FP3 Vertical spindle bearing.

[jeroen]

Good day,

I noticed the vertical head of my FP3 was running quite warm when exceeding 1500rpm for longer then 20minutes or so and making quite a bit of noise. Together with the play measured at the cone of about 0.025 radially and 0.07 axially it's a good excuse to take it apart.

I share the images to inform others and get some point of views of the more experienced members.

I've purchased the machine converted to CNC by the previous owner. It seems that at some point in time they decide it was time to stuff the spindle with plain bearing grease.


As far as I understand what is said on this forum this may be the main reason to cause the spindle to heat up.
After a quick clean up of the grease I couldn't find no mayor damage like pitting. When running your nail over the surface you can't feel any imperfections.



When looking at the surface by a x60 microscope I can only see color differences bteween surfaces on the spindle races and on the needles of the bearing. The marks on the lower race are from light rust. The lower race on the housing is a bit worse.



When running your nail over the surface you can feel the rust impressions. I guess at some point moisture came in to the spindle. At this point im blank about where it came from. Could it be condensation? The mill is sitting in a unheated garage.

Has anyone tried to brush off such superficial rust (scotch brite?) and was succesful?
Probably together with the amount of play on the bearings it would be wise to send it over to Singer for them to referbish it. Has anyone had experience with that lately; what am I probably looking at regarding cost (grinding races, new bearings, assembly)?

Regards
Jeroen

 

[jeroen]

Hi All,

I've send an email to Singer if they could repair this spindle. It was a short answer. No, it is damaged they say.

I get the feeling the economic situation is against me in this case and Singer just doesn't have the time to deal with this minor repair work. Which I could understand eventhough it doesn't help me if they would say it out load.

Has anybody have experience repairing this kind of damage successfully?
At the moment the machine is just a expensive paperweight.

Kind regards
Jeroen



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[AlfaGTA]

I get the feeling the economic situation is against me in this case and Singer just doesn't have the time to deal with this minor repair work. Which I could understand eventhough it doesn't help me if they would say it out load.

Jeroen

Would not call this a minor repair...
Options to make this serviceable are very limited.
There is a very narrow range of "oversized" needle rollers available.

Looks like what needs to happen to to grind or lap the ID of the lower bearing race in the quill to remove the pitting caused by the rust...
Likely also the spindle will have similar pitting which will require grinding to et to a smooth surface....

The result will be a smaller shaft (spindle) and a larger OD in the quill.
To fill that space larger needle rollers are required, and there is simply no available over-sizes big enough to make up the dimension lost by removing the damage....

Fitting more conventional bearings i out because of the size of the Quill and spindle...there is not enough wall to allow a conventional bearing having both an inner and outer race to fit without
removal of critical wall thickness from the quill or spindle.

Repairs like hard chrome on the damaged surfaces to return to standard dimensions although possible (chrome can be plated inside a hole using special formed anode, etc ($$$)
But it is pretty well accepted that chrome is not a good surface to run a needle roller over...Tends to roll the chrome off the base material....

likewise, processes like flame or plasma spray to build up the original parts has the same problems with needle rollers.

Might look into having a specialty needle roller made (special) that was outside the normal range of available rollers...But you have to get the surfaces cleaned up first in order to know what you need, but
getting rollers made will be expensive.

Might explore making a new Quill....Not a beginners job, requiring precision....Could be done or hired out to an engineering firm with the capabilities....

Might find a vertical head, perhaps even singer.....Maybe a new spindle assembly, but be careful here, as i believe that the quill is fitted to the vertical head casting when the machine is built...not all the quills
are exactly the same OD...If you find one slightly bigger, easy, the housing can be honed to fit. If a replacement is smaller than the bore, then you will need to build up the OD of the replacement to suit.(hard chrome)

Might give FPS a call. They are building new FP3 machines, perhaps they can supply a new spindle assembly sized (OD) to your needs......

Good luck, sorry about your problem, wish it were simple....

Cheers Ross

 

[jeroen]

Thanks Ross, I probably underestimated the issue and overestimated the capabilities of Singer.

Making a new head assy with a aftermarket cartridge seems the ea̶s̶i̶e̶s̶t̶ least costly option at the moment.
I'm not looking for a ultra precise machine.. I just want to make a decent part one's in a while.

I'm gonna sleep a night or two over this one.

Regards Jeroen





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