I know of one person who has done it but I am vague on the details. It would have to be a real cheapo...If it works as a scroll saw it probably won't be - as I have seen so far.
True.
M3 is smallest I can get locally.
That I have done. Sort of.
Or just use the indicators :-)
Too big for my mill. Great as shuriken.
All solid. Will make a live center - I think (diameter just right on .500").
That may well be, but you should see the crude slot in the bottom, i.e. I suspect it was added later to a possibly factory made item.
It is interesting to speculate how the cross-slide was attached to the lathe. Also why operation by a hex key?
I thought it was just a quick change tool-post which rotates on the central screw.
I shall get that. Is there much force on the steady rest in operation?
I was thinking an automotive rim, concrete and a 4x4 post with a platform on top.
You could make tee slot bolts out of larger screws. Mill the heads and the adjacent shank to fit in the slot. Electronic standoffs would serve as coupling nuts.
Hmm ... MSC has smaller -- but they have the nasty habit of sending via UPS, which means obscene brokerage charges when it crosses the border -- even if no duties are due.
O.K.
I use both the properly calibrated handwheels and a 5" range dial indicator on the cross-slide of my Clausing. Sometimes one is more convenient, sometimes another part.
Hmm ... I don't remember what the pitch is on the cross-slide leadscrew. 20 TPI would give you 0.050" per turn which would be nice.
10 TPI would also be nice, but too coarse for something the size of the Taig. Almost any other thread would be a real pain to sum up dial rotations. :-)
Nah! My 6" ones for my Nichols horizontal mill are better for that. More mass and more teeth. :-)
[ ... ]
O.K.
It looks as though it was machined entirely from solid steel, not from a casting so home made was more likely. Do do the slot neatly would require something like the 6" conventional milling cutters for my horizontal mill. The 3" one which you show would not cut deep enough. So -- he probably either cut it with a hacksaw, or a bandsaw.
[ ... ]
Probably he had not gotten around to making a nice leadscrew with a crank handle yet. I presume that all of this came from an estate sale?
A quick-change toolpost normally stays *fixed* with one face parallel to the axis and another parallel to the face of the chuck or a faceplate. The holders fit in one or the other station as appropriate, and some holders will have angled tool edges for beveling or the like. The only time I loosen the clone of an Aloris BXA on my compound is when I change the angle of the compound for threading Acme or left hand threads or the like. I then loosen the toolpost hold-down nut and shift it so it is again parallel to the chuck face and the lathe axis.
That is a function of the cutting forces in your workpiece (and the flexibility of the workpiece), but one significant component of the forces is straight up. Granted, you aren't going to get that much force on a Taig, but still. :-)
O.K. Add some bolts through the post to give it a good grip in the concrete. And use one of the rot-proofed outdoors woods so you don't have it rot in place in the concrete, leaving you with a heavy object to dispose of. :-)
Not even sure they ship to Canada. Either way the shipping will make it one helluva expensive screw.
I just love the 62.5 thou per turn in my mill. I think the Taig is 20 TPI.
I have enough mass myself. Also a partially torn rotator cuff...
GOK
I see. It makes sense: You cannot get two toolholders on the toolpost at once. Not enough room. BTW I looked closely after what you had said and *he* made his own T-nuts for that application. They fit the big slots in the Taig but the screws are 6-32.
OK, I have added the detailed photos of the steady rest and the "live centres" to the set here:
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Rot proofing is pretty much a condition of residence in Campbell River. Cedar rules!
The way to do it I think is to contemplate the jig first. BTW do you use the common Aluminum Oxide wheels to grind tool bits or something more exotic, e.g. like this:
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I have one on my other grinder together with a hard felt wheel which I use for knives.
I cheated, at the time, I had 5 short sections of 1/2" water pipe welded around the end of the 3" post, (like a star) then used 1/2" redi rod to tie it all together such that I could adjust the plumb on the column. Gerry :-)} London, Canada
16 TPI on the mill -- one of the more "interesting" choices. :-) That I would be tempted to turn new leadscrews for. (Of course, I need to do the same for the compound in my shaper, which has exactly the same poor choice. :-)
Try it with one of mine which is 6" diameter and something like
0.750" or 0.800" thick. :-)
[ ... ]
O.K.
O.K. Comments in order of photos:
1) What do you see if you remove the screw securing one of the fingers? Is there an elongated hole there, or just a round hole large enough to clear the screw? If the latter, it is only good for a single size, You need to make rectangular fingers with elongated holes, and a somewhat wider groove for them to slide in to allow adjusting to different sizes. (It *might* have just enough adjustment to allow use with really small workpiece diameters -- which are of course what needs it the most.
The attachment screw seems a bit stronger in this photo, without the jpeg distortion.
2) This shows a little more of the cam -- but not much. It looks as though it clamps onto the rectangular part with the screw.
3) This looks even more as though it is clamped onto the center piece with the screw. And the hole in the external part of the cam is pointing the wrong way. It needs to have a piece of steel in it to act as a lever to turn it, and probably turn to near vertical to lock and horizontal (towards the back of the lathe) to release.
I think that the part moved by the cam extends to the other side, where it is held by a pin or a screw but allowed to slide sideways a bit.
4) Or maybe the cam lifts the horizontal piece with the screw to clamp it tightly to whatever bed it works in. It probably is for a split bed, not a dovetailed bed like the Taig. The screw goes into a clamp plate beneath the ways, and the cam pulls up on it to lock it in place.
Can you stick a rod into the hole in the external part of the cam and see what motions you get when you operate it? If it lifts, it is the latter function. If it slides sideway, it is the former function.
5) O.K. You meant a small ball bearing *race* assembly, not just a single bearing, which could act as a hardened center.
6) A hardened center -- unless that tip and its flange rotate in a hidden bearing (which is possible, the flange would keep chips out of the bearing most of the time.)
7) What is the dark material sticking out of the center? It *could* be a long piece of felt to wick oil to the bearing. And the knurling would be to allow it to be positioned by hand, sliding in a tailstock prior to being clamped in position.
Oh -- your comment says rubber. If it is withdrawn, can you feel the way to the other end of the device where the bearing is?
O.K.
Those particular wheels are for grinding woodworking chisels -- very hard metal is best ground with a softer wheel.
I should have a coarser grit version of those wheels for my grinders, but have not yet bothered to change them, as I mostly use carbide inserts.
However -- I *do* use the white wheels on my little benchtop surface grinder, and I have used that to produce accurate Acme thread form tools in HSS.
O.K. Again, not for HSS, but for a high carbon steel.
I think it's neither -- it looks like a setscrew that bears on the finger, rather than a bolt through it.
That is how I interpret the pictures -- the cam raises the cross bar, which is hinged with a roll pin on the other side, thus raising the bolt and thus the clamp plate.
O.K. I could not see what the screws were threaded into. It looked as though they passed through the fingers. With that little meat to thread through, it would be rather weak.
[ ... ]
Which makes sense for some lathe designs -- but not for the Taig, which is a solid dovetail.
The fingers slide freely and are held in place by set-screws.
See more of the dissassembled rest in the same set here:
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The cam seems kind of pointless: The only reason I could see is that it lifted to top part off the small detent (see the last pic how they all fit) - but the screw goes right through the whole thing so it is not like you can slide the rest in and out after releasing the detent. Was the screw added later as the cam-detent arrangements were too weak?
You can turn it over and over - make the hole face wherever...
GOK.
See above and the pictures.
They do rotate - sadly the body is 0.003" bigger than the Taig tailstock.
A probe will go the length of the body minus 0.5".
Back to the steady rest: It seems to me that taking the guts out of the foot of the thing and machining some sort of new pedestal with dovetails matching the Taig should be possible. Or not?
I was off news yesterday -- Conjunctivitis making it difficult to read what I was typing -- along with what I was replying to. :-)
It has been long enough so I forget what I was describing. But I don't think that I have anything designed for Godzilla. For that, one of the lathes with 40" swing or larger might be getting close. :-)
Oh -- looking through the flicker photos again, I see that it was a conventional milling cutter. There are larger ones. Certainly my mill could drive thicker ones, but not larger in diameter. Others may be larger -- but I've not seen a mill which enough clearance between the arbor and the overarm bars.
I've finally realized what I'm seeing. (It would have helped to see one removed.) These are truly headless setscrews, and they are threaded into holes which were tapped before the groove was milled through for the fingers. I thought that I was seeing the heads of Allen head cap screws instead, which would have had a smaller diameter threaded part, and thus my expectation for a hole or slot through the fingers.
I don't really like this construction -- the slot has weakened the threads significantly. Is the material of the main frame aluminum or some steel alloy?
There is a part missing from the photos. A rectangular plate which fits onto the end of the screw, and pulls up against the underside of the rails in the lathe bed. At a guess, the center piece which the screw goes through is the width of the slot through the bed, which would suggest a watchmaker's lathe. Anyway -- think of the typical lathe bed (not the Taig):
This is what my Clausing's bed looks like (end view), with the "~~~" indicating that more material goes on down from there. Also left out are transverse reinforcing sections, which would be below the area shown.
Anyway -- the carriage runs on the left (front) V as shown, and the right (rear) flat as shown.
The Tailstock, and the steady rest fit on the left (front) flat and the right (rear) V.
South Bend lathes have three Vs instead of two.
Anyway -- the tailstock and the steady rest have a screw which reaches between the ways, and attaches to a plate which it pulls up against the bottom of the inner rails (shown as "######" above. There are lots of ways that these are pulled up, and often the head of the screw is below the plate, and a nut in the tailstock is pulled up. The steady rest normally has just a nut to be tightened, as it is not adjusted as frequently.
Yes -- but in *operation*, the hole must face upwards to lift the bar to the maximum. You install the plate, place the main assembly on top of the bed, start the screw, and tighten it until the steady rest can just barely be slid -- with the hole (and the rod which should live in the hole) pointing to the back. Lift it towards straight up, and it will lock the rest firmly in place.
You *can't* turn it with your fingers when it is nearly tight enough in the clamping. That is why the hole is there. It is either for a permanent lever, or to accept one of the rods which fit into some of the chucks for a watchmaker's lathe.
[ ... ]
So -- pick up another tailstock and bore it out to fit. Or do you mean that it is 0.003" bigger than the OD of the tailstock casting? (It is too late to go down and check that now. I should be in bed already. :-)
So yes, it is a lubricating passage to the bearing.
First thing to do is to check two measurements (maybe three):
A) The distance from the bottom of the steady rest, (excluding the screw and the block which fits in the longitudinal slot) to the point at which the fingers meet.
B) The distance from the top of the Taig's bed to the point of a center in the headstock.
C) Repeast (B) above, but with the riser block in place under the headstock.
Now -- if Measurement (B) and (C) are both larger than (A), then you can make a dovetail block onto which the existing steady rest will fit. If it is close, leave out the bottom block which fits between the rails, and instead mill a raised spot to fit into the groove for centering -- and tap a hole for the screw in the right place. Keep the existing locking system and the bar for future things like getting a watchmaker's lathe at a particularly good price by luck.
If measurement (A) is between (B) and (C), then you will only be able to use it with the riser block under the headstock, and will make a mounting block of the proper height for that only. (Otherwise, you would make it for use without the riser block, and make another riser block for when the headstock is on a riser block -- except that you will not be able to use such a small steady rest for anything large enough to
*require* the headstock to be on the riser block, so don't bother.
Not necessarily -- consider the part as looking like this (from end view) (again -- view with a fixed pitch font like Courier to avoid image distortion):
+-Z-+ | Z | | Z | _________| Z |_______ |__________Z________|
Consider the 'Z's to be a tapped thread, and the vertical part to fit between the ways -- the same width as that central bottom piece, almost tall enough to touch it, but not quite.
It depends on whether it has been hardened after turning. To turn it, I would fit a center into the tailstock, and bring it into contact with the bearing inner race (with no center in the bearing), while gripping by the knurled end to try to turn down the OD. For
0.003" diameter reduction, you are going to want very sharp HSS tooling, not carbide, and just the right amount of feed pressure, or you will either skim too much off, or rub against it and work harden it (while reducing the diameter perhaps 0.001" or less, but making it hard to get a bite with future tooling.
All of this is being stored up for the future (including the centre turning etc.) Right now the Big Beast is occupying all of my spare time. I have a page-long list of pimping issues for the Taig but gotta get the other stuff finished first.
The arrival of golfing weather at last is not helping...
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