Adjusting boxways because of chatter?

Hello
I've a question regarding my lathe (emco 140)
It's in surprising good condition for it's age. But since I have the machine it has some chatter.
Z axis passing are all fine. But the X axis (during parting or grooving for example) always leave chatter marks.
I tried to keep the stock as close as possible to the chuck. And played around with different feeds and speeds. But no improvement.
It's a box way machine and I think it was never adjusted (it came from a local school).
Should a boxway be adjusted and how?

tcncj said:

Hello
I've a question regarding my lathe (emco 140)
It's in surprising good condition for it's age. But since I have the machine it has some chatter.
Z axis passing are all fine. But the X axis (during parting or grooving for example) always leave chatter marks.
I tried to keep the stock as close as possible to the chuck. And played around with different feeds and speeds. But no improvement.
It's a box way machine and I think it was never adjusted (it came from a local school).
Should a boxway be adjusted and how?

Click to expand...

Well, yes. Boxways are adjusted by measuring the movement. You push left/right while reading the movement with an indicator and adjust until you read what the manufacturer says in the Service Manual. Often, the manuf. kept changing it's mind which is rather confusing... The way I do it is to test the movement with the ways dry/lubed with very light oil and set to around 15 microns. Way oil will then stiffen this considerably. If the ways are worn this becomes a shade more complicated as you'll need to take a measurement at more than one point and work out some sort of acceptable average. My suggestion is to avoid adjusting ways "by feel" as the feel changes with temp ( a lot !), it's not based on any "insight" and it's practically impossible to gauge the middle ground between too tight and too lose particularly on a heavier axis.

Set the gibs on your VMC Box ways just like this. Depending on wear you need to adjust the saddle or table near the ends so the gib doesn't jam. Or if you never run the machine to the extreme never worn area (original) adust them in the worn area. I always say .0002" per side or a total of .0004" so you have an oil film. Scroll to minute 7. Milling Machine Maintenance: Adjusting Gibs and Ways - YouTube

The machine can have a little lube on the ways. If the table is long screw in 2 eye bolts into T nuts about 12" apart and insert a round shaft and use that for leverage to pry and push the table or saddle to measure the gap. Pry over till solid, then release to measure the "lost motion".. If the ways have Turcite on them you can have zero clearance as Turcite or Rulon does not meet full capacity as far as lubrication until it is loaded. Rich

PS: align and level the bed first. You can also mic (mike) the box ways every 4" to discover where the ways are worn the worse. THen use a happy medium. If the gibs screws are in all the way and the adjustment is gone, you will need to replace the Turcite or.

I don't have a manual of the machine.
I know how the dovetail guides work. Work boxways the same way? So there should be bolts along the axis to tighten them?

This is the bottomside of the x axis slide

The aluminium plates hold the oil scrapers
The block on the right next to the hole (for the ballscrew)
Is this one being used to do adjustments?

The black block on the right side is a tapered gib . It looks like it has a push with sets screw and a lock with cap screw for adjustment. You can also make a wiper for that one too can use 2 bored holes and 2 small hold down screws to hold it to the gib. It looks as if some crud is on there now? I would suspect in the middle of the slide there is 4 cap screws and 2 dowel pin holes that holds the ball screw nut.

Thanks Richard
no it was some way oil
I cleaned the complete machine at the beginning of this year.
I only notice one of these adjustment blocks is that correct? Top of the slide doesnt have one