I wanted a starwheel tailstock for a long time – and finally got one on a company liquidation. It was not in a good shape, but I like a lot to refurbish this kind of tools.
The item how it was presented at the auction
Disassembled parts of the gray tailstock
The toolchanger is mounted on a W20-collet and had some problems: it was sloppy and had some broken parts (which I don’t know how they are named officially).
It’s the part where the tool/toolholder is clamped. The clamping force is obtained by thightening the screw on the top of the part. Two of those screws had ruined threads, one was broken off completely! I think this happened to somebody, who didn’t know about the function of this clamp – but I have to admit, that I’ve also never seen this kind of clamping by pushing a rod upwards…
After disassembling and cleaning the whole tool, the same old steps again: sanding off the old paint, priming, filling, sanding and painting again. This time without the indulgence of a sandblaster (really a lot of handwork).
The chipguard on the lathe was never installed. Not because it wouldn’t be great to use – simply because you couldn’t see through 🙂 The mounting is fast and easy and can be set to the appropriate height or lenght (and tilt too). So it would be great to use this again…
I looked at different solutions and even thought about bending one. But this would really top my skills. Searching on the net, I finally found one which fits the present mounting.
Since I bought this lathe, one side of the lever on the tailstock was broken. I was looking for this item for a long time – but never found it. A repair isn’t a simple task for me: it’s casted…
Part after sandblasting
Detail of the break
After milling a small recess…
Recess with the old, broken part
Milling the recess
Checking after milling
… I was able to pin the new steel part in place. Pinned? Yep, because of the quite intense force that this constellation has to face – I didn’t want to rely only on some steel screws.
Screw holes
Pinned on place before threading
Finally, the part is fixed by two pins and three screws. Works fine – kindly for a long time!
Simple but convenient – tool organisation for the tripan toolholders! This is what it looks like at the end of the day…
Self-made bender
Measuring the lenght
Jig – double sided
Cutting to lenght
The layout is set «by eye». After some weeks using it, I would change this and give some more space for «overlength» tools. Luckily some pins were used to fix the bent parts! This gets handy if you rework the layout – just change the pins.
Some parts of the Schaublin were overhauled in a way, that doesn’t accomodate my style of work. The parts were overpainted without being taken apart – most of them «freehand» without masking or something alike. Moreover, the wrong paint was used: it began to blob and to sliver apart…
Saddle with cross-slide and bed-guards removed. The ways look ok – I won’t do anything on those (this needs a professional).
The right side of the saddle. The piece on the bottom that looks out a little bit, is on of the two end-stops of the powerfeed.
Closer look on the right side. Notice the coatings and the different types of paint.
Well… here the wrong type of paint was used. Nothing to say more here.
Dismantling
The apron was tricky to disassemble. Probably, this was the first time for years, that someone did that. Perhaps it was even a premiere, that every detailed part was disassembled and cleaned – some parts revealed the original paint, others the «history» behind it.
On this picture, the saddle is separated from the apron. This was a lot of work – those two buddies stucked togheter like two pages of wet paper!
The back side of the combination. On the left: the heavy leadscrew-halfnut, on top the saddle. The cap on the leadscrew-assembly is the filler plug for the leadscrew lubrication.
The leadscrew assembly. The part is hollow and operates as oil reservoir. The leadspindle is lubricated with a disc in the middle of the leadscrew-nut. On of the rare non-metal-parts.
The leadscrew-nut in detail. We’ll see more of this later. Mounted in the middle: the lubricating disc of the 40mm leadscrew.
Cleaning and inspecting
As you will see next, the inside of the machine wasn’t cleaned for years probably. But this mix of oil, grease, chips and dirt comes loose quite easy – yes, it’s a mess though. I’ll address the grease and oil chapter lather.
Top view of the apron’s inside. The rail with the oil grooves functions as end-stop (working on both ends) for the power feed.
The axle which connects the apron-saddle combinations to the leadscrew part
Inside the apron. Notice the pipe in the middle: it’s a oil pipe lubricating the axle on the left picture
Lower side of the saddle. This is a important and delicate part!
Underneath the mud, a beauty appeared! The craftsmanship of Schaublin is really a joy to have a look at – nothing compared to todays «chineasium machines» (to have AvE mentioned).
I’ll show some parts just to show the high quality and how they are made. After more than 60 years, I’ve found just one piece that really is broken! The remaining parts have wear of course – but nothing to be really concerned about.
The leadscrew-nut and some axles in detail. The nut shows some wear on the entry and the exit of the thread-grooves.
The backside of the leadscrew nut. in the middle, the cavity for the lubrication disc…
… which was broken! Yeah: one non-metal-part and guess what breaks? Not sure how to fix this yet – the axis sits bombproof.
Here another pic of the sliding axle (the one where the direction of the powerfeed is set). Due to the sliding functionality, this wear is really common.
Oil not grease: the nipples
On the same time, Bob Miller is also digging in his Schaublin. Besides also being one of them… well… in his words:
bob_mllr What appear to be grease nipples are not always for grease 😢. Someone thought so though when they lubed the Schaublin 102vm apron.
I used a kind of really fine grease for that – and probably didn’t perish too much. But after degreasing everything and cleaning it really deeply through all oil tubes and oil paths – it’s the right time to switch to an appropriate oil ! Being invited at Schaublin in Bévilard in a few weeks, I’ll get the right one from them.
Preparing for sandblasting
All the parts were cleaned and prepared for sandblasting. This is the first time that I give something to be sandblasted, and right: I’m a little nervous about this. I hope this will be done cautious – I prefer doing some handwork compared to damages that are hard to fix! Here’s what it looks like:
Five different options: ducktape (once or twice), piece on pipe (on the left), piece of scrap rod (on the right), some wooden pieces and some kind of sponge-bob.
We tested the used abrasive material on two uncomplicated pieces. Works fine: all paint is gone!
Back from sandblasting
The blaster-master did a really good job: the parts turned out fine. No major parts were damaged! Some dents though, but not on important areas.
The parts turned out nice and clean, no major parts damaged (some small dents though but not on important areas).
The part I was concerned about was a oil-window peering out of the main case. This one wouldn’t be easy to change – I saw somebody breaking it out and turning a thread into the case, but this was something I’d liked to avoid.
Priming, filling, sanding and painting
The first steps are tedious, but you’ll be honoured with the results. All coatings are 2K-compounds (primer, putty and the paint). It takes some coats to have a nice, even surface and yes, it’s a mess 😉
The used putty is a two-component-filler with a very short can life. This forces a fast application but has the positive effect, that you can sand the item after a short waiting time.
Reassembling
What I’d love to know before
I don’t own the original manual of the machine. There are more than a dozen of manuals on the net: varying languages, different years and diverging types – but all of them in a poor quality. Very difficult to see if a handle is set as a screw or only plugged or plugged and pinned. After studying the manual and inspecting the part from all sides (more than once), you could use a pair of pliers or even the soft-head hammer.
Yes – they were doing a really gread job, manufacturing this machine. I never saw such thight seats! And if the machine’s old and «crusty», it takes some gentle force to convince a part to move…
I really liked the idea of Jim Schmitt (on a post here) about the «inverted» retractable threading tool. Based on the concept of Charles Dolan (his post is here) it reverses the pull-handle to a push-handle – what in my opinion eases different things.
On the one hand, it’s easy to add a spring, helping to fully retract the tool completely in the right moment. On the other hand, it’s possible to let the tool clip into place by the right angle of the mechanism (and supported by the spring). This way it should be possible to cut repeatable and precise threads on the lathe.
Mechanism
The first sectional view shows the lever mechanism in neutral position.
The through hole on the left is tapped on the end and holds the spring. The two blue circles next to each other are the pins on the slider – the last one from on the lever.
In neutral position, the spring-rod pushes the carriage and the lever back. The lever is in the upper position.
In the activated position, the angle of the link in relation of the lever circle is slight above the center. In combination with the spring tension, this latches the setup in an safe engaged position.
Desengaging the tool needs minimal action and force – as soon as the angle drops below the center of the lever, it’s retracted by the force of the pushing spring rod.
Making
The tool is made of 1.0570 (S355J2+C, or in the USA: 1024). This is low-carbon steel and not really made for hardening (possible tough) – don’t know yet, if this tool needs to be hardened…
Most parts were milled on the Tormach PCNC440. There were tricky ones, like the dovetails, which need to be smaller than the ones of the back of the toolholder (btw.: yes, also the little version of the dovetail cutter showed on insta works like a charm), or the small cross-section for the lever, which needed a precise angle on the top as back stop. Some screenshots from the «lever side»:
Another difficult part was the axe which connects the slider to the lever: even though it’s possible to simulate almost everything in CAD/CAM, I had to make another version – 0.3 mm longer. It worked perfectly, but in the neutral position, the slider poked out a little bit 😉
After assembly, it turned out, that two pins on the slider was overkill. One is enough – with the benefit, that a stronger ball-point-pen-spring could be used.
Plans
For those who are interested in: here are some PDF-Files of the different parts which were made:
And some photos of the working in progress:
Using the tool
First: the tool works! It’s quite sturdy and won’t move while turning the thread. Though, you really have to set up «soulful» the force of the dovetail clamp. A too high clamping may block the carriage – a too low results in sloppy toolholding!
These images were taken from my next project. An M20-something with a fine thread. That was an easy task to do with this tool.
I have a Tripan toolholder system on the Schaublin-102VM lathe. It’s an «old school» quick change system with adjustable height and quite a good clamping capability. I really like the quality and the versatility this system offers – and it matches perfectly on this lathe.
Just because I live nearby where it was produced and probably mainly used, this doesn’t mean, that we could get them cheap – they are still quite expensive (we get them unused for about 85€ p.p.). Therefore and because I’d like to have a better feeling for machining mild steel, I wanted to make a run of 10-12 of them. Right: about a dozen – a mechanical artist on Instagram about that fact (Thanks Robin):
robinrenzetti Looking good, no such thing as too many tool holders. 💪👍👌
CAM
I own some original toolholders – and there are some plans with measurings on the net. So, making a CAD-file out of that material was an easy task. At the moment, my favourite CAD/CAM/Rendering program is Fusion360. Take a look – you can manipulate the image yourself:
Prototyping
I always like to test some setups, materials, speeds’n’feeds, etc. – even too in the production run! The prototype means the previous step for me: a first physical output, which you can move in your hands and study directly on it. Even though CAM and CAD are quite sophisticated these days, they won’t beat the physical output.
The first prototype turned out well. The dovetail cutter won’t take a whole production run, and there were some «design issues» – but technically the «proof of concept» was done…
CAD
For machining this little piece, three different setups were needed. If you make a production run and have the stock-pieces in the same dimensions, you can ease your life by indexing them in on the lower back inset – this way, you don’t need to bother about heights (you set them in the CAD-program). The mentioned setups are:
Back face – with the dovetail, where the toolholder is clamped
Top face – with the three clamping, and the height adjustement screws
Front face – the one where the tool is mounted
Back face
As mentioned above, on the first try I noticed, that tool wear would sooner or later be a issue on the production run. The dyi-dovetail-cutter solved the problem (and lasts till today – after a dozen of dovetails milled).
By the way: the width of the dovetail isn’t that critical in my opinion. On the drawings I mentioned before, really tough tolerances are given. But finally it defines the way the base lever (on the Tripan 111) has to travel – nothing significant for working with it.
