Hi all,
I'd been really frustrated lately because I'd not been getting an even turn on my pens. The lathe would vibrate ever so slightly, and the pens would not be even by a very slight amount--less than a millimeter but plenty big enough (to the discerning eye) to cause the fittings to be offcenter when I mounted them to the blank for final assembly. The classic problem here, is that the mandrel got bent. So I tried a different mandrel. Same problem--both of them must be bent. But I kept rolling them on my workbench looking for slight amounts of light and any lack in uniformity, to no avail. And I use a mandrel saver so I was kind of surprised that they could be bent at all. I was really stumped.
So I said, I"m going to turn between centers. I'll get rid of the mandrel entirely. I had some convertible bushings. I don't normally like TBC because I like to turn the body and cap at the same time, but these were for a one-piece twist pen so I figured why not. Same problem. An off center turning. Now I was really stumped. I had no idea what was going on or what could be causing the problem. I was worried that I'd somehow messed up the headstock on my lathe and got that spinning off axis or some other such problem.
So I removed the pen, pushed the tailstock up to the dead center I'd had in the headstock for my TBC bushings. And I rotated slowly, by hand. The dead center moved around the tailstock point in a circle of about 1 mm radius. I was really worried and really concerned, thinking this would be an expensive fix.
I took the dead center out and stared at the machine, contemplating the least expensive way to figure out what was going on, and then I saw it. I small chip of wood from one of my previous turnings had made its way into the headstock and gotten smooshed against the interior of the headstock where you put the morse taper. It was small enough to push anything I put in there into a slight angle. I cleaned it out, put the center back in and tested it. Good as new. And, thankfully, I was able to selectively sand down the side of the body that was too long relative to the other and get a perfectly fitted pen.
Moral of the story: Keep your headstock clean.
I'd been really frustrated lately because I'd not been getting an even turn on my pens. The lathe would vibrate ever so slightly, and the pens would not be even by a very slight amount--less than a millimeter but plenty big enough (to the discerning eye) to cause the fittings to be offcenter when I mounted them to the blank for final assembly. The classic problem here, is that the mandrel got bent. So I tried a different mandrel. Same problem--both of them must be bent. But I kept rolling them on my workbench looking for slight amounts of light and any lack in uniformity, to no avail. And I use a mandrel saver so I was kind of surprised that they could be bent at all. I was really stumped.
So I said, I"m going to turn between centers. I'll get rid of the mandrel entirely. I had some convertible bushings. I don't normally like TBC because I like to turn the body and cap at the same time, but these were for a one-piece twist pen so I figured why not. Same problem. An off center turning. Now I was really stumped. I had no idea what was going on or what could be causing the problem. I was worried that I'd somehow messed up the headstock on my lathe and got that spinning off axis or some other such problem.
So I removed the pen, pushed the tailstock up to the dead center I'd had in the headstock for my TBC bushings. And I rotated slowly, by hand. The dead center moved around the tailstock point in a circle of about 1 mm radius. I was really worried and really concerned, thinking this would be an expensive fix.
I took the dead center out and stared at the machine, contemplating the least expensive way to figure out what was going on, and then I saw it. I small chip of wood from one of my previous turnings had made its way into the headstock and gotten smooshed against the interior of the headstock where you put the morse taper. It was small enough to push anything I put in there into a slight angle. I cleaned it out, put the center back in and tested it. Good as new. And, thankfully, I was able to selectively sand down the side of the body that was too long relative to the other and get a perfectly fitted pen.
Moral of the story: Keep your headstock clean.