One Man's Vices

[AussieJimG]

A few years ago I did a course at the local Technical College and one of the exercises was to make a rail vice from 25x25 cold rolled steel. I modified the drawings a bit (as one does) and the resulting vice has been in regular use as a milling vice ever since.

It was so handy that I made a smaller one from 20x20 CRS and took some photos of the build.

With a bit of luck, here is a short video and the drawings for the vice are attached.

I will add the construction photos later.

     

Jim

[Fredbare]

Thanks Jim for sharing, cant have too many vices.

John

[90LX_Notch]

Jim,

Thank you.  I really like the vices.  I've been wanting to make a small viceand this design looks like it will fit the bill.  I have to study the drawings and see if it will scale down to what I want.

Thanks,
Bob

[PekkaNF]

Thank you. Drawing looks very clear and descriptive.

Pekka

[Stilldrillin]

Those are handy vices Jim! 

Well demonstrated. Easily made. 

David D

[AussieJimG]

First, the Squares

While not strictly part of the 20mm rail vice, the accuracy of the vice depends on the accuracy of the squares for setting up. And having accurate squares reduces the need to index everything during construction.

A bar was setup and indexed along the y axis and each square in turn clamped to it while a truing cut was taken along the x axis. Runout on each of the squares was measured at less than 0.01mm.

Then the major components were cut from the bar with the bandsaw and marked roughly with a felt pen to show the cuts to be made and their orientation. I find that this helps to avoid those gross errors like making two of the same item.
The item numbers subsequently changed when I altered the design to eliminate the spacers shown at the ends of the rails from the final device.

[SwarfnStuff]

Thanks Jim,
     Your PDF has been duly downloaded into my ever increasing "Things to make file". I am a few clicks south of you, VIC. I seem to be making tools and bits to make more tools at the moment. The $s being in short supply. But hey, it keeps me from rusting. Also, like Bob, I will be studying the drawings. 

[SwarfnStuff]

Ha, Your comment about marking to avoid gross errors, reminds me of the time I was making a book case for my son during his Uni days. I carefully measured twice (or was that three times) then prompty cut and routed two left hand sides. 

[tekfab]

then prompty cut and routed two left hand sides. 

Does it matter ? Your in Australia 

[drmico60]

Hi Jim,
That is one of the simplest and neatest vice designs I have seen. I shall definitely be making something similar.
Mike

[AussieJimG]

then prompty cut and routed two left hand sides. 

Does it matter ? Your in Australia 

Yeah, it's tough down here, we have to put the CDs in upside down which means inverting the laptop each time. But we manage.

Here are some more photos. I set myself the task of making this vice without using a vice. This was probably the best way to do it as everything was setup directly on the table.

The first use of the newly trued small square was to set a vertical stop on the angle plate to square the ends of the cross bars Items 1, 2 & 3 and to cut them to length.
One end of each was squared and then they were put back in the jig so the other end could be squared and brought to length. The z axis was left unchanged for all of them which should have resulted in them all being exactly the same length.

Photo 61 shows that there are minor differences. Not critical to the project but annoying and a bit mystifying as well.

[AussieJimG]

The Spacers and Retainer – Item 5
Photo 68 & 70

It is critically important that the spacers all be the same width since two of them hold the rails apart and parallel and the other controls the moveable jaw.

The spacers were held together with double sided tape to prevent relative movement during machining. They were then clamped to an angle plate set square with one of our newly trued squares and machined using a shoulder mill.

They were then reversed for the other side to be machined. The actual width is not critical, neither is the dimension of the small extension at the bottom both of which can be measured with a rule; the critical element is that they all be the same.

Photos 71 – 73
The critical width of the spacers was not the same: 9 measurements taken (3 across each spacer) ranged from 30.09 to 29.92 – a variation of 0.17mm which is far to large.

From the measurements, it appears that the spacers tilted sideways during machining; neither the bar nor the adhesive preventing the movement. I was a bit apprehensive about the clamping bar only applying direct force to the outer spacers but felt that those outer spacers would hold the central one sufficiently. I did not consider the possibility of rotation between the spacers.
So the group of spacers was clamped as shown and a cutter run down both sides to just remove the marking blue. After that, all the spacers measured 29.66mm – slightly under the nominal 30mm dimension but at least all the same.

In retrospect, they should have been clamped as shown in Photo 71 in the first place but along the y axis instead of the x axis.  Using the x axis would have enabled them to be squared up and possibly set against a flat bar to hold them square. Clamping them as shown would hold them securely while permitting the width to be measured with a micrometer.

[AussieJimG]

Thank you for all the kind words; they are much appreciated particularly since this is my first thread and I am a bit nervous.

Item 6 – The Rails

Photo 98 For the next series of operations, a bar was carefully indexed along the y axis as the reference.

Photo 100 The rails were held together with double sided tape and squared to length.

Photo 102 While still held together with the double sided tape, the 5x5 rebates were cut. The width of the rebates is not critical so they were cut together with a 10mm slot drill. The depth itself is not critical but it must be the same on both rails – this is the depth from the top of the rails to the top of the rebate and it determines the amount of tilt on the moving jaw when it is tightened.  Cutting them together ensures that the depth is the same for both and also that the surface finish is clean.

Photo 104 The rails were now separated and the mounting slots cut. These slots are in the centre of the rails and although the dimension is not critical, care was taken to orient each rail with its top side against the bar so they were both the same.

[AussieJimG]

More Work on the Jaws

Photos 105 - 111
The holes in the fixed and moving jaws for mounting the soft jaws, the hole in the moving jaw for the screw and the hole in the screw jaw for the screw are all at the same distance from the top of the jaws. Once the quill was set at this distance, all of the operations were performed to ensure that the distances remained the same.

[Stilldrillin]

By, 'ek Jim.

There's a bit more to getting things right, than first meets the eye!

Good work, and, well shown...... 

David D

[SwarfnStuff]

Yeah Well Tekfab, we just bung em upside down, back to front  and all comes out right.  Doesn't it? 
       Sorry Jim, this if off track. Really enjoying your writeup and pics. I don't teke pics, too busy doing. You are more disciplined thankfully, or we all would be the poorer info wise. I've gotta bookmark this thread for later. Thanks again.

[AussieJimG]

Thanks David, I appreciate the encouragement.

No worries SwarfnStuff, we are all here for the amusement.

Relieving the moving jaw

Photo 112 The setup lent itself to relieving the moving jaw so this was done next.

[AussieJimG]

Photo 113 The next series of operations is critical to the accuracy of the final product so a trial was conducted of the second setup to ensure that it could be put in place without disturbing the work.

Photo 114 The rails are separated by the spacers cut at the same time as the retainer and the slots cut for the fixed jaw and screw jaw. These are cut so the jaws are a neat fit.
The slot for the fixed jaw is particularly important. With the right hand rail pressed to the bar that has been indexed along the y axis, the slot should be exactly along the x axis. And with the left rail held parallel to the right rail by the spacers, the final product should be square.

Mounting Holes for the Jaws

Photo 116 This is the second setup. The rails are still held in place and the fixed and screw jaws inserted in the slots cut in the previous operation. All the holes are now cut and each of the screw holes is completed without moving the quill – spot drill, clearance drill, tapping drill and counterbore. Then holes for the pins were drilled through the jaws and the rails.

And here is where I made a mistake. I should have tapped the holes and bolted it all together before taking it off the mill. My concern at the time was that I wanted to use Loctite on the screws and the pins but I needed to use tapping fluid to tap the holes. In retrospect, I could have cleaned the holes after tapping.

Despite all my care in the machining, when the vice was assembled, it was not square. It clocked about 0.04 out along the fixed jaw. I actually had to re-establish the setup and tap the jaws and rails into position while clocking them in order to get it all square. It would have been much better to do it at the time.

Photo 118 The threading operation that should have been done in situ

[AussieJimG]

Photo 119 Here it is together, and this is where I  found that it was not quite square.

Photo 120 Tapping the soft jaw mounting holes. Of course these should also have been tapped after photo 112

[vtsteam]

Great instructional series Jim, and also it's a really cool design, using one size of bar throughout. I really like that! 

[AussieJimG]

Finishing the Retainer

Photo 122 Drilling the mounting holes for the retainer and the hole for the pin. These were drilled through into the moving jaw. The pin holds the screw in the moving jaw.

Photo 123 Facing the retainer to depth. Th is is the other critical dimension; it is the one that stops the moving jaw from tilting when the vice is tightened.

The depth was marked from the moving jaw in the vice and the retainer was cut down to there, leaving it a bit long. It was then removed and the gap measured with a feeler gauge. The retainer was then replaced and the quill adjusted to remove the remainder. The result was a snug fit.

[AussieJimG]

Thanks Vtsteam.

The screw is a length of allthread and the handle is a simple turning and knurling operation (I am sure you don't need photos of them).

Photo 126 The vice was setup on the table using the square and clocked. It clocked to less than 0.01mm across the width of the jaw. A very satisfactory result.

It was not clear at the time just how repeatable this measurement is – whether setting up with the square would always result in this accuracy. But it has been in use for some time now and it still seems to be accurate.

But it can still be clocked and tapped into position if required. Or pieces of aluminium can be screwed to the jaws to act as soft jaws and a cutter run across them if this is more convenient. Either way, this vice can be used to obtain as much accuracy as the milling machine can deliver.

The Result

Photo 127 And here it is together with the clamps that hold it to the table. The clamps were made from a section of 50x50x6 angle iron. They also fit the 25x25 vice and some ER collet blocks that I made.

And that's it. Thanks for watching.

Jim