Mill sticky x axis

[houstonceng]

Wondered if anyone could share some light on possible causes. My Warco A1S mill (similar to a VMC) has a problem. Winding the X access right to left is OK. Winding left to right takes a lot of effort. I checked the gib and the adjusting screws are tight, so my initial thought that the gib was loose and tightening up in one direction, does no appear to be the root cause. Next thought was the weight of the vice and material, but the Y axis is OK and the X axis is only sticky in one direction, so that doesn’t seem to be it.

Anyone have any thoughts, or possibly had the same thing happen ?

[Jo]

Has a bit of swarf has got into the ways?

If you are clamping down onto the bed as it is Chinese the bed is soft and flexible and it could be bending. You may have over tightened the clamps against the bottom of the vice which may have a bit of swarf under it = it is trying to pull the bed up unevenly so it is being forced into banana shape so it going to jam in one direction..

Jo

[houstonceng]

Just released the vice clamps, and that made no difference. Lifted the vice off the mill, and could not detect any difference. I was wondering if the central lube system isn’t getting oil to the X axis.

Can’t see how a bit of dwarf could get into the X axis slide, as it’s well protected from the table.

Next step is to remove the rubber mat that protects the back part of the Y axis slideways, just in case that’s jamming the table in some way.

[uuu]

Is the stiffness within the table, or the leadscrew? I've seen stiffness associated with the restraint of the leadscrew - roughness in the thrust surfaces.

If you released the leadscrew would the table slide freely?

Wilf

[springcrocus]

Andy,

Another possibility is the leadscrew nut, or block actually, which may be slightly loose in it's holding point. Winding in a particular direction may be causing it to rotate slightly, thus locking down onto the leadscrew.

Regards, Steve

[ettingtonliam]

May 24, 2020 17:54:28 GMT houstonceng said:

Can’t see how a bit of dwarf could get into the X axis slide, as it’s well protected from the table.

.

Yeah, bits of dwarf cause all sorts of trouble.

Seriously though, presumably there is an adjusting collar for the end float on the feedscrew? Check if this is loose, because if so, it could be rotating itself tight when turned in one dirction, and then freeing itself off when turned the other way.

[racinjason]

Does it have the tapered wedge type of gib strips that have a screw in the ends to set the clearance. They will pull in and tighten the travel one way the back out when moved the other way.
Cheers Jason.

[houstonceng]

Thanks for the suggestions. I will check the nut and leadscrew end float. Yes it does have tapered gibs, but the two screws were definitely both tight, so I can’t see how the gib could slide. I will check it again.

[houstonceng]

Checked the gib and it was OK. No sign of it sliding when the table was reversed, however, did notice that there wasn’t much oil on the X axis, but plenty on the Y and Z, so looks like the central oiler isn’t working as it should, copiously oiled the slides, gib and lead-screw on the X axis. Table now moves with same force in each direction. Will investigate further on the oiler when I have time.

Thanks to everyone for the suggestions.

[92220]

I found lubrication of my Senior Universal mill slideways, problematical. I use a Phoenix Paints Refillable aerosol to lubricate my slideways. Makes it very easy to get oil just where needed. I use butane cigarette lighter gas as the propellant.

Bob.

[ettingtonliam]

Rocol slideway lubricant in an aerosol can is good for getting to the slideways under a mill table.

[92220]

Didn't know about the Rocol aerosols. Must try that. Thanks for the pointer.

Bob.