How do you renew scale markings?

[HMF]

You look at your lathe tailstock- 50+ years has rendered the scale markings next to useless, with the most used section (the front) unreadable and the rear section only just visible.

What do you do to renew them??

1- machine a shallow groove in the ram (this should be possible because a previous owner has filed marks in the ram, so it's not dead hard) and then embed a trimmed down section of steel rule in the ram?

2-removing the ram and reengraving measurements on the ram?

3- mount an external pointer (or even a digital scale)?

4- take the quill out and mill a shallow slot that will allow you to glue in a steel rule?

5- pull the quill, put a blank arbor in it and chuck it in the lathe. Put a sleeve over the screw that lets it go half way into the quill, and put it in a steady. Use your carriage to mark it where you want. Roll the chuck by hand to make the marks?

6- remark it yourself by either using a flycutter on the mill or a shaper to get very accurate marks, then either take it to the engravers or simply use a stamp set to carefully mark it?

7- buy a Black paint stick and rub it on the scale. Wipe off with a rag all the black in the grooves will stay?

8- mount a Digital Read Out on your tailstock- like this http://www.mrrace.com/Mini_Lathe_DROs/ ?

What would YOU do?

Thanks,


Nelson

 

[trumpy81]

GDay All,

Nelson, the answer is going to depend on how much you rely on those graduations and how often you need to use them. Another point would be just how much wear is there in the bore of the tail stock and how badly is the quill worn?

Does the tail stock as a whole, need an overhaul?

Maybe it would be more cost effective to repair/replace the quill and/or the tail stock.

If the quill / tail stock is OK, then I'd probably add a digital DRO to it.

 

[HMF]

Assuming I don't have a DRO (pretty expensive though certainly extremely useful) or a tailstock DTI, and assuming a new tailstock cannot be found, can the markings be renewed somehow?

I know there is a process to re-engrave the markings, but it looked very, very complex....

Just trying to assess options...

Thanks,

Nelson

 

[randyjaco]

Nelson,

Those tail stock markings aren't particularly accurate. It is a great place for a Chinese DRO. I adapted a $15 HF digital caliper. I now couldn't even tell you if mine had its original scale. The DRO is easier to use and a damn sight more accurate.

Randy

 

[trumpy81]

Assuming I don't have a DRO (pretty expensive though certainly extremely useful) or a tailstock DTI, and assuming a new tailstock cannot be found, can the markings be renewed somehow?

I know there is a process to re-engrave the markings, but it looked very, very complex....

Nelson, my apologies, when I said DRO I was thinking of Randy's suggestion of using a digital caliper and NOT a full on multi axis DRO with a large display.

You didn't mention whether or not there is much wear in the tailstock quill/bore. For now I will assume that there is wear present.

To restore the tailstock quill/bore it may be necessary to bore the tailstock bore 1/16inch to 1/8inch oversize and then machine a phosphor bronze bushing to fit the now oversize tailstock bore. After fitting the bushing into the tailstock you would then lap the quill to suit the inner dimension of the bushing (which you left slightly smaller than the diameter of the quill).

If you are not confident in doing this yourself, see if you can coax a local machinist to do it for you. Beer and Donuts are good incentives I hear

Once you have restored the tailstock/quill bore and you have a nice shake free sliding quill action, then you can set about restoring the graduation markings on the quill.

The first step will be to devise a set of stops to limit the amount of rotation of your lathe spindle. For example, making the longer 10th's graduations, you might want to limit the spindle rotation to 10 degrees and 5 degrees for the shorter units graduations. Of course it will depend on what length of markings you will need to make.

Now that you have limited the rotation of the spindle you will place the quill into the chuck so that only the graduation mark you are working on, is protruding, plus a little for clearance of the chuck, then you will place a suitably ground HSS tool bit into your tool holder. A threading tool is pretty good for this.

Now position the tip of the tool bit inline with one of the graduation marks and slowly advance the cross slide until the tip of the tool just touches the quill at the point you wish to start the graduation marking/remarking. With the tool just in contact, rotate the spindle clockwise/counterclockwise between the stops by HAND. Retract the cross slide sligthly, remembering its position, and return the spindle to the start position. Move the cross slide back into the remembered position + .001 and repeat.

Keep repeating the above until your markings are at a suitable depth and then move to the next graduation and so on. Try to keep the marking you are working on as close to the chuck jaws as is practical, this will give you the best rigidity in your setup.

Now, you can simply reassemble the quill and be happy with it, or you can invest in a set of number stamps of the appropriate size and proceed to re-stamp any numbers that are present on the quill. If you choose to re-stamp the numbers, you would be advised to build a stamping jig of some kind, to hold the stamps in place and in alignment with the quill etc. whilst you gently hammer them to mark the quill.

HTH

 

[8ntsane]

Hello Nelson

I have redone the grads on two tail stock quills. The first quill was a round clyinder type, with no machined flat. The second quill had a machined flat done at the factory and the grads put on that.

The way I happened to do this was on my mill. I mounted the rotary table , with a 4 jaw chuck. I allso mounted up the tailstock. After getting the quill chucked and idicated in with the tail stock at the far end, its time to start cutting the grads.
The cutting tool mounted up in the mills collet with the spindle locked, I brought the mills quill down .002 at a time, and used the rotary table to rotate the quill to scibe the grads. My mill does have a DRO, so once I had the cutting tool centred over the first grad, it was as easy as moving the X axis to your next #. The length of the lines was just recut to the same as the factory lines, reading this in degree,s on the rotary table scale makes this move along pretty quick.

The paint marking the lines can be a bit of a pain, depends how you try to do this. I had tryed a rag to wipes the excess paint off, and it also wiped the paint out of the lines. I found that if you use a strip of paper, to wipe the excess off, it will leave the paint in the lines. With a rag , I just kept putting paint on, and wiping it off again,lines included.


The second quill had the machined flat , and I set up in the same way, but used the Y-axis to cut the grads. I used the rotary table only to get the flat indicated in so it was zeroed out/ paralell to the table.

This quill the owner reqested the #s be restamped to. For this, I went to the lathe, chucked it in the 4 jaw, and used the boring bar in the QCTP, and the boring bar to hold the stamps and align them, with the set screw just snug to let the stamp stay straight.

Though many people wont want to stamp the #s while be held in the chuck, my old Sidney Lathe is built like a tank, and I doubt it would suffer any bearing damage.

I have allso stamped the #s on dials with a newly made dial still in the chuck on the rotary table. Same deal, just take your QCTP off the lathe, and get it set up on the mill table, and use the boring bar to hold the stamps, and go to town.

Thats just how Ive done them.

I uderstand that not all people want , or care to mount up a caliper based read out on the tail stock. I know I woundn,t. I would not want to be drilling holes to mount one of those things to my tailstock. I look at it this way, if I really want to know how far Im drilling in, I would just slap a drill chuck in the QCTP, and read my DRO for travel, but for 99 per cent of the time, the grads in the tailstock quill are good enough. Though I have used a magnetic backed indicater on rare occasion, If I really need to know how deep Im going. Usually if I had a milling cutter in the tailstock.

Paul