Mikron F75

[Bill YorkParticipant @billyork72513]

Good morning guys.

I have recently purchased a Mikron F75 milling machine and I have started the process of stripping down and restoration, everything is going fine apart from removal of the spindle, I have loosened all bolts, screws and retaining rings but the thing will not come out or even move although it still has free movement to spin, any help on the process of removal would be greatly appreciated. Thanks Bill.

[Bill YorkParticipant @billyork72513]

Spindle removal

[Rod AshtonParticipant @rodashton53132]

Bill – If this is the belt driven horizontal head. I tried for a long time to figure it out. In the end I converted it to something else. Not too helpful I know!!

[John HaineParticipant @johnhaine32865]

Have you contacted David Samways at Anglo-Swiss Tools?

[Bill YorkParticipant @billyork72513]

Thanks for the reply Rod,It is the horizontal head and every thing is fine I just want to get the spindle out to polish it. every thing about the machine is great, the build and finish is what you would expect from the Swiss. There must be someone out here that knows how to dismantle this thing.

[Bill YorkParticipant @billyork72513]

Thanks John I have spoken to Anglo-Swiss but David said he has never had to remove the spindle and does not know how to do it nor can I find any literature on the subject.

[Bill YorkParticipant @billyork72513]

I have added some pics in albums if any one would like to cast an eye over them and maybe have a suggestion.

[Pete RimmerParticipant @peterimmer30576]

I think the answer probably lies with that off-set square drive fitting in the cone pulley. Have you figured out it's purpose Bill?

[Ady1Participant @ady1]

[Ady1Participant @ady1]

loosen all the screws to disengage the pulleys from the spindle, the pulley will probably be on a long key so still cannot be turned independently

The main thing is the direction of removal, usually a spindle exits on the load side but that's with lathes

Then get a big hammer….

Edited By Ady1 on 25/10/2018 15:36:46

[Michael GilliganParticipant @michaelgilligan61133]

Given the oiling point in the small step of the pulley … is there a backgear built in ?

MichaelG.

[Bill YorkParticipant @billyork72513]

Yes it is an oil port and yes there is a 3-1 back gear in the large step.

[Bill YorkParticipant @billyork72513]

Posted by Pete Rimmer on 25/10/2018 15:14:03:

I think the answer probably lies with that off-set square drive fitting in the cone pulley. Have you figured out it's purpose Bill?

The square bolt you refer to is released to engage the back gear that is located in the large step pulley and as far as i can see does not locate on the spindle

[Bill YorkParticipant @billyork72513]

Posted by Ady1 on 25/10/2018 15:29:52:

loosen all the screws to disengage the pulleys from the spindle, the pulley will probably be on a long key so still cannot be turned independently

The main thing is the direction of removal, usually a spindle exits on the load side but that's with lathes

Then get a big hammer….

Edited By Ady1 on 25/10/2018 15:36:46

I have released every screw nut and bolt but there is no lateral movement at all, i have given it several gentle taps with a lead hammer but still no movement, I am reluctant to give it the big hammer treatment as often the result is irreversible.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Bill York on 25/10/2018 16:26:45:

… and yes there is a 3-1 back gear in the large step.

.

Nice !!

MichaelG.

[Neil WyattModerator @neilwyatt]

I suspect you have to undo the ring nuts with c-spanners in a co-ordinated manner as the spindle slowly edges left or right through whichever is the largest diameter hole…

But… if it ain't broke, why take it apart?

[Michael GilliganParticipant @michaelgilligan61133]

Bill,

It appears that the headstock is similar to that of the T90 lathe

… You may find more information about that.

MichaelG.

[Bill YorkParticipant @billyork72513]

Posted by Neil Wyatt on 25/10/2018 20:20:34:

I suspect you have to undo the ring nuts with c-spanners in a co-ordinated manner as the spindle slowly edges left or right through whichever is the largest diameter hole…

But… if it ain't broke, why take it apart?

It's all about the finish, easier to polish the pulley off the head than on and once I know how to do it I can pass it on.

[Bill YorkParticipant @billyork72513]

Posted by Michael Gilligan on 25/10/2018 20:36:07:

Bill,

It appears that the headstock is similar to that of the T90 lathe

… You may find more information about that.

MichaelG.

Yes all the heads on the T90 will fit the F75 and vice versa the only difference is the t90 heads tend to have 4 speed step pulley, but still cannot find any info on strip down.

[Michael GilliganParticipant @michaelgilligan61133]

Hardly a service manual, but … The last few pictures on this page might help, a little:

**LINK**

http://www.lathes.co.uk/mikron/page4.html

MichaelG.

[Ady1Participant @ady1]

Posted by Michael Gilligan on 25/10/2018 21:22:33:

Hardly a service manual, but … The last few pictures on this page might help, a little:

**LINK**

http://www.lathes.co.uk/mikron/page4.html

MichaelG.

ooooh, scary bearings

They look like pultra 1590 ultra high precision bearings

1 Buy a manual

2 Consider not opening them up unless very very necessary

Edited By Ady1 on 26/10/2018 10:10:54

[Ady1Participant @ady1]

I have released every screw nut and bolt but there is no lateral movement at all, i have given it several gentle taps with a lead hammer but still no movement

If you have to do it even on a simple drummond then you have to break the spindle key from the pullies with a decent whack, there can be considerable resistance to that first movement because the final fit in a decent lathe is very firm, the key turns the two parts into a single solid unit

So you will probbly have to release the bearings with a c-spanner to get some movement in the spindle and pullies to start with (a bit of jiggle), then figure out which direction to whack it in, the spindle should be slightly bigger at one end compared to the other because of step downs along its length

I wouldn't really be scared of taking it apart, my fears would be about getting it back together

[Bill YorkParticipant @billyork72513]

OK chaps after a whole day of poking, pondering and trying different methods I have decided to leave the spindle alone and instead mounted the head on the lathe bed with suitable packing and used the chuck to provide drive to the spindle and polished the pulley, I have heard people say that all information is out there on the internet, you just need to look for it, well that's not true, I spent almost a week contacting the original makers, the import company or whats left of them and many knowledgeable sites in various countries all to no avail but having said that the information I have gleaned has been invaluable and will be retained for future use. The Mikron is nearing completion and will soon be up and running (touch wood). and I will list some pic's of the completed machine. Thanks for all the help and suggestions.

[larry phelan 1Participant @larryphelan1]

I agree with other Members,let sleeping dogs lie ! They are seldom in good humour when you disturb them,your spindle might be the same !! Why risk it ? Clean it where it is,the belt should soon clean up what,s left.

Never tempt the Gods !! How do I know ? Ask me ! Been there,done that,more than once !

[Bill YorkParticipant @billyork72513]

Posted by larry phelan 1 on 29/10/2018 12:09:32:

I agree with other Members,let sleeping dogs lie ! They are seldom in good humour when you disturb them,your spindle might be the same !! Why risk it ? Clean it where it is,the belt should soon clean up what,s left.

Never tempt the Gods !! How do I know ? Ask me ! Been there,done that,more than once !

Hi Larry, yes you are right, except the pulley will not be used so the belt will not have the chance to do the polishing, the machine is going to be driven via a pulley on the end of the spindle with power coming from a DC motor giving variable speed control.

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