harrison m300, spindle run out…bearings?

[Grindstone CowboyParticipant @grindstonecowboy]

Silly question, and you may already have checked, but your chuck jaws aren't bell-mouthed, are they?

[CarlParticipant @carl48656]

Although work is tight in chuck jaws it can move causing vibration/bad finish and still be tight after moving. Jaws may not be true and gripping along their length.

How much work was out of the chuck when cutting and was it supported ?

I have seen seen the bolts supporting top slide shear causing movement under load whilst top slide felt tight, also clamping on a Dickson style tool post was damaged and the tool moved under load but felt tight to the hand.

C

[Sebastian YorkParticipant @sebastianyork93348]

Update…

Ran the machine without a chuck fitted…this is cold admittedly…

The motor sounds fine…there is a nice whir…with a very very faint dull repetitive thud…

Also while the dti reads very little run out at low rpm…and 800rpm it throws about…and the spindle visibly wobbles…can be felt by allowing spindle to run under the fingers…checked by more than 1 person so not imagining…

Edited By Sebastian York on 18/12/2018 14:09:43

[Neil GreenawayParticipant @neilgreenaway71611]

If you pre-load the spindle bearings artificially with the tailstock by applying a thrust load with a revolving centre towards the headstock do you experience any movement? I remember this was the case with my spindle and when you force the tapered roller bearings together you can eliminate the "slop". Might be worth a quick check before investing in any purchased parts such as belts etc – although of course belts sitting in one position for a time can take on a "set". If the rubber isn't dozed they may still be OK when warmed up a bit.

Neil.

[Sebastian YorkParticipant @sebastianyork93348]

Tonights update on investigations…

Had the top off the headstock. Oilways clear and no visible gumming. Lots of tiny phoshpur bronze looking glittery bits rested in the oilways, but cannot ascertain where they came from…all gear teeth intact and no visible damage to any component. I expected to see small filings as in most gearboxes. May pay to put a magnet in in there somwhere as a collector for any steel that finds its way in…In neutral the bearings can be heard rotating, but no rattle or tight spots…

Loaded the headstock spindle from the front with a revolving centre in the tailstock, and with a calibrated 0.01mm dti mounted on a magnetic base directly on the headstock ( to eliminate the risk of the saddle being a contributing factor) and with the nose of the dti on the smoothest part of the spindle I could find…was able to remove the run out. Even at 2500rpm the needle hovers around 0…so within 0.01mm run out…will assume its more of the surface finish on the spindle than actual runout as when rotating by hand with neutral selected…0 measurable run out with a 0.01 dti.

With the top off exposing the gear train, and the dti engaging the approx centre of the spindle, there is a eccentricity of 0.14mm rise/fall…which I attribute more to the gears that are splined onto the shaft rather than a distortion, as I very much doubt it'd bend in the middle when supported at both ends…

Changewheel end there is an eccentricity run out of just about 0.02mm,

So from what I can fathom the spindle is not rotating true in the headstock…and is spinning at a very slight (0.02mm ish) angle.

So…if the machine has taken a topple at some stage, could this be enough to knock the bearings off centre? Are there any other options that could cause a spindle to either distort or shift the bearing seat to run eccentrically?

On the M300 is the spindle adjustable for eccentricity?

Did however notice that the spindle got very warm, almost to warm to hold for extended period, while the rest of the headstock was at a comfortable temperature.

To much pre-load on the bearings causing the whole lot to get hot quickly? or possibly inadequate lubrication keeping them cool?

Other tests:

dti mounted on the rear of the saddle with the tip bearing on the V and there is no crabbing/movement of the needle over the length of saddle travel.

Still a lot of vibration, so next task is to remove the belts, check the motor for play and ensure all pullys are properly aligned.

[Sebastian YorkParticipant @sebastianyork93348]

Incidentally anyone with far more experience of these things live anywhere near Exmouth?

[Neil GreenawayParticipant @neilgreenaway71611]

Hi Sebastian
Don’t suppose you took any photos while you had the cover off and headstock opened?did you notice if there was a pair of preload adjustment ring nuts on the back side of the inner race of the front taper roller bearing? When adjusted correctly you may also have similar adjustment on a pair of deep groove angular contact bearings on the rear end which would also need fine tuning.i am wondering if the preload were slightly out could this cause heat generation.i would doubt if there is bearing eccentricity adjustment…..they normally seat in a machined shouldered bore in the front end with the inner race fitting in on the shaft from tailstock to headstock fitting direction and the various preloads being adjusted. My memory is a bit woolly on the exact details however and trying to put recollections into words! Do you have a manual with assembly general arrangement drawings etc?

One of your concerns as mentioned relates to a potential fall or impact in the past…..I could see features such as the carriage and handwheels being damaged……but the spindle is well in board of the outline so just wondering what spindle or bearing damage likelihood is potentially going to be?
Neil

[Neil GreenawayParticipant @neilgreenaway71611]

Another thought…..I think the m390 series had an external oil pump driven inside the changewheel/belt guard. Does the m300 use this forced oil circulation…..if so is it circulating oil as designed or maybe it’s just using splash lubrication up to the bearings and causes.

[Sebastian YorkParticipant @sebastianyork93348]

Hi Neil.

No pics taken yet, but as am currently seriously considering a full strip and clean I may make a photo diary…perhaps should have done it with the chucks as they were very dirty inside…with a layer of surface rust…and are now nice and clean…

From my initial inspection there are no pre-load springs or nuts. This is backed up from the exploded parts diagram in the manual…it looks like the races front and rear press in, and preload is adjusted by by a nut at the rear of the spindle.

My concern about it getting hot was if I had introduced too much force onto the front face of the spindle in order to remove the run out…but once the revolving centre was withdrawn the spindle continued to spin true…

Oil delivery is simply by splash…hits the roof of the headstock and is gravity fed down to the bearing races.

Addition of forced oil circulation may be a consideration…along with the magnet and maybe a gauze filter…

Tomorrow I will also tap my parallel bar into the spindle to see how true that happens to be…but at the moment I am feeling that its a combination of lack of use setting the belts, old oil and just being sat, and the spindle having gone very slightly loose, as I cant hear any bad noises…or feel any roughness…only thing is how hot the spindle got…

Incidentally…if I do opt for a full restore…whats the preferred method of paint removal…sandblast with vital areas protected with anti blast tape…or acid dipping?

[Phil PParticipant @philp]

I have an L5A and when I bought it many years ago it was turning strange pitch but uniform patterned lines on the work.

It took a bit of fathoming out as to what was causing it, in the end it turned out to be the main spindle bearing behind the chuck had a faulty cage, and every revolution of the cage caused the strange lines to appear on the work.

Because the bearing cage rotates at a slower speed than the inner race/spindle it took a bit of finding.

At the time a new flanged taper roller bearing from Harrisons stores was £250, so I went to a bearing supplier in Leeds and they supplied one for around £40. I mentioned to them how much Harrisons were charging and was told that they actually supplied Harrisons with bearings. !!!

Once new bearings were fitted and adjusted all was well on my machine.

In an earlier post you mentioned hearing a "very faint dull repetitive thud" I would certainly be looking to see where that was coming from before you do anything else.

Phil

[Mike PooleParticipant @mikepoole82104]

I think you need to find the source of the bronze particles and this will probably be where your problems lay.

Mike

[Swarf MakerParticipant @swarfmaker85383]

Following up on Mike Poole's and Phil P's responses, one of the more significant possibilities for the erratic behaviour of your spindle is that the cage of one of the spindle bearing is breaking up. The cage may well be a bronze one and the source of your oil contamination. If the cage is allowing the rollers to take up their own positions there will be occasions when they will crowd together and thus allow the spindle to divert off axis. At other times, particularly with a longitudinal load on the spindle, the forces may well cause the rollers to distribute themselves more evenly. Worth serious consideration I feel.

[not done it yetParticipant @notdoneityet]

The three preceeding posts make sense – certainly enough to be checking them out. Anyone ignoring swarf in the lubricating oil in a gearbox needs to find the origin/cause of that swarf.

[Nigel McBurney 1Participant @nigelmcburney1]

You mentioned possible restoration and repaint ,do not use a shotblaster to clean any parts on machine tools with the possible exception of sheet metal covers . If you must clean off the paint use a rotary wire brush in an angle grinder.Regarding your spindle problems,the bronze particles in the oil and the severe overheating of the spindle sound serious and a strip down is essential,on a normal lathe the spindle never gets that hot, I read through this thread yesterday and waited to have a good think,the reader who suggested the bearing cages may be breaking up may be close to the truth,I have seen cages break up on old motorcyles,and once saw the table lead screw bearings cages on a large cnc mill break up and and produce oval grooves rather than circular grooveson the workpiece. When the lathe handwheel was broken it may have been a minor shunt with a forklift or a big bang ,ok the hand wheel is away from the spindle,but if the four jaw chuck or a faceplate was fitted at the time that may have also come in contact with some immovable object and given the spindle bearings a big shock,I have also seen machine movers put a lifting strop on the spindle behind the chuck or another favourite is to thread a strop down the spindle bore,put a large spanner into the loop and lift by using the loop at the other end of the stop,both methods putting 2/3 of the lathes weight on the spindle bearings. I would get a handbook,some websites sell handbooks /copies, shop around as some dealers are a bit greedy,assuming Harrisons are still in business,try a phone call.Also when stripped check the straightness of the spindle,if there is a slight error ie bent this may have caused bearing damage in the first place,and it would be a waste of time time fitting new bearings to a damaged shaft.

[Mike PooleParticipant @mikepoole82104]

The castings have probably been smoothed with a filler layer so you may make work for yourself if you go back to bare metal. A rub down and fill of any damaged areas may save some time and effort.

Mike

[Sebastian YorkParticipant @sebastianyork93348]

The latest:

All measurements taken with a calibrated 0.01mm Oxford dti (is this accurate enough or so I need to dig out the 0.001mm?)

Lathe and bearings cold.

Starting from the front, having supplied artificial preload from the tailstock with a revolving centre:

Dti at 90 degrees to spindle, on very tip of spindle nose, no real measureable run out…needle hovers over 0 line.

Dti at 90 degrees to spindle, on camlock mounting diamete, no real measurable run out…needle hovers over 0 line.

Dti parallel to spindle bore, again, no measureable run out.

Fine needle movement is attributed to surface finish.

Very centre of spindle as previously said has eccentricity of 0.14mm, but this is attributed to the gearing splined onto the shaft…it cannot bend in the middle right?

Having removed the rear bearing cover, and mounting the dti as close to the bearing as is possible, again there is no real measureable run out, needle hovers over the 0 line within 0.01mm. This again is attributed to surface finish.

At the very very end of the spindle there is eccentricity of 0.01-0.015mm. As the spindle looks to only be turned, and not ground finished, I assume this to be just manufacturing tolerances, but would welcome another opinion.

With a no 3 morse taper parallel bar mounted into a 3-5 and then into the spindle bore and tapped into place with a nylon mallet, the tool post runs true to the bar, 0 measureable deflection, needle hovers over the 0 line. Likewise, when measured up close to the spindle 0 run out, when measured at the very tip of the bar, a very small amount of run out, but a few gentle taps with the nylon got it pretty much bang on to 0…

Frustratingly removing the tailstock preload did not allow the spindle to relax, so currently still measuring as I have said…

With all that said, I am 99.99% certain that the spindle is not distorted. Other opinions would again be greatly appreciated.

Nigel has mentioned that some dealers load by stroping around the chuck. Ironically this was exactly how mine was loaded many years ago. Remember distinctly as thought at the time, that cannot be right, or why would they machine a purpose built threaded hole into the bed for a lifting eye…but at the time said nothing…that will not be the case ever again…

Bearing wise, and this is where I think I may have seen issues…

Looking into the rear bearing the needles are hollow, you can actually move the inner race between fingers…and when rotating the spindle you can see the needles rotate, and even move position…ie shift there axis…by inserting a drift into the bore of the needles it is possible to wiggle them left and right very very easily…I don't think thats right. Some of them actually drop just through gravity as they rotate past the TDC position through 45 degrees into 90 degrees rotation…so I am going out on a limb saying that the preload is way off…even though I cannot hear or feel anything wrong when turning the spindle. The heat being generated is possibly down to the front bearing having to have had to work a lot harder to remain concentric, which has led to premature wear.

I am going to endeavour this evening to take some footage of all said above to post for better passage of information…as pictures paint a thousand words.

As for the bronze looking bits in the oil…I cannot see any where they may have come from…but on the exploded diagram I have from a downloaded manual, there are some bushes on some of the gear shafts, which may well be bronze material but hidden from view till stripped out…Looked for evidence of contamination of the rear bearing but cannot see if any of this has made its way into the rear one to cause damage.

The saga continues…

As said, anyone near Exmouth on here that knows more than me?

[Swarf MakerParticipant @swarfmaker85383]

Go no further – including running the lathe under power – until you have resolved the issue with the rear bearing – that is most clearly wrong!

[Neil GreenawayParticipant @neilgreenaway71611]

What sort of bearings are fitted in the rear end of the headstock – cylindrical roller bearings, needle roller or is it another taper roller bearing? If its a taper roller bearing and the rollers are appearing to not be pre-loaded then this can be rectified with whatever adjustment is provided- if they are cylindrical roller bearings or needle rollers and the rollers are moving in the cage then perhaps this is indicating wear. If you had a headstock cross section drawing you could upload a photo of this might help everybody with the diagnosis advice.

Neil.

[Swarf MakerParticipant @swarfmaker85383]

Tony's lathe site declares that "The spindle, which runs in Gamet Super-precision opposed-thrust roller bearings."

So adjusting the end float might well cure things although there will likely be the usual problem of the bearing not wanting to move in response to the adjustment after this amount of time. Not withstanding that, I think that there has to be some damage to that rear bearing for the rollers to have that amount, and degree of freedom, to move as they are. The bearing cage should still support the rollers in their correct place and orientation, no matter how slack the bearing adjustment is so my money is still on a broken bearing cage.

[Ex contributorParticipant @mgnbuk]

We have a Harrison VS330 at work, which is similar size & vintage to an M300 (our machine is an '87).
While I can't guarantee it (can't find an M300 parts book online), I would expect the spindle bearing arrangement to be similar if not the same.

The VS330 has a Gamet 124070/124112xC front bearing and a Gamet 110055/110100C rear bearing according to the parts book. Hope these are OK, as Simply Bearings list the front bearing at £325.62 & the rear at £271.07 – both plus Vat.

The VS330 manual spindle preload setting proceedure is to check the drag torque on the spindle after running at 800 rpm for 10 minutes.

The correct torque is given as 0.9/1.1Nm (8/10 inch pounds), checked by wrapping a cord 3 times around the chuck & attatching a light spring balance to the free end of the cord. Gently tension the spring balance until the spindle just starts to turn & maintain the rotation – read off the value of the spring balance. Example given is using a 160mm dia. chuck, the balance reading should be 1.14/1.38 kg (2.5/3 lbs).

Bearing adjustment is via a nut under the rear bearing cover. Remove the end drive guard, changewheels, swing frame & rear bearing cover. Release locking screw in the adjusting nut. Using pin spanner provided with lathe, adjust the nut clockwise to increase preload. As overtightening will shorten bearing life, work in small (3mm at nut periphery) increments. After each incremental adjustment run spindle for a few minutes & re-check drag torque.

Loose rollers suggest adjustment is required – all the rollers should rotate when the spindle is rotated.

HTH

Nigel B

[Sebastian YorkParticipant @sebastianyork93348]

Cheers for all your help gentleman.

They are Gamet opposed taper roller bearings, as named by Nigel B (same part numbers in my manual).

Have made short videos of all I previously posted…but this is where technology beats me…I cannot fathom out how to share them on here!

I'm currently feeling Swarf makers theory on a broken cage may be right… as said I can actually move the cage of the rear bearing between my fingers. This is just the rear as cannot get to the front without pulling at all apart…

Not wanting to power it up…I tried the torque test as described…admittedly with a 200mm chuck…and without running the machine…but only took just over 1lbs of force to rotate the chuck…so potentially it is loose on the preload…

I also don't have the adjusting wrench yet…so either need to make or buy one.

If anyone knows how to…or is willing to post the videos for me…I can show clearer the state of things…

regards

Yorkierm

[JasonBModerator @jasonb]

Easiest to upload it to You-tube then put the URL in a post.

[Sebastian YorkParticipant @sebastianyork93348]

OK then…some short (20 second roughly) clips.

Whats the general thoughts gents? all very much appreciated.

parallel to spindle bore

**LINK**

90 degrees on spindle nose

**LINK**

90 degree to chuck mount

**LINK**

centre of spindle

**LINK**

close to rear bearing

**LINK**

90 degrees at end of spindle

**LINK**

traversing along parallel bar

**LINK**

rotation at end of parallel bar

**LINK**

BEARING PLAY…these are probably the tell tale ones…

**LINK**

**LINK**

**LINK**

That turned out to be a lot less painful than I imagined…and I now have a you tube channel

hope these help…

[Anonymous]

Posted by Sebastian York on 19/12/2018 17:38:21:

Not wanting to power it up…I tried the torque test as described…admittedly with a 200mm chuck…and without running the machine…but only took just over 1lbs of force to rotate the chuck…so potentially it is loose on the preload..

I'm afraid it doesn't tell you anything of the sort. We're talking microns of clearance, so even a small temperature difference is important. Running my M300 for 10 minutes or so reduced axial play to undetectable, even though the front cover, by the Camlock fitting, still felt cold. When I've run the lathe for some time that cover is warm to the touch, probably around 30/40 degrees. In order to make comparisons with the manual you need to follow the same procedure, although the temperature of the bearings will have a bigger effect than the diameter of the chuck. Of course a bigger diameter means more torque for a given force.

Andrew

[Neil GreenawayParticipant @neilgreenaway71611]

Wondered if the symptoms here have any similarities?

https://youtu.be/CHzCXm6DXCU

[Author]

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