Seadog
Save the planet. It's the only one with rum!
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Last year I was lucky enough to pick up a set of 8 step collets from HomeWorkshop for the princely sum of £70, quite a bargain I thought. I want them for my Boxford, but they're of unknown origin so the original Boxford item won't fit, mainly because the thread is smaller on these.
Wind forwards about 9 months and they resurface when I do the second clear up of the workshop. Time, I thought, to make a draw bar ( because I did actually do something recently that would have been easier with a step collet. No idea what, now).
I was thinking about making an adaptor so that the Boxford bar could be used, but that's languishing at the back of my storage shed and I couldn't be arsed to dig the whole lot out.
I also have another draw bar that I made some time ago. I thought it was for a Clarkson chuck but it ain't, so now I'm racking my brains to remember just what it is for
I know that it's something I've used a fair number of times.
Anyway, I digress.
The drawbar (from now on known as the DB)
When I made the DB I used a lump of unknown steel (It could have been a knackered arbor press spindle, thinking about it, so tough but workable) and a piece of thin wall tubing from a frame tent, or suchlike, that a friend was going to throw out about 5 years ago. So I opted to cut a piece more of off the remnant to repeat the exercise. It's not straight, and it's coated in paint, but it does clean up OK and seems to have been heat treated.
The tube
The rather clunky handle of my DB
Since I use the bar for an as-yet unremembered task (BTW, it does fit my small boring head, but I definitely didn't make it for that), I decided that it would be nice to have one that could be interchangeable. After several mental iterations of how best I could really complicate the issue, I settled on the simple expedient of a screw
Radical perhaps, but there you go. Above shows the handle ready to be clearance-drilled and counterbored for a 5/16" BSW machine screw.
The thought occurred to me that I didn't actually know what the thread on the collets was, probably a useful piece of information to have, so I investigated. It turns out that, as near as I can make out, it's 1/2" BSB, so 26tpi. Amazingly I had both a tap and die to suit
The plan is, then, to plug the end of the tube with two threaded pieces. One to suit the collet, the second to suit the fastening bolt.
I found another wonderful piece of tough steel which used to be a bearing or seal drift, probably Triumph when it was younger.
It was pilot drilled and then 1/4" then finished 29/64" which is the correct tapping size. I thought that I'd use my BSA tap chuck, since it rarely gets an outing.
And it fits, at least it did once I'd cleaned the bruising from the thread.
I like pushing the lathe and tooling. Here's a short video with a 1mm DOC being taken, under power, with lots of nice hot blue, curly springs.
Next we need to part it off.
Wind forwards about 9 months and they resurface when I do the second clear up of the workshop. Time, I thought, to make a draw bar ( because I did actually do something recently that would have been easier with a step collet. No idea what, now).
I was thinking about making an adaptor so that the Boxford bar could be used, but that's languishing at the back of my storage shed and I couldn't be arsed to dig the whole lot out.
I also have another draw bar that I made some time ago. I thought it was for a Clarkson chuck but it ain't, so now I'm racking my brains to remember just what it is for
I know that it's something I've used a fair number of times.Anyway, I digress.
The drawbar (from now on known as the DB)
When I made the DB I used a lump of unknown steel (It could have been a knackered arbor press spindle, thinking about it, so tough but workable) and a piece of thin wall tubing from a frame tent, or suchlike, that a friend was going to throw out about 5 years ago. So I opted to cut a piece more of off the remnant to repeat the exercise. It's not straight, and it's coated in paint, but it does clean up OK and seems to have been heat treated.
The tube
The rather clunky handle of my DB
Since I use the bar for an as-yet unremembered task (BTW, it does fit my small boring head, but I definitely didn't make it for that), I decided that it would be nice to have one that could be interchangeable. After several mental iterations of how best I could really complicate the issue, I settled on the simple expedient of a screw
Radical perhaps, but there you go. Above shows the handle ready to be clearance-drilled and counterbored for a 5/16" BSW machine screw.The thought occurred to me that I didn't actually know what the thread on the collets was, probably a useful piece of information to have, so I investigated. It turns out that, as near as I can make out, it's 1/2" BSB, so 26tpi. Amazingly I had both a tap and die to suit
The plan is, then, to plug the end of the tube with two threaded pieces. One to suit the collet, the second to suit the fastening bolt.
I found another wonderful piece of tough steel which used to be a bearing or seal drift, probably Triumph when it was younger.
It was pilot drilled and then 1/4" then finished 29/64" which is the correct tapping size. I thought that I'd use my BSA tap chuck, since it rarely gets an outing.
And it fits, at least it did once I'd cleaned the bruising from the thread.
I like pushing the lathe and tooling. Here's a short video with a 1mm DOC being taken, under power, with lots of nice hot blue, curly springs.
Next we need to part it off.
