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1964 FP2 horizontal spindle adjustment

I am sure the Kluber engineer is well versed in a breadth of applications using their lubricants....
I have posted on several occasions about using relatively small amounts of grease in these spindles....
My information came to me directly from a German field service engineer who showed me the technique in person at my shop.
When my FP4NC was purchased (used) directly from the factory, it came with instillation and warranty.
The horizontal spindle was noisy and it was overhauled at my shop as part of the warranty...Service tech .Volker Spitz who had done his apprenticeship
at the factory was working here in the US at the time of my machine purchase and did the machine install..........

That FP4NC by the way is still in service in my care since 93' and runs pretty much every day...its run long programs (80,000 blocks+) lights out overnight (10-20 hours continuous)
at full chat (3150 RPM) Never a problem with either spindle...runs warm at full speed of course (130*f or so).....
Might be due for a refresh on the spindle lube by now....And i will be repeating the technique shown to me by Herr Spitz....hard to argue with results.
Cheers Ross
 
More likely he was being polite and didn't want to tell me that I was a Dummkopf. Might also be my inability to understand Barvarian (as opposed to German).

I had considered the Bavarian thing as a source for misunderstanding from your first post on this :). I am sure that, if I every get to visit Singer I'll need you along Bruce...I can do a bit of German but I understand that's totally useless there :D

Thanks for the additional details.

Did the 1/2" lever add another 300mm to the length, so effectively your lever for rotation was about 400mm long? Then 20kg/200N of force gives you 80 Nm. ....

You're right Bruce on this. However I think I did use my long torque wrench (like 800 mm or more) so that I could keep track of what I am giving to that nut.

... It's too small and too short to deform the taper or anything higher up. That part can just be tapped off with a plastic hammer and replaced with a brass part. ...

Might do it some day. If it pops out with a mallet, I'll replace it, if not I'll leave it there :P


...

"Rest assured, at 2000 rpm, these bearings will not overheat due to excessive grease fill. ...

This seems to contradict standard wisdom, which is to only use small amounts of grease on the bearings. ....

I have gone as Ross has suggested, though the 'not too much grease' is, of course, pretty objective and cannot, easily, be passed over via pictures. I erred on the 'more' side, nice to hear that the Kluber guy thinks there isn't any possiblity to do harm.

(in any case, after practically each 10 min cut, my horizontal quill gets tighter in the bore. Nothing alarming, just a small but noticeable difference in force required to retract it. I love how precise that fit is, admire it every single time)

....

That FP4NC by the way is still in service in my care since 93' and runs pretty much every day...its run long programs (80,000 blocks+) lights out overnight (10-20 hours continuous)
at full chat (3150 RPM) Never a problem with either spindle.....

Good to know that!

BR,
Thanos
 
I'm making good progress. Yesterday I used solvent (kerosine) to wash off all of the old grease and today I did the serious cleaning. Each part was wiped down, stoned, blown off with compressed air, then blasted/flooded with brake cleaner, blown off again, and placed into a brand new ziplock baggie. Then all tools also cleaned. New layer of kraft paper for the workbench, and a new set of hand gloves for me.

I went through two full cans of brake cleaner (500ml each). Fortunately a pack of 4 cans costs 8 Euros at the nearby Hornbach hardware/builders shop.

Putting it together completely dry worked well. I was able to slide all the parts into place with hand force, though I did need to make a pusher (and then clean it!) to push the outer shell of the top bearing into place. I was amazed at how smoothly everything turns. I wasn't expecting that without oil (this is my first-ever experience with precision bearings). Ross, your detailed how-to notes were very helpful to me, thank you again for posting them.

(Note that there was one scare: I could feel some hang-up in the rotation at one point. Then I remember Karl had had a similar issue, and it was identical on mine. The spring washer was not perfectly centered and was kissing the outer nut. I did the same thing as Karl, turned a smidgen off a short part of the outer nut ID to get additional clearance, and that fixed it.)

Now on to the important stuff:
The radial play at the nose is basically not measurable, less than 1um.
Axial play is also hard to measure, again I'd say below 1um.
The radial play at the back is 14-16um, and independent of rotational position. I want to reduce that by about 12 microns, which means shifting the bearing along the tapered shaft by 12x12 = 144 microns = 0.144mm = 0.0056". It seems like a lot.

As always, the question is if I have the rear bearing properly seated. I think I will pull it out, put some light oil on the taper and grease the nuts and washer, and reassemble it to be sure. But my tightening wrench works well. I was able to get the spring washer completely flat, and turn the inside nut almost a full turn more than when I disassembled it. Here is the setup:

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I have an SK40 long boring head clamped in the vise, and the spindle fastened to that. It's a very solid clamping arrangement, so I can bear down on the wrench with my full body weight and turn with both hands.

Reducing the spacer washer by 140 microns seems like a lot, but I think that's what's needed to get the rear bearing to make proper contact, and it certainly explains why the spindle seemed noisy to me. It might also explain the appearance of the outer race.
 
Update:

After dinner I went out to measure the radial play again. It was significantly less than before at the back bearing, about 6 microns instead of 16. So the bearing race must have finally succumbed to the pressure and jumped along the shaft by 0.1mm. I was able to easily tighten the inner nut some more, and now the radial play at the rear bearing is 2-3 microns.

Bottom line: the last people who re-greased the spindle did not tighten the inner nut enough. From the appearance of the slots, they didn't have the correct tool for it. When properly tightened, everything is as it should be. All that is needed now is a fresh cleaning, and new grease, hopefully tomorrow. I think it will go very quickly, because I know what I'm doing this time around.

Thanos, Ross, your threads and your comments have made this possible. Without that, I wouldn't have had any idea how to even start. Thank you very much for that.

PS: grease quantity, I've seen these photos from Ross and will use those as guidance:
https://www.practicalmachinist.com/...ndle-assembly-lots-photos-206981/#post3370190
Seems like a couple of grains of rice per roller or ball.
 
That's another horizontal spindle (almost) ready!

Well done Bruce...

Exactly like you, my horizontal spindle issues (much worse to start with than yours) were EXACTLY due to the fact that the previous guy that lubed the spindle didn't have the tools or knowledge to treat that nut as it deserves. Problem with my case is that this guy was me.... (I might be wrong, that time I did a lot of work on two FP2s and I might be confused but I think I am the one to blame). And, actually, I did it so wrong that bearing wasn't even remotely seated which caused excessive end float!

Well done again, and....my FP2 is a bit noisy as well if you would like to come over ... :D

BR,
Thanos
 
My horizontal spindle issues (much worse to start with than yours) were EXACTLY due to the fact that the previous guy that lubed the spindle didn't have the tools or knowledge to treat that nut as it deserves.

Wouldn't the following procedure be better?

(1) tighten the inner nut and bellville washer
(2) remove the inner nut and bellville washer
(3) put a length of brass pipe over the rear of the spindle, and tap/strike it with a hammer, to drive the inner bearing shell downwards, firmly against the spacer.
(4) put inner nut and bellville washer back on, and tighten

The idea is to properly seat the inner bearing shell by directly applying force/shock to it, rather than fighting the friction in the screw threads and nut/washer interface. The only danger here I think is damaging the thrust bearings.
 
Trying to wrap my head around this...
I think, if you hit only against the spindle (which is, of course, what you are after) then thrust bearings won't be affected. It's the spindle's shoulder that will accept all the load.

Yes Bruce, I think you have a point here. It's no good fighting the race with that poor nut and the fact that your race kind of 'settled' after the first attempt proves this.

Issue could be brass/copper chips leaving the drift from the impact and getting captured there....

Wondering what Mr. Singer would say about this....
 
I think, if you hit only against the spindle (which is, of course, what you are after) then thrust bearings won't be affected. It's the spindle's shoulder that will accept all the load.

There are two cases.

(A) If the spindle SK40 end is sitting are a hard solid table, and the quill is "hanging in the air" then you are right. The force is transmitted from the inner shell of the top bearing to the spindle, and from the spindle to the table. No force goes across a bearing (except that the quill has some inertia).

(B) If the spindle is free and the quill is supported (not clever!) then I believe the force goes from the spindle through the top spacer to the top thrust bearing. This in turn pushes on the central spacer, which pushes on the bottom thrust bearing, which pushes on a step in the quill. So a hammer strike here would transmit force across bearing surfaces.

Does that make sense to you?
 
A couple of days ago I ordered a new nut from Singer. It arrived along with an unexpected gift - a slightly dinged but functional brass replacement for the bottom stub on the spindle:

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When I rang to thank him, I asked about how much grease to use. After I had confirmed that I was using NBU 15, Franz told me to completely fill all the bearings. I asked him, won't it run too hot? No he said, it will be fine, it won't overheat. So I'm going to try it. If it doesn't work out, I'll just take it apart and redo it one more time. I'm getting faster with practice.
 
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The attached drawing shows this Deckel FP2 horizontal spindle version (completed with the ring that Bruce shows in the preceding post). I made it from almost well taken measures.
The drawing can help to understand.
Because the forum software can't handle this picture size (4321x1061 pixel), the attached file is compressed and needs to be unzipped.

Cheers,
Karl

View attachment FP2_horizontal_spindle.png.zip
 
Karl, that's a beautiful drawing, kudos!

Anyone who is planning to work on one of these spindles should download the drawing and study it carefully. Once you have understood that the NN3008K/NN3009K bearing outer shells are free to move in the axial direction, and that their inner races have a 1:12 taper, it's very easy to understand from the drawing how the inner nut controls the radial free play and the outer nut controls the axial free play.

Cheers,
Bruce
 
Anyone who is planning to work on one of these spindles should download the drawing and study it carefully.
I guess I should man up and pull my horizontal spindle for re-greasing. My FP2 is 1966-vintage according to FS. Is there a way to know ahead of time which spindle configuration I'm going to be looking at?


Once you have understood that the NN3008K/NN3009K bearing outer shells are free to move in the axial direction, and that their inner races have a 1:12 taper, it's very easy to understand from the drawing how the inner nut controls the radial free play and the outer nut controls the axial free play.
This does seem like a better design than using plain roller bearings, as there is adjustability for wear. I wonder how much wear the tapered races will accommodate for, though.
 
I guess I should man up and pull my horizontal spindle for re-greasing.

In the next day I'm going to post a list of all the tools and bits needed for my horizontal spindle, which might be helpful.

My FP2 is 1966-vintage according to FS. Is there a way to know ahead of time which spindle configuration I'm going to be looking at?

I think it's enough to post a clear photo of the back end of the spindle here, and we can tell you. I think if it has the same Spies nut and the same inner nut, it's the same spindle.

I wonder how much wear the tapered races will accommodate for, though.

A surprising amount. If you look at the SKF bearing specs, the outer shell allows for 1.5mm of axial movement on the inner shell, which is enough to generate 1500 microns/12 = 125 microns of diameter change. (That's probably more than allowed, because there is also some tolerance for alignment, but I think half that, say 60 microns, is probably reasonable.) The normal clearance of these bearings is C1 which I think is 17-30 microns, so at least 40 or 50 microns must be possible for operating these with a preload (standard in many designs). Someone here with more bearing experience (Ross?) might know for sure.
 
Hi Siggi,

This should be helpful to you and others, a list of what you should have on hand before getting started. Note that you'll need to clean a number of the tools as part of your final cleaning step before assembly, so they don't drop dirt into the bearings or grease. My procedure is the clean the parts one by one, sealing them into ziplock bags when they are clean. Then clean tools, same procedure. Then lay down fresh kraft paper, check that you have everything ready, then proceed to grease and assemble.

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Here's a picture of the bits, going from left to right as you go back to front on the spindle.

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I can not stress enough the importance of a good wrench and inner nut. A lot of torque is required -- I had to extend the handles of the wrench shown here. If the nut has any damage in the slots, replace it. I suggest using a locking plate on the spindle (see photo, item L) to prevent the wrench from lifting off the nut. You can see this "in action" below. In order to apply force, you also need a very secure way to lock the spindle down. I did this by clamping a long boring bar (which had a flat area) into a vise. Then clamp the spindle to that with a drawbar. You need something that is completely hands-off and rigid. While that is also useful for measuring radial and axial run-out, it is absolutely necessary when securing or removing the inner clamping nut.

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If you want to remove/replace the spindle nose piece with a brass one, I suggest you make a plastic ring (shown in photo) to pull off the old one and push on the new one. The nose piece is thin enough that I would not even try to use a hammer or mallet to take it off. But when you install it, leave a mm-size gap to the quill. Once the spindle is full tightened and run-in, you can adjust the gap with soft hammer by tapping.

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I asked Franz Singer about the quantity of NBU 15 grease, and he said "fill all four bearings". This spindle is different than the spindles that use needle bearings, for example the vertical spindle on the same machine. Franz said that the needle bearing spindles need very little grease, but these ones can be filled. If you compare the instructions in my FP2 manual for greasing the horizontal and vertical spindles, you can also see there is difference in wording. When discussing the horizontal spindle, they warn not to use too much grease. For the vertical spindle they warn to use very little grease.

After a progressive run-in to distribute the grease, this is working well, it's not too warm. Here's a photo of the run-in setup, using my lathe to spin the spindle (reverse rotation on the lathe). Here it's at 1700 rpm, stable at around 43C, monitoring temperature at two points. The run-in extended over most of day, starting at 200 rpm, run 30 minute, if temp stable increase speed by 25%, and continue up to 2000 rpm.

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Here's the run-out after regreasing, measured at the nose and at 250mm. The indicator is 2 microns per division = 0.00008", slightly under a tenth.

4D364CA8 87FB 40DD 8A91 6AE68E12D55A - YouTube

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After greasing and run-in, I can not measure any radial or axial play on the spindle. Franz says that this is OK, that both the cylindrical roller bearings and the thrust bearings can/should operate with some slight preload. Earlier Ross had commented that the thrust bearings should always have some clearance, but a cursory look at SKF pages for the 51109 thrust bearings indicates that some preload is a good, because otherwise the balls will skid instead of turning. Ross, does that make sense to you, or do you think it's misguided?

Cheers,
Bruce
 
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Guess one would have to settle on their definition of preload.....
For me preload means that all the clearance is taken up then some additional load is applied.
Deep groove ball bearings tolerate this well, as there is some deformation that happens when "preload" is applied. the balls act with a wedging effect on the races working opposite.

Thrust bearings are different....all the loading is straight compressive...no wedge effect and the only deformation is in making the balls oval...
My partner setup a Hispano final drive rear axle once (without talking it over)....Pinion was carried using plain roller bearings and ball plate thrust bearings (sound familiar?) .
He set the thrust with slight preload as one might set ball or tapered roller bearings....Thrust bearings failed within 200 miles....

Figures i have posted in the past using .0001/.0002" end float was supplied by the same guy that gave me the info on grease amount....
All i can say is as i have done already,that his technique has worked for my machines ,used in real work situations, in likely more demanding conditions with higher running spindle RPM's (3150 on the CNC's)
Maybe it was just stupid luck on my part.
Sounds as though you have settled on a technique and i am sure its perfect.
 
Hi to all,

as small note on this spindle, after some thoughts I had stemming from a friend's work on adjusting radial play on his Schaublin 13. The horizontal spindle on that machine only has one roller bearing, at the front, similar to the FP2's. Nut to push the bearing onto the taper and make it swell, but, no backing washer at the other side that would stop the bearing from going further, which seemed strange to me at first.

At the rear bearing on my FP2, as described here, there is a ground washer behind the bearing, dictating how far it will go on that taper. I had to grind it down to allow for the bearing to go in further and eliminate radial play. Yet, neither the Schaublin nor the FP2's front bearing have such a washer!
It seems that it's not needed: bearing won't go (by itself) further down the taper, no need to back it off.

On the FP2, the washer is the captive-to-the-spindle feature for the thrust bearings to work on. So, it's the bearing that keeps the washer in place and not the other way round! You have to thin the washer down in order to allow for the bearing to be set axially on the taper where it needs to be for perfect radial play but no more, or else washer would have axial play on its own and would ruin spindle axial play adjustment!

My 2 cents.

BR,
Thanos
 








 
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