Mounting Bench vise A or B?

[motorcitykid]

My vise is pretty hefty at 130pounds, I’m interested in mounting it so I have two corners of the bench to utilize and have the static jaw flush with on both sides. The bench is over 2,000 pounds made of steel, 4’x9’ so I’m not concerned much about the weight tipping it.
Would you mount the 3 ears inside or to the edge? A or B?

 

[General Geoff]

The bench is over 2,000 pounds made of steel, 4’x9’

Third ear to the corner edge. If it was a wooden bench, I'd have said put the third ear to the inside.

 

[larry_g]

A is going to put you fixed jaw further from the edge than B. My suggestion is to try both ways and see if both work for you or if only one does what you want. The last vise I mounted would only work one way.

lg
no neat sig line

 

[RTM]

B

 

[GeoBruin]

Whichever way allows something tall to be clamped in the the jaws and still clear the edge of the bench. I suspect that is B in this case.

 

[pelletman]

B and make sure the static jaw is a bit proud of the edge of the bench so you can put long things in it down to the floor.

 

[motorcitykid]

Both A and B have the same clearances which are marginal as the swivel base flares at the bottom which causes it to stick out 1/8” if I wanted it at a right angle to the face of the table.

 

[2oolhound]

All my vises have always fit closer using the B position.

If you look at the vise and imagine you have an 1800 lb object clamped in it, if not bolted down the vise would want to roll off the bench. In the A position the front is being held up but all the rest of the stresses run across the 2 side bolts. In the B position the back bolt would also seemingly take some of the load off the 2 side bolts and utilize the strength inherent in the body of the vise in spreading the holding force toward the back. In the A position there is nothing making the back of the vise body beyond the 2 side bolts, hold anything.

Disclaimer: I'm not an engineer

 

[PierceA]

Clamp it in place with large 'c'-clamps for a week or two, and decide which you like best.. I think I'd go with B, I agree with 2oolhound's assessment of stresses taken by the mounting ears.
Also: make sure the bottom of the base is FLAT. No bumps or waves. If you need to, use a flat file or put the base in a mill and machine it flat. If there are any high spots, when you bolt it to a steel bench top, it will break an ear off the base.

Pierce.

 

[tarmy]

Clamp it in place with large 'c'-clamps for a week or two, and decide which you like best.. I think I'd go with B, I agree with 2oolhound's assessment of stresses taken by the mounting ears.
Also: make sure the bottom of the base is FLAT. No bumps or waves. If you need to, use a flat file or put the base in a mill and machine it flat. If there are any high spots, when you bolt it to a steel bench top, it will break an ear off the base.

Pierce.

This. I would temp install as mentioned and see what works for a few projects.
Nice vice too!

 

[motorcitykid]

I drilled one hole and utilized one existing from my previous vise and mounted in the b orientation. The reason being that A would require the base being a slight bit setback and I want to have as much useable space beyond the static jaw as possible. So far it’s great, in a perfect world I’d be able to also raise and lower the vise depending on the task I’m using it for.
But, it’s really impressive so far. I appreciate all of your insight greatly.

 

[Sumboodie]

Where do the boltholes line up in relation to the vise? I assumed 2 on the side and 1 in back, but that's not making sense with what you drew out.

 

[motorcitykid]

Where do the boltholes line up in relation to the vise? I assumed 2 on the side and 1 in back, but that's not making sense with what you drew out.

This is the vise/base.

 

[seber]

B. The leverage of a part hanging over the front of the bench will try to tip the vise forward and off the bench. That force is counteracted by the third bolt. That's why it is there. Otherwise it serves no purpose.