Motorising Assembly part 1

…if we evolved over millions of years, why is there so few of us? Where is everyone?…

I like the way engineering solutions evolve. This lathe wasn’t the first lathe ever built. It’s design evolved from countless previous lathes, but at some point in the past, there was a first lathe. Probably to turn wood. Something like a pole lathe or such like. Many incremental steps – design led – eventually produced a simple mass produced machine that works well, with all the niggly adjustment, lubrication and vibration problems resolved. Key point – design led.

Anyway, all power providing devices need a means to hold them in place. And so to the motorising assembly…

I’ve no pictures of the assembly in place before dismantling, but this is it laid out, so you can see the muck which has collected on it…

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This view is the other way up…

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…and shows:

A Motor base. Guess what sits on that?
B Countershaft arm
C Swing Head Assembly

The big pulley is the Countershaft Pulley with the Countershaft sticking out. This Countershaft goes through the two coaxial bores at the right hand end of the Swing Head Assembly.

Disassembly was quite easy. Basically unscrewing grub screws, unbolting things and using The Persuader to knock out shafts and pins. Here’s a selection…

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Taking photos like these two…

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…relates each Socket Set Screw – as they’re called in the diagram – to the part out which it came. Helps with reassembly. I felt this was necessary as each was a slightly different length. The second hole in the right hand collar is for the long pin shown in one of the previous photos.

The one difficult section was getting the Countershaft and the Countershaft Pulley to part company. After releasing its Socket Set Screw, I tried turning it with a big screwdriver here…

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…because that seemed obvious. The screwdriver kept slipping out and damaging the slot. I resorted to a very large persuader and that did it. Why the screw slot is there, I’ve no idea.

Here’s all the parts arranged for their team photo…

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Cleaning followed the usual process. Brushing off general muck, brushing on or soaking in Green Gunk, scrubbing off with various brushes, rinsing in water and drying by cloth, paper towels and hot air.

Fettling and reassembly next…

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Headstock finale

…Schrodinger’s cat must be dead by now…

…so there’s no need to open the box. Does anyone get his cat thing apart from Sheldon Cooper?

Funny the nonsense with which you can occupy your mind when you’re not fit to work. Too many things came to a head and now my Doc won’t let me fly for a while. Fine. I’ll get stuff done. Including reading science stuff so that I can pretend to be intelligent a little longer.

Part of the fun of this renovation is figuring out why some bits don’t work as well when you put them back together. The logic path is; if they worked before, they can be made to work again. If they don’t work as well as before, then something’s not right or there is an adjustment to be done. Look at this picture again…

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These are the little Gear Studs and up until now I hadn’t noticed that the smaller diameter shaft is eccentric. When I reassembled the 20T and 18T Tumbler Gears onto them and the Tumbler Sleeve Gear below them…

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…they wouldn’t turn properly. Initially I thought they were too tight, or that they had worn themselves into a set way (lubrication hasn’t been a strong point in the past, it seems), but then I noticed that as I was tightening the nut at the back, the Stud revolved and the Gear translated in a regular manner perpendicular to the axis (it moved a bit). When I took them off, then I could see the eccentricity. What a relief! The Tumbler Gears weren’t worn, they were extremely well designed! The eccentricity in the Stud enables translational adjustment.

Next, the lower Spindle Bearings were fitted to the Headstock and the Spindle Assembly dropped back in, using a good amount of oil…

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Then the upper Spindle Bearings and Shims…

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…and finally, the Bearing Caps were bolted back on…

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The Sight-feed Lubricators can be seen in the background. They screw into the holes in the Bearing Caps and drip oil through holes in the upper Spindle Bearings, lubricating the Spindle. I didn’t fit those yet in case they get broken during future assembly operations. I put a lot of oil in the holes, though, and turned the Spindle Assembly by hand to spread it.

The entire Headstock Assembly was bolted to the Bed. There were three sizes of bolt and they had to go in the right holes. Each went through a different thickness of the Headstock, this picture, from the rear, illustrates…

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Once I know what I’m doing, I’ll be able to adjust things more finely, but for the time being, I oiled it as much as I could, refering to the Lubrication Chart in the manual. The Lathe so far…

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Next up, the Motorising Assembly. Oh, there’s a cat…