Any tips for aligning mill vice / workpieces?

[Dr_GMJNParticipant @dr_gmjn]

[Dr_GMJNParticipant @dr_gmjn]

All,

For my current project I’m having to move the milling vice quite a bit, and also align long workpieces on the SX2P bed.

Im doing this by putting a finger gauge on the head, in contact with the part, then traversing in x, noting the direction of needle movement, and tapping the part with a hammer to correct the errors.

It’s taking ages to get a constant zero reading sometimes. Are there any tips/tricks/standard procedures for doing this more efficiently?

I used to struggle with centering work in the 4 jaw chuck until using the two chuck key/dial gauge method. Now I can do it often within three adjustments. Anything similar for aligning on a mill bed?

Thanks.

[Anonymous]

For aligning the machine vice I set it roughly parallel using the bolt slots and a T-slot. Nip down the lefthand bolt and then indicate the rear of the fixed jaw. If the indicator moves tap the vice to bring the indicator back to the original reading. Repeat as needed. Tighten both bolts and do a sanity check pass. The whole operation takes less than minute to get within 1 thou in 6".

For aligning parts on the table I use two methods. One, a length of gauge plate in the T-slot as a fence. Two, I made a couple of cylinders with spigots that are a close fit in the T-slots. These can then be bolted as far apart as needed. The two cylinders were ground as a pair, so they are within a tenth of each other. My mill is industrial, so the T-slot is aligned with the ways. The methods don't work if the T-slots and ways are not aligned.

Andrew

[Dr_GMJNParticipant @dr_gmjn]

Thanks Andrew, I’ll see if my T-Slots indicate true.

[JasonBModerator @jasonb]

Much the same as Andrew here with regards to dti on the vice fixed jaw and a couple of round bosses with spigots that can be fitted to the tee slots.

[KWILParticipant @kwil]

+1. I work in a similar manner to Andrew. If you want to be pernickity you can align the 6" to better than 0.001" when required. I also have a set of 6 similar cylinders which I can put in the T slot right along the bed as long as I require. Similar industrial mill.

[Dr_GMJNParticipant @dr_gmjn]

Ok so do the boss/spigots need to be bolted down into the slot or can they just be dropped in and held by hand until the workpiece is secured?

[Chris GunnParticipant @chrisgunn36534]

One way is to machine a slot in the underside of the vice and add a tenon which is a close fit in the slot in the machine bed, and then the vice is aligned automatically. There has been a couple of threads on this topic recently.

Chris Gunn

[John HaineParticipant @johnhaine32865]

A trick from YouTube if you have power feed is to nip down one vice nut but leave the other slightly loose. Use the power feed to move the table back and forth with an indicator in the spindle on the fixed jaw, tapping the vice gently as you go until aligned. If you don't have power feed then ignore!

But personally I have put an alignment key on my vice.

John.

[Anonymous]

Posted by Dr_GMJN on 14/05/2021 14:56:42:

Ok so do the boss/spigots need to be bolted down into the slot or can they just be dropped in and held by hand until the workpiece is secured?

I bolt down as the work is often on parallels, so I can drill through, and the cylinders would tilt when the work is tapped into contact:

Mid left above is a third cylinder, of a different size, used as a stop. I forgot that I made two short cylinders, mostly for stops on the CNC mill, but also used to align parts on the manual mill, see bottom right:

Andrew

[JasonBModerator @jasonb]

I also bolt mine down, you don't just have to use them for work along the table you can also set them at right angles or at an angle set with a square or DTI. I could do with making some taller ones but usually just stand a tall block in front. If your tee slots are out then just make the spigot a bit smaller, rest a straight edge against them and adjust until the straight edge runs true.

[Fowlers FuryParticipant @fowlersfury]

Re "Are there any tips/tricks/standard procedures for doing this more efficiently? "

Not professing this to be more efficient, nor is it a standard procedure but it might qualify as a tip……..

• Ensure vice is pulled back so mounting bolts are tight against T slots, tighten bolts enough for light grip.
• Use one of the methods (dti against a parallel?) for aligning your vice with the mill table wound right out – or in – so its hard against the stop. Tighten the vice down.
• Lightly clamp a laser pointer (ideally metal bodied, there''s one for GBP1.99 on Fleabuy) in the vice jaws so the spot shows on a far surface.
• Now you need a vertical line right under the point (I find thin black felt tip line on small piece of baking foil glued to wall is best with a red laser).
• Despite the invited ridicule, I find this to be reproducibly accurate with the mill table in original full out (or full in) position to reset the vice parallel to table movement.

[Anonymous]

I made some tenons for my dividing head and tailstock, but I don't use tenons on the machine vice (although the slots are pre-machined) for three reasons. One, when not in use the machine vice often sits lengthwise on one of the other mills and I don't want to ding the table/tenons. Two, sometimes I need to set the vice at an odd angle. Three, the T-slots vary in width slightly across each table and from mill to mill, so I'd rather set the vice properly each time to eliminate the last couple of thou.

Andrew

[Dr_GMJNParticipant @dr_gmjn]

The t-slots on the mill aren’t a mile out, but not accurate enough for the spigot bosses assuming I’m aiming for zero movement on the gauge.

Ill stick to tightening just one corner down and tapping with a hammer.

Thanks all.

[Dr_GMJNParticipant @dr_gmjn]

Posted by Fowlers Fury on 14/05/2021 16:33:39:

Re "Are there any tips/tricks/standard procedures for doing this more efficiently? "

Not professing this to be more efficient, nor is it a standard procedure but it might qualify as a tip……..

• Ensure vice is pulled back so mounting bolts are tight against T slots, tighten bolts enough for light grip.
• Use one of the methods (dti against a parallel?) for aligning your vice with the mill table wound right out – or in – so its hard against the stop. Tighten the vice down.
• Lightly clamp a laser pointer (ideally metal bodied, there''s one for GBP1.99 on Fleabuy) in the vice jaws so the spot shows on a far surface.
• Now you need a vertical line right under the point (I find thin black felt tip line on small piece of baking foil glued to wall is best with a red laser).
• Despite the invited ridicule, I find this to be reproducibly accurate with the mill table in original full out (or full in) position to reset the vice parallel to table movement.

Ive not got hard stops on the table.

Doesn’t your method rely on the laser axis being absolutely co-axial with the body? I’ve had a couple of laser collimaters for my telescope, and even with those the dot describes a circle on a distant wall, if the body is rotated in a v-block.

[Tony Pratt 1Participant @tonypratt1]

Practice & a good lever DTI is the answer, yes you can also add tenons to your vice for rapid alignment. I would suggest lasers are just a gimmick.

Tony

[Nigel McBurney 1Participant @nigelmcburney1]

I use a 12 in long hardened and ground parallel in the vice jaws and clock over the whole length,i use a Mercer dial type indicator,In my early days first job, all the vices had tenons they were used on 2 Victorias with identical tenons,the method does not work so well if the vice or vices have to be used on 2 or more mills with variation of tee slots. When the vice is set true with the parallel ,I then use my edge finder against the parallel and set the edge of the fixed jaw to zero on the index dial, the parallel is 2 x 1 ins and protrudes about 1/2 inch out of the jaws.

[Martin KyteParticipant @martinkyte99762]

Posted by Tony Pratt 1 on 14/05/2021 18:48:31:

Practice & a good lever DTI is the answer, yes you can also add tenons to your vice for rapid alignment. I would suggest lasers are just a gimmick.

Tony

It's an idea though. What if you had a square block you could clamp in the milling vice with a dead square mirror on one end. If you had a laser pointer mounted on a suitably distanced wall with a vertical line through the centre and swung the vice around so the reflected spot came back on the line you will have effectively squared the vice.

Well thats so much for the theory, how it translates into a practical approach that is quicker than the dial gauge remains to bee seen.

regards Martin

[Fowlers FuryParticipant @fowlersfury]

"I've not got hard stops on the table."

I should have been more explicit. By "hard stops" I meant at the end of the lead screw (threaded rod) which moves the mill table i.e. the point at which the table wont move further. It is the reference point for repeated measurement.

"Doesn’t your method rely on the laser axis being absolutely co-axial with the body? I’ve had a couple of laser collimaters for my telescope, and even with those the dot describes a circle on a distant wall, if the body is rotated in a v-block. "

Apologies for previous brevity again. I don't believe that "being absolutely co-axial with the body" is too critical providing the laser pointer is held in the vice jaws at the same angle to the horizontal (hence shining on the cross lines on wall). The cross lines in the workshop are about 4 metres from the laser source so when lined up, it repeats the original, DTI-based, set up accurately enough. I do check from time to time and haven't found significant change. Below is a picture taken of the laser spot centralised.The image is poor as the laser spot didn't focus well.

One of those many jobs awaiting my getting 'a round tuit' is to mount the laser pointer in a substantial block which would sit within the vice jaws at the correct angle and orientation just to save a few minutes each time.

[Howard LewisParticipant @howardlewis46836]

MC,

Look at one of my albums. There should be a picture of the "Goalpost" fixture that I made up.

The final, op is to take a skim along each side of the cross bar, so that the vice clamps, onto a surface that is the plane in which the table moves under the cutter. It will realign my vice within a thou (0.025 mm )

HTH

Howard

[Martin ConnellyParticipant @martinconnelly55370]

For critical parts it is possible to have a set of soft jaws that you can machine once the vice is mounted. Think of them as a simple jig for the part you are doing. Another option is to hold a sacrificial piece of material in the vice that is then machined to give a datum surface or other feature that a part is positioned by. I recently did some profiles that were done by drilling a piece of scrap aluminium alloy with 2 holes for ground dowel pins to position the workpiece on where it was then held down with a couple of through bolts. It didn't matter how well the vice was set up, the dowel holes were in the correct position unless the vice was moved again or the temporary jig in the vice was moved.

Martin C

[HopperParticipant @hopper]

Mount your vice semi-permanently near one end of the table, not in the middle. Then you can use the rest of the table for other jobs and move the table to the one end when you want to use the vice. Relies of course on your machine having a long enough table and travel and small enough vice etc.

[Dr_GMJNParticipant @dr_gmjn]

Posted by Hopper on 15/05/2021 09:20:29:

Mount your vice semi-permanently near one end of the table, not in the middle. Then you can use the rest of the table for other jobs and move the table to the one end when you want to use the vice. Relies of course on your machine having a long enough table and travel and small enough vice etc.

That's the problem: The job I'm doing at the moment takes more than the whole bed up. Initially, the four parts in question needed co-ordinate drilling in the vice. Then they required milling along their entire lengths. For milling, the parts were secured on 3D printed, handed jigs, through the co-ordinate drilled holes. Each part had to be moved half way through the cut, and overhung the bed by quite a bit on each side. I designed the jigs so that I could move the part along them and re-secure without having to re-align every time, but there were still two sets of jigs to align.

It all worked out in the end, but because I'm not used to doing it, part/vice alignment took a significant amount of the total time for the job. I was also using a 0.0005" finger gauge, and was aiming for zero indication, which in hindsight was a bit silly for parts that are supposed to simulate castings. Good practice though I suppose.

[mechman48Participant @mechman48]

Posted by Chris Gunn on 14/05/2021 14:57:54:

One way is to machine a slot in the underside of the vice and add a tenon which is a close fit in the slot in the machine bed, and then the vice is aligned automatically. There has been a couple of threads on this topic recently.

Chris Gunn

+1… I have done the same with my vice.

George.

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