Keys for a new mill vice

[HillclimberParticipant @hillclimber]

ArcEuro have a pretty amazing deal on Versatile Vices right now. So I ventured to replace the well-marked vice that had come with my used Sieg SX2.7.

The new vice came with keys, to position it in the table slots. These are 12mm and I need to mill the protruding part to c.11mm to match the slots on the top of the table.

Before I reinvent another wheel, does anyone have a recommended procedure to achieve this?

I had thought: fit them into the vice with a shim below; invert the vice with a parallel in the jaws located in a table slot and clamped down; and face off one protruding face of the keys, or maybe both?

Cheers, Colin

[Tony Pratt 1Participant @tonypratt1]

Colin,

Sounds good to me but make sure you ‘indicate’ the parallel with a DTI to make sure it is truly in line with the table movement.

Tony

[JasonBModerator @jasonb]

Having first confirmed that the slots ran true I clamped a bar to the table, clocked that and then clamped the vice to the bar. Washer below key to raise it up a bit for milling.

[Howard LewisParticipant @howardlewis46836]

Fitting ther Tailstock for the HV6, to the table meant that the T slot and tailstock keys were different sizes.

I turned up a pair of stepped dowel,  so the dowels are a snug fit in both and give a good location.

Howard

[Howard Lewis]

On Howard Lewis Said:

I turned up a pair of stepped dowel,  so the dowels are a snug fit in both and give a good location.

Howard

Yes, that’s what I would do.

In fact my vice has holes for mounting so I turned a pair of stepped bushes that are a press fit into the vice and a snug fit into the T slots on my mill. Perhaps I was lucky but the vice (Soba) mounting holes are perfectly aligned with the jaws. I believe this is because at one point it was sold with a separate base for rotating it.

[JasonB]

On JasonB Said:

Having first confirmed that the slots ran true I clamped a bar to the table, clocked that and then clamped the vice to the bar. Washer below key to raise it up a bit for milling.

Jason, did you face one side of the keys, or both?

Jason, did you face one side of the keys, or both? And I suppose, having zeroed that bar, there is a bit of mental juggling to ensure the keys are then the right way around when the vice is flipped back onto its bottom?

Cheers, Colin

[JasonBModerator @jasonb]

I took a bit off either side, this keeps the slots for the hold down bolts central with the tee slot. Keys fitted in the position they were machined.

Good for 0.008mm or 3/10ths in old money. there is enough clearance between slots and keys that would allow that to be clocked out if anyone felt the need. Also some of those 8 microns is likely down to movement of the table on the X-axis ways.

[JasonB]

On JasonB Said:

I took a bit off either side, this keeps the slots for the hold down bolts central with the tee slot. Keys fitted in the position they were machined.

Good for 0.008mm or 3/10ths in old money. there is enough clearance between slots and keys that would allow that to be clocked out if anyone felt the need. Also some of those 8 microns is likely down to movement of the table on the X-axis ways.

Now you tell me! When I replace the vice on my mill the bushes I made get it within .0005” to 001”. A quick tap with a soft blow gets it bang on. I’m now wondering if I’m wasting my time though … 😆

[RobinParticipant @robin]

The keys are as hard as the top of Gods’ head so it’s carbide or start over with softer material.

I put keys on my splendid new Xin dividing head and foot stock. Dismal failure, way out of alignment with each other 😀

Robin

 

[JasonBModerator @jasonb]

HSS cut the Arc ones in my image above.

[RobinParticipant @robin]

Hi Jason, I must admit I did not test every key from every vice supplier. Far from it, the sample was 2 mill vices, one dividing head/footstock and one YouTube video showing someone else having the same problem.

I will also admit that by the time I have slid the jolly old adjustable parallel along every slot in the mill table, settled on 13.94mm as clear, subtracted 12.7mm for the half-inch UNC clamp/hold down set I bought 30 years ago, realised I have to locate the T nut screw hole to within 0.62mm of centre and hope I don’t wobble the tap and cut an oversize thread… by that time I am starting to think the computer is a better bet for turning the handles than me 😀

Robin

[Nigel Graham 2Participant @nigelgraham2]

Having made a pair of tenons to fit my Warco dividing-head and its tailstock to the Myford mill, whose Tee-slots are of different width to the attachments’ mortices, surely what is critical is ensuring only one tenon face need be parallel to the vice’s fixed jaw.

These two tenons are of T-section and their lengths are such as to put them neatly between the clamp-studs, but that is only because the keyway is machined centrally to the holding-down slots.

For a vice, the key’s actual dimensions are much less important, within reason, unless you need locate a pair of vices in-line; as long as the mating face is always the parallel one. In use, simply push the vice gently against the slot wall while tightening the clamps.

 

[Anonymous]

I have tenons on my universal dividing head and tailstock, but have never felt the need for them on my machine vice. The vice is moved between three milling machines. Although all the T-slots are nominally 5/8″ what fits one mill will not fit another. Even on one mill the slot widths are not perfectly constant along the slot, or from slot to slot.

From a practical stance tenons would be a pain on the vice. By ME standards the vice is large and heavy, so it is useful to be able to rest it on the edge of the table and slide it on. One can’t do that with tenons. Plus, if the tenons are not perfectly aligned when putting the vice on the table one ends up creating small indents in the tenons and the table.

It doesn’t take long to indicate the vice when fitted to the mill. A significant amount of the milling I do on the vertical and horizontal mills doesn’t use a machine vice anyway. The work is bolted direct to the table or angle plates/box cubes.

Andrew

[JasonBModerator @jasonb]

When I machined the tenons for that 80mm vice they were sizes an easy fit in the SX2.7 mills table which happens to be the smallest of my three mills so I can swap it about between all three though it mainly gets used on the KX3. Though I expect most here only have the one mill so swapability won’t affect them. Also easy to hold in one hand and lower it down onto the table, the chamfers on the slots guiding it in.

That easy fit takes care of any possible variations in the slot widths on the smallest machine and also allows for clocking as mentioned above when a job needs the accuracy. Just push the keys back against the tee slot as you tighten the vice.

The KV-4 vice mainly gets used on the X3 and that does not have keys so I can work either way

Yes I also hold work to the table, use angle plates etc but that does not affect the tenons in the 80mm vice.

[Clive FosterParticipant @clivefoster55965]

I remain resolutely unconvinced as to the ultimate value to folk like us of fitting keys to vices.

Leaving aside the obvious inconvenience of the keys preventing the vice sitting nicely on the shelf when removed from the machine. There are potential fit issues both on older machines whose Tee slots may be less than pristine or inexpensive ones whose slots may vary a little in width as being made fit for purpose rather than super accurate. 20 thou or 0.5 mm variation in slot width being totally irrelevant from a functional point of view but seriously upsets nicely fitted keys.

Best industrial practice was for keys to be made quite tight fitting so alignment was reliably maintained to very close limits after removal and re-fitting. Tight keys can make manipulation something of a pain and demand well maintained slots. The pragmatic Model Engineer or Home Workshop Guy/Gal follows Jasons lead (always good practice!) and makes the fit a bit slack so the vice needs to be pulled or push back against the edge of the slot to take up the aligned position. Which works just fine.

However if you are going to pull or push back against the edge of the slot keys hardly seem necessary. On my Bridgeport I simply do the pushing with the basic bolt and Tee nut set up working in the fairly slack lug slots on the swivel bases of my Vertex VJ400 vices. Depending on how anal I am about things repeatability is something better than a thou per inch, under 4 thou over the 4 inch wide jaws, which is good enough as is for a lot of things. Retaining the swivel base makes setting to dead nuts alignment easy. But running a Bridgeport means I don’t have the Z axis space limitations faced by folk with smaller machines so plenty of room for the swivel. Repeatability would be improved making sleeves nicely fitted to the lugs and bored to fit the bolts with one end cut to fit the Tee slots. They have been on the to-do list for maybe 20 years so I can’t see it happening as what I do works well enough.

Prior to getting the pair of VJ400 vices I used a 6 inch Abwood vice in the same simple pull back against the bolts manner with similar accuracy. I had intended to make a refined version of the aforementioned sleeve system with one sleeve carrying an eccentric adjuster running on one sleeve to controllably rotate the vice about the opposite one to more easily take out the residual error. But Rotagrip exhibition offer prices on the VJ400 pair were far too good to miss. I’m convinced they made a mistake but not complaining!

Clive

[Tony Pratt 1Participant @tonypratt1]

From my industrial experience location keys in milling vices were useful to get you fairly close and then a quick pass with a DTI would get you spot on BUT with heavy vices the draw back is you can’t slide the vice over the table but you have to manipulate it into position from a lifting platform, a bit tricky at times.

The CNC mill on my last ever paid job had a beast of a vice with thankfully no keys, it was pushed from the Hi-Caddy onto the table then slid into position.

Tony

[Author]

Posts