Limit switches m&m 3000 Z axis

Finally getting around to starting up the M&M

Started out Z axis would only move up .
Figured the lower LS was stuck or broke .

Removed sheet metal pannels for acess,

checked upper & lower LS's with ohmeter , both are NC and function consistantly with hand activation.

Then realize there is a 3rd switch that is NO which travels with the tailstock , and is NO as it is on the old (parts donor) M&M we have.

When the NO switch is disconnected and the upper and lower LS's are wired in series the tailstock moves in both directions.

However we hesitate to try to run it this way because the may be used for the center /and/or homing routine.

Any input or comments appreciated

David Lawrence

Realized the moving tailstock Limit Switch is to limit powered tailstock
clamping force , DUH . . . .its on a spring loaded carrier on the tailstock ball screw nut.

Its just stuck open and can apperantly only be accessed by deassembly that causes the tailstock slide balls to come out.

All 4 slides X, Y , Z and tailstock do not have recirculating ball linear slides but slide on almost loose balls just retained in somthing ,looks like a leather strap with holes in it for each ball .


For now the tailstock will move with the upper and lower Limit switches wired in series.

now the 12 inch diameter air flotation rotary table is kicking out the Drives circuit. Wondering if oil or moisture has gotten in the flotation area.

The air drier that came with it does run and i blew out the 4 airline filters , have heard of putting isopropyl alcohol in air line to scavage both.

Its gone through 2 air pressure switches in 6 hours of on time . I believe the air pressure has been between the required parameters . . . two air pressure switches going bad almost together so soon thou ?

I know this machine was working well before we moved it. . . .

There have been several connectors knocked or shaken loose on the trip

I'm almost ready to believe these things should be moved PROPERLY

air ride , new shock adsorbers

seizmagraph or vibration recorder on board . . . Do it right or suffer later.

What a learning experience

David Lawrence

"M&M"...."tailstock" ?... I have no idea what you are talking about.... since when does a measurement machine have a tailstock ?

M&M Precision has been the leader of the pack in 4 axis CMM's packaged with software for checking gears especially bevel and hypoid.
They are now owned by Gleason .

Typically a gear is checked by putting it on an expanding arbor, which is then held between centers.

This link shows the tailstock setup.


David Lawrence