severe chatter issues

Might be worth looking for small fractures that might have opened up or a rogue piece of swarf trapped in the ways or gibs. Pull the compound and cross slide off and clean and oil and reassemble whilst having a look.

Always annoying when something that used to work stops working :(

Stuart
 
Hmmmm, one thing we haven't suggested but should have looked at first before we progresed to the cutting parts 7 other things mounted on the saddle etc .

Bearing & gears check ?
My new top meSphere cum Atlas lathe had so much crud in the head stock bearings on both sides it 's a wonder it could rotate .
( My head stock bearings are 3 inch taper roller bearings lubricated by grease by the way )

( If there are any meshed gears on the gear box end leave them in place undisturbed at present ) Get a 2 foot long 2x2 thick baton of wood stick & block of wood , so you will be able sit the block on the ways under the chuck to lever off the block , to press the stick on a smooth area of the chuck ......... before you start secure the tail stock to the right hand end & move the saddle to the right end & use a pair of decent protective gloves to help prevent splinters in your hands .

Start the lathe fairly fast , lever on the block with the stick somewhere near the rear of the chuck .. does it make any noise or cause undue vibrations
If none put a 4 inch long thick round bar in the chuck so it protrudes 2 .5 inches , tighten it up & repeat..... this time pressing the lever up on to the bar top ... any difference in noise ?
 
i will have a go at this and let you know how it goes. Just to be clear am i putting my lever block on a smooth part of the chuck to push on it while the chuck is moving?
 
So I had an issue where my parting tool was chattering. I tried re-grinding no improvement. Finally I bought a new piece of tooling. Problem solved. I think there is a microscopic crack in my bad parting tool.
 
jason30809 said:
i will have a go at this and let you know how it goes. Just to be clear am i putting my lever block on a smooth part of the chuck to push on it while the chuck is moving?
Click to expand...

Yes, to see if it induces chatter ,when it's close to the back of the chuck , doing it on the end of the bar puts a bit more pressure on the bearing again to show up chatter .


Reading the above post do you get still chatter when winding in a different cutting tool to your parting off one ?
 
Probably not your solution, but I eliminated a bunch of chatter by slacking off the tension in my drive belt. It was transmitting hum from the motor to the spindle of the lathe.
 
I found the top slide on mine was worn at both ends. Once I ground/lap it flat a lot of the chatter I was getting was reduced. Later I made a new top slide that was longer and dead flat, what a difference!
Pierre
 
As I stood by my lathe turning up a cup / holder that will fit in the drill, press or a tailstock chuck to hold a button type threading die I though more about chatter & could I find an easy way to locate it . .

Turning the internal part of the cup to take the die I found several ways of getting chatter .
One was cutting tool flex as it was sticking out the QCTP by a good 70 mm . Others were incorrect tool tip height , wrong cutting & clearance angle & wrong cutting speeds either too fast or too slow . Having the drive belts a bit too tight also gave a bit of chatter type noise .


I decided to try something to see where else unwanted movement was on my lathe .


I stopped the lathe , brushed off all the noticeable crud . sprayed it with WD40 , cleaned it off with a soft lint free miracle fibre cloth , then sprayed it but very lightly , again with WD 40 on the ways & also at every point of contact where the saddle , cross slide & compound slide touch each pother . I also included the QCTP & tool holders in the light spraying .

I then ran the saddle & slides back & forth to flush out any hidden stuff . Set the lathe running & started to take heavy cuts off a slug of round steel . With all the man cupboard lights on it & using a magnifying glass ....it was easy to see tiny microscopic movements in the meniscus of the WD 40 at the join lines of the ways slides & QCTP .
I then cleaned the tailstock runway , set up the tail stock , centre bored the slug & put the tailstock live centre on the bar , again did the light spraying & whilst doing a heavy to the chuck cut observed the meniscus under the magnifying glass .

The QCTP is best set mid way of the compound slide travel & nigh on locked with the compounds gibs for if it is fully to the chuck you have lengthened the lever by a couple of inches & this does tend to give a fine cockle shell looking finish & light screeching chattering noise . If you want to use the compound it's a matter of a minute to slacken it off enough for the job . & a minute again set it tightish at the half way point when you've finished.

Pleased to say nothing was dramatically out of order, but I've proved that you can see places that may be the cause of chatter .
 
Round in circles said:
...it was easy to see tiny microscopic movements in the meniscus of the WD 40 at the join lines of the ways slides & QCTP .
Click to expand...

Good eye David, I have noticed that too on the big dovetails of my mill with a heavier oil, the "juice line" seems to wiggle with any movement in the joint.
-brino
 
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