So this will finally be the last technical post about putting Darrens lathe to rights.

I left it last night with the backplate requiring skimming. Normally a dead easy job, but not on this type of lathe, it has no saddle lock, so the facing cut could end up any shape as the tool tip was pushed out of line by cutting forces.
So the first bit is how I cured the problem. I fitted an easy to do and use saddle lock.

After rooting thru my racks, I found the ideal bit to do the job, an 8mm steel bolt with a fitted brass tip. It isn't necessary to use a bolt the same as this, you could drop say a 6mm long slug of close fitting brass rod down the hole and screw a bolt down onto the top of it.


So I found a position for the lock bolt to go. About half way across the tailstock slide, and positioned so that the adjusting grub screws for the cross slide would miss the bolt head, no matter what position the bolt head would end up at. I chose this rail because I thought that the tailstock should never reach the area that this bolt will be working in.
So I just then put in a good centre, but make sure you don't break thru the saddle, you will end up drilling the bed.


After removing the leadscrew end support, I was able to slide the saddle so that it just overhung the back of the bed far enough so that I could drill right thru the saddle. The saddle was drilled and then tapped out to fit the bolt. You need to be careful that the hole is drilled truly vertical, if needs be, get someone to watch you while you are drilling and to tell you if you are going off square.


So saddle run back up the bed, leadscrew support bracket fitted and adjusted and the bolt fitted into the hole.
It only takes a light nip up to get the saddle locked solid. Another successful job, time to carry on.


To cut a long story short, I got all the electrics in and then run the machine up. It was working very intermittently, sometime power, sometimes not. The problem was found just after Ralph arrived. A loose connection in the interlock block hanging at the back of the machine.

So I could then carry on. Saddle was locked up, and the face was blued up to show me what was going on while I cleaned it up. Ralph was looking over my shoulder, and he commented on how much it was out.
Ignore the blue ring in the middle, that is a recess. If you look at the left hand side, the face is nearly cleaned up, whilst opposite to it, there was hardly any removed. I carried on until I had a clean face all the way across.

So the face cleaned up, ready for the chuck to be remounted.

I couldn't wait, so chucked up a lump of 3/4" hex and in low gear ratio put a cut on of 0.100", speed 800, pushed down of the leadscrew feed and took a cut. I wasn't happy with the finish, so tried it again, same thing.
Then it clicked, this was a mini lathe, not mine, plus it was doing an interupted cut. So a cut on of 50 thou, and things started to improve. I eventually ended up at a 25 thou cut, and was almost happy with the finish.
The problems Darren had been having have now disappeared.

So I flipped the bar round in the chuck, locked up the saddle and hand fed across the end. Not too bad, and I am sure I could improve on it with a bit more use of the machine.

So I now thought I would have another go at improving the finish, so changed over to high ratio (this will give a finer feed).
Usual 50 thou for rough cuts, and a final of 5 thou.
Now happy with the results.

Now for the bad news. On checking over the chuck, it has a built in runout of about 2 thou. This is about normal for a generic chuck like this.


Not much I can do about it.


I have just one other issue, the machine is cutting slightly tapered, so tomorrow that will be fitted in during a private job I have to do, it just requires a small tweak on head alignment, a quickie tap with a sledgehammer might just do it.
So Darren, your lathe is ready to pick up after tomorrow.
Everyone else. If Darren hasn't contacted me in the next four weeks, I will have for sale a one user refurbished lathe.
I fly out tonight, to a secret location in the Bahamas for a five week holiday.

Very happy Bogs