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This year visit to RUEMEMA

TNB

Stainless
Joined
Aug 18, 2002
Location
France
After our visit at Rümema last year (wether I should spell Rümema oder Ruemema is something I still have to figure out - see http://www.practicalmachinist.com/vb/deckel-maho-aciera-abene-mills/iron-tour-2015-lots-pics-301415/ if you didn't follow the beginning of the adventure), I talked about our experience to a few friends of mine here in France.

It happens to be that one of them was in the market for a high quality lathe and was considering the purchase of a used Schaublin 125 as it seemed to him that model lathe was the perfect fit for his needs.

He had considered all the machines that were offered on the web, visited all the dealers he could, but was always disappointed.

All the machines that were offered to him were used machines i.e. machines that been *used*. Some more than others, but all in all, he was not offered a single machine he felt he could buy with absolute confidence in the precision and service he would get.
And unlike me, that friend is far from being a cheapskate !
We’re talking about machines in the 15/18.000 euros range, wich is a fair amount of money for a small manual lathe.

I had told him about Rüdiger Kramer’s work. At first, the price tag was a little frightening but after thinking about what was behind the numbers, he began realizing Ruemema machines were worth considering.
18.000 euros for a used machine bought “as is” from the word of a dealer or 30.000 for a fully rebuild Leinen… Hum. May be it was not so crazy.

So after a few mails back and forth, things got a little more precise and we went to Oberhausen to see a Leinen DLZ 140 rebuilt by Ruemema…

As a side note, I have to confess I’ll use several pictures of my previous visit along with newer images, because I didn’t take as much as I wanted this time. This was not due to restrictions from Rüdiger, but being there with friends who constantly disturbed me with their “ohhhh's !” and “ahhhh's !”, I think I was kind of sidetracked of my initial goal of keeping pictured records of everything…

We began with a coffee talking machines with Rüdiger Kramer, wich is always a nice way to start a good day.
We had taken the opportunity of that visit to set an appointment with Peter (peterve) and another friend of mine so despite the stakes of the journey, the atmosphere was very relaxed and friendly.
Rüdiger is an incredibly nice and warm host who will put you at ease right from the start.

After our second coffee, came the time to get down to the shop and inspect the the Leinen for wich we were there.

By the time we were there, Rüdiger explained us he had just finished the overall preparation cleaning of two Leinen lathes, and that was the reason why the shop was much dirtier and dis-organized than for our previous visit. Well, I wish my shop was dirty like that !
There were indeed parts almost everywhere, but always clean and in organized way.













The Leinen DLZ140 was sitting in a corner of the shop, under power and quietly waiting for us. Discovering a machine from Rümema is always a blast.

Everything is clean as a surgical instrument down to the slightest part. Dead perfect.
One can really feel that each and every part down to the most remote obscure screw was taken apart, cleaned, checked and replaced or rebuilt.

You'll notice that some of us had really hard time hiding their excitement and happiness...


















After the usual “handwheels spinning tests” and instead of talking hours about the machine, Rüdiger offered us to fill the Prüfprotokoll of the machine on ourselves, performing all the tests, checkings and measurings involved.
That’s what we did.

I must say that reading a machine tolerances sheet is one thing, but actually performing the tests to fill it is another thing. Actually doing it put figures in perspective much better.

So Rüdiger gave all the equipment we needed : a Mahr Millimess indicator, test bars for the spindle and quill tailstock, some stock and a Mahr digital micrometer (with micron readings too) and we performed all the tests on the data sheet.

I noticed a detail that clearly shows the quality of Rüdiger’s work : he did not demonstrate the machine for us.
Intead, he let us do what was to be done on our own.
That’s a huge difference because on a lesser machine, one realize that there could be some “tricks” to obtain such or such result.
An operator knowing the machine could easily perform such or such operation in a certain way so as to get the desired readings... Details in the way to operate the machine, tighten the locks and such…
We all know what it takes to accommodate a machine that’s not absolutely perfect.
Not in that case.
The quality of the machine takes the operator out of the equation. Well to some extend of course !
The operator has to know what he’s doing, but you get the picture.

So Rüdiger put us right in front of the machine and let us do everything by ourselves.
I must admit we had to check if the tip of the indicator was in touch with the part checked on several occasions ! And that was a Millimess !

We tested the ways parallelism, squareness, the spindle runout and performed all the acceptance tests to fill the sheets below :





The eagle-eyed reader will notice that the sheet is from the 14th of november 2015. That's because this was the date the machine passed final inspection after completion of the rebuilding. I didn't scan the sheet we filled in person, but I can testifty those values are correct and I have witnesses !! :D

As an example, we tested the action of the tailstock quill lock.
Put the tip of the indicator on the quill, and tightened/loosened the quill lock with various forces.
Well, the needle of the indicator refused to move. Not even a micron.
But barely touch the indicator holder with the finger and the needle would travel like crazy from one end of the scale to the other !
That says something.




The quill on that lathe was hard chromed.


 
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Then came the time to put the machine to the test for real and see how it actually cut metal.

We mounted a three jaws chuck on the spindle, and tightened a 40mm 4140 steel bar with about 200mm sticking out *unsupported*.

Various finish passes were taken with a positive rake insert tool (seem to recall it was a simple DCMT insert). We weren’t able to detect more than a few microns variation on the diameter over the whole length whatever we did…
The readings we got for the last pass we did were exactly the same all over the length of the bar (that’s with a Mahr digital outside micrometer).
Good enough for us !

Perhaps even more impressive, we then tried to take the smallest pass we could.

We performed various tries down to 0,01mm depth of cut on the radius. That was still with carbide and even if the surface finish was of lesser quality than with more “aggressive” cuts (talking about finishing values), whatever DOC set on the lathe readout before the pass translated into the exact same value taken off the diameter of the part on the micrometer reading.
Incredibly predicable and precise.

Moreover, at the end of the pass, bringing the carriage back to the starting point *without* withdrawing the tool would show no tool drag ... No cut on the return travel, and even no mark on the part !
That also says something…



What is nice with Rüdiger Kramer is that he knows the machines he rebuilds in the slightest detail and will be able to understand his customers needs and give them sound advices on how to get the very best of their lathe.

Just ask...



Listen and learn....



And verify...



Dead on.

For example, he told us about the various spindle bearings found on the Leinen DLZ140 and the Schaublin 135 and 150, and then the different arrangements found on older 135’s with NN bearings and the newer ones with 7000 series spindle bearings.
He explained how and why the Leinen and older generation 135 spindle bearings offer greater rigidity but have a lesser high speed capability.

We talked about the difficulty to fine tune radial play on the NN bearings series.
The Leinen has its spindle running on needle bearings. This is an arrangement that were are used to on Deckel mills, but I had never seen it on a lathe.



Those bearings, be it roller or needle type, have grooves ground on the outer diameter of the outer race. When tightening the race in the bearing housing, those grooves will allow some very light shrinking of the race, but enough to alter the play with the other elements.
I asked Rüdiger if he used some specific device to measure and set play but as I was expecting it, he answered experience is the keyword. Those are things you are only able to do with experience. A lot !

Despite all the inspection equipment he has at hand, there are things for wich experience is invaluable.










Rüdiger told us in his beginnings, he had nearly finished a machine and was giving it the usual breaking-in run before calling it good for service.
So the lathe was running in a room and Rüdiger was in another part of the shop, when he suddenly heard the machine stalling.
That’s when too little play is too little…
As you can imagine, we’re not talking about some dumb wannabe rebuilder over-tightening a nut with a 2 meters pry bar, but about someone running on the edge, squeezing the last microns that will make the difference between a very high precision machine and… a machine.

So that’s what cool in dealing with Rüdiger Kramer. The man is an absolute enthusiast who lives his work 1000% and will take all the time required to understand his customer’s requirements and come up with the right solution, listen and explain.
During the day we spent there, there was some serious head scratching around particular questions my friend wanted to solve with the machine he was about to buy. All the aspects were discussed absolutely freely.









Rümema is able to answer those questions because Rüdiger (Rümema or Ruemema stands for “Rüdiger Metall Maschinen” btw) masters all the aspects of machine rebuilding.
He showed us how he micro-welds the slightest scratches on a bed before grinding it in house on his slideways grinder. The use of micro-welding equipment together with specific nickel based filler metal prevents the creation of hard spots in cast iron and indeed the ground ways look absolutely perfect.
The slideways grinder is a machine Rüdiger overhauled and installed in the basement of his house ! (yet another sign of the personnal involvement of the man : he works where he lives and lives at work).
He explained us it takes up to one full week to grind a lathe bed, letting the casting cool and settle down between passes to ensure the highest quality obtainable...



He also uses a big T&C universal grinder for smaller jobs. Every machine in the shop is incredibly clean and beautiful, with an obvious attention for detail.





While we were at it, we also had the opportunity to play with a finished Schaublin 135…
Owning a used 150 wich is basically almost the same machine, this is a lathe I know pretty well. I know the noise it makes, I know its vibrations, I know how the handwheels feel.
Well… Just turning that machine on was an eye-opener.
Everything was soooo smooth and tight in the same time. The variator drive was so perfect and almost silent… and the vibrations… what vibrations ?
My machine is not in so bad a condition, but there is clearly no comparison.
May be I shouldn’t have seen that Ruemema 135 !







As you can imagine, the decision of buying the Leinen was taken well before the end of the day.
That, I had no doubt about it coming to Ruemema. I had told my friend he wouldn’t come back without buying his lathe.
So to end up I’d say all I can do is to strongly advise anyone who would be on the market for a new high quality – high precision lathe to consider those machines and if possible to pay Rüdiger a visit.
But let me warn you too : if you’re interested enough to go over there, you’ll buy one.

 
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He showed us how he micro-welds the slightest scratches on a bed before grinding it in house on his slideways grinder. The use of micro-welding equipment together with specific nickel based filler metal prevents the creation of hard spots in cast iron and indeed the ground ways look absolutely perfect.
Are only the small scratches filled or the complete wear of the bed, so everything is made back to orginal size?

I never heard of this technique.
 
Kees

Only the scratches and dings.

It's not spray welding, but more something like micro tig welding to fill the holes and allow for a perfect finish of the ground surface without having to go deeper than needed with the grinding process.

Rüdiger told us that there's not secret and the less you have to grind, the better for the bed.
 
So the saddle is a little lower as orginal.How does he compensate that with the drive-axis going through?
 
Hi All,

Nice photos and interesting trip but can anyone tell us why such accuracy is required and what kind of components would this lathe be needed for?

Alan
 
I think he does it just like you, by milling the appropriate amount of stock on the apron to restore height, and recutting the gears for the cross slide.

I didn't hear of turcite nor moglice.

There are a lot of questions that I would have liked to ask but you know, once there, there are so many things to see and to talk about. Plus we were there for the Leinen firstly.

One of those questions is how the 135/150 bed is trammed on the way grinder.
Due to their particular construction, those Schaublin adress a few specitic problems that I'm not sure the average rebuilder could handle easily.

So yes, I'll have to back again and this time I won't forget to give the 160 a try !
 
This lathe and the Leinen in general was well known for its ability to turn highly accurate smaller items in a production envirement
Grinding accuracy without the need of emery cloth
Pricewise it is still a good deal if you are in the market for a high end small conventional lathe
About the same price as a new Weiler but way more accurate
Even hard turning is possible on this machine But for (small)production hardturning Ruemema would advice the Schaublin 135 or 150

Peter from Holland
 
One of those questions is how the 135/150 bed is trammed on the way grinder.

The trimming itself is not that hard, the trick is how to get the bed mounted the same on the machineframe as it was on the grinder . I suspect he does that by scraping the underside absolutely flat.
I am not that good in scraping so I prefer to have a bed regrinded while it is still mounted on the machineframe. My VDF is regrinded on a huge grinder, the brand was Billeter/Von Roll which was Swiss manufacturer of bedway-grinders.

Funny fact: on Youtube is a company image-movie of Doosan I believe, where they show produktion of their CNC machines. Now this is a large company and they can make whatever they want. But at some point you see the grinding of their huge bedway-frames and what do they use as a grinder? A 1950's Waldrich Coburg!
 
The trimming itself is not that hard

In my opinion, the tricky part is to align the ballscrew bearings housings with the axis of the grinder.
I've been thinking about it and on the Schaublins, all the alignment goes from the leadscrew axis.

Seeing where the ballscrew is hidden in the 135/150 bed casting, it is probably not THAT simple.

May not that difficult on a machine without rapids, where one could somewhat tram the ballscrew position playing with position of the end plate supporting the bearings.
I was under the impression that machines with rapids had the housings of the ballscrew bearings bored directly in the bed casting.

Thinking about it, now I wonder.
Have to double check.
 
On most bedways the far ends have no wear
the saddle cannot come in that position
So you can align it from there
And on most lathebeds there are no holes bored in the casting So aligning is not a huge point
I know of the Hembrug where the headstock and bedway is one casting they used a bar put in the bores of the headstock as reference
On the Schaublin I could imagen a bar in the bores of the leadspindle and use that as a reference



Peter from holland
 
Thanks for sharing this tour! I love the cleanliness and order of that place, and the natural light as posted earlier.
 
For me it was a 4.5 to 5hours drive
So I drove there friday afternoon and spend the night there
I met Mr Krämer fridayevening for dinner
When I came at his house a person opened the door which was somehow familiar to me
i was invited in for coffee Met Ms Krämer while waiting for Mr Krämer
Well it turned out that the person was in fact Deckelfan on PM
He was at my shop about 9 years ago looking at a Deckel FP42NC with D11 I had at the time
And lateron he visited me with Martin P once
It turned out he was a friend of Mr Krämer :confused:
Its a small world

Peter from Holland
 
This one's for you Kees !



This 160 is the personnal lathe of Rüdiger.
To be honest, he explained to us the machine wouldn't be his favorite but he needs its capacity for certain jobs.

As an exemple, on the Leinen we saw, the spindle bore had been enlarged on special request of the customer.

Rüdiger told us the ergonomics of the big Schaublin was not as user-friendly as on a 135 or 150.
I seem to recall that's the same reason that was already discussed here.
It probably has to do with those rows of push-buttons but if this is the sole reason the 160 didn't have the same success as its little brothers, I wonder how come that no one ever thought about replacing them with a pair of joysticks conveniently placed on the apron.



For the moment, the sole milling machine in the shop is an Aciera mill drill, but Rüdiger patiently rebuilds a Deckel FP42 (I think) that will become his mill of choice for big jobs.

 
This one's for you Kees !

Wow , it is beautiful rebuild.
I do have some plans to do my 160 too but I also want to change a lot of things on the machine.I think the 160 has a lot of potential. When it all works out, it will became a lathe very different, but still convential. Let's call it a Schaublin with Activ DRO.
But it will take a few more years...

I don't know if it is a secret, but what type/brand of paint does Mr Rudi use? It looks very good.
 
So how does he keep swarf from scratching the paint one the saddle of his Schaublin 160?
Mark

As I noticed it during the visits we payed to various shops with Peter, a shop that rebuilds or works on machines is not a machining shop.

Rüdiger Kramer needs to machine parts on several occasions but he does not run a fabrication shop.
All in all, I think it's a safe bet to say his machines see a relatively moderate use.

That, plus his natural inclination for surgical cleanliness, and you probably have your explaination.

Kees, you're gonna start a debate with Peter again !
The textured paint is the sole thing he may change when he orders his Ruemema Leinen for retirement ;)
The paint looks perfect, but it is probably a little more difficult to keep absolutely clean than a glossy finish.
Seems it has become the industry standard nowadays though.

Would you care to elaborate your 160 plan a little bit ?
Seems interesting !!
 








 
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