Deckel FP1 vertical milling head issues

Hey folks

The following pictures stem from a Deckel FP1 vertical milling head (machine serial 28564, head serial 50114, manufactured/assembled 1950 A.D.). The head emits a unhealthy, crunching sound, even if running on low rpm (e.g. spindle turned by hand).





After disassembly the source of trouble could be tracked down to the following bearing (supporting the bevel gear).



Here a view of the whole train of elements from which the bearing comes. Left to right corresponds to bottom to top when assembled.



Since this is going to be my first machine tool bearing replacement and I would like to support the old lady at its best, advice and guidance is seeked herewith. We can go slowly, no need for a rush. Any input, even if commonly considered trivial, is highly appreciated.

Anyway, for me there are already these questions:

1. What would be the correct contemporary replacement for the noisy ********* 6008X CO2?
(maybe https://www.brw.ch/1/BRW-ToolShop/1...c-43be-a624-a0ca3973593c&pOnlyPromotion=False or better the 2Z version Werkzeuge, Normteile, Arbeitsschutz - Brutsch/Ruegger Tools, Schweiz - Einreihige Rillenkugellager SKF 2Z, mit Deckscheiben auf beiden Seiten)

2. What is the issue with this bearing anyway?
(despite close examination from the outside there are no missing parts or broken balls, why is it making that noise?)

3. What is the difference between the two bearings of the bevel gear ********* 6008X CO1 and ********* 6008 CO2?

Looking forward to receiving your thoughts,

best, Stefan

I would replace these bearings with 2 good brand 6008 open bearings
One could consider 6008Z One steel shield opposite from one another to contain grease
No RS (rubber seal) as these have more drag and generate heat
I cannot help you with the Xco1 and co2 But for this application a 6008 will do Its not a spindlebearing Just a bevel gear bearing

Peter

The co1 and 2 on the bearings seem to be added in handwriting, indicating that they were tested together, and measured for run- out, consentricity etc, and paired.

Personally I'd buy two brand name (SKF for example) 6008 bearings and just install them. If all you can find are 2RS1 (rubber shields) bearings you can pull out the seals easily but be warned that the edges are weaker due to the seal groove and care must be taken when pressing or tapping them in as a small piece of the edge could potentially break off.
Stay away from the extremely cheap stuff on ebay because sometimes the internal clearance is not within spec and also the surface roughness can be off. These bearing shortcomings can cause undue wear to your Deckel parts.

Dear responders

Thanks a lot for the helpful input.

Let us proceed to the next issue. Upon cleaning the interior of the head from gummed up unknowns, the following fragments have been recovered from the junk.



Looks like these pieces once constituted a Beleville washer, that is missing now. From an old 1955 Deckel FP 1 spare parts catalouge, there are two different descriptions, one with the washer in place and without any other additional shims, and one without the washer and with some additional shims.
From the actual serial, it seems that the original configuration, without shims, has been replaced with the later configuration with shims. Any opinion on this, I really like this kind of retrospective forensics...

If you are going to replace your bad bearing, just for fun I would run it through an ultrasonic cleaner with warm (60-70 Celsius) cleaning solution for half an hour. Probably the bearing is damaged but perhaps it will clean up....

This sounds very interesting. So just a contamination could have caused the noise!
I will definitely try this, thanks ballen

quarkgluonplasma said:

This sounds very interesting. So just a contamination could have caused the noise!

Click to expand...

This probably won't fix it. But if you have easy access to an ultrasonic cleaner, it costs very little to try.

I'm pretty sure the X on the part number is a special class bearing, don't know if a standard bearing will cause problems. I would think any run out will be transferred to the spindle and may not be desirable though. I have a head with that type of spanner type retaining and end play adjustment nuts. The manual for that machines says one takes up play and care should be taken not to over tighten causing damage to the bearings.
I don't know what it means but I'm seeing two different numbers on the head, the arm casting has one number and the head itself is a much lower number? Funny thing the number on the arm is high enough that it would be for a much newer mill with 4 allen head socket cap screws on the tilt adjustment but it appears made to fit that style head?
Does the spindle feel smooth to turn out of the head assembly?
Dan

From SKF Website:

Suffixes T - Z

X
Boundary dimensions not in accordance with ISO dimension series
Boundary dimensions changed to conform to ISO
Cylindrical (flat) profile of the outer ring running surface
Polymer ball bearing with components made of ceramic Si3N4

cwilcox said:

From SKF Website:

Suffixes T - Z

X
Boundary dimensions not in accordance with ISO dimension series
Boundary dimensions changed to conform to ISO
Cylindrical (flat) profile of the outer ring running surface
Polymer ball bearing with components made of ceramic Si3N4

Click to expand...

Yes but these are ********* Bearings
From the 50ies??
I recall to have replaced those bearings once and IIRC those were standard bearings
I can check on monday because I have one lying around somewhere
BTW no ceramics in the 50ies

Just get some name-brand 6008 bearings and install them. They are transmission bearings, not spindle bearings. Surely the gears' pitch-line runout is far bigger than any runout in the bearings, even for normal accuracy bearings. The minute amount of bearing runout is not going to affect spindle runout in any meaningful way whatsoever.

Note, however, that you may need to adjust shims to get the bevel gear mesh where it belongs. You do this by marking one of the gears with layout dye and noting the pattern where it gets rubbed off. Don't run it fast or with more than hand load when doing this. The wear pattern should appear in the middle of the tooth faces. Other folks use spotting blue to test the mesh, but I like layout dye that dries like Dykem for this application, because there is less chance of a smear causing uncertainty in reading the pattern.

Danny VanVoorn said:

I have a head with that type of spanner type retaining and end play adjustment nuts. The manual for that machines says one takes up play and care should be taken not to over tighten causing damage to the bearings.

Click to expand...

It is not a bearing of the spindle assembly but one from the bevel gear.

Danny VanVoorn said:

I don't know what it means but I'm seeing two different numbers on the head, the arm casting has one number and the head itself is a much lower number? Funny thing the number on the arm is high enough that it would be for a much newer mill with 4 allen head socket cap screws on the tilt adjustment but it appears made to fit that style head?

Click to expand...

The number on the outside of the head is the same as on the machine etiquette, looks like the original mating of machine and head, as on first delivery from the factory. That number is not the number of the head.
The vertical milling head numbers (heads plus arms) of Deckel FP1s have a different numbering. So in our case the head with the number 50114 really also comes from 1950 like the machine.
In a 1955 Deckel spare part manual they list machine numbers in the 30000s and vertical milling head numbers in the 60000s. The reason could be that every arm and overarm was put in the same numbering group.

Danny VanVoorn said:

Does the spindle feel smooth to turn out of the head assembly?
Dan

Click to expand...

Yes, why?

Peter from Holland said:

Yes but these are ********* Bearings
From the 50ies??
I recall to have replaced those bearings once and IIRC those were standard bearings.
BTW no ceramics in the 50ies

Click to expand...

I totally agree with this.

Peter from Holland said:

I can check on monday because I have one lying around somewhere

Click to expand...

This would be great!!!

I am at the shop right now
And the head i have has a needle bearing and 2 thrust bearings For a FP2 probbably
Are these the bearings for the bevel gear on the hor shaft or for the vertical spindle ??

Those beleville washers are there to get a preload on the bearings Normally done on angle bearings but also possible on deep grove bearings
But you need 2
As far as I can see on the drawing the bearings have a distance ring between the bearings on the outer races and then the outerraces locked in place with a nut ring
Then 2 belleville washers between the bearings in a O configuration to push the innerraces apart


Peter

rklopp said:

Note, however, that you may need to adjust shims to get the bevel gear mesh where it belongs. You do this by marking one of the gears with layout dye and noting the pattern where it gets rubbed off. Don't run it fast or with more than hand load when doing this. The wear pattern should appear in the middle of the tooth faces. Other folks use spotting blue to test the mesh, but I like layout dye that dries like Dykem for this application, because there is less chance of a smear causing uncertainty in reading the pattern.

Click to expand...

Your words are gold to me! I will definitely test this after reassembly. I would have expected, if replacing with bearings of the very same dimensions this would have put everything to the original geometry automatically. So you mean that the variation of height of the bearings within the allowed tolerances (which are generally how many microns btw?) could cause a significant difference in bevel gear meshing?

Since the bearings are not angular contact bearings, there could well be slight differences in axial position. It's worth doing the dye check regardless, just to see the health of the mesh.

Peter from Holland said:

Are these the bearings for the bevel gear on the hor shaft or for the vertical spindle ??

Click to expand...

The bearings are for the bevel gear on the vertical spindle.

Peter from Holland said:

Those beleville washers are there to get a preload on the bearings Normally done on angle bearings but also possible on deep grove bearings. But you need 2
As far as I can see on the drawing the bearings have a distance ring between the bearings on the outer races and then the outerraces locked in place with a nut ring
Then 2 belleville washers between the bearings in a O configuration to push the innerraces apart

Click to expand...

Yes, I agree. But according to the head serial number and the parts I have, this is not the setup of head 50114. It is this one:



So I think no longer of the fragments having been a belleville washer, but the thin washer that can be seen on the drawing below the second bearing directly above the head of the bevel gear.

Yesterday I first had trouble connecting to the practicalmachinist website and then, after it being available again, editing posts with the notification "database error". Is this common trouble or a 1 in a 1000 event?

Peter from Holland said:

Yes but these are ********* Bearings
From the 50ies??
I recall to have replaced those bearings once and IIRC those were standard bearings
I can check on monday because I have one lying around somewhere
BTW no ceramics in the 50ies

Click to expand...

I agree. Bearing suffix can be one of those possibilities, not all of them and certainly not a guarantee that ********* suffix equals SKF suffix from the 50's. Added the X for a point of reference only.

I stand by my original suggestion. Get two quality 6008 bearings and install them.

quarkgluonplasma said:

It is not a bearing of the spindle assembly but one from the bevel gear.

Click to expand...

I wrote that about using a bearing with the same class because it drives the spindle so is a part of the spindle assembly. Another class of bearing also might affect the gear clearance but a non quality bearing can show up in the spindle performance. One example is the argument with Bridgeport heads with step pulleys compared to variable speed drives. The guys with step pulleys claim their heads leave a better finish for jobs like boring holes etc. Now why would the variable speed set up affect the performance of the cut? All they do in drive the end of the spindle with pulleys instead of a gear as in the Deckel head. Vibration, not concentric enough, off balance, I really don't have the answers but the question remains. Don't get me wrong, I really don't care what you put in there because it's your machine. I just don't understand why any one wants to own a Deckel but then re invents it after they get it.



The number on the outside of the head is the same as on the machine etiquette, looks like the original mating of machine and head, as on first delivery from the factory. That number is not the number of the head.
The vertical milling head numbers (heads plus arms) of Deckel FP1s have a different numbering. So in our case the head with the number 50114 really also comes from 1950 like the machine.
In a 1955 Deckel spare part manual they list machine numbers in the 30000s and vertical milling head numbers in the 60000s. The reason could be that every arm and overarm was put in the same numbering group.



Yes, why?[/QUOTE]
The number system is sort of a mystery to me but I'm learning.