# Round Work, V Blocks and Parallels



## EmilioG (Feb 19, 2015)

Like most of you, I've had to drill holes or machine round rods, tubes, pipe etc..
What is the best way to hold round work in a milling vice like a Kurt?
I have some short tubes that fit on my B&S v blocks but I can't use the clamps
because they get in the way of the drill chuck or spindle w/R8. 

Is it OK to sit these short tubes on parallels fairly low in the vise and clamp?
Can I use angle iron and clamp the tube on each end with vise grips? 
What is safe and not safe? Please advise, 

I would like to get Starrett 568's, also the thread on the B&S v clamps is a strange 5/16"-20!
Maybe I could cut short clamp bolts in 5/16-20? (don't have a lathe).


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## rgray (Feb 19, 2015)

I had to hold a small round item in my mill vise just the other day. Can't remember what I was doing but I held it with a small V-block I made on the surface grinder out of some D-2. Worked great.
Pic is of a 1/2" boring bar in it....much bigger than I was working with, would probably want to use a spacer on the opposite side of the vise jaw with something that big.


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## JimDawson (Feb 19, 2015)

Setting rods and tubes on parallels is completely acceptable.  Rods are not a problem but tubes can be an issue sometimes in that the can be crushed a bit by the vice.  You can't tighten the vice any tighter than the crush strength of the tube.  Make sure when setting on parallels, that you keep the diameter below the top of the vise or it will just squish out.

Many times I set larger shafting right in the bottom of the vice, for keying and the like.  Sometimes I will clamp a rod in the vise and then hang the end out to work on that.  Angle iron works as you describe in some cases, I have done that before.

Just about anything is safe if you are comfortable that the setup will not allow the work to move under the forces of machining.  About 1/3 of machining is figuring out how to hold on to the work.
.
.


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## Andre (Feb 19, 2015)

JimDawson said:


> Setting rods and tubes on parallels is completely acceptable.  Rods are not a problem but tubes can be an issue sometimes in that the can be crushed a bit by the vice.  You can't tighten the vice any tighter than the crush strength of the tube.  Make sure when setting on parallels, that you keep the diameter below the top of the vise or it will just squish out.



That bring up a very good point.    Whenever I have to hold a thin piece of material in a lathe chuck or vise I turn a wood dowel to snugly fit inside and boost the crush yield strength.      Still can't wrench on the chuck key, but it helps.

This was a rolled piece of sheet metal from a friends factory-flawed Daisy 8888 front sight.       With the wood plug it didn't crush in the 4 jaw and allowed me to shorten it with ease.

http://i1379.photobucket.com/albums/ah150/andregross3127/182_zpsa402765b.jpg


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## machinistmarty (Feb 19, 2015)

You can make a set of jaws with vees milled in them. One jaw will usally suffice.


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## EmilioG (Feb 20, 2015)

machinistmarty said:


> You can make a set of jaws with vees milled in them. One jaw will usally suffice.



That's a good idea.  I've been thinking of making soft jaws in Al and brass.  Just make them thicker and with grooves
to hold round work. Thanks to all.


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## uncle harry (Feb 20, 2015)

You could drill some square or rectangular material to the rod O.D. & saw it in half making a pair of conformal jaws.


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## EmilioG (Feb 20, 2015)

Thanks.  I will proceed carefully. I can't afford to ruin these Cnc'd and welded parts. 
I drill and tap the bungs (welded) then weld both tubes together.


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## EmilioG (Feb 20, 2015)

This should work. (in a Kurt vise), or should I use just one v block?


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## Andre (Feb 20, 2015)

EmilioG said:


> This should work. (in a Kurt vise), or should I use just one v block?


Probably best to use two; four points of contact not just three. If you find it slipping, put some printer paper around the tube to prevent movement.


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## EmilioG (Feb 20, 2015)

I'm going to try the two v blocks on Monday. I can't see how this will not work.
Thank you all.


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## Bill C. (Feb 20, 2015)

Andre said:


> That bring up a very good point.    Whenever I have to hold a thin piece of material in a lathe chuck or vise I turn a wood dowel to snugly fit inside and boost the crush yield strength.      Still can't wrench on the chuck key, but it helps.
> 
> This was a rolled piece of sheet metal from a friends factory-flawed Daisy 8888 front sight.       With the wood plug it didn't crush in the 4 jaw and allowed me to shorten it with ease.
> 
> http://i1379.photobucket.com/albums/ah150/andregross3127/182_zpsa402765b.jpg



Tubing is just tricky anyway. I do like your use of a dowel rod to strengthen the tubing.


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## Bill C. (Feb 20, 2015)

If you use a V block with a clamp be sure if it doesn't have a swivel foot to use a piece of aluminum or copper between the bottom of the clamp screw and the part so not to mar the finish of the shaft.  I do the same thing for lathe dogs


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## Reeltor (Feb 20, 2015)

I would use only 1 v-block in the vice.  I am by no means an expert, just what I've seen done by some good machinists on YouTube.  I had to mill a circular object the other day.  One v-block worked well for me in a horizontal mill.

Mike


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## Andre (Feb 20, 2015)

Reeltor said:


> I would use only 1 v-block in the vice.  I am by no means an expert, just what I've seen done by some good machinists on YouTube.  I had to mill a circular object the other day.  One v-block worked well for me in a horizontal mill.
> 
> Mike



For a solid object one would be fine, but for thinner tubing you really want 4 POC not just 3; a reason 6 jaw lathe chucks are nice. Spreads the load and helps prevent crush.
The object OP is working on has fairly thick walls so it's probably fine with a single block, or even just sitting on parallels. (By the looks of things anyway)

Gotta get one of those self centering V jaw vises like Keith Rucker has!


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## machinistmarty (Feb 20, 2015)

Since you have 2, use them both. It certainly wont hurt.


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## EmilioG (Feb 20, 2015)

what is the self centering v jaw chuck?


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## stupoty (Feb 21, 2015)

EmilioG said:


> what is the self centering v jaw chuck?


I think its the vices where the moving jaw can pivit for non square woork pieces, they often have some vee shaped lines horizontaly and verticaly for holding smaller diamitors of round stuff.

Stuart


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## EmilioG (Feb 21, 2015)

Here is some good info>
http://www.carrlane.com/catalog/ind...B2853514059482013180B041D1E173C3B2853524B5A59


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## EmilioG (Feb 21, 2015)

Work holding>>
http://users.encs.concordia.ca/~m_rembac/CON-EDML-039 Work Holding.pdf

Great clamps>>
http://www.kopal.eu/en/produits.asp?IDFam=37


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