Repairs

A tale of two (well actually three!) Myfords

peter 15/10/2023 No Comments

Well, as it states above, I couldn’t help myself… I bought another, later version (around ’65) Super7 in super condition with loads of accessories for a very reasonable price. It included everything needed to run a 400V motor on 240V without losing power or any of the other advantages of the 400V system. Also in the deal was a manual Capstan setup including six tool posts and the separate stop-system which belongs to it. Also a Norton gearbox including the metric thread conversion kit all boxed up. That alone was covered by the purchase price, so I was very happy!

The longed Super7 above is the fruit of my labours. it has a 400V motor running through an inverter from 240V -very smooth power-delivery and due to the three-phase, much smoother cuts as well! (240V motors ‘stutter’, due to the missing phase and so the cut is not as smooth). I had to cut the end off the main spindle, of course, to fit in the gearbox. I shall get a new, full-length, spindle, so that I can remove the box and refit the standard setup, in case I have to cut threads outside of the box’s scope, like BA and CEI. I have all the covers etc to convert back to original, of course.

I have a Myford vice and nearly all the possible gearwheels and some-such which I shan’t bother to photograph, plus the odd faceplate, too and a turning tool-rest.

Once I have everything mounted on its pedestal and is up and running, I’ll post it here…

So here a few of the goodies I acquired: The manual capstan head and a full set of tools:

This is the stop-setup for the above unit:

Vertical slide, swivelling type:

The mystery lever-operated collet attachment, for which I haven’t yet been able to find any collets on the internet…(still needs cleaning up!)Here are the dimensions:

This is what the standard-bed 1959 ML7 now looks like (minus the belt-cover transfer, which is now on it!)
Now standing in the corner minus chuck, headstock and motor (stored underneath the bench!)


So now back to the long-bed again: The new drive belt. Now I can split the clutch from the drive unit without dismantling everything “above the waist” and it is grippier, too!

The ‘new’ Gearbox with the original panel (not the new ones available now, which are subtly  different…)

Coolant-feed (The actual feed and box is still not made…)

My nice lever and chuck for the tailstock!:)

So now you have a good idea of the swapping and changing that went on, as the long-bed was originally an ML7 and the standard bed was fitted with a Super7. The first super& needed lots of work and cleaning to bring up to standard. The bed was reground and now sits under the ML7 pictured above and some of the other parts, too. The second Super7 was in much better condition and most of those bits ended up on the Long-bed also pictured above.

A mix of parts, including most of the first one (1960, so Mk1) which I had done considerable work on (covers, saddle, cross slide, tailstock etc.) and the really good bed still in original paint, are up for grabs as a complete machine or in bits. The internals of the motorising assembly and headstock from the first one are pretty filthy and I didn’t have ago at that yet, but being Super7, all in good working condition (the main bearing being an adjustable taper!) We’ll see!

 

A tale of two Myfords

peter 13/02/2023 No Comments

Life goes on despite the terrible war in Ukraine now for over a year…

Well, here I have acquired two metric Myfords of similar birthdates (1959 and 1960). For comparison’s sake, the one is originally a Myford Super 7 of ‘normal’ length, while the other is a rather more interesting and rarer long Super 7 bed with a ML7 drive-train and tailstock. Both of them, actually bit of a ‘bitsa’.

First the ‘shortie’, which is the one shown above, photographed in the seller’s cellar workshop, without any oil… I HOPE THAT HE DIDN’T RUN IT LIKE THAT; it looks like a perfectly normally shabby Super 7, it has the usual saddle and carriage , but the later top-slide (machined from a block instead of from a casting) and the rather ugly machined cross-slide end-plate. The tool-holder that came with it is one of those quick-change ‘Multifix’-style jobs which are expensive, that I am not fond of and that are a pain to set up properly. It also has only one tool-holder, as well, so why bother with the thing in the first place – the other ones were probably kept by the owner I bought it off in November of 2022 or he never received them either. It actually doesn’t work at all to my liking and is probably the reason why the sold the lathe in the first place (I’m sure that when properly setup, that ti would be great to use, but I can’t be bothered, to be honest… The rest of the Myford is OK, but has been quite heavily used in the past. The 1/3rd of the length of the bed nearest the chuck is worn more than the rest, as one would expect, and more on the back than the front. It is now being built up as an ML7 which I shall sell to ‘subsidise’ the longbed for myself, which will get the Super 7 Drive elements, headstock and tailstock off the ‘shortie’. The shorty will become an ML7 as a result.

The Longbed ML7 is in pretty good shape, especially the Super 7 bed, leadscrew, original saddle and cross-slide, which will be kept on it due to the differences in the leadscrew thread form and the split nut. Paint is in places a bit tatty, but will be cleaned up as I go along, all bearings will be replaced and the bed will be hand-scraped/flaked by myself when I feel that I need a workout!

This one came on an original Myford cabinet stand (the style of which I have not yet seen illustrated), which I shall, of course, be keeping. The door is, I think a later addition, as is the ‘drip tray’, which looks sort of home-brewed. I will add a cutting-fluid feed, for which I also found the important parts.

KSL 49296 also had a few accessories with it including original toolholder and a quick-change ‘four-poster’, some face-plates and a nice fast chuck for the tailpost, along with lots of change-gears. Both of them have 380/400 Volt motors, which I can use at home with the necessary emulator/converter giving the same power output from the motor without having to get a 400V. setup installed by an electrician. The cost of the ‘black box’ and switches is around €250 (or up to €650 if you really want to pay that much) for everything, so actually cheaper than a new motor and is portable, so usable on any other machines that I might get in the future with ‘Starkstrom’! The beauty of that is that the 400V motors runs a lot smoother and gives a better finish than the jittery single-phase ones and they are not as sensitive to frequent switching on and off – in this case not so important for me as the Super7 has a clutch (missing on the ML7). Being a 1959 model, it is the first clutch system, for which there are no longer parents, but the last one I had ran perfectly, so I’m hoping that this will do so as well.

I started work on the shortie a few weeks ago and since they were both dismantled for transport and had already been carried upstairs(!) to work on on my closed balcony, I thought that I would start with stripping and painting the bed. My left elbow has been playing up again after my mishap with the Husqvarna a while back, so I thought some light work was the best place to start!

Oops, that was a lot easier said than done. Although the paint looked tatty, cracked and scrubbed off in places, it is VERY tough and difficult to remove, especially since the ‘modern’, ecologically-friendly paint-strippers commercially available here in Germany are largely useless on older oil-based and baked on finishes. I tried multiple applications, scraping and scratching in-between coats which was pretty ineffective; in the end I resorted to the even messier ‘abrasive’ method, causing huge amounts of dust. Here some pictures of my efforts:

Scraped with flat and half-round chisels after a thick coat of paint-stripper:

After the second application etc:

This was a workout for sure… all done with the right hand 🙂

Here with a first coat of primer:

Front and back were treated to a proper cleanup, both easily accessible just by tipping forwards or back and a wire-brush (which had the negative effect of closing the pores), so everything had to be sanded again to give a key to the paint. Primed with Hammerite applied with a brush. After priming, the whole thing was treated to a few coats of Myford Old Grey (from RDG) with a roller and my own mix of pale yellow pigment mixed into Hammerite gloss white between the shears. Eventually looked like this and this is how it will go to the grinder’s – if I can find someone willing to do the job…

I also treated the carriage/saddlle/apron and tailstock to the re-painting treatment and cleaned up the contact surfaces. The split nut is of bronze, which is suspicious…Perhaps a later purchase? Wrong material, wears far too quickly and is probably the cause of the wear on the leadscrew. At the moment the split nut is not easily available to buy, but the leadscrew is also fairly worn from about 1/6th up to ¼ of its threaded length, so both would need replacing at the same time, of course to do the job properly. Interesting to note is that both lead screws have 8tpi, but a slightly different threadform!

Here is a photo of the setup provisionally put together, sans tailstock. All will have to taken off to get the bed reground, naturally. All done in a jiffy 🙂

Here the rather square top slide and cross-slide end plate are fairly obvious, as are the large hand wheel on the apron (which catches your fingers on the corners of the cross-slide when you wind quickly, if you are not careful!) and the home-made ‘teardrop’ on the cross-slide hand wheel. Also visible is the ‘Multifix’-style tool holder.

Here are a couple of pictures to show the difference between the two: the first is as ‘should’ be for the Super 7 (notice the top-slide casting and the cross-slide end plate) and the second is what I received on the shorty (originally Super 7).

The wheel on the left is what was probably originally fitted to the apron and the one on the apron originally came off a tailstock (compare with the above picture)  – apart from the modification! The topside hasn’t been cleaned up yet – that will come later.

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02.03.2023

Yesterday I got a call-back from a machine-shop, who said that I could bring the bed around and he would do it for me. So I did just that. Later around 13:00h, he called to say that it was done! Well, I was shocked, as nearly everyone else I called obviously didn’t want to to ‘bother’ with it. So I picked up the standard-bed SK 7246 from the toolmaker’s, NAD-Form, in Lage, Westfalen. Beautifully fine grinding job. Not for nuffink (but very reasonable, I must say), of course, but well worth it, as the shears were rather worn ‘all over the place’. 2 tenths of a mm or nearly ten thou taken off to clean up 99.9%, so not that bad, but better done than not.

Pictures taken before stoning but after smearing a bit of cycle-chain oil on them for preservation!

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24. 03. 2023

Well, I just discovered that the ML7 and the Super7 have different mountings and castings for the motoring department, which means that I have to measure, mark, drill and tap the back of both beds to swap them over to the respective types. Thankfully this is the only ‘surprise’ awaiting anyone doing the same ‘conversion’,is not difficult to do and allows the re-conversion back to the original configuration without any limitations. Pictures to follow, of course, when I get around to it. Left elbow still enjoying being ugly and hurting 🙂

 

Masspacher finals :)

peter 15/03/2021 No Comments

Now at last I am approaching the time to assemble everything and try out the bridge that I made (of ebony, of course!), string it up and try it out for the first time…

The new machine heads – without screws (still waiting for the correct domed slotted ones instead of the modern cross-head-screws)

Nice and simple inlay work on the ‘rosette’

Ready for the bindings/purfling and the frets and nut already fitted – notice the subtle difference in the colour of the top where the original bridge would have sat for years, shielding the wood from darkening (more obvious in the photos below this one).

Here with one side taped to glue the bindings.

The second side being glued…

After fitting the bindings, all could be finally assembled… Here is the binding at the bottom showing the corrective build-up of veneer around the bottom end of the top. I can’t claim that it is invisible, but at ‘player’s distance’ hardly noticeable. It retains the the original top without replacement, retaining the idea of using as much of the original as possible. Putting a new top on would have defeated the object and to my mind, ruined the guitar.

The finished article after shellacking and rubbing the front with 0000 wire wool and applying furniture wax. It will still need a little work and a few more applications of wax before it gets a proper sheen, but hey, this is a 100-year-old guitar and doesn’t have to look like it just rolled out of the factory!  The back and sides were shellacked and de-nibbed with wire-wool and left in the gloss that remained

Its place on the wall at home (camera-distorted angle to the bridge, by the way!) next to an old Ukrainian ‘Trembita’ (Epiphone copy?) and a ’70s Höfner bottom-of-the-range (¾?) classical. The bass also (now) works active and passive, but was an electronic mess when I got it 🙂

A new day dawns on the Masspacher which played very nicely from the word ‘Go!’. I may have to adjust it a bit as time goes by and it settles, but despite the gargantuan thickness of the neck, it plays with a light touch and strong tone – the sustain is great, of course!Maybe at a later date I will even post a sound sample, who knows!

Ca 1915 Masspacher guitar resto 2

peter 06/01/2021 No Comments

And so it was, that Maryna and I went off to England on a false hope and the belief that we could settle there for my retirement. Well, that didn’t materialise (in retrospect I can only say ‘Thank God!’) and so we returned to Germany in August 2017 to Plön in the north and were there until the work (and the owner of the Boatbuilding yard) I was doing there proved unfruitful and so the die was set to return to the Bielefeld area, where at least three of my children were near. We landed here in mid March, just before lockdown – but that is another story!

Vincent had looked after the Masspacher for me and returned it soon after our arrival here and the original work restarted. It had neither deteriorated nor improved, so I scraped off all the old shellack to allow it to breathe and gave it a regular good soaking, inside and out. After a few weeks, that paid off and the width-dimension of the top and back were very close, but there was another problem: the length had hardly changed at all, so the top was about ⅛” or 3mm too short. Added to that, the cross-spars inside had to be shortened at the ends to compensate for the change in dimensions of the sides and edging, so the top had to be pried free and reglued after shortening the spars. Although it doesn’t show on the photos, the top was not just split down the middle, either.

Here is the back after the scraping – beautiful, even if ‘only’ veneer over ply 🙂

The soundhole after securing the loose pieces…

After carefully fiddling all that together without actually removing the top altogether, that was when the difference in the length of the top (along the grain) became really evident at the bottom and a plan had to made, to make the whole thing go back together playable again.

First the edging/purfling had to be removed as non-destructively as possible to ascertain the exact amount of ‘fill’ required. Thankfully a little gentle heating had the desired effect, even though the ebony had become very brittle and was showing the stress of the original bending around the curves of the body by being unfortunately rather flaky.

I decided to use some 40-year-old old spruce and ebony veneer that ‘I had lying about’ to fill the lost space, carefully feathering the ends and building up to the final dimension at the bottom of the curve of the top. The cut was lengthwise along the grain, as cross-cutting would have been very difficult to keep together and would never have matched the pattern and rhythm of the original grain anyway.

After having done that, it was time to carefully layer it all together while keeping the measurement close enough to put the original purfling back without steps in either direction – not quite always possible, but close enough. The white was celluloid, so easy enough to scrape down – carefully!

The difference can best be seen from the centre to the bottom of this photo, where the ply of the top and the sides is better revealed. That is the space that had to be ‘veneered-up’

Here are the first plies being tried. You can see how the gap at the bottom (on the right) is wider and narrows towards the sides, in this case on the left of the pic.

First one in place (on the other side):

Layered up and ready for the final check with the purfling.

Now have to turn my attention to the top near the fingerboard on each side and the ‘waist’, where the shrinkage of the sides was most apparent

Now pretty much ready to fix the edges back on

Taping the purfling on to double-check dimensions

The purfling at the top has separated, so needed special care when fitting, so as not to lose any of the brittle veneer in-between the celluloid strips

Here it is a bit more obvious, but the top is not looking bad for 100 years old! It can also be seen that the celluloid has lost some ‘length’, resulting in a gap in the middle, which will be covered by the rather nice (and typical of the French guitars of the period) tailpiece – or string-holder – 

Ca 1915 Masspacher guitar resto 1

peter 08/08/2020 No Comments

The story of this guitar as far as my ownership is concerned, goes back about two and a half years. I bought it on eBay ‘for a song’ in France, where it was made – in Paris. As far as I can work out from research, it was made between 1915 and 1920, which makes it about 100 years old 🙂 Masspacher was a retailer and manufacturer, with a shop and workshop and was better known for its accordions. This particular guitar is unusual and quite rare, as they were made in their own ‘artisanal’ workshop and preempted the gypsy-jazz or manouche style, which they also made later on in ‘petit-bouche’ after the Selmer/Macaferri makers in the late 20s and 30s.

It was in a sad state when I received it, damaged from being too long in too dry an environment (centrally-heated?) and as such the wood of the top was split and had shrunk in all directions. I started by stripping it down as far as possible, also removing the frets and the varnish/laquer, so that it could breathe again and the top could take up some moisture from the atmosphere. I made a simple humidifier and hung it in the wash-cellar for months on end in an attempt to humidify it. Here are a few pics of it in it’s condition as I received it back then in 2017? It looks a lot better in the pics than it really was, as the shrinkage was everywhere…

There was a sponge inside the pot which was wetted every day and the whole thing was hung in the wash teller foe a few months, until we left for the UK…

Plenty going on

peter 23/01/2020 No Comments

At the moment there is too much going on all at once… We are moving in the next month to Spenge in NRW, as a result of my having work there with a previous employer – for more money. OK, there won’t be more left over (rent is higher), but everything else is altogether more convenient and closer to three of my four children 🙂

On the camera front, my Minolta-35 D model turned up and is having a good looking at at present, still waiting for the lens and I’ll be picking up a black SR-1 (b) and a nice black XE, too in the next few days, photos to follow, not sure when – beginning to pack in between working, eating and sleeping!

Minolta RF Rokkor 500mm f8 sunshade

peter 30/11/2019 No Comments

Well, I don’t know about you, but the pitiful length of the sunshade on both mirror lenses I have owned have always disappointed me… I realise that the coatings on these lenses are nothing short of wonderful, but especially mirror lenses are very sensitive not only to vibration, but also to adverse light conditions. So I thought I’d do a test. I made up a sunshade out of card and tested how far I could go without vignetting on the 500mm shown here. Believe me, I was surprised! The whole inch of the original sunshade was well under a sixth of the shade I built WITHOUT any sign of vignetting. I don’t think that anything shorter than the diameter of the front lens is useful or that anything much longer has any actual added benefit (I’m willing to be corrected on this), so I decided to improvise myself and use ‘easily available resources’ (i.e. without resource to a lathe) to make a usable and effective sunshade. Originally a little tongue-in-cheek, the finished product works wonderfully, was really cheap to make and is light and can store all sorts of stuff – even a lens – inside it in the camera-bag! Win-Win 🙂

The diameter of the lens makes it unusual, so getting one from another lens was out of the question. Looking around the house, I found a consumables tin that fit actually very nicely and also had he benefit of a plastic lid that would be handy as a lens cap! Originally filled with nuts bought from a supermarket (the same size is currently available here for the equivalent of £2.50), I carefully removed the bottom with a cutter and pressed/rolled the ragged inside edges flat with a cross-head screwdriver blade (anything metal or hardwood would do the trick) and put some ‘zebra’ tape (paper, actually) on the inside to stop it scratching the paint on my beloved lens… 🙂 At this stage, the functional work has been done, as it now slide-fits snugly over the front of the lens including the original sunshade and butts up nicely against the barrel, without being loose. I then decided that rather than spraying it matte black on the inside, that I would line it with black rubber foam sheet available at almost all supermarkets in their craft department in various colours. A strip 44mm wide is perfect, as it fits exactly from the front to where the original sunshade is and gives extra ‘Register’ there, to hold it nice and snug.
Look at the photos to convince yourselves of the fit and function – regarding the optics of the outside, perhaps you will decide for yourselves what is more appropriate. I went for a cover of thin, black leather, but matte black spray paint, card or anything else will do according to your taste; you could even leave it as it is (as I have for months!) or do a pink fur and Smarotzi-Diamond job on it! Enjoy!


To be honest, even the Original cap fits (as seen on the photo above), but the original for the tin is of course a perfect fit.

You May also have spotted another ‘modification’ that I have for this lens to take the light input down a stop, without having to swap filters in the back! I converted it to an f11 lens with a ring of the same foam rubber sheet as above (formerly tested with black card) which is cut to fit nicely under its own tension in the front of the lens. No glue, just fits nicely and doesn’t fall out an can so easily be removed or replaced, doesn’t get damaged or damage anything and doesn’t take up any space either! The doughnut-ring Bokeh ist thinner, of course, but for a quick and dirty solution, this works nicely. I can’t claim that the depth-of-field is influenced to any degree, though. Still, it does offer a bit more than just one ND4 in a pinch!

The case on the Sony is also one of my handmade additions, too, by the way. The top will be completed soon, too!

Here is the budget sunshade as finished and used at present: I could have used black thread, but, “what the hell”, I thought… 🙂

Dr. Peter is a frequent contributor to thingummybob.com

Minolta SR Slow Speed governor checkup

peter 29/11/2019 No Comments

Hallo SR Fans! Ever wondered where the slow speeds (less than 1/15th) are clockworked? Like most other mechanical movements that are past their ‘sell-by-date’ (in this case nearly 60 years out of guarantee!), the works are often glued up or just plain sticky. The oils and greases after so long turn to sticky goo and don’t do the intended job anymore.

With this particular camera, as with many others, a good clean with lighter fuel is all that is needed to keep things running smoothly for many years to come without any lubrication. Let’s face it, how often do you use shutter speeds of ⅛ or less in general – or the self-timer, for that matter, unless you are needing the slow speeds, of course… For macro work, for example?

Nevertheless, it is annoying when they don’t work on an otherwise usable camera, so here is a quick fix for those who are interested:

The clockwork for the low-speeds are under this cover; hold the mirror up and be careful when undoing the screws, as they are not very ‘deep’ and you are going at them at an angle, because the prism housing and lens-mount are sort of in the way 🙂 The paint scratches easily and you don’t want anything bright or reflective in there!

This is what it looks like under the cover and is where the buzzing comes from:

Upright the camera when rinsing out with lighter-fuel (as in this pic), please and then cock the shutter and release a few times at each speed, until it sounds right. Don’t be be tempted to add oil, it really isn’t necessary. Any traces of old oil will pool where it is needed through capillary action and be left when the fuel evaporates. If it sticks again in ten or twenty years, you now know where to fix it! 🙂

l recently received an SR-2 that behaved strangely: The shutter seemed oddly stuck, but somehow released, but left the mirror up… One shutter blind worked, but the other just stayed put. What was the problem? When I took the front plate off, I found the shutter blind completely wrapped and stuck to itself. Melted, actually! Some over-zealous previous owner had diligently removed the top cover and ‘cleaned’ the works by pouring acetone over it… No problem for the metal parts, but what dropped through onto the roller-blind fused it together for keeps! So, please remember, use a fine artist’s brush to apply fuel/cleaner or a very thin Pipette, so that you can control where it goes 🙂

This is what greeted me inside:

Minolta SR-2 vs SR-1 comparison

peter 22/10/2019 No Comments

Ever wondered what the real internal differences are between Minolta‘s first SLRs? First pic is of an SR-2 stripped of the ‘leather’, top and bottom plates off and my high-tech protection for the mirror box internals. The front plate with the mount and self-timer has not yet been removed.

SR-1 partially dismantled, but with the front mount section already off and the self-timer no longer fitted. Notice the difference between the castings and the ‘SRC’ in relief on the front next the mount: on the SR-2 there is not any such marking.

Here I’ll give a short look inside to still your curiosity (and mine!). So the SR-2 was the first in late 1958 and is put next to an SR-1 from around 1961, the ‘c’-version; the last one before the change was made to the aperture automatic. Two quite different mechanicals altogether, despite looking very similar, especially the bottom end, where the aperture and shutter actuation takes place.

Optically, the early and later models are relatively easy to tell apart if you know what to look for.. all the 1959 models have a much smaller eyepiece on the back, which is not so easy to spot at a glance. Easier to notice is the shutter-speed knob on the really early ones (the SR-1, too) that needed to be lifted to change the shutter-speed. On the top the scale is not quite evenly distributed, the 250, 500 and 1000 look evenly spaced, but they do have a little white line engraved to show the actual position needed to dial in those three speeds. From the front, the early dial is more conical in shape, wider at the bottom and smaller in diameter on the top than the later model (there is about a 2mm gap to the winder-lever). The later one, as you can see, is more straight from the side, and is as a result larger on top and has evenly spaced engravings up to 500, without the extra lines. The earliest SR-1 shutter-speed dial was similar in shape and size to the SE-2, missing the top speed, of course. There follows a series of photos showing some of the the external and the internal differences. Later I will show the internals of the first SR-1 model, but the differences between these two models are more obvious 🙂 The picture below shows the SRC on the casting rather more plainly.

There are, of course, lots of detail differences, that are too many to mention here, but worth mentioning and visible in this shot, is the mirror-fixing with screws, rather than the riveted-on mirror in the SR-2 🙂 There are also subtle differences between the self-timers, not only the front casting which they are mounted to: The one on the bottom or the right in this picture is off the SR-2 and fits behind the oblong brass plate. It also has an extra large flat screw (taken off on this picture below, but visible later once mounted) on the front side and the teeth on the spring-gear (the largest one) look like they have been ground or worn down… look closely at the pictures and you will see what I mean! The difference in the gear is plain to see.

SR-2 with the sellotape and here the differences in the gear-teeth are more obvious on this one. Note also that the backing plates are not the same, though the mechanisms are largely interchangeable:

Here the SR-2 self-timer is fitted and the large screw which is no longer on the later models at the front is rather obvious. The screw behind it on later ones is also significantly thicker (see pictures above).


Below shows the shutter-release mechanism in the base which is distributed half-half between topside and bottom. Most jamming can/must be sorted down here, the shutter speeds are controlled on topside. The lead-wires are for the flash synch and every camera seems to have them differently routed, depending on the wishes of the assembler! Here the difference in the size and shape of the tripod-mount is also visible, along with the completely different mechanical layout… few interchangeable parts here!

A look at the base plates shows that both are also different, as the mechanism on the SR-1 needs a cut-out at front (behind the lens-mount) to accommodate it – in preparation for the following model. At this stage, they both still have the long-travel aperture lever. the hole for the tripod-thread is also larger on the baseplate of the later body.

Well, that wraps it up for today. I will sort out the orientation of the pictures when I get home… I wrote this on my phone and it won’t let me do everything I want to!

Early Minolta Auto Rokkor-QE 1:3.5 f=100mm comparison

peter 09/10/2019 No Comments

How interesting it is to get two lenses like this next to one another to compare, made only a few years apart. The two in question are probably the most underestimated in Minolta’s lineup for very many years and still perform very well even against modern lenses at 43MP… These are just as sharp, if not better, certainly in the edge resolution than the 2.5 and the 100mm 2.0 that is in high demand (only because it is rare, not for its performance).  I might  go into that in more detail later, around when I release a test of the 24mm VFC 2.8, how to use it to do what it does, what VFC is actually useful for and some ideas about lens-testing methods in general, including inherent non-flat focus field (curvature) in lenses in general – which is always taken as given.

So, to start off with, looking at the fronts, I have two 100mm, 3.5 lenses from Minolta, built only a few years apart. The early one, an ARI, ser 1201946. Looking at many lenses, I might conclude that this is a lens of series code 12, number 01946 produced? There are many theories about the Minolta serial numbers and any of them could be right or wrong in the absence of any proof 🙂 Made somewhere in 1959-60. Whatever, the front engraving is as expected. The second one, an ARII with the serial 1213805  is missing the expected ‘Lens made in Japan’ engraving on the front, so is one of the earlier ones of this series produced.

If you look closely, you will also see that the front lens is more deeply recessed into the front on the later model.

Now turning to the back, we can see more differences: ARI-typical closed ring and screwed-on aperture link, ARII-typical linkage poking out of a slot in the back and, of course the stop-down lever now necessary after the automatic diaphragm was introduced on the SR-1 (4th model) and the second run of the SR-3, meaning that after the exposure, the aperture opened immediately. Yes, the knurled ring is missing on the stop-down lever, but will be added when I get one in 🙂

Also note the relative position of the rear lens elements, both focussed at infinity in this picture.

Here shown at an angle to emphasise the differences between the two, the ARI sits considerably deeper, which makes me wonder about them being the same formula for lenses and groupings…

Now both are focussed as close as can be done, 1.2m and 4ft, ARI Stil much deeper.

Interesting how both are so different internally, obvious from the back. Look how the shrouding goes right in to cover the full depth of the travel of the rear element here on the ARII…

… Whereby here the thread of the focus ring is exposed when wound to close-focus!

Now take a look at the difference in size between them: First the length is obvious. The added length of the later one (here on the left) seems to have mostly been added on to the front of the focus-ring :). Just also take note of the difference in the thickness of the focus-ring (which is why there is a bigger step in the front of the barrel of the earlier lens).

Here the nice even engravings are obvious (except for the ‘4’ on the ARI, missing on the later one altogether) as are the absence of engraved dots indicating half-stop clicks. Nice unblemished ‘Minolta green’ on the ft. engravings!

Same again at infinity, same difference in length (3mm)

Now the other side and here the white ‘Lens made in Japan’ on the ARII  and the simple ‘Japan’ in black on the early lens.

The big change for the ARII was not only the rear actuation of the aperture but in the iris itself, which had to be lighter and better balanced to react quickly to shut down and reopen adequately for the new shutter action on the now modernised cameras. Take a look down the barrel and the differences are obvious in the different shape of the iris itself. Still 8 blades, but very differently arranged, ‘back to front’, so to speak.

At f8 both look pretty much the same, though the earlier one is just a tad ’rounder’, but not enough to make any difference to the bokeh.

One surprise yet, is that the earlier, shorter by 3mm and narrower by 2mm in diameter lens, is heavier (402g against 382g) than the later one! Remember the difference in the thickness of the focussing-ring-casting?

The extra overall diameter of the later lens does have one potentially slightly annoying drawback… The DK57KD lenshood designed for it no longer fits on the lens backwards as it did on the early lens, so extra storage has to be found for it. Not really anything in the least important, but nonetheless worth mentioning.

Next up? Not sure yet, as I go into hospital on Tuesday to operate on my right shoulder again 🙁 I also have to make sure that the car is back on its wheels by then…

Minolta AES Viewfinder repair

peter 30/09/2019 4 Comments

A Minolta AES viewfinder, rather desirable if not so dented! If it were only the dent, that would not be so bad, but usually other things have also suffered as a result of the bash that caused the dent in the first place. Let’s have a closer look ‘under the bonnet’…

OK, this kind of space is all you need, so there is no excuse for not having a go yourself! Yes, I could have cleaned up before the photo, but it just goes to show the general arrangement. There are tools and materials for all sorts of tinkering and yes, while I’m actually working, there is more space around the working area as such.

So, having taken the top off (easily enough done on this) it can be seen that the dent wasn’t all that was wrong: the mirror and lens which allow the numbers on the aperture-ring to show in the finder are gone! The thin red outline shows the aperture-link in the ‘normal’ position without a lens in place – more of that in a minute.

Here a clearer view from the top and at the back, the long mirror for the shutter-speed display is also missing, but thankfully had dropped inside and could be reduced in its proper place 🙂

Here even more obvious, the REASON for what it missing and how it lines up with the lens ring. All I needed was to find a mirror and lens in my goodies-box and the case was solved. If I’m honest, a piece of 1mm thick polished Stainless would replace any missing mirror if you don’t have an original handy (the mirroring on these is on the FRONT surface, not on the back like a household mirror). For the lens, any one cut out of another Minolta SLR will do, even if you do have to trim it to size, it will do the same job since the distances of all finders from the lens-ring are very similar.

Below is a very different problem which afflicts almost every Minolta AES and AE viewfinder (not the others, since they don’t have metering). When the finder is removed, before replacing it the aperture ring follower has to be ‘cocked’, so that it snaps into the right place, should a lens be on the camera (in use that would be the norm). However, these cameras are a few years old now and have gone through the hands of many people, some salespersons, some of them photographers, some of them collectors and some of them without any knowledge of the workings of such things, from any of the above. This design was intended to save the camera being damaged by replacing the viewfinder with force and perhaps bending the linkages in the process. If you try to replace it ‘just like that’, you will notice that it doesn’t sit quite right at the front. Unfortunately, the uninitiated will just press harder until it clicks in place – the result of which can be seen below! The arrow on the right shows the follower correctly cocked on the right hand side and in the middle the release lever to reset it.

See the flat on the release lever? That comes from pushing the viewfinder down at the front until it clicks into place, as this lever, when the follower is not cocked, protrudes a bit as a reminder… of cocked properly, it retracts out of the way, of course.

So, who cares if it has a flat on it? Well, the user, actually, because having read the handbook and having cocked the lever properly, when the viewfinder goes back on, the follower doesn’t return to it’s proper place again and the metering is all haywire as a result!

The cure is to build up the front of the camera-frame, where the lever ‘lands’ with a strip of tape or whatever you have handy that it just thick enough to ‘trip’ the lever and something that does not permanently fix to the camera or damage it. Here I took a strip of cardboard and some insulating tape to fix it. It’s cheap and easy, works fine and doesn’t do any damage. Win-win! Don’t worry about light-leaks up here, the well is deep enough to shield any light that might come in – don’t forget, the eyepiece lets a lot more light into the prism.

Just a reminder of how the top looked like before. Suffice to say, I did a bit of persuasion with an appropriate piece of wood and repaired the dent without needing any touching up of the paint, which sticks like shit to an army blanket (ask anyone who has ever been a soldier).

You can’t see it here, but once the mirrors etc. have been replaced, the next step is re-assembly, which is pretty straightforward. Working from right to left in reverse order of disassembly.

 

 

 

 

Finally assembled with ISO 160 showing here and ready to go! All adjustments and cross-checks of the mechanics and metering were also done while the lid was off, of course.

The repair to the top is acceptable, I think.

Next up for discussion? The comparison of two very early 100mm F3.5 lenses an AR1 and an AR2 (by the way, one of Minoltas best-kept secrets, an inexplicably underrated razor-sharp lens). Construction, mount, iris, size and weight are different… Though they look very similar, until you have them up close 🙂

 

P-39 Airacobra Restoration

peter 29/09/2019 2 Comments

For those interested in Aviation, warbirds and the modelling of the aforementioned, here are a few pictures I took while working on the Airacobra in Australia at the ‘Classic Jets’ Museum at Parafield Airport in South Australia. Actually the busiest airport in the whole of Australia, mainly due to it’s being the home of a number of flying schools, including one used for flight training of quite a few large airlines, Parafield is also home to a number of classic ‘fly-ins’ and the Museum, of course, where almost all the work is done by volunteers. I worked on a few aircraft, but this is the one I spent most time working on.

Here a couple of views inside the workshop hangar.

Gives a general idea of things. The RAAF Airacobra in question in the background. Here are a few pics of the instruments and cockpit as it goes together:

And here a closer view of few of some of the individual instruments:

 

Lots of engine-details for the modelling enthusiast. These pictures are big, just click on them for larger, click again for super-size! Not much chance to see one of these up close, though used for many aircraft. Carburettor at the top and induction charger below it, the (shiny!) induction manifold on the top of the engine between the ‘V’. The pic on the top left shows it in the initial stages of build. As we progress it gets ‘smarter’ 🙂

  

The pictures below are of the other, running, engine in the public hangar which was originally out of a P40, which is why it has the reduction gear on the front, unlike the P39, which had it installed just behing the propeller and spinner, of course, fed by the propshaft which ran between the pilot;s legs… Makes quite a racket in the hangar and we converted it to run on Gas, as when on Avgas, the open carburettor spat flames to the roof on a cold start… 🙂

Here a few official pictures of the engine from Allinson themselves:

   

 

Here some detail pictures of the armament and ammo-boxes being built for up front. Ours didn’t have guns in the wings. Two machine-guns synchronised through the prop and a cannon shooting through the centre of the spinner. Convenient that the reduction gearbox, mounted on the front-most bulkhead had a hollow spindle! Drive from the prop-shaft enters at the bottom of the reduction-gear casting and the actual drive to the prop is a larger gear above it, allowing plenty of space for the ‘shooter’.

The rearmost, larger but narrower, munitions-boxes are for the machine-guns, the wider curved rails are for the larger (and fewer) cannon-shells:

Here how it is set up in the ‘plane still in primer:

 

Not in primer anymore and fitted up in TG*R !

And finally finished and mounted : (this one in Victoria, another A/C, another museum) The red box is a battery! More weight up front, critical for the distribution of weight and balance necessary to fly the aircraft. The mid-engine made it more maneuverable, but more sensitive to weight distribution. Cannon-shells fitted, MC Ammo-boxes not yet.

Here a few pics of some work I did on a pair of rearmost wing-fillets. We had one original on loan to copy and I had to make up left and right copies, hence the reversible template. The finished items were made slightly large all round for final ‘fitting’:

 

Here the aircraft ready and finished for the Parafield Airport Vintage Fly-In in 2009

Renault Megane/Scenic RX4 gearbox swap 1

peter 31/08/2019 No Comments

Let’s start at the very beginning: This is a Right-hand-Drive, 2001 Renault Megane Scenic RX4 2litre (permanent 4WD), bought in England, now registered in Germany and being used (when it runs again!) in Ukraine. No, this is not a new model that is hovering in the air, I have already taken the wheels off! That is a starting point for removing the gearbox, which involves taking the whole of the front sub-frame with the lower wishbones and the steering-box (rack and pinion) attached. The engine has to remain inside, as undisturbed as possible and the steering has to be locked in the dead-ahead position, also because of the airbag sensors. The steering-wheel gets locked first:

The picture above shows all you have to do – then loosen the wheel-nuts and the large wheel-bearing/drive-shaft nut on each wheel (Both R/H thread) with the brakes on for obvious reasons. Then the car can be jacked up and put on blocks and the wheels can be taken off.

From under the bonnet, the first thing that is useful at this stage is the removal of the battery and battery-box, so that you can get at the gearbox and its mount from the topside:

A nice open space with the gearbox-mount showing (bottom centre to the right). Then it’s back to our right, to work on the left-hand-side under the wheel-arch, as there is a fair amount to be done before we are finished.

At this stage it is worth mentioning that there will be a load of screws and nuts that will have to be taken off. Where it is sensible or convenient, put the screws or nuts back where they belong after taking off the bits that they attach. That way, you won’t lose anything or mix them up. For those bits, and there will be many, for which that is not possible, a large piece of card or a cardboard box is very useful to store the screws and ANNOTATE where they belong. Here I have just begun:

It will, of course, fill up as time goes on… The beauty of the box is that it does not take up so much space, that the screws can be stuck through it and grouped on different sides and, most importantly, that we all have at least one lying around somewhere just begging to be used in this way!

I’ll be updating this on a regular basis as I progress. Due to a shoulder injury, I have to take my time and try not to overdo things, so I am taking it slowly, so as not to do any more damage than I have already done! If you like this sort of thing – and I hope that it could even be useful to see how it is done – come back later and see how it all comes together!

Vintage 135mm f2.8 with sticky Aperture Blades

peter 24/08/2019 No Comments

This is one of the rarest lenses that I have had the pleasure to work on: a 1958 Minolta Auto Tele Rokkor with yellow LV engravings, apparently less than 2,000 ever made, to coincide with the release of the new SR2, Minolta’s first SLR in a long line, with loads of new features. I digress. The lens is a 7-lens construction and actually very good even by today’s standards. Not as clinically sharp as the much later 5- and 4-lensers, but still very nice.

This one is outside very pretty, the problem with it is that the iris had oil on it, making it rather sluggish. Not SO much of a problem, but definitely needed looking at to use it regularly.

Actually quite easy to dismantle (I never had one of these in my hands yet!) and the solution to the problem, largely due to the iris assembly being in the centre of the lens, was also simple enough.

There are a few things that can be done incorrectly regarding the order of dismantling – guess how I know – so it would be wise to stick to the order given as follows:

1: Undo the three black screws round the aperture ring. The one at this spot is the longest and belongs back here on reassembly. Inside the ring there are tiny balls that detent into the slots on the barrel (as can be seen on the picture) to give those snappy click-stops and to smooth the turning of the ring. Don’t lose them! A spot of grease will hold them on place for reassembly.

2) Remove the three silver screws around the barrel, which then can be easily pulled off the front.

3) The front lens element needs to be taken off next to access the blades. Do this CAREFULLY and with the PROPER TOOL, otherwise you risk scratching or damaging the ring, or MUCH WORSE, the lens, which if it is in good nick, will be almost impossible to replace in a hurry. If you have undone the grub screws by accident due to impatience or curiosity, you will now reap the reward by having a pile of separate (thankfully only six) aperture blades rattling around the inside! Oh Joy! Never mind. The construction is so simple and needs no explaining here, apart from to mention that a steady hand and a pair of nice pointy tweezers do come in handy 🙂

At this stage, you should be able to see the blades and what condition they are in. If they are only oily, then no further dismantling is necessary and they can simply be washed with a paintbrush dipped in some Methylated spirits or lighter fuel. While doing so, you can wiggle the stop-down lever thingy, to make the blades move open and closed, so they get a good rinsing. Be careful not to use too much meths and splash the rear lens from the inside. If you did, then you need to disassemble a bit more from the back (see further down) and wipe the lens properly using a moist lint-free cloth.

READ THIS FIRST BEFORE GOING ANY FURTHER: If you haven’t already done so, turn the whole assembly so that you are looking down the front at the blades. NOW, AFTER you have marked the position of the outside ring in the barrel, you can at last undo the grub screws and take out the inner ring holding the blades in. When you undo the grub screws, the outside ring could rotate, so mark it BEFORE you undo even one screw. The position of the outside of the ring is critical to the iris opening and therefore the exposure, so please don’t forget this. Dead centre in this picture, you can see the little silver ball that detents the aperture ring – lose it at your peril!

Now you can remove the parts carefully with preferably copper tweezers (make your own!) and clean and inspect properly, prior to reassembly – with cotton gloves on, please: fingerprints on the blades are so unprofessional!

OK, so yours, like mine were not only oily, but one was a bit bent? I can only assume that someone else with good intentions tried to fix it years ago and oiled them for good measure, but was not very light handed with reassembly. It’s always only ONE blade that gets bent, the last one, since it has to be tucked under rest that are already in place – a bit like Escher’s endless staircase! You know how to do it, if you have ever closed a cardboard box by overlapping the ears on the lid: Same principle, if a bit smaller. It will be obvious when you get that far. Not much is needed to make the blades ‘sluggish’ due to the added friction and no amount of oil helps (it in fact makes it worse, as we now know).

This is what they look like when reassembled through the replaced front lens. Reassembly is simply the reverse of the dismantling job, not forgetting to place the long screw where it belongs. In this picture, you can just see the nick on the top screw slot on the lens-ring, where I slipped despite having the correct tool – the lens was VERY tight. I suspect that it was secured with Loctite or similar.

Here a bit closer, in focus and nice and clean!

So, just because we are curious and maybe because we spilled meths on the rear element, or to get at the mechanism and to be able to not only disassemble but also adjust, the rear end has to be taken off. There is actually no reason to NEED to disassemble further, as everything for the aperture blades can be accessed from the front, but since we got this far, here goes:

4) Remove the rear mount (4 screws)

5) Unscrew the tube and rectangular hole (!) around the rear lens and put them out of  harm’s way.

6) Now you can safely unwind the focus-ring and PLEASE note and mark the spot where it comes off the thread to realign it when reassembling. Time consuming if you forget and have to find the right spot by trial and error – there are lots of possible ways to start the thread (8, actually). Once off and with the simple barrel at the front removed (3 screws), this is what it looks like:

The red arrow shows where the end of the spring belongs when the rear end is reassembled – tucked INSIDE the front tube/barrel when replaced!

In the above picture, the stop-down-knob is around the back, hidden by the rear lens element in this shot, but this shows the arrangement of the spring on the lever which actually causes the iris to open and close. Its function will be obvious when you actually have it in your hand and actuate the stop-down. It also shows the rear element which can simply be unscrewed to clean.

Reassembly:

7) Put the blades back together carefully (especially the last one), arranging firstly the blades the only way that they fit – yes, there is only one way! – and then placing the front ring over them and aligning the pins on the blades in the slots/holes provided.

8) Line up the outer ring with the mark you made OR look for the bright-spots/ dents in the aluminium where the grub-screws originally were. You might have to turn the ring once or twice, since there are three possible positions 🙂 Replace the grub-screws and make sure that they pinch not too tight, but hold everything in place.

9) Now you can test the freedom of the blades by twiddling the stop-down-knob.

10) If all is OK, replace the front end complete with aperture-ring and lens as a reversal of the disassembly. If not, try again!

11) Fix the screw-thread for the focus in place and the front tube/barrel, not forgetting to tuck the little spring inside by the stop-down-thingy before securing the 3 screws.

12) Position the outer focus barrel to screw onto the inner thread in the right place to enable to focus full length without fouling the stop-down-lever (you marked the position, remember?). If not, it’s trial and error time, looking at the bottom of the thread-travel for the stop-down-button to sit where the swept cutout is in the front edge of the barrel.

13) Once you have managed that, replace the rest of the parts around the rear lens and the mount and you are done! (Oh, and you’re a HERO, too! Have a beer/coffee/tea/wine/lemonade/schnapps!)

Actually a lot simpler than it was to describe, so have a go. You can pick up a similar one of these lenses for not much more than a tenner (if you find one with the yellow numbers engraved, BUY IT, KEEP IT!) to practice on, so don’t be afraid. What I haven’t shown in pictures here is self explanatory when you are doing it ‘live’, so don’t be intimidated.

Have fun!