Is there a good way to prevent a vice from shifting when tightening the second bolt

FrodoLoggins · May 22, 2020

So to set up a vice on the bed, I:

1: Clean the bed/vice.
2: Apply a small amount of rust preventative to the bed.
3: Position the vice fairly parallel.
4: Tighten one screw like a mother.
5: Tram the vice
6: Once parallel, I then tighten the second bolt.

(TLDR: Exactly how the HAAS tip of the day vid shows)

Now, when I tram the vice it's within a couple tenths. But when I'm tightening the second nut, the vice always moves an extra couple of tenths, even if I don't apply a rust inhibitor.

So I basically see which way the vice is moving, and tram again purposefully off to try and compensate. Usually works ok, but it's kinda hit or miss.

Maybe tighten the second side with a toe clamp first and then tighten the bolt maybe? Idk, what do you guys normally do?

Mike1974 · May 22, 2020

FrodoLoggins said:
So to set up a vice on the bed, I:

1: Clean the bed/vice.
2: Apply a small amount of rust preventative to the bed.
3: Position the vice fairly parallel.
4: Tighten one screw like a mother.
5: Tram the vice
6: Once parallel, I then tighten the second bolt.

(TLDR: Exactly how the HAAS tip of the day vid shows)

Now, when I tram the vice it's within a couple tenths. But when I'm tightening the second nut, the vice always moves an extra couple of tenths, even if I don't apply a rust inhibitor.

So I basically see which way the vice is moving, and tram again purposefully off to try and compensate. Usually works ok, but it's kinda hit or miss.

Maybe tighten the second side with a toe clamp first and then tighten the bolt maybe? Idk, what do you guys normally do?

I think #4 is your problem. I normally snug both bolts, indicate square, then go back and forth between bolts and incrementally tighten them. THEN you "tighten like a mother".

DMF_TomB · May 22, 2020

tighten both 1/4 tight, check / adjust, tighten 1/2 both tight, check, tighten full tight, check
.
at 1/4 tight also check with .001" feeler gage make sure its not on dirt or burr

ChipSplitter · May 22, 2020

+1 for Mike's post.

Also, you can try putting two washers under each bolt head.
Kind of a thrust bearing efffect and doesn't twist the vise.....

DDoug · May 22, 2020

....and try using a torque wrench.

Start trying some different numbers and see what you get.

Goff · May 22, 2020

I agree with Mike and Doug. Also use a washer under the bolt head, make sure the underside of the bolt head and both sides of the washer are flat and smooth. Use an endmill to dust the surface of the clamp area of the vise, so it is flat.

Anytime you torque on a non flat surface, something will move and you will also lose clamping force. A thick, hard, large OD washer that spans the whole clamping area is helpful .

Ken hosford · May 22, 2020

Thoughts on tightening like a mother

Mill tables droop not because gravity has pulled them down or they were over loaded .
mill tables get peened into warped state, the bottom side of the tee slot gets put into extreme compression when tee bolts over torqued , metal deformation takes place
better to use strap clamps in outer slots front and back (4) and reasonable torque .
I fit tight keys to my vises which means making step keys to fit table and vise the if not in tram you grind keys till they are loose enough to tram vise then you are always very close to start with only minor tweaking
Last comments do not apply to swivel bases which in my opinion should be off the machine till needed when installed preferably next to trammed vise .

jrmach · May 22, 2020

There is the problem that a lot of vice surfaces are only cast instead of machined.
And everything already mentioned.
No torque wrench needed,just common sense

Larry Dickman · May 22, 2020

Bolts? Who the fuck uses a bolt to hold down a vise? Stud and a flange nut.

Another vote to shitcan #4.

DMF_TomB · May 22, 2020

I often set large parts and fixtures (over 40") to within .0001" and even if tolerance is .0002" I find torque wrench is useful. that and a indicator touching part / fixture while tightening to "watch movement while tightening".
.
soft foot is where part / fixture not touching even or parallel and going from 1st contact (uneven contact) to full tight the "foot" is being forced / bent / distorted flat going to full tight. indicator helps to see distortion movement as torque increases in my experience.
.
varying torque to reduce error .0001" or .0002" is common, that and shimming part if needed. sometimes vise / table is not clean enough or there are burrs or distortion where you can get a .001" feeler between table and vise when bolts only 1/4 tight. also if vise hold down stud / bolt too long and forced to bottom of tee slot it can push bend tee slot create table high spot. if you stone table and see shiny high spots its a indication usually of lack of flatness
.
obviously if .001" shim on one end and .0015" shim on other end you are shimming .0005" difference end to end.

EPAIII · May 22, 2020

I was thinking the same thing about rough, cast surfaces. If the nuts are bearing on such a surface, then it could easily apply a torque to the vise as it is tightened. I would machine such a surface flat.

I also like the idea of using two washers under the nuts. You could even put a Teflon washer between two steel ones. But it may become a sacrificial one.

jrmach said:
There is the problem that a lot of vice surfaces are only cast instead of machined.
And everything already mentioned.
No torque wrench needed,just common sense

Larry Dickman · May 22, 2020

EPAIII said:
You could even put a Teflon washer between two steel ones.

ever hear of cold flow?

Joe Gwinn · May 22, 2020

jrmach said:
There is the problem that a lot of vice surfaces are only cast instead of machined.
And everything already mentioned.
No torque wrench needed,just common sense

Yes. If the tops are not flat, the vise tends to squirt out sideways when the bolts are tightened. Very frustrating.

What I've done is to machine flat the tops of the lugs where the heads of the bolts to the T-nuts rest.

I also made up 0.125" thick 12L14 steel washers to go between bolt head and lug top. In this case, the bolts are trimmed to the exact correct length, so no threaded rod and flange nut is needed. Class eight bolts from the hardware store work just fine.

DDoug · May 22, 2020

jrmach said:
There is the problem that a lot of vice surfaces are only cast instead of machined.
And everything already mentioned.
No torque wrench needed,just common sense

I suggested the torque wrench, not because I use one (I don't), but apparently the OP has a problem with control/feel.
A torque wrench will help the OP (not you) gain some experience, and develop some sense of feel.

Richard Winn · May 22, 2020

Larry Dickman said:
Bolts? Who the fuck uses a bolt to hold down a vise? Stud and a flange nut.

Another vote to shitcan #4.

any one that is tired of fucking up there table

T-Slot Bolts | Jergens Inc

fuck those flange nuts also

Spherical Flange Assemblies | Jergens Inc

gbent · May 22, 2020

If you are going to Tighten one screw like a mother, you may be moving the entire table through the backlash in the ballscrew/nut.

bhigdog · May 22, 2020

Snug up both NUTS over washers, not bolts. Indicate. Moderately tighten one nut. Indicate and tap the looser side into square. Moderately tighten the looser nut. Indicate. TAP into square if necessary with a soft hammer. Indicate. Now tighten both to less than a "mother". A post pubecient girl's worth is usually sufficient...........Bob

CarbideBob · May 22, 2020

One thing I see way too often is "tighten like a mother".
Outside or a wreak or crash how often does a vise move?
Maybe in these cases it's best that it does.
Snug is a better word and one comes up on both a tad at a time.

This a common enough problem that I do a walk through on power multiplication on a bolt with newbies along with a pull on this fish scale and "get" pounds produced plus how wrench length works.
It is weird to me now that so many don't know this but I did not when younger so I certainly can't call the kettle black and likely ruined a few T-slots and table tops in my past.
It is a pet peeve on fixture, vises, table clamps and wheel mounts. Some call it ham-fisted.
I've been know to scream out "Who the h... tightened this bolt?".
Over-tight is very bad for life of all parts involved. These are not motor main caps taking 500 HP.

The real question is how little torque can one get away with so that even stalling the spindle in a hogging cut the vise stays put?
Lube or anti-sieze on both sides of the top washers help keep the twist from number two as you come in. Same with mounts for clamp arms.
Lubing or greasing clamps or hold downs seems so very counter-intuitive..... just logically a plain violation of what you want to do.... It just seems all wrong.
Bob

dian · May 23, 2020

if you are really concerned with the vise moving when tightening, make a (preferably heat treated) washer with a leg that goes into the t-slot. then just make sure its contacting in the direction of rotation..

metlcutr55 · May 23, 2020

CarbideBob said:
It is a pet peeve on fixture, vises, table clamps and wheel mounts. Some call it ham-fisted.
I've been know to scream out "Who the h... tightened this bolt?".

45 years ago as an apprentice @ Newport News Shipbuilding, one of my fellow apprentices was a very powerful young fellow likely the strongest man ive ever met. as a gag he took joy in doing this to his mates....a few of the manual machines we ran, a huge vertical slotter and a big taper cincinnati horizontal mill both used cast one pc tslot bolts in the 7/8 to 1" range. Don would wait until you were gone, and tighten your bolts until they wouldn't move. you'd have to go find a longer wrench or a cheater, and you could hear them "creak" when releasing. I watched one fellow Fred work for at least 5 minutes unable to loosen, before someone else helped him with the cheater bar method. im sure it wasn't good for the bolts or machines. then there was the other extreme, that same fellow Fred who worked to loosen for 5 minutes set up that hor mill once, put a 4" sq pc of alloy steel in the vise, and buried a 4" multi flute endmill side cutting 2" deep, and tried to climb mill. even with the climb mill dial engaged, it made a horrible noise when the vice was yanked off the tbolts and the mill exploded into shards. I guess he should have had Don tighten them bolts for him first.

Is there a good way to prevent a vice from shifting when tightening the second bolt

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