Vise Stop for the Kurt Vise
This project is based on
stop made by "Widgitmaster", who may be found on the CNCZone.
When I saw it, I knew immediately that it would be a handy gadget to have
around as well as an excellent project to help me explore the capabilities
of my new Industrial Hobbies mill further. The original Widgitmaster creation
looked like this:
Widgitmaster Vise Stop...
Widgitmaster Vise Stop in Use...
As you can
see, it's a handsome and very straightforward design. I thought I would
add a small embellishment in order to personalize my version in the form
of using split cotter clamps with knurled finger wheels rather than the
allen held clamp arrangement in the original version. I'm just going to
present the highlights here, rather than a step-by-step construction article.
Here are 4 views of the basic concept...
I made my rear
bar 0.770" diameter because that's what fit the hole my 3/4"
Silver-Deming bit made in the clamping block. YMMV. Also, check the holes
in the back of your vise carefully. Mine looked like they were on 4"
centers, but it's actually slightly less. I wound up milling the end hole
into a short slot to make due. It wasn't off by much, but just enough
to be annoying.
Rear Clamping Block
blocks are hole drilling exercises, but the holes overlap for the split
cotter, so you have to lay them out and drill them precisely! Also, don't
just dive into these unless you understand how to machine the split cotter.
See my note below for details, but you will be drilling the shaft holes
with the cotter cylinders in place in order to cut the little crescents
out of them in one operation.
Front Clamping Block
I am using
progressively smaller rods as we move from the rear rod (bolted to vise),
to the cross rod, to the stop rod. The rear rod is 0.770" in diameter.
The cross rod is 0.5" in diameter. And, the stop rod is 0.25"
in diameter. You will want to round the end, or perhaps point the end
of the stop rod so it can act as a precise stop.
below for a drawing of the cotter cylinders. You will need to make up
4 of those.
Face Turning: How to Teach an Old (Lathe) Dog New Tricks
When it came
time to turn the bigger bar that attaches the stop to the vise, I decided
to try a piece of tooling that's been sitting in the corner of my shop
for some time. It's an Asian imported constant face turning rig that I
bought from an eBay seller called "800watt". I'm not sure whether
they are still available--at the time nobody seemed to have any idea what
one was and I got it cheap, being the only bidder. The idea is pretty
simple. You're turning between centers, but the driven center operates
by using teeth to engage the workpiece. A little hydraulic force gives
it some spring load as well:
Face Turning: The Business End...
of this rig is you can access the entire length of the workpiece without
any waste. So, I chuck up my workpiece in the 6-jaw, faced and center
drilled both ends, and then popped it into the constant turning rig to
see how things would go:
You can see
here I had already milled the flats on either side and drilled the holes
to mount the bracket to the Kurt vise. It was nice to be able to turn
the whole thing for a nice finish in one shot. This sort of thing, albeit
fantastically more expensive and sophisticated, is used in industry quite
a bit. If you can reduce the number of setups or waste with such a thing,
you'll make a lot more money on your job. In theory, the most accurate
way to turn is between centers, and it is also important to turn between
centers if you need to take the part off the lathe and put it back on
while maintaining concentricity.
I don't know
how often I'll use the face turning rig, but I was feeling very happy
to have tried it when I finished fooling around with it the other night.
Here are a couple of links that provide more information if you are curious
about face turning:
Face Driver Article
And speaking of gadgets, another great tool is the collet
block (at least they are if you have a set of collets to go with them!):
Using a collet block to hold the rear bar while
I make one of the 2 holes a slot to allow greater range of freedom on
They make it
easy to grip round stock for milling, and they're indexed so I can just
flip the square block over to access the other side of the bar and make
sure everything I do is parallel to the first surface. A set of collets
are pretty expensive, but collet blocks are cheap.
the Split Collet Clamps
These are interesting
little clamps that take a little ingenuity to make. Guy Lautard details
them in his Machinist's Bedside Reader, Volume 1 book. Their chief
virtues are twofold. One, they are just neat little gadgets that one can
take pride in crafting. Two, the convert a very little finger pressure
into a whole lot of clamping force. These two qualities made them seem
idea for this project. They can be made with just an Allen-head bolt,
or with the knurled finger screws such as I am planning. Here is the basic
barrel you need to turn on the lathe to get started with one of these:
As you can
see, it's a pretty simply little widget to make on a lathe:
Flange OD and shoulder turned. Center drill and
then drill the two diameters...
Can't resist a shot of my favorite QCTP tool: Aloris
carbide insert parting off tool...
I turned my
stock to 0.600" OD, turned down the end to 0.500" to create
the flange shoulder, center drilled, drilled a #7 hole (recommended size
to tap for 1/4-20) full length, and then a slightly larger 0.27"
hole for half the length, starting at the non-flange end. Parted it off,
filed the parting flash, and voila:
Cylinder with flange...
More cylinder with flange...
Now that you've
made your cylinders, and I just cranked out all 4 at once while I had
things set up and convenient, it's time to make the clamping blocks that
hold the cylinders.
First, I squared up the blocks using 2 different
cutters so I could compare their performance. Block on left is a 6-flute
corn cob hogger. Block on right is a flycutter with brazed carbide lathe
tool. More info on my surface finish
Just finished squaring the larger rear block with
Next step is layout. Blocks have been blued (er,
redded?) with Dychem, and they're sitting on my surface plate. Got the
prints in back.
I'm measuring for hole centers from the two ends,
just like the prints are marked. Height gage and surface plate make this
Now we scribe the center line. A light tap with
a centerpunch and we're done laying out the block...
Several things to note. First, the improvised vise
stop using a Kant-Twist clamp. It lets me remove the block from the vise
and get it back into exactly the same position. Second, the split cotter
barrel is bolted into it's hole in the block. We're busy drilling the
big hole for the shaft using a Silver&Deming bit in my Lathemaster
See the oval in the wall of the big hole? We've
cut the split cotter barrel to exactly the right shape by having it bolted
Now we can pop the block back into the vise, having
checked it for fit, and it goes right back to the same place due to my
simple vise stop. I am deburring and chamfering the hole with a Zeo Zero
Flute Deburring Tool.
One cotter, needing to be split and a perfect couple
of bores to use it in. I popped the cotter in the lathe, turned off the
flange on the bottom, rounded the end, and then used my Aloris part off
tool to split the cotter.
Using a temporary bolt, I tested it. Split cotters
have a very tight grip on the shaft with very little tightening force
required. As such, they're ideal when a small knurled clamping knob is
used. This one works great. Now I have to do 3 more!
I turned some
knurled finger wheels on the lathe real quick and easy to use with the
clamps. I don't have drawings, photos, or narrative on them. They're dead
easy to make and I did it entirely by eye without making any measurements
except a swipe with the calipers a couple of times to make sure the threaded
portion would be the correct diameter for the 1/4-20 thread I had planned.
My trusty tailstock dieholder facilitated the threading operation. I made
them from brass, which is a material I love both for its good looks and
ease of machining.
further fanfare, here is the finished result of my tinkerings:
The completed vise stop on my 6" Kurt Milling
Slightly closer view...
the joys of a vise stop (remember my improvised Kant-Twist clamp mentioned
above?), I am looking forward to using this beast. My chief disappointment
is that I shall have to make at least one more. This was for my 6"
Kurt Vise, but my favorite vise is a 4" Kurt, and the hole centers
I do differently the next time? Well, Widgitmasters uses the slit sawed
style clamp, but I really like the split cotters, so I wouldn't change
that at all. I believe the biggest thing I would change would be to use
all the same diameter shafts. On the first iteration, I made each shaft
a little smaller. It made sense to me at the time, but if they were all
the same it would make the task of building one of these widgits simpler
and faster. So, that's what I'll be doing when I make the stop for the
give thanks to the Figditing
Widgitmaster who put me onto this concept in the first place!
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