Cam lock Tail stock for 7x12

[RotarySMP]

You know how I wasn't going to do any cosmetic upgrade to this crappy tail stock.

I changed my mind.

I just hated the way the twp castings did not fit properly together. So I figured I'd strip it down, clean up the wonky joints and bog it up, before painting it.

Most of the existing paint and bog flaked of really easily with a scraper. The rest I when over with a stainless brush in the angle grinder. The details got hit with the Proxxon fine grinder, and then I could file the casting joints by hand.

This photo is about half way done. Shame I don't have access to a sand blaster.

[RotarySMP]

One thing lead to another, (as they do), and I starting thinking about the way the center drill makes a slight jump as it enters the work. Maybe this thing is not that well aligned. I couldn't remember how anal I had gone about aligning the thing back when I did it in 2004.

The lathe quite accurately between centers with taper of only a few tenths over 3 inchs, so it can not be far out.

I set about measuring.

[RotarySMP]

First I looked at the centering of the casting hole.

You can see that the vertical height is pretty good, but this is not centered horizontally. Looks like I didn't spend the time to get it adjusted right back in 2004.

Luckily, the adhesive I thought was epoxy between the upper and lower castings turned out to be super glue, so a half hour in the over was enough to reopen that joint.

[RotarySMP]

Next I measured the ram, first retracted...

[RotarySMP]

...then extended.

You can see that the vertical alignment is now a little low (Ram not concentric to casting? Play between casting hole and ram?, and gets progressively worse as ram extends (Ram angled down?).

[RotarySMP]

Then I looked at the rams angular alignment, both horizontally...

[RotarySMP]

...and vertically.

The ram, or at least it's outer surface, is reasonably well aligned vertically (less than a though over 2 ") , but about 0.0025" misaligned horizontally. I can't remember how bad it was before I started in 2004, but I guess I have learned a bit more about precision in the last 6 years.

[RotarySMP]

While doing this I took a little detour into looking at the rigidity of the thing.

There isn't much!

With a single finger I can push it through 0.005" sideways, and that was with the quill locked. Vertically it is better.

Unlocked the range of movement is about the same, but not force is required.

[RotarySMP]

I also did checks with a dead center and with a mill shaft chucked in the drill chuck. The results shed no new light on things. Good news was that it makes little difference how the mill shaft was chucked, or in which rotation the chuck morse taper was installed in the tail stock, the basic misalignment stayed pretty repeatable.

So I cooked out the superglue, and measured the shims I used in 2004. 0.008" of paper shims on the front mating surface, and .013" of metal and paper shim on the rear. Nothing one the vertical alignment face.

My aim was to add 0.001" front and rear to raise it up, and a thou to the rear of the vertical alignment face to kick it around straight with the ways.

I then spent a whole evening removing and installing the whole thing about a million times with different stacks of shims, made from 0.010" brass shim stock, 0.004" beer can, and 0.0004" household food wrap foil.

This was frustrating, but I ended up with a good feel for the repeatability, and plan for how I'll attack the horizontal adjustment for the final assembly.

Plan is to get a good shim pack, and then do a wet final assembly with epoxy, where I get the thing aligned during the gel time of the adhesive.

Wish me luck

[Crevice Reamer]

Good luck Mark!

CR.

[RotarySMP]

Thanks CR. I am sure that helped.

I managed to get it centered within about 0.0003" horizontally (with the quill retracted), and about half a thou high. Since the error increase as the quill extends, and I have no way to measure whether the morse taper is aligned to the quill outer surface. I decided this would be enough.

Well here it is, the candy coated one piece tail stock.

I have about 20L of JB Weld epoxy structural filler which was getting tossed at my old job because it was life ex. Well, although it expired in 2004, it still hardened fine for this job. That hour in the oven at 70°c probably helped.

I figured I'd do the surface filling with it rather than bog, since:

1/ I have this.
2/ I don't have bog.

[RotarySMP]

Man, do I hate painting things. I sanded back the blue epoxy filer and the undercoated with a rattle can. Looked good with a couple of minor defects, which filled in the next three coats of undercoat. Sanded back with 600 grit wet between each coat.

On the third coat got some fish eyes/ pin holes (not properly dry before the coat?), so I didtwo more coats trying to fix that.

The green paint (also a rattle can) came from a model store a few years ago. When i sprayed that it looked okay, but with fish eyes and pinholes again. So I sanded that back off, diluted some of that blue filler with acetone and filled the defects, then undercoated again. The under coat dissolved the bits of green which were not completely sanded off. I wish I was smart enough to heed this waring over paint incompatibility.

Once I got those defects sanded back and another coat of undercoat applied and sanded back, I put on a couple of top coats. They didn't come out as well as the original coats with the fish eyes (wish I had called it quits back then).

I sanded the green a little with 1000 grit wet, and then put on coat of clear gloss.

Big time incompatibility.

Now I have ignored it for a couple of weeks, trying to decide whether to sand it back and do it properly, or accept that it is a turd and is supposed to look like one.

[Crevice Reamer]

Man, do I hate painting things.

DITTO!

Good effort, but:

I don't know how to break this to you gently: The tailstock takes a lot of dings. No matter how good you get the finish, if you actually USE it, sooner or later turner's rash will begin to degrade your paint job.

Put that thing together and make some chips!

CR.

[RotarySMP]

Yep. I already have put it together.

I polished the turd as practice for the day I get a real machine which is worth doing up. When that day comes I'll be painting it with epoxy paint.

I used that same crap green paint on my enclosure. What a waste of time, as it now looks like hell. I only painted it because it was mild steel sheet, and picked up rust easily. Once you spray a bit of cutting oil around, rust is a no longer a concern.

When I make an enclosure for the mill, I am not going to paint the inside of the sheet metal. Swarf is a great paint stripper.

[RotarySMP]

I forgot to post a photo of the finished product.

[Crevice Reamer]

She's a beauty! Nice Work!

CR.

[knudsen]

Looks great! Now you should buy a replacement and put that one on the shelf to keep it purdy :rainfro: