Mill Wobble

[Graham MeekParticipant @grahammeek88282]

Posted by John Rutzen on 13/05/2020 18:08:11:

There is not a lot of metal around the taper, only about 4mm. Would it be a good idea to turn up a steel ring and loctite it in place?

Hi John,

You are indeed fortunate the spindle is not that hard. The 4 mm should suffice provided you don't over tighten the drawbar. For peace of mind an additional collar could be fitted with Loctite 630 or similar. I would however put a large chamfer on the exposed corner to allow better vision when using small cutters with an R8 collet.

Regards

Gray,

Hi Michael,

I purposely did not provide any details of the internal taper as this spindle can be had with a Morse taper as well. Plus the outside dimensions were all I took at the time. Had it been necessary for me to make my friend a new spindle. Then I have the details of the R8 socket on file somewhere.

Regards

Gray,

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Graham Meek on 13/05/2020 21:24:17:

Hi Michael,

I purposely did not provide any details of the internal taper as this spindle can be had with a Morse taper as well. Plus the outside dimensions were all I took at the time. Had it been necessary for me to make my friend a new spindle. Then I have the details of the R8 socket on file somewhere.

Regards

Gray,

.

’

Thanks for responding, Gray

It’s no problem at all … I was just surprised [given its tittle] that the sketch was the external detail of the spindle.

MichaelG.

[JasonBModerator @jasonb]

Best ask Neil about that as he gave it a title, Gray said it was just a rough sketch.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Michael Gilligan on 13/05/2020 19:19:58:

Thank you both … Gray & Neil

[…]

.

But it was only a comment, not a direct question

MichaelG.

[Nigel McBurney 1Participant @nigelmcburney1]

There is a statement in the above that the roundness was checked with a vernier,this usually does not work on ground steel bar as it was and I assume still produced by using a centreless grinder,it very basically works in a similar way to the travlling steady on a lathe,there is the grinding wheel plus two two support wheels of a reasonable diameter ,one support wheel has an axis parallel to to the grinding spindle,the other wheel has the axis set at an angle so this wheel supports the work plus plus provides endways feed to the bar. If the machine is not set correctly the result will be a bar which is lobed,the lobes will give a constant diameter,but will not fit a circular ring gauge.A quick test is to set two vee blocks on a surface plate and and place a dial indicator on the bar where it rests on one of the blocks any lobing wil show up, When say fitting a lobed bar into its mating reamed hole and it is found to be tight but can still be rotated, the lobing will show as high spots on the bar,sometimes there can be 3 or 5 high spots,may be more and always an odd number. I came across this effect when making travelling microscopes a long time ago,the fine adjustment rods were made from centreless ground stainless steel,to make a batch of rods about 100 ft of steel in 6ft lengths was used and occasionally one bar woud be found with some lobing,our cure was to lap out the reamed holes in the microscope base as the lobing did not affect function on this particular instrument.Silver steel was also produced by centreless grinding and it was very rare to find roundness errors and that produced by Stubbs was very good regarding roundness and dimensionally,

[not done it yetParticipant @notdoneityet]

I was just surprised [given its tittle]

Perhaps you should explain the meaning of “tittle” for those that never understand your waffle?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by not done it yet on 14/05/2020 18:53:16:

I was just surprised [given its tittle]

Perhaps you should explain the meaning of “tittle” for those that never understand your waffle?

.

Begad Sir … Thou art something of a wit

… almost a half-wit !!

Now, tell me honestly … have you never made a typo.?

MichaelG.

 

 

Edited By Michael Gilligan on 14/05/2020 20:44:25

[John RutzenParticipant @johnrutzen76569]

Hello Graham Meek, Thank you for your helpful reply. I have made a collar today from a piece of 57mm mild steel I already had and loctited to the spindle. I had to alter the spanner to fit but it fits a lot better now and is much more secure. I checked it at 1500rpm and no vibration so I haven't any unbalance either. I think it's a worthwhile mod if you have an R8 spindle on one of these mills even if you haven't any cracks, just a worthwhile precaution.

[Graham MeekParticipant @grahammeek88282]

Hello John,

I don't think you need worry about cracks now, and like you say, "a worthwhile precaution".

Regards

Gray,

Generally,

There seems to be a a problem as I take it, with the title of the PDF Drawing. There are in my AutoCad files several R8 Spindle drawings, not all are for milling machine spindles. I know by this title exactly which it is.

No doubt had I have given this PDF the Machine model number, as well as those for the associated variants, I may have upset a whole load of trade suppliers. Some of whom do not seem to suffer with this problem.

Regards

Gray,

[Author]

Posts