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Halifax614
23rd Sep 2020, 06:58 PM
Tailstock rebuild:

Before, as below.....
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Found a bent lead-screw, damaged/cracked hand-wheel & finger piece, damaged eye-bolt & all gummed-up inside, upon dismantling. Some corrosion too. The unit must have been off the end of the bed & bounced off the floor at least once in the past..

Now; all fixed...
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I straightened the lead-screw & repaired the hand-wheel with Devcon epoxy. I wasn't game to try brazing or welding it; fine now. The eye of said bolt was stretched into an ellipse; it had gone out of round by well over a mm., which surely can only happen because of excess force on the over-centre locking cam arrangement. It was a bugger to get that cross shaft out because the diameters now clashed. Anyway I later put the eye bit in the hydraulic press & squashed it back the other way so it is now out of round a little across-wise. I thought it would be made of a harder steel than that. MT2 taper inside the sleeve was OK condition. No other major dramas. A good clean, remove crappy finish & repaint to finish up.

Installed back on to the bed....
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Here is the simple stop that I made to prevent the tailstock making another bid for freedom off the r/h end of the bed. Just a piece of 25mm galv. steel strip bent to suit, secured with a 6mm winged bolt into a nut-sert in the end of the strip & through the edge of the drip tray. It bounces back the other way now.
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Here below with a view from the back, we have all the major parts re-fitted back together... The tail & headstock centres [MT2 & 3 respectively] were used to check that the heights match, which they do thankfully, & the cross-wise alignment was set too.

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So now on to the motor & step-down drive system; as you can see in the r/h side of the pic., that area is empty at the moment. The drive motor as originally fitted was a big older single phase 1.5 hp. unit, i.e. three times larger than required. I have checked & rebuilt it with new bearings & start cap & it runs fine. However, I'm considering fitting a new VFD & three phase smaller 0.5hp/0.75Kw kit to it. Or maybe just a standard small single-phase motor. Dunno yet. Seeking advice on VFD's etc. elsewhere on this forum.

Subsequent to all of the above, I've started an alignment check using the trusty ground alignment bar that plugs into the MT3 socket in the headstock, using a magnetic base & DTI on the carriage & have found a bit of an issue with longitudinal run-out; due I believe to the suspect condition of the inside surface of the headstock taper, with some light corrosion pocketing I think.
I earlier stripped & rebuilt the TOS chuck, which seemed in reasonable condition after all the swarf was removed, except that the jaws need a serious grind to straighten the bell-mouthing out on the inside faces. Obviously I can't do that until I refit a drive system, whatever that may be. There is wear on the jaw scroll teeth too; because they are dual inside/outside jaws I need to compare them to a newer example for acceptable wear. It might be preferable to buy a new 125mm chuck.
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BaronJ
23rd Sep 2020, 11:32 PM
Hi Halifax614,

Do you know that you can simply reply to your existing thread by clicking on "Reply to Thread" at the bottom !

Then all your posts will be kept together and in posted order, rather than be spread out across several threads all with the same name. It will also allow you to scroll back through the additional posts and read previous comments.

Hope this helps.

Halifax614
25th Sep 2020, 07:27 PM
Hi Baron... Yes, I thought about that a few weeks ago. Stupid me. However I decided to keep going 'as is' on this particular subject, which is just about finished, unless I can figure a way to roll it all into one thread retrospectively.
I'm not smart enough to do that - I'd probably buggarup the whole thing.

Unless you or another contributor/moderator can point a way to do that without losing all the photos or sending it all haywire?


Any new subject I'll certainly keep in one thread. I have a couple of other possible sagas/stories in the pipeline...


Thanks
H614

Halifax614
1st Nov 2020, 04:44 PM
Here are a few more photos of the Sheraton C lathe that I have more or less finished rebuilding. I started in June with this project...


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So four months spent in the workshop under the house, keeping away from the dreaded Covid lurgy out there, resulted in this...


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I did consider the idea of fitting a new VSD & 3 phase motor.... but that money would be better spent on my 'main' AL-300 lathe if necessary. So this one has a new 3/4hp / 1.1Kw single phase motor to replace the previous overly large 1&1/2hp example, & new Chinese 3 jaw 125mm chuck* to replace the worn-out Czech 'TOS' original (This last item is odd in itself as the same 3-jaw set is reversed for both inside & outside gripping tasks, neither of which it did well due wear & bell-mouthing). The only 'wearing' part of the lathe itself needing replacement was the worn thrust bearing in the headstock. Of course there were many smallish problems along the way, i.e. the cast steel cantilevered arm that supported the heavy gear-covering l/h door was previously cracked through & poorly weld-repaired, so a new post arrangement was made to fix that, which works fine & definitely won't break in two.
Remarkable really considering the machine had sat unused here in the tropics for two decades.
I can't be fussed with fettling & refitting the original ugly sheet metal guards that covered the belt drive & countershaft. Will make & fit some sort of splash guard at the rear. Metal or wood? Don't know yet...
Anyway it runs very well & tests as accurate, having sorted out the slightly damaged 3MT taper inside the headstock with a borrowed reamer. What to do with it now? I don't need a second lathe & I'm running out of room. Might have to sell a motorbike.
There is an old 'Neslien'? wooden toolbox (of UK origin I believe) that came with the lathe - partly visible in the last photos. Might refurbish that next... or put it on gumtree.
And thanks to Baron J I have just continued this last thread in the approved manner.:)

YBAF
1st Nov 2020, 05:25 PM
I see yer wearing tropical work boots..:U




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