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Trick to grab round object in mill vise if their radius is more than the jaw height?

JasonPAtkins

Hot Rolled
Joined
Sep 30, 2010
Location
Guinea-Bissau, West Africa
Does anyone have a clever way to clamp a piece of round stock lengthwise in the mill vise if the centerline of the object is higher than the vise jaws? I need to drill and ream some holes in 5" OD pipe, and would normally secure it with hold downs, but wondered if someone had some great trick for doing it more easily.

I don't know how I ever clamped short pieces in my horizontal bandsaw until I had a half circle of heavy pipe to do the job, for example - and wondered if there's some great trick or jig I'm missing for this application.
 
I'm sure others will have neater solutions, but I would go the hold-down route. Use the vise jaws to stabilize and align the bar stock then use a strap clamp from on top to hold it down and secure it.

Interested to see what others come up with.
 
That, at least, is better than my hold-down only route, which would require reindicating the tube every time I have to slack the clamps to slide the tube further through for the next hole a yard later.
 
Since you mentioned you have to move the work a yard to drill the next hole I would make up some taller vise jaws. Maybe machine a slight V in them so you can use them on multiple diameter round stock that wont fit in the vice normally.

If you had enough travel on your table you could use a 2 piece vice.
 
...Most tables have little V's at the top of the slots
do away with vice and clamp directly to the slots...

That works great for smaller stock. As the diameter of the workpiece increases it can be a bit difficult to
line it up on the slot--still doable in most cases.

For most situations like this I just made up a few different sets of higher jaws. Easy to do with some cold-
finished flat bar. They work fine unless you're doing something that requires super accuracy--then you may
need to have them ground...
 
I have ran a lot of larger diameter round parts in vises. I made some tall steel jaws that had about a 5 degree angle on the inside faces.

When the vises were closed, the jaws came together at the top but left a gap at the bottom. Whatever diameter I was holding didn't matter- the material sat on the bed of the vise and the angled jaws prevented it from lifting up. The same jaws worked whether it was 2" or 8" diameter material.
 
With considerable trepidation, I will offer a suggestion / question. Warning: this may be brilliant ... or hopelessly home-shop-harry.

Recently I was fixing up an old woodworking jointer for my sister's partner, and needed to hold the tool head body (the part that the blades mount into) in my vice in order to put a key way in the shaft that runs through and powers the tool head. Due to considerable age and many years of abuse or neglect, I really needed to put the key way in at a very particular place on the shaft. However ,the tool head body, while an overall round shape, has various flats and cutouts that prevented secure clamping with the shaft positioned as I needed it. So ... I decided that I needed to make a simple jig, basically two 1" or so thick squares with a hole through the faces large enough to hold the tool head, and a slot cut out of one side to allow clamping pressure. But rather than mill this jig out of some scrap steel or aluminum, I decided to draw it up and print two copies on my 3d printer. (Drawing it up took < 5 minutes; printing it out took an hour or so while I worked on other things.)

Long story short, the resulting jigs/clamps worked extremely well. I am quite sure they were not precise down to +/- .001", but based on the results, they must have been precise at least to +/- .005", which was plenty good enough for what I was doing.

So, what says the collective wisdom of the pros - would something like this ever be considered or used in a commercial shop, or is it, as I suspect, strictly a home-shop solution?
 
2 cold finish 1 x 4 x 6 (or longer) flat steel bar with two holes each drilled to match my Kurt vise hole pattern will hold up to 8" dia rounds. If used often, case harden and grind for long term use.
 
You wanted a trick so here is one. It uses two pieces of uneven angle.

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I am sure it is for light duty only. And it may be more trouble than it is worth. Both angles need to be held down by the round so the two fill blocks should be the same thickness.

Personally, I would just clamp it. But that would require removing the vise and putting it back again when this job is done.
 
I would take an angle plate and clamp it to the table. Then I would clamp the pipe in such a way that would push the piece down and against the angle plate. If you dial in your angle plate it should be plenty repeatable if you want to slide it down for your next hole. When I was an apprentice my boss would always frown on putting everything in the vice. he said to many machinists become vise dependent.
 
I have some parallels I made that are ground the same height as the base of the vise. I.25" thick x 8" long,c/bored to clamp to the table slots and some 1/2-13 holes in the top to fix hold down bars.I put back fences like a mag chuck to serve as stops if needed.You can add threaded holes in the sides and ends for extra hold downs.

Really large stuff the vises come off and bolt to the table, some times some plate in the slots to serve as a squaring/back stop.
 








 
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