Before I can go any further with my lathe, I need to get the single point threading sorted. I have no trouble doing it, as it is one of the basic things you should learn very early on in your machining life. My problem is that because my lathe is a metric machine, but is also capable of imperial threading, the leadscrew half nuts need to be left engaged all the time for Imperial threading (and also some of the metric as well)
This is a common problem, and over the years a few people have come up with ideas to make the job a lot easier. I am not going to go into a lot of detail, only to say that being able to withdraw the tool quickly, and be able to put it back into the same position really helps to make the job a lot easier.
This is only the start of the project, and will not be picked up again for a little while, because I need to be able to work on my machines safely, and as yet, I am not in that position. But I am able to do a little bit to prepare for that time.
Here are a couple of designs that have been knocking about a while.
This first one is good in that it will retract for doing both internal and external threading, but that is about it, everything else is a non starter.
http://www.hemingwaykits.com/acatalog/Swing_Tool_Post.htmlThis one goes most of the way there, but is limited to external threads only.
http://www.hemingwaykits.com/acatalog/Retracting_Tool_Holder.htmlSo I will be coming up with something that does the same as the first, but operates very similar to the second one. There will be no plans or drawings (but I might measure it up at the end and make a few sketches), as I will be making it to fit, and of course changing my mind half way thru. Also, it will drop onto my QTCP just like a normal holder.
So to start.
I feel very guilty about this picture. A few months ago I let Ralph take away this lump of metal (over 6" wide & 1.5" thick) to cut some off for a job he had in mind. It is a piece of gauge plate, and is real tough stuff to cut. Anyway, I said that it wouldn't fit onto my saw, so he took it away and cut a piece off by hand.
Sorry Ralph, I have just found out that by turning it over half way thru, this saw will cut it (now crawling into the back of my cave in shame).
So anyway, I wacked a piece off, then chopped that into three pieces. About an hours easy work.
![](http://i202.photobucket.com/albums/aa102/bogstandard_photos/retract01.jpg)
So here is my motley collection of metal, the three at the front will definitely be used, the bits at the back are there for backup, just in case I need something else to be made that I haven't thought of yet.
![](http://i202.photobucket.com/albums/aa102/bogstandard_photos/retract02.jpg)
So that is it for now, just keep your eyes peeled for when I start to knock the lumps into some sort of shape.
Bogs