Schaublin 102vm & 12 maintenance (and oil blog-post)

Since the bigger machines in my workshop have been sitting still for a few years now I wanted to make sure everything was in good order before putting them to use. They could use some cleaning, adjusting, check-up and fresh oil. But since I have never owned these kinds of machines before myself (I alway's used once owned by others), I didn't really know what kind of care and fluids they needed other then "Oil" and "Grease".

This post is mainly for documentation and progress purposes. And has some info about oils and greases at the end of this post.

Schaublin 102-vm Lathe, AEG DT-10 drill-press, and Schaublin 12 mill finding its place in the workshop.

Readjusting machines

Some of the functions on the machines did not work as intended and needed readjustments. One of the more interesting adjustment was the feed direction handle. On the lathe I could not get the feed direction to go into neutral and it also wouldn't always fully lock into a direction resulting in a slight hammering noise of a pin/arm not wanting to catch into an rotating spindle. There was also a lot of free play in the feed direction handle. The place where the play was coming from seemed to have a key and keyway that had a lot of play on it. After removing the key it looked like someone had trouble adjusting this function and decided to make it easier by removing two corners to give it more play.

Top key is the old key with cut-outs. Bottom key is new key.

Not only could a make a new key, the manual includes a lot of parts on the lathe with measurements, so I could recreate the original key. Sure it is a simple thing to make, but it felt more special to have the actual original dimensions ;) . Though I was able to get the handle to work again as intended I could understand people not having the patience for it as there was only a really small area that turned out to be the sweet spot, and adjusting the system required some tricks.

Pulling the feed direction handle up gives access the the screw, while using the grease nipple to adjust instead of moving the handle.

For most part of the movements you could not reach the screw to loosen and tighten the system. Though, by rotating the system using a grease/oil nipple you could turn the system far enough to loosen, adjust, and tighten it again without directly losing the position you started with.

Preparing tools

When I took over the machines from my father I knew it did not come with any tools yet. So I got a set of carbide insert tools as I hear great things about them.

After starting to actually unpack all the boxes (from moving houses)I found a lot of tools from a friend of my father who sadly had past away but who had offered us to take over some of his tools and equipment. I have to thank him and his family also for ending up with the machines of my father and the possibility to start my own workshop this way.

Adjusting every tool to correct cutting height.

Cleaning

I used just rags and slideway/machining oil (leibaanolie in dutch) on all the mechanical parts. But I didn't know what to use on the paint and all the spilled oil and grease. I really didn't want to use water or soap. After some tests I chose WD40 as it cleaned the most spots, and also cleans up old spilled oils and grease really good without leaving a sticky finish. While it does leave a layer of protection against corrosion. (and it smells just so good ;) But be very careful using this stuff! Really prevent it from coming in contact with any mechanical parts that should have a proper layer of oil or grease on it. WD40 dissolves all the oil and grease it came in contact with while not having the same level of lubrication itself.

Opening the lathe (Oil Leak?)

When filling up all 4 oil reservoir I noticed a leak behind the spindle-head. My dad, from who I got the machines, also warned me about this leak. I really wanted to prevent accidentally running the machine without oil so I bought some special liquid seal (HYLOMAR) and was committed to open up the lathe, find this leak and seal it. It would also be a great experience, learning about this machine and the way it is build while also giving the internal mechanics a check up.

The leak was by the headstock, but the headstock has 2 different reservoirs and I did not know which one was leaking. Though I suspected the leak came from the reservoir behind the head/chuck as the oil sight glass did not show any oil level, even after filling it with what seemed to much oil. My thought was that the reservoir might be so full that the sight glass was already fully submerged for all its live time it spent in my family. Adding could mean it submerged the bearings and leaking thought them.

Opening the backside of the headstock was pretty easy to do, loosen the two screw on the top cover and it came right off. Removing the cover on the front (head side) of the headstock took me some time to figure out. On internet I saw other Schaublin owners that seemed to have a much more easier construction then mine had. Turns out mine needs to loosen the whole headstock frontal (head) portion from the rest of the automatic feed resevoir portion. Then pull/slide it over the bed toward the carriage.

Red arrows on the four screw holding the lid of the headstock reservoir.

Now you can access the 4 inbus screws on the bottom side to unscrew the top cover. This cover had some liquid sealing in between it, so you need to use a soft hammer to knock it off.

The inside looks really nice to me and I also found prove that the the oil level was indeed way to high and was seeping through the sealing toward the belt chamber. It then traveled a whole distance through multiple seams and corners what made it look like as if the gearbox reservoir was leaking.

After getting the correct oil levels I did not see any leaks anymore and I was happy to not have to disassemble the whole gearbox. The reservoirs and oil look really clean except for a few shaving from the steel to brass worm wheel. On forums people said this was pretty normal and can happen sometimes when engaging the worm wheel to aggressive. Everything looks good so I'm not worrying over it and will just keep this in mind when engaging the automatic feed function myself.

Type of Oils and grease

The machines came with 2 different types of oil and a grease hand pushe gun to inject grease through all the nipples on the machines. Since I was quickly running out on all of them I decided to do some research what oils and greases I should replace it with. After some digging in the manuals that came with the machines I found out they want you to use oil instead of grease in the hand push pump and use oil on almost everything including the, what seemed at first, grease nipples. This confused me a bit, but searching around on internet and forums confirmed that you should use oil instead of grease.

Head stock bearings :

I knew from the past running these machines that the head-stock could become a bit warm after long sessions of use. I got worried that this might be because of the use of grease in them instead of light oil that it should have following the manual. The manual even states : "Never use grease, grease pressed into the bearing may produce such great friction that the rollers or balls begin to slide in their races." Though, after searching up replacement bearings (the NN-3009K) I found a lot of manufacturers stating something like "Grease may be used up to 75% of the max bearing speed" or "Grease lubrication : 11000rpm, Oil-Air lubrication : 13000rpm". The original SKF manufacturer states even higher rpm on their detailed page here : https://www.skf.com/in/products/super-precision-bearings/cylindrical-roller-bearings. The Schaublin 102-VM only goes up to 3000rpm.

In the end I decided to follow the manual of Schaublin regarding the main bearings and at least get proper oil back into them. The manual states petrol can be used to clean out oil before adding new. I decided to just flush it with a lot of Vitrea oil because I was afraid to lock the rollers up when rotating the bearings to help flushing them out and I did not have petrol at hand. While flushing the bearing I did not know yet grease was actually allowed by the manufacturer of the bearings, and I was afraid they might be ruined. When flushing out the brown grease a lot of black oil/grease started to come out with chips in it and the bearing also made the bad sound and did not feel nice.

Left the black oil in on of the many rag, left the oil color that I put in.

Parts that came out of the bearing with the oil, turned out to be just work shavings and not bearing.

At this point I was really sweating it and I decided to do it the proper way by remove the whole bearing to wash it out by hand and check for damage. But I could not get the aluminum bearing tensioning nut loose in order to remove the spindle and bearings. It needs more force to get it lose but I didn't dare to do it without making a special tool with correct sized pins to not wear out the 2 opposing aluminum holes.

Aluminum cylinder nut on the back side of the spindle, it has 2 opposing holes that need a special tool to apply enough force to loosen or tighten it without deforming the holes.

After some thinking and discussing it with a friend from England who is experienced with engines we got the knowledge that it should not get this much damaged from just having grease in it. We looked at the chips that came out and discovered some parts where magnetic while others where not, and some could even be burned which meant they where plastics. We ended up with the theory of it being machining chips that got stuck into the grease. And by dissolving the grease it now started to come out but also could leak into the bearing. I decided to just flush it out with pressured oil and after a few more turns by hand the oil started to clean up and there where no more sounds coming from the bearing. Because we knew now these bearings are still made and we could get new bearings for decent prices we decided to not do a further investigation and just see if the bearing becomes worse over time before actually going through the effort of removing the spindle and bearings.

Grease :

After having taken care of the main bearing I had a look at other places where grease was used. I tried cleaning some slides and put oil on it. But I did not like the feel of it and found grease to give a much better feel and coverage. So I decided to keep using grease on all other places with nipples. Be sure to use oil and grease combinations that are compatible with each other and does not accelerate the degradation of each other.

Now, what Oils and Greases to use?

The lathe came with one bottle of Shell Vitrea 32 and some unknown slideway-oil (leibaanolie in dutch). The brown grease was also unknown.

The manual states to use the following :

Schaublin 102-VM
1.    2.5°E    -    Bearings and oil bath
2.    4°E      -    Slideway's nuts and feedscrews
3.    Greas    -    Feedscrew (scale handle) & Electric motor bearings   
    
Schaublin 12 
4.    <4.5°E   -    Oil bath (and I assume all else)
3.    Grease   -    Electric motor bearings                                              

In the manual there is also an example sheet included with oils to use from different brands.

What I find strange is that the Schaublin manual points to different °E value's for different parts, while ending the manual with this last page showing to use Vitrea 27 for everything except for the greased parts.

Viscosity :

On internet I see most people using oils with the number 32 and 68 in it. This number often states the Kinematic Viscosity Centistokes (Cst.) of the oil.

I wanted to figure out for myself if this is actually the correct oil to use and tried to figure out what kind of numbers I needed following the Degrees of Engler (°E) stated by the manual. I found different comparisons between the old Degrees Engler and modern Kinematic Viscosity Centistokes (Cst) used in today's oil ratings.

I settled with this sheet that seemed to be a good average of all the different numbers I found.

Comparison sheet with Cst. and °E and numbers that the machines use.

Oil conclusion :

Finding correct oils seems to be harder then I though. The name Vitrea was replaced by Morlina, but Morlina only comes with closest Cst. value's of 10 or 68 what is to low or to migh. Then you also have the problem of actual getting the selected oils as they can be hard to get in small volumes. I also get the idea that there are just a lot of different oils these day's that all have there specialty, but might all actually be good enough for this machine application. I also can't really find horror story's of people breaking there machines by using wrong mineral oil. I see people claiming to using normal car transmission fluids or hydraulic system fluids without problems.

At first I wanted to make a compromise and go for one type of oil for everything (Tonna 32). But someone who has a lot of experience in machine working (Wim Willems) I got the advice to not use it for transmisions as it does not have an anti air-bubble/foaming function what might damage the gears. For this he said to use mobile transmision fluid or any hydrolic fluid. I am going to keep using grease for all other parts that had already grease on them as it feels more logical then thin oil.

I ended up buying the following :

- Tellus 46 >> Transmision boxes and main bearings nipples.

- Gadus S2 V220 2 >> All other nipples.

- Tonna 68 >> Everything else.

But I'm curious to other peoples selections, advice or experiences. If you like to use an other brand then Shell, there is this list I found that compares a few brands with equivalent oils and there names.

Repairing Glass Scales :

I'm also repairing the glass scales on the lathe, but will make a separate post for this.

Link : https://www.acecraft.eu/post/making-your-own-rubber-seals-glass-scale-repair