Amolco mill

[Michael BowdenParticipant @michaelbowden71260]

I have recently acquired an Amolco stand alone mill from a deceased estate.

After running for about 10 minutes, the bottom bearing area is quite hot and with the drive belt removed, the 4 step pulley is very stiff to turn. Same condition hot or cold.

I have removed the bottom bearing cover plate, (3 screws) and the bearing appears good. A small amount of grease is apparent.

Any advice on rectification would be welcome.

Mike.

[Michael BowdenParticipant @michaelbowden71260]

Spindle bearings

[Oompa LumpaParticipant @oompalumpa34302]

I would replace the bearings. Grease could well be present, but you have no idea whether or not it is hiding shagged bearings. If they have stood for a long while they could quite well be corroded. It isn't going to cost much to replace them and you know for certain it will be right then.

graham.

[oldveloParticipant @oldvelo]

Hi Mike

A couple of checks before replacing bearings. Is the (1) "Pre Load" too tight (2) Too much grease in the bearings.

An Ampere meter on the motor leads is invaluable for checking the load on the motor and for setting pre load on bearings.

Or as Graham suggests New Bearings.

So a strip and clean examination.

How hot was the bearing housing and the motor casing Hand on for three seconds is fine.

Scorched skin on wet fingers is big trouble.

Eric

[Michael BowdenParticipant @michaelbowden71260]

Hi Gents and thank you for your speedy replies.

I have been unable using non brutal methods to remove the stiffnut at the top of the spindle.

As there is visible corrosion on the V belt grooves, I guess that the pulley is corroded onto the spindle.

I have also been unable to remove the motor pulley.

I am assuming that the shaft removes upwards and therefore the pulley must come off first.

The pulley will have to be sacrificed to gain access to the top bearing assembly. Once there, should the spindle come out of location with a low force or will the headstock need to be presented to a press to remove it?

With respect to the temperature of the headstock, it is just warm after about 5 minutes under no tooling load conditions.

As in my first post, the lower ball race has shiny balls and a sensible amount of grease visible. But what is hidden above? I was originally concerned that there may have been a corroded plain bushing as well.

Thank you for your help and advice so far,

Mike.

[oldveloParticipant @oldvelo]

Hi mike

Before you get all destructive with the pulley.

Try heating up the aluminium pulley and penetrating oil on the spindle.

Drill and tap three 8 or 10 m holes in the top of the pulley threaded rods and 10 mm thick plate drilled on the same layout as the tapped holes back off the the nut holding the pulley a couple of turns.

The spindle comes out the bottom of the housing the top bearing should be a light push fit on the spindle.

With the pulley removed you can press the spindle out the bottom or use a brass or soft metal drift drive it out.

Check that the spindle nut is Left or Right Hand Thread and to remove the key from the spindle.

Eric

[Michael BowdenParticipant @michaelbowden71260]

Hello Eric,

Thank you for your welcome advice, I will attack (?) the mill on that basis.

Regards,

Mike.

[Michael BowdenParticipant @michaelbowden71260]

Hi Gents,

I am pleased to advise that the fault has been eliminated.

Based on the advice received, I drilled 2 x 10mm holes well off the centre of the driven pulley.

Then I made 2 plain spigots for those holes which allowed me to use a breaker bar against the torque required to release the top spindle nut.

As the tension was relieved on this nut, the spindle began to rotate freely.

As a precaution, I will install new bearings.

The driven pulley was not tight on the spindle and came off freely.

Thank you for the good advice received.

Mike.

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