wefalck

And the show goes on ...
 
**************
 
The gun barrel and lock
Turning the barrel
Because there will various visible areas of bare metal, the material of the original, that is steel, was chosen.  A piece of round bar was faced, centred and rough drilled for the bore. This hole served as a protective counter bore for the tailstock centre during the following turning operations. In order to get a good finish the automatic longitudinal feed for the lathe was set up with the change gears. Unfortunately the minimum feed per revolution on the watchmaking lathe is still too high to get a 'mirror' finish. One day I have to construct some sort of reduction gear. The outer part of the barrel has a slight taper (1 degree included angle) and the top-slide was off-set accordingly for this operation.
 

Facing and centring a piece of steel rod for the gun barrel
 

Rough drilling of the gun barrel
 

Turning the barrel using the automatic fine feed
 

Taper-turning with slide rest off-set
 
For rounding off the ends of the rings the lathe’s hand tool rest came to good use. The work was finished off with fine wet-and-dry paper (remember to cover ways!) and steel wool. The bore was bored to diameter using the slide-rest and a micro-boring tool. I had originally envisaged to also show the rifling, but a quick calculation told me that for a 1 mm bore and 72 rifled fields I would need a tool edge tha is just over 0.04 mm wide ...
 

Rounding the 'rings' using a hand turning rest
 

Boring the barrel using a micro boring tool
 
To be continued ...

@bear, I must say, you rather embarrass me with your praise   I gather, a professional mechanic would throw up his hands into the air seeing me doing things, being just a self-taught amateur. Actually, collecting old machine tools and their restoration developed into a hobby of its own: http://www.maritima-et-mechanika.org/tools/toolsmain.html
 
********
Back to the subject ….
 
Rack-and-pinion drive for training the gun
 
The gun was trained by pinion acting on a circular rack. The pinion was driven from under deck by a sets of gears and a couple of cranks manned by a number of sailors. The chief gunner was able to connect and disconnect the drive with levers from his aiming-stand behind the gun.
I set up my hand-shaper (http://www.wefalck.eu/mm/tools/shaper/shapers.html) for cutting the rack teeth, but had to throw away the first two attempts because of the poor material and because - again against better knowledge - I did not lock the traverse slide when cutting. The table was removed from the shaper and the home-made dividing head bolted on instead. For lack of a proper tool grinder (another project now in hand) I hand-ground a cutter for the rack teeth (0.1 mm at the bottom) from a rod of high-speed steel. For holding this tool-bit in the shaper, an old lantern-style tool holder from the watch lathe came very handy. The unwanted parts of the ring were cut away on the shaper using ordinary left and right hand lathe tools. Finally the necessary sections were trimmed off with a fine saw blade on the lathe's sawing table.
 

Hand-shaper set-up for cutting the toothed rack
 

Cutting the toothed rack with a specially ground tool
 

Cutting away the unwanted part of the ring with an ordinary tool
 

Rails and rack provisionally in their place inside the barbette
 
 
To be continued ...

The 30.5 cm Rk/l22 gun
 
The main armament of the WESPE-Class was a massive 30.5 cm (12”) Krupp breech-loading rifled gun (Ringkanone, abrev. Rk). This caliber stayed the bigges in the German Imperial Navy for many decades and well into the Dreadnought-era. It is this gun that essentailly made the boats in floating batteries, rather than ‘real’ ships.
 
http://www.dreadnoughtproject.org)
 
A few years ago a detailed dtawing of gun-mount originating in the adminralty archives in Berlin surfaced on the site ‘dreadnought’. The arrangements for all the heavy Krupp guns of the time were similar, so that a visit to the Finnish fortress Suomenlinna (http://www.maritima-et-mechanika.org/maritime/models/wespe/suomenlinna/suomenlinna.html) off Helsinki was helpful; here a number of Russian clones of 28 cm coastal Krupp guns are still in place since the time, when Finnland was part of the Russian Empire.
 

28 cm Krupp-clone coastal guns in the Suomenlinna-fortress off Helsinki
 
Rails for the Lower Carriage
The lower carriage of the gun is supported on four races that run on semicirucular cast-iron rails bolted to the deck inside the barbette.
These rails need to go into their place in the barbette early during the construction. The same applies to the semi-circular toothed rack that is part of the gun-training machinery. I decided to make the rails from steel, even though ferrous metals in model construction are frowned upon by many. My justifications were that it is difficult to represent cast iron or steel by paint and that there hundreds of models in museums around the world that contain iron. I have used steel in models some twenty years ago and presumably due to the lacquering they shows no signs of rust.
 

Roughing out the rails from a metal disc with the backing of a wooden disc
 

Grooving the races with a specially ground bit
 
Cutting thin disks from round stock of large diameter is a pain I wanted to avoid. Against my better knowledge I picked a suitably sized steel washer as starting material. Unfortunately, the steel used did not machine very well and lot effort was spent to avoid chatter marks while turning and to obtain a reasonably good finish. The various types of wheel collets and chucks available for the watchmaking lathe came into good use for working on inside and outside diameters of these discs. The rails were shaped using a specially ground forming tool.
 

Cutting out the inside of the large ring for the tail-races of the lower carriage, while holding it in a so-called bezel-chuck
 

Trimming the outside of the smaller forward ring holding the material in a so-called wheel-chuck
 

The rails laid out in the barbette
 
To be continued ...

Yes, Plexiglas is a nice material to machine. I have been making small deck-houses etc. with this method since the late 1970s. My late father worked for a sister company to that manufactured Plexiglas (Röhm GmbH) and we had easy access to it in all sizes and shapes. Röhm GmbH also produced a comprehensive technical manual for working with Plexiglas, of which I have a copy - very useful.

Engine-room skylight
 
The frame of the engine room skylight consists of a an etched brass part, folded up and soldered together. On the inside, grooves have been etched that will serve to locate the protective bars to made from thin copper wire. The lower frame was constructed from Pertinax. The ‘wooden’ gratings on both sides of the lower frame are again etched parts.
 

Unglazed framework for the engine-room skylight
 
Once this structure was complete, a square block of the size of the footprint of the skylight was milled from a piece of Plexiglas.
 

Squaring up a Plexiglas block for the skylight
 
In the next step the roof-shaped faces were milled on. To this end, a small insert vice was set to the appropriate angle of 40° in a larger vice bolted to the mill table. The fixed jaw of the insert vice pointed upward and the side of the block to be milled rested against it. This ensured that all four inclined faces would have the same angle and would start from the same height with respect to the reference (bottom) face of the block.
 

Milling the sloping faces
 

Polishing the sloping faces  
 
A very smooth surface with little tool marks can be achieved on Plexiglas. The final polishing of the surfaces was done using CRATEX-type drum polishers followed by a felt drum loaded with polishing paste. All in the same vice setting to ensure a flat surface. I was lucky the Plexiglas 'house' fitted like a plug into the skylight frame.
 

Finished Plexiglas 'glazing' block
 

Glazed engine room skylight
 
To be continued ...

Thanks 
 
*************
 
Skylights, Companionways etc.   I have used two basic techniques for the construction of skylights, companioways etc., depending of the type and purpose. Skylights particularly were constructed around small blocks of Plexiglas milled to shape. Other types were constructed from strips of Pertinax. More intricate parts were etched from brass. For some of the skylights a combination of the techniques were used.   Etched parts for skylights   Boiler-room skylight The prototype construction of the boiler-room skylight is not completely clear from the drawings I had, so that I had to 'fudge' it a bit. First the central piece that supports the chimney was shaped from a piece of Plexiglas. The PROXXON drilling machine was abused as a milling machine to this end: a diamond-cut milling bit was taken up into a collet and the height of the machine set so that the bit reached just below the table. Now the Plexiglas part was passed free-hand along the mill. The form to be cut out was printed on a piece of paper that was stuck to the Plexiglas. It was tested against the shape of the etched grilles in order ensure a snug fit. The box around the skylight was constructed again from Pertinax.   Shaping a Plexiglas-core for the boiler-room skylight   The assembled boiler-room skylight   To be continued ...

Chain-stoppers
 
One pair of chain stoppers is located immediately behind the hawse pipes as usual. A second pair is placed above the chain locker, which is located immediately in from of the armoured barbette. The bodies of the stoppers are rather complex castings, calling for some complex machining operations in model reproduction. The same basic technique as for the bollards was used. Given the complex shape, however, machining is not possible in one set-up. For certain operations the axis of the spigot has to be perpendicular to the milling machine, while for others, such as drilling it has to be parallel. For the latter and for milling the various slots, I choose to transfer the dividing head to the lathe. This has the advantage that its centre line is at the centre of the lathe spindle.
 

Milling the profile of the fore chain stoppers
 

Milling operations using a dividing head in the lathe
 
The slots were milled using a micro-tool made from a broken carbide drill, the end of which was ground flat. This results in a non-ideal clearance of 0º, while the cutting angle and side rake are that of the original drill bit. However, not much metal is removed so that this doesn't really matter here.
 

Home-made milling bits made from broken carbide drills ground flat
 
One set of stoppers was milled from brass, while for the other one I used PMMA (PLEXIGLAS®, PERSPEX), the main reason being that I ran out of brass stock. However, genuine PLEXIGLAS®, is pleasant material to machine and easy on the tools. It holds sharp edges and it easier to see what you are doing than on the shiny brass. Acrylic paints seem to key-in well - basically it is the same molecule, of course. On the downside one may note that small and thin parts are rather brittle. Using diamond-cut carbide tools gives a nice smooth finish, but normal CV- or HSS-tools can also be used.
 

Milling in an upright collet-holder on the milling machine
 
While for the bollards and the front pair of stoppers the spigot could be on the geometric centre of the part, making it easy to measure while machining, for the after stoppers I had to place the spigot to the centre of the pipe down to the locker, so that the concentric rounded edges could be milled. The pictures show this operation.
 

Round-milling the body of the after chain-stopper using the rotary table of the milling machine
 
The stoppers have now completed with etched brass releasing levers, etc. The fore stoppers were also soldered to surface etched base plates.
 

The completed chain-stoppers (right column, the grid of the cutting mat is 10 mm x 10 mm)
 
To be continued ...

Working close to the collet improves precision due to less run-out and side-play, which are minimal on a watchmaker's lathe already ...
 
*******
 
Completing the capstan
Again the guiding rollers are a simple turning job. The shapes were produced with a free-turning graver and by rotary milling in the dividing head.
 

Using a worm-driven dividing head to round-mill the head of the chain-rollers
 

Using a worm-driven dividing head to round-mill the head of the chain-rollers
 
In the meantime various etched parts had been produced, including the base plate made up of two different superimposed parts and minuscule pawls. Also a chain separator from 0.3 mm copper wire rolled flat was produced. The various parts were soldered together.
 

The etched parts for the spills
 

The completed capstan (lower left corner, the grid of the cutting mat is 10 mm x 10 mm)
 
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 ...

The maker of the miniature Bridgeport is the British model engineer Barry Jordan: http://www.craftsmanshipmuseum.com/jordan.htm
 
@hof00: Proxxon (and all the other makers of small milling machines) don't make a machine of the Aciera/Sixis/SIP type as I discussed above. They all are conventional 3-axis-machines, to which perhaps a fourth axis can be added by deploying a rotary table or a dividing head. Even the smallest Proxxon, the MF70, still is somewhat bigger than what I am building here.
 
Updates will follow over the weekend, didn't have time to take and process the pictures yet.

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

Actually, I wanted to continue with my SMS WESPE model, but run into some technical difficulties and then this project came my way ...
 
The complex manual machining of very small parts on a milling machine requires smooth and precise movements of the slides as well as small masses to be moved. The slides of a watchmakers lathe fulfill these requirements. In addition, work-pieces and tools should be visible very well during machining.
 
Milling machines such as the Aciere F1 (or the older F12) or Sixis 101 are ideal for working on small parts, but are still far too large for my workshop (and have a too big price tag ...). Interesting from a design point of view would be also jig-borer and milling-machines by SIP (Société Genevoise d'Instruments de Physique), but they are very rare and difficult to come by. All these machines are massive and heavily constructed in order minimise vibrations by their inertia during the machining of precision parts for watches and instruments – too massive for my small workshop.
 

Aciera F1 milling machine (Source: http://www.lathes.co.uk/aciera/)
 

Sixis 101 milling machine (Source: http://www.lathes.co.uk/sixis/)
 

SIP jig-borer and milling machine  (Quelle: http://www.lathes.co.uk/sip/)
 
A special feature of these machines is that the x-slide is not arranged horizontally under the milling spindle, but vertically in front of the main column. This permits the easy installation of a fourth and fifth machining axis.  However, this arrangement means that the movement in the y-axis is not effected by the cross-slide, but by the milling head. This in turn means that milling head and motor should ideally form a unit. A belt-drive is more difficult to arrange, because the angle between the pulleys changes, when the milling head moves along. The SIP jig-borer for these reason originally was driven through a flexible shaft.
A watchmakers lathe is a good starting point owing to the precision of the slides and spindles, but it lacks the z-axis. In more recent years kits became available to convert Chinese-made watchmakers lathes into small vertical milling machines, but the milling table on them is arranged in a conventional way.
 

Conversion of a modern Chinese watchmakers lathe into a vertical milling machine
 
In my stock of watchmakers lathe bits and pieces I have collected over the years parts for several D-bed lathes of variable state of conservation. Some ‘scrap’ was also bought on purpose. From this parts I now want to construct a micro-milling machine with as little work as possible.
As design specifications I decided that the mill should be able to machine in a space of u 20 mm x 20 mm x 20 mm. This requires movements along the x-, y-, and z-axes of around 40 mm. There should be a fourth axis with a 360° rotation, that should be able to rotated under load. This axis should also be able to be moved from the vertical into the horizontal (5th axis). All those movements should be realised with parts from watchmakers lathes, so that no dove-tail slides need to be machined from scratch.
The back-bone of the mill will be a special D-bed that I obtained recently. It was originally meant for the conversion of a lathe into a small precision pillar-drill. Its lower end is turned down to a diameter that fits into a lathe foot. The foot that I am going to use probably came from a British Pultra-lathe (http://www.lathes.co.uk/pultra/page8.html).
 

Column and foot
 
Another key part is an old and somewhat battered cross-slide from a Lorch, Schmidt & Co. D-bed lathe. This will be the x- and z-axis of the new milling machine.
 
Cross-slide from a D-bed watchmakers lathe
 
The y-axis will be constructed with the help of a nearly scrap lower-slide from the cross-slide of a Lorch, Schmidt & Co. WW-lathe that I was able to buy cheaply. The spindle and micrometer-dial will have to be made from scratch. A 6 mm-grinding spindle of unknown make will serve as milling spindle. This limits somewhat the maximum diameter of cutters that can be used to ones with about a 4 mm-shaft, but the machine is meant for light work after all. On the other hand, many years ago I made an adapter for 6 mm end-mill for use in the lathe together with a vertical slide (before I owned a milling machine).
 

Lower slide from a WW-lathe cross-slide and grinding spindle
 

Future arrangement for the y-axis of the micro-mill
 
The fourth and fifth axis will be formed by the dividing head that I made some years ago from a 6 mm-watchmakers lathe grinding-spindle. For the moment it will be simply screwed onto the cross-slide as for use with a lathe. This gives considerable flexibility for the positioning at any angle between vertical and horizontal. The setting will be a bit time-consuming and has to be done with templates.
 

Column, cross-slide and dividing head assembled
 

Column, cross-slide and dividing head assembled
 
So far the existing parts that need to be re-conditioned somewhat at a later point in time.
 
To be continued ...

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 ...

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 ...

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 ...

There are a couple of basic questions to ask first:
 
- is the model made from wood or other material, namely plastics ?
 
- if it is made from wood, do you intend to keep the appearance of the real wood it is made from, or do you intend to cover it in opaque paint ?
 
There are various painting guides around the Internet for aged wood, namely in the railway and diorama modellers realms. Some use real wood as a basis and other plastics.
 
In the case of real wood, this is usually stained in some grey, controlling the process to keep perhaps some of the original wood colour. Applying white, black, and burnt umber as washings allows to modulate the basic grey. At some places a technique called 'dry-brushing' may be applied to highlight surface features.
 
On plastics, you would apply similar processes, but you would start from an undercoat of light ochre to simulate the wood.
 
Like the Old Master, in principle all the various aging or weathering effects can be achieved by painting. However, in particular the plastic modeller community has developed a range of processes that involve more or less controlled random processes, such as stripping paint layers with adhesive tape, deliberately reducing the adhesion of paint layers in order to partially strip them later to achieve a flaked impression, etc., etc. Again, there are numerous tutorials on the Web as well as in printed form available.
 
In think I pointed to some of my own work in a similar thread. This is a 'resin' modell with an ochre undercoat and various washes of burnt umber (both acrylics). In addition water/salt 'stains' were applied using white pastel chalk:
 

 

 
In the scenic setting of the above model I used real wood for the landing stage etc. that was treated with stains and acrylic washes:
 

 
I tried to give some keywords to search for in the Internet that give more detail than this short post.

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 ...