PDA

View Full Version : Mill vise moving



QSIMDO
08-02-2015, 11:24 PM
Do I remember correctly reading about putting a sheet of paper between a vise and the table for traction?

I re-installed the vise on the mill after using a rotary table and after a normal tightening of the hold down bolts it can still move if I tap with a hammer.
Not really a tap...more of a hit but not like driving a nail.
Brand new Glacern and the bottom is quite smooth as is the table.
Also, no high spots, table or vise.

Think the paper would help?

quasi
08-02-2015, 11:56 PM
I have heard guys recommend paper under a mill vise to keep coolant from entering and corroding the table.

JoeLee
08-02-2015, 11:57 PM
Never had that problem............. but I've never hit my vise with a hammer either!!!!
If your moving the vise either the table or bottom of the vise is warped or distorted, your bottoming out the hold down nuts on the threaded studs...... if they aren't threaded all the way giving you the false impression that the nuts are tight.............. or your just taking to heavy of a cut.

JL..................

JoeLee
08-02-2015, 11:59 PM
I have heard guys recommend paper under a mill vise to keep coolant from entering and corroding the table.Coolant is supposed to contain anti corrosion inhibitors.

JL......................

RichR
08-03-2015, 12:41 AM
Is it visibly moving or are you using an indicator to see it's moving? If this is based on an indicator reading, maybe it's table moving and not the vise.

Forrest Addy
08-03-2015, 01:56 AM
No slot keys?

Yeah, it could be shock of the hammer blow caused small shift along the Y axis. Residual tension on the lead screw may have resolved as a thou or two move.

What happens if you center the lash, snug the clamps, then tap the vise?

boslab
08-03-2015, 03:02 AM
I found a sheet of wet and dry paper under one once, it had been there for a while
Mark

Mark Rand
08-03-2015, 04:59 AM
Use a high-nickel rod because of the cast iron in the table. :p

lakeside53
08-03-2015, 10:42 AM
I don't use slot keys and ever have a problem with my Kurt 688 vise moving on my BP table.. In the weekend.. taking an excessive DOC with a 1.5 inch insert mill under power feed (cnc servo) resulted installing the spindle ( vfd) stalling and the 25 lb block of steel moving IN the vise, but the vise didn't' move.

Oh... when you crash like that... chuck you tram! I didn't.. damnit...

metalmagpie
08-03-2015, 10:45 AM
I think I'd try some bluing and seeing if the vise and the table really have full contact.

metalmagpie

Juiceclone
08-03-2015, 10:56 AM
agree with the bluing method above...or just relieve the bottom (contact) surface of the vice near the hold down bolt(s) ?

Toolguy
08-03-2015, 11:05 AM
If the vise and table are in good condition, your hold down bolts are probably bottoming out just as they start to get tight. On the good T nuts the thread won't allow the bolt or stud to go all the way through. With T nuts where the bolt can go all the way through, there is the danger of cracking out a big chunk of the T slot when the bolt acts as a jack screw by pushing against the bottom of the T slot. In order to keep the vise and table from corroding with coolant I grease the bottom of the vise and the table prior to mounting the vise. Even with grease in there it still doesn't shift under normal to moderately heavy cuts.

dian
08-03-2015, 11:27 AM
if you have something like 12 mm screws and tighten them properly, there is 10 - 15 tons holding your vise. must be a big hammer to move it.

QSIMDO
08-03-2015, 11:57 AM
I'm checking with an Interapid .0005" indicator in the spindle.
I'll admit to OCD when it get's down to one or two lines, but they put the marks there for a reason and I'm gonna' try!
So, yes, were only talking minimal movement.

Hold down bolts are dedicated to the vise. I had no hold down stud short enough for the vise so I threaded a bolt, nut and washer into T nuts, welded the bolt to the T nut and the other nut runs down on top of the washer which bears on the vise. Nothing bearing on the bottom of the slot.

Yes, slot keys are present.
I'll have to try centering the table lash though I'm pretty sure I wasn't nudging it THAT hard.

Mark, I'd rather use silicon bronze so I could melt it all off with a rose bud later! :p

No, no big hammer...I'm just wicked strong....

And I'll generously provide you all with another opportunity to NOT sound like our wives when they "answer a question with a question" by putting it out there that the paper under the vise idea is "totally busted"? ;)

TN Pat
08-03-2015, 05:57 PM
I don't know that I'd worry about it too much. I believe the force from hitting the vise with a hammer is different from the force from cutting with an end mill, face mill, etc.. I don't bear down super-hard hard on the vise on my mill, or the mills at work. It can still be adjusted a bit with a hammer, but cutting won't move it. Seems like that's normal. I'd be a little concerned about causing table warpage and such if one tightened it that tight...