How to Properly Seat Work in a Milling Vice

[HMF]

I promised not to ask questions, but this is one I really need to know.
I was reading up on the VN 12 milling machine in preparation for moving mine into the basement, and found this thread on properly seating work in a milling vice. I know to use parallels as a "step" for the work, but, apparently, there is a technique to "setting" the work in properly.

Here is the thread:

http://www.practicalmachinist.com/v...y-trecker-vn-usa-heavy-iron/vn12-vice-218081/

How do you guys accomplish this to keep the work and/or the parallels from moving?

Nelson

 

[rleete]

I use an old broken wooden hammer handle. I call it the beater bar, but the "real" machinsts here at work use a plastic coated deadblow hammer.

Lightly snug the vise, and tap (a light tap, not a hard whack) down on the part to seat. Tighten the vise snugly. Shouldn't take too much force in a decent vise.

 

[Highpower]

I use a plastic dead blow or a lead hammer to seat parts in the vice.
This is a good video describing the process and using parallels at around the 13:45 mark.

Having a good vice makes it easier, I agree.

 

[HMF]

When I got the 1946 #12, I had a choice of an old beaten up BP vice or a chinese vice in decent condition. I took the Chinese vice, which looks like a decent vice. Still, you won't get exact alignment of the moving vice, so what's a fella to do? The harder you hit it, the more you loosen it. Apparently, you need to strike it at a certain angle.


Nelson

 

[Blogwitch]

Nelson,

The harder you hit, the more it loosens. The job and parallels bounce off the bottom on the vice jaw base.

I always use a lead hammer, in fact this last weekend I cast up a dozen of them in two different sizes, mainly for giving away to visitors to my shop.



But back to using a dead blow, I don't hold it by the handle, but by the head, that way you have more control. It is a bit of a knack and it is just a matter of gently tapping down around the area that the parallel is loose. I always use the same technique for the vice handle, always gently tap the handle downwards to tighten (handle in a horizontal position), never across (handle in a vertical position), you are liable to knock your vice out of being parallel to the bed. Move the handle rather than the vice.

John

 

[Blogwitch]

Turbo,

I am not quite that naive ##

Good try though.

But they are really easy to make yourself. I made the large mould, a mate made the smaller, he supplies the tube, I supply the lead, and we each have a casting session every couple of years.

I don't just use them on the mill, but the lathe also, for bedding in items when I am using soft jaws.


John

 

[Magnum]

I no longer use parallels - unless I am making a single part or prototype part. No matter what I tried I could never get the part to sit on the parallels, the always came loose. If I am understanding the question correctly.

I started using two different approaches. For parts where the sides will be machined away later I use a set of Mitee-Bite TalonGrip jaws. Rather expensive but really eliminates the hassle in part setup in my vise now. Needs very little material to grip and I have not had anything rip loose with heavy cuts.

The second option is I have several sets of hard and soft jaws with a machined step. It's easier to get the part to sit flat on the step of the jaws for me. I actually need to order more soft jaws and will need to machine my own steps as I find it hard to find already machined jaws with a small steps. I also use this option if I don't want to mar the side of the parts.

Generally I will machine a part and send to the person for approval. If I need to make several parts later (like 20-50) then the soft jaws are well worth fighting the parallels on multi part runs.

 

[brucer]

i have used 2 vises in my life that i didnt have to seat a part in , it was 2 brand new kurt vises, a 6" and 8" vise.. you put the block in it, held it down with 2 fingers and clamped in down by hand, no beating on the vise or handle..

everything else i've used i use a 2lb or sometimes the 5lb deadblow ... I also have a chunk of brass for more stubborn stuff


if your running several of the same parts, get a set of die springs and put them between the parallels in the vise, your parallels wont move around or get debris under them.. plus it kind of helps spring the jaw prior to clamping..