, the guardian of which is the International Institute of Weights and Measures in Sévres near Paris (a stone-throw from where I live). Talking about stones: giving a person's weight in stones absolutely gets me - no feel at all for that measure.

Must be a dangerous animal that you are breeding there - as you keep it in a cage I like the concept of a high-adjustable head and well executed ! What kind of machines are you working on - that parts you are working on are pretty massive (at least for the scale I am working on).

Some travel got into the way of progressing this project and on reporting on it …. ****************************** In order to mount the y-axis to the column, an adapter is needed. This adapter is fashioned from a small aluminium-block that was bored for the 20 mm column. The top-side was milled to a close fit on the lower slide from the WW-lathe, which is clamped down with a bolt. In this way the lower slide can be moved by about 15 mm, giving a greater depth of throat, if needed. It was planned to use a rectangular key to lock the adapter to the column. However, it appears that the two set-screws lock it sufficiently secure to the column. Practical experience will show whether this is true. Drilling the adapter for the y-axis The 20 mm-hole was drilled and bored on a face-plate in the lathe to ensure that it is exactly vertical to the top and bottom of the adapter block. The aluminium-block was srewed down onto the face-plate using a 6 mm hexagonal bolt. Luckily, a suitable hole was needed anyway for the locking bolt of the slide. Other hexagonal bolts prevent the block from moving during the machining operations and act as counter-weights. Boring the adapter for the y-axis After the functional machining was complete, the adapter was 'beautified' by giving the edges a half-round camfer. For occasional jobs on aluminium like this, I use cheap woodworking router bits ... don't tell any real mechanic. Camfering the adapter for the y-axis Finished adapter block The Lorch, Schmidt & Co. milling attachment will be held between two angle-irons screwed-down onto the slide. The locking will be effected by an excentric bolt acting as a cam. I had hoped to use the threaded holes that a previous owner of the slide had made, but they did not fit the angle-iron I had in my stock, so new holes had to be drilled and tapped. The pair of angle-irons was squared and trued on the mill using a fly-cutter. Squaring and trueing angle-irons in pairs Angle-irons to hold milling-head Angle-irons to hold milling-head The above picture shows also the drive unit made for the toolpost-grinder of the WW-lathe, which in fact looks very similar to what the future motorised milling head will look like. Provisional set-up of motorised milling head To be continued ...

Yes, having them alongside the boat on some blocks or trestles sounds a good idea.