Moore #3 spindle bearings

I have a #3 Moore Jig Borer, spindle seem fine but as old as it is I'm sure the bearing will need to be replaced. They are life time oiled but I have flooded the top bearing with spindle oil and it very sloooowly went down into the spindle bearings. Does anyone know what bearings it uses?

I'm not sure if it uses commercial bearings, or something built in house by Moore. Definitely, the balls were hand picked with extremely tight tolerances.

Paolo

Fine working,, why play around.
What is you lifetime experience in precision spindles and rebuilds.
Not broken do not fix.
This not a bolt in replace thing like a car strut or axle.
Taking apart will likely damage it and there is that fix to start with.
Do you have a "clean" room?
Bob

I have replaced a couple sets of bearings in Moores before. None of the newer models used oil in the bearings. They all used special grease like Kluber or some other very high quality grease. The bearings are ABEC7 or better also a P4 or better. Their are a few tricks to taking it apart if needed. Look at the parts book very carefully and the bottom bearing retainer is left handed threads. At least it was on the machines I worked on. Good Luck
Brian

Anyone have the bearing number? I'll look again but don't remember it being listed in the manual. As to why I'm thinking of changing them since they seem OK is that once in a while while spindle is disconnected and I'm spinning the spindle by hand so as to indicate location it feels gritty. Could be another bearing.

Did you read the part about ABEC 7?

Also, while you are at it, read Fafnir's dedicated pub on installing super precision bearings. Its their Form number 449

Yes John, I was thinking of ABEC 7 at the least, Might spring for ABEC9. Old girl is in good shape, table like new came with 3 axis Anilam Wizard DRO 0.0000 readout.
Would be nice to have the bearing number, while it's still working I can search for bearings. Have a #2 I would like to get rid of, nice machine but need the room.

Froneck said:

I have a #3 Moore Jig Borer, spindle seem fine but as old as it is I'm sure the bearing will need to be replaced. They are life time oiled but I have flooded the top bearing with spindle oil and it very sloooowly went down into the spindle bearings. Does anyone know what bearings it uses?

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I have no experience with Moore but do with SIP. I would respectfully suggest the best thing might be to buy the old girl a set of bearings but postpone replacing them until work visibly/measurably suffers. That might be never. The grittiness can come from a number of reasons, not only worn bearings. One peculiar reason is "grease worms" - hardened small grease particles. They feel wrong but are not abrasive. Of course, another obvious reason might be rubbish in a non contact seal. In general these machines saw/see very little "action", i.e. many lifetimes to wear the bearings. I do remember that ages ago was told the bearings in Moore spindles were sometimes factory adjusted tight/too tight. I would be curious if anybody knows anything.

millermachine said:

I have replaced a couple sets of bearings in Moores before. None of the newer models used oil in the bearings. They all used special grease like Kluber or some other very high quality grease. The bearings are ABEC7 or better also a P4 or better. Their are a few tricks to taking it apart if needed. Look at the parts book very carefully and the bottom bearing retainer is left handed threads. At least it was on the machines I worked on. Good Luck
Brian

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I would be very curious if after replacement you found the accuracy fully restored as new, better than new or slightly worse. I would appreciate a PM if possible.

Yes it's my plan to get bearings and keep them on the shelf until needed if that happens. I have enough projects to complete so starting another isn't my plan. But need the bearing numbers! I do have set of books (one is 3 volumes other is 2 that will give me all bearing numbers ever made from Dimensions though some are proprietary and not for sale to General public, other being discontinued. But I do not want to disassemble the machine until I have to. I did buy another #3 from HGR, photo looks good! But knowing HGR it might be a boat anchor! But better to screw-up a boat anchor in a learning attempt!

The machine was being used to make parts for gaging. As I recall the bores had a tolerance of -0 +.0005 and the bores where out of round .0002. I was not the inspector of the parts. But I know they where air gaging them. After the installation of the new bearings I was told out of roundness was down .00004 and that the parts were with in tolerance. As to what the factory specification for run out was I do not know. The bearings where made by Fanfir and the cost was around $3800.00 for both matched sets about 10 yrs ago.
Brian

Bearings seem to have been ABEC9 maybe better just for Moore. Yeah I expect the bearing cost to give me a price shock, I'll be sitting I hope when ever a quote comes in if I can find the number.

The machine is way out of spec, the replacement bearings will be Barden grade 9.
Here is the bad part, the nose pair of bearings will be custom preloaded to twice normal heavy preload.
The preload is controlled, by spacer length between the angular contact pairs of bearings, but new bearings can not be simply installed using the old spacer length, because, the modern replacement bearings, have one more ball, thicker races. The old spacers will cause excessive pre load.

This is a machine with custom pre load spindle bearings.
The only viable way to effect a custom preload is to, actually load each bearing in pounds weight, and measure the deflection, then apply to spacer length.
Accurate fixture needs to be made to contain and apply pressure to the bearings inner race in an arbor press using a hydraulic scale mounted to the ram for pressure, then using an indicator for deflection measurement.

Moore used medium preload bearings, then used spacer length to effect the custom pre load.
There are no formulas, of pre load charts from any bearing maker, they will tell you not to do it.
The only way Moore can do this is, make the spindle shaft and housing to the accuracy of the bearing, not your typical tool company.

Something to consider in addition to the comments above is that Moore spindle bearings typically have a very high, custom preload far beyond the bearing manufacturer spec.

Colt45 said:

Something to consider in addition to the comments above is that Moore spindle bearings typically have a very high, custom preload far beyond the bearing manufacturer spec.

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Anybody knows what was the reason for that ? Been around the block once or twice and can come up with none.

Orbital77 said:

Anybody knows what was the reason for that ? Been around the block once or twice and can come up with none.

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All the deflection curves I have seen for bearings end up linear after a seriously non-linear portion at low load, so I have to ask the same question....."why do that?".

If the usual preload does not get into the linear region, OK, I can see that. But it was my impression that generally it is at or almost to the linear region, in which case the advantage would be pretty small, even by Moore standards.

Not an expert, believe it is done in the interest of making the spindle stiffer and reducing deflection.

Think it's fair to say Moore was fanatical in chasing details and seeking improved performance, however so slight, wherever they could get it.
My experience is that once you get to a certain high performance level in any endeavour, there is no "one thing" that gets you to the next level, it's usually a combination of small refinements that work together. Also, getting to the next higher level can require significant compromises and expense.

The Moore machines do have excellent performance and when properly maintained, retain it over a very long life, so maybe they figured some things out that defy conventional wisdom and the charts.

I have many hours on the Moore, even went so far as to pay a seasoned expert to teach me how to use the machine.
One cant gain in one area without losing some in another, the way it is.
The spindle differs from a standard vertical mill by having two pairs of angular contact bearings, one pair each end. A vert mill spindle uses a pair of angular contact at the nose, and a single spherical bearing at the back end.
The Moore design is much stiffer, allowing the use of longer bars before chatter sets in, and just better for using a single point tool, including a fly cutter.
The stiff spindle is not designed for side loading with an endmill, it can really send a rattle through the machine, so any end mill work will be done with light cuts.
Anyway, the table screws are designed only for table position, not for any loading.
So, the machine is made to accurately locate, and bore holes.
The machine has no spindle lock, if you want to hold the spindle in a fixed position, the spindle stop is set, and the feed gears are jammed against it. Sounds bad, but it work fine for fly cutting, as does the bearing arrangement, very nice!
The quill feed handwheel, using reasonable pressure, will only drill a 1\2" hole in steel, but the machine can bore larger holes 8" or so.
Boring accurate holes really demands using dial bore gages. On a standard mill, either the table or the knee has to be moved to use a dial bore gage.
The Moore, has a spindle head that slides on the vertical ways on the column, the drive is from above like an old drill press.
The spindle head is counter balanced with a weight in the column, when the lock is released, the spider wheel lifts the head up out of the way, gage the hole, the head is lowered back to a micrometer stop exactly, and quick.
The machine can not be used in reverse, because of the screw in shanks, that are weird, but change out exactly every time.
The machine is really for fine finishing, if a large part needs to be made, its best to knock off most of the material on a regular mill.
Writing about jig boring, or getting the high accuracy out of the Hardinge, or Monarch ee, pisses off a certain segment of this forum, so the trolls will probably rise!

JST said:

All the deflection curves I have seen for bearings end up linear after a seriously non-linear portion at low load, so I have to ask the same question....."why do that?".

If the usual preload does not get into the linear region, OK, I can see that. But it was my impression that generally it is at or almost to the linear region, in which case the advantage would be pretty small, even by Moore standards.

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The only way to speculate with some profitability would be to know what percentage of max load is the Moore preload. In the '80s I worked next to a cubicle housing two Moore Jig Grinders - pretty large machines,too. New. The operators told me ( repeatedly ) they would get an accuracy of between 2 and 3 micrometers. Dies for e/motor laminations . That's impressive but not Earth shattering.

donie said:

Writing about jig boring, or getting the high accuracy out of the Hardinge, or Monarch ee, pisses off a certain segment of this forum, so the trolls will probably rise!

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Let 'em rise...