play in bearing to spindle

Any ideas or is it acceptable? I have receive new bearing today and as I assemble it I'm finding some play. The bearing is suppose to slide to take up end float and pre-load. The dti is in mm. If you watch the bearing close you will see it rocks a little best seen after I zero dti. Would the movement get better or worse as spindle warms up? Is there anything like bearing lock that would take up the movement but still allow bearing inner race to slide.

Just editing to say dti  end is on inner race.

http://vid1118.photobucket.com/albums/k620/irlunn/lathe/My%20Movie%20bearing.mp4

Edited By Ian L2 on 02/01/2015 19:02:19

Looking at the video I'm not sure just what you are measuring, if the spindle is assembled is there play in the spindle?

Is there any sign or wear on the shaft?

Bob

Are you saying the inner section is a loose fit on the spindle as it looks like it is moving to me.

Video here

Hi Guys Yes the bearing inner race rocks on shaft. Shaft has been skimmed using old bearing to check fit as the old bearing would not move (slide) and needed hydraulic press to remove it. Thinking just tadd to much has been took off. looks like 0.05mm on dti.

Should be a press fit on the shaft,

I think that would be too tight. The bearing at this end of the spindle has to slide along the spindle to adjust the preload on the bearingsby the action of the threaded collar on the thread visible in the video. I suspect that the reason this thread was damaged in the first place was because the old bearing had seized onto the shaft.

Having said that, 0.05 mm diametric clearance is too great. Something like 0.01 mm clearance should give a good push fit.

The shaft should not have been skimmed, polishing with some fine emery should have done the trick. Unfortunately the only option now would be to build up the shaft again, perhaps by electroplating.

Russell.

Thought that might be the case, will make some enquires next week. Does electroplating build up uniform in thickness or will it need re-skimming after?

Electroplating should if done correctly build up an even coating and you should be able to calculate the amount of material applied by current and time but nothing to stop the item being measured, I would be inclined to nickel plate.

You can get DIY kits.

Bob

Before attacking the shaft, try fitting the bearing with Loctite bearing retainer, it works. The place I used it was the top bearing on my Rexon mill drill after the bearing spun in it's housing, but I have used it on other types of machinery to fit the bearing to the shaft.

Ian S C

Hi Ian S C

Wont it also stop the pre-load adjustment and being able to loosen the pre-load when not being used. When bearing is fitted using bearing retainer how hard is it to remove should one need to? I'm wondering if the original had been fitted with the use if it which would also explain why the old bearing (which did not come off easy) does not have as much movement (but still has some) if there,s thin layer still on inner race.

I notice that your thread goes to a shoulder. If all else fails could one not turn down to the bearing point, fit a heat expanded sleeve and then recut?

Hi Ian

Read you reply to Ian S C it appears that the bearing had been "Loctited" before and was successful

You have to work quickly when setting preload on a bearing when using Loctite before it sets.

The bearing manufacturer can supply the information on how much torque-resistance is required.

or

A product I have used is "Ezi-Sleeve" to slide on to a shaft that has been damaged were an oil seal has run

Perhaps this may be of some use

Try an E-Mail to them @

[email protected] or their website

www.castleinternational.com.au

Eric

With Bearing lock the bearing can be moved with ordinary bearing tools, it's not a shaft lock. The original bearing wasn't going to move much, pressed on the shaft, the shoulder I presume locates the bearing inner race.

Ian S C

Photos added:-

Edited By Ian L2 on 04/01/2015 11:31:47

Before you start electroplating you can try if thin brass foil (0.025 mm) wrapped around the spindle does it, Niko.

Contrary to what has been said above, the bearing pre-load isn't set cold. According to the handbook the correct procedure is to run the lathe for 30 to 60 minutes to warm up the spindle. The adjustment nut should then be loosened until play is observed in the spindle ( I use a dial gauge to monitor the end float). The adjustment nut is then carefully tightened until the end float is just zero and then tightened another 1/16 of a turn and locked in place with the grub screw.

The above procedure would seem to prohibit the use of Loctite as it will set before the adjustment can be made.

As long as the finish on the spindle is good it shouldn't be necessary to grind it after plating. You only need about 1 thou of plating so the finish on the spindle will come through on the plating. Someone suggested a home nickel plating kit. It's about 40 years since I did any nickel plating at home but it wasn't too difficult so I think it's worth having a go. You will need to mask the screw thread as you don't want to build that up.

One more observation. From your photos you seem to have flat disks instead of the part 10A-3 dust cover shown in the parts list and fitted to my Atlas. It may be that this was a design change for your split casting version of the headstock but it's worth checking.

Russell.

Hmm... just done a quick calculation. From Faraday's Law and using a typical current density of 50 A/m^2 it looks as if it will take about 14 days to build up the required thickness of nickel (unless I've dropped a zero somewhere!). So, plenty of time for keeping a check on the diameter.

Russell

Have a look at the sectional view of the headstock I put in my album (Misc folder) a while back. You should see that there is a flanged pressed steel part fitted either side of the bearing. That's what I was referring to. In your picture it looks as if the front disk is trapped between the bearing and the end of the spindle. Like that it will just rotate and fling the oil everywhere. It should be flanged and a push fit into the headstock casting and have a small clearance to the spindle.

Can you explain what you mean by "not as smooth as one would expect". Do you mean that there is vibration or grittiness? Or do you mean that it has a wobble as it rotates?

The place to check for the spindle running true is on the register behind the thread on the spindle nose. I get 0.005 mm on the cylindrical part and 0.01 mm and I've never changed the bearings in the 40 years I've owned the lathe although I did remove them and give them a good clean in solvent.

Russell