squaring mill vice on combo lathe mill machine

[werowance]

i have been complaining for a long time about having to change between lathe tool post and mill vice on my combo lathe / mill machine. every time i have to switch to the mill vice i usually spend a considerable amount of time getting the vice square. it doesnt have tabs on the base to fit the t slots of my slide to self center it so i use the test indicator in the mill chuck and back and fourth with the vice until its square. sometimes i get lucky and only takes a couple of minutes but usually it takes a long long time and my arm gets tired of cranking back and fourth. you know the losen nuts, gentle tap on one side or the other then run the slide back and fourth to get a overall reading and try to split the difference, then repeat until the needle doesnt move or is "close enough"

so last night i had an idea. since its a combo lathe / mill maybe i can use that to my advantage. using the lathe chuck, a piece of 1/2 round stock and a piece of plate aluminum i made a for lack of better words a framing square. the 1/2 inch rod is pressed into a reamed hole at a right angle into the plate aluminum. with this i just chuck the round stock in the lathe chuck, move the table over until the plate aluminum can go in the mill vice jaws and then clamp the vice down on it. this squares the vice at a right angle to the chuck. if i want the vice parallel to the lathe chuck then i simply use a 1/2 rod only and clamp the rod in the chuck and also in the vice. i was happy to find out that the lathe chuck and the mill vice are close enough to the same height that this actually works.

hope this can help anyone using a smithy or a bolton tools combo lathe.

 

[Asm109]

Very clever. The technique I use for squaring up a vise is this:
Snug one bolt up. One hand on crank for the axis, other hand has a soft face hammer.
Start cranking the axis and watch the indicator, while cranking tap the vise and watch the needle. Keep tapping until the needle motion slows and stops.
reset. the axis and do it a second time. I can usually be within a thou or two on the first pass. Second pass nails it.
I intentionally set the vise off in the direction that tapping the back of the vise moves it in the direction of square.

 

[BaronJ]

Very clever. The technique I use for squaring up a vise is this:
Snug one bolt up. One hand on crank for the axis, other hand has a soft face hammer.
Start cranking the axis and watch the indicator, while cranking tap the vise and watch the needle. Keep tapping until the needle motion slows and stops.
reset. the axis and do it a second time. I can usually be within a thou or two on the first pass. Second pass nails it.
I intentionally set the vise off in the direction that tapping the back of the vise moves it in the direction of square.

I used to do that dance, until someone pointed out to me that the threaded holes in the bottom were for a bar that fitted into the slots on the table. Now all I do is place the vise down and snug it up.

 

[werowance]

yeah, but mine doesn't have those threaded holes on the bottom......

 

[Asm109]

The bars are good to a thou or so. Sometimes it has to be better than that.

 

[L98fiero]

yeah, but mine doesn't have those threaded holes on the bottom......

I bought an import Kurt vise clone that had the key slot on the bottom in an awkward location so I turned the vise upside down, closed the protruding vise jaws in two T-slots and milled a new one where I wanted it. You could do the same by putting parallels in the slots if the jaws of your vise don't protrude enough or making a pair of soft jaws that will fit the slots. If the vise is cast/malleable iron, not having tapped holes is pretty easy to fix.
As an aside, having specifically milled parallels that are a tight fit in the T-slots are handy to have, I've made them from mild steel and had them hardened, it depends on your mill but mine, on a Bridgeport size mill, are made from 2" wide stock so they protrude about an inch. They make setting up angle plates simple.

 

[grahamgollar]

Wouldn't a quick solution be to put the blade of an engineer's square in the vice jaws then offer the stock of the square up to the OD of the chuck and adjust as necessary? I use this method for squaring parting blades in a QR toolpost to the lathe longitudinal axis.

 

[photopro]

These are all good shortcuts, and I have tried them all at one time or another, but I have found the only way to get true accuracy on the vice is to tram it with an indicator. It might seem like a pain, but in the long run it's only a few minutes out of your machining time. A machinists square held in the vice jaws will get you close and save time on the initial setup. When tramming the vice, indicate on the fixed jaw. If it isn't in the best shape, hold a thick parallel in the jaws and tram on that. ASM 109 has described the easiest method.
You rarely need that kind of accuracy with a toolpost but if you do, just square the tool to the chuck face. If you can't get the toolpost close enough, a 123 block between the toolpost and chuck face will usually work.

 

[werowance]

These are all good shortcuts, and I have tried them all at one time or another, but I have found the only way to get true accuracy on the vice is to tram it with an indicator. It might seem like a pain, but in the long run it's only a few minutes out of your machining time. A machinists square held in the vice jaws will get you close and save time on the initial setup. When tramming the vice, indicate on the fixed jaw. If it isn't in the best shape, hold a thick parallel in the jaws and tram on that. ASM 109 has described the easiest method.
You rarely need that kind of accuracy with a toolpost but if you do, just square the tool to the chuck face. If you can't get the toolpost close enough, a 123 block between the toolpost and chuck face will usually work.

the thick paralel in the jaws is the way i was/usually doing it. i just wanted something quick and easy for the things that didnt need to be .0001 acurate or even .005 acurate for that fact. but good to know that i was doing it the correct way with the parallel in the jaws. sometimes doing the parallels in the jaw way takes me half an hour or better. sometimes i get it in just a minute or 2. luck of the draw with me and my limited skills. hopefully with time and experience this will become easier and less time consuming for me.

the other suggestions folks have mentioned above are also pretty neat tricks that i would never have thought of. thank you all for the ideas.

 

[miglincit]

Why don't you just align the bar with the surface of the chuck? No need for an additional screwed-in bar.

 

[kwoodhands]

A quick and easy solution but may not be as accurate as using an indicator is as follows.
You need a flat plate 1/4" or more thick and flat as possible on one side. The plate should be at least 12" longer than the vice is wide. Set the plate in the vice, measure down to the bottom of a slot. Notch the plate so it sits in the vice and the outside "legs" are 1/16" or so short of the bottom. The length of the notch should be 3" or 4" more on each side. My vice is 3" wide, the plate is 16" long . The notch is 10" long, I do not recall the depth. After notching the plate ,check for flatness. My plate stayed flat after cutting the notch. Now place the plate in the vice. Install plate flush to the moving jaw. Pack out the space between the fixed jaw and the plate. I start with a 1 2 3 block and then parallels. Tighten jaw, pull the vice forward til the plate legs touch the slot on both ends. Tighten the vice hold down bolts and your ready to mill.
The first time I did this I checked with an indicator. I got lucky, The needle barely moved. Then checked again with a parallel in the chuck. 6" parallel showed .0001.
Good enough for me. I have been setting the vice this way for 20+ years. I was taught this method by relatives that are machinists.
mike

 

[packrat]

kwoodhands...can you post a photo or two of how you do that.?

 

[Soundguy]

As a learning amateur these are some great suggestions. Thank you for your input.
Paul