Pipe threads require a special flapper stylus, so when the carriage is returned the tool doesn't make contact with the work piece, destroying the thread. They're spring loaded and move out of the way when the carriage is reversed, allowing the tool to, once again, make contact with the work piece.
Harold
Wise people talk because they have something to say. Fools talk because they have to say something.
For threads, any threads. as long as you have everything set right there should be no problem. if the template has enough length before the threads, and an ample wall on the end. run the thread down, up the retract wall at the end of the threads. flip the retract switch on the tracer, it withdraws the slide giving clearance, move back to the start point, flip the retract switch off. the slide moves back to the template, on the tracer head dial in your next cut and continue, unless I am missing something?
Grant
been doing some real head scratching figuring how I want to mount the template holders. searching the web was not much help on this one! The HLVH style lathes do not have a lot of open space to mount things on, as well as this tracer is pretty compact and will not reach very far to get to the template. the width of the saddle, one of the features of the HLVH, takes up most working room. and the tail stock overhang means you need it right up as close as you can. there is mounts on the back bed where the taper attachment goes. but by the time you use those, then up and behind the bed, you run out of working space. the over all height of everything and the height of the styles holder brings up interference issues. and I want the tracer mounted on the front. I feel the crosslide tail is too week and not rigid enough to work from there. plus I want a holder that works for facing, turning, and will hold bobins for masters. one other consideration, most work will be in the small category up to around 4 inch diameter, probably not much longer than 8 / 10 inches. most small work I see me doing will be in collets and short enough that I wont need the tail stock.
for most facing projects, I see the tailstock being removed to get working area. for shaft work need to be able to bring the templates up along the front of the tailstock.
also I see needing to be able to accurately position and measure template locations, for sizing the workpieces. put in a template that locates with dowels to machine features to measure diameter, and length, then replace the curvy template with one that has no way to measure on.
I think I have a pretty good plan and Idea now,
started one the clamp base. will clamp on the flat dovetail bed. again web search had no luck finding dimensions of the dovetail!
ok, measure the width, then the vertical flat on both sides. measured the angles with a protractor. punched everything into the computer. lay out the block, grab a block off aluminum and put it in the machine and cut away!. one end I made a cut in to make that side a little flexible for clamping. if its not flexible enough, will cut a horizontal cut lo loosen it a bit more! made the mount 2 inches wide so it should repeat squarely pretty well. just flying with a pic in my mind. might need to upgrade a few things as we go.
cut the block on the wire machine, pulled it out when done. it slides very tightly on the bed , tried a couple thou shim under the dovetail, could not slide it in.looks like it has only about .0015 clearance! my dimensions where right on the money!
Grant
okay, now start to mock up how this little erector set thing will work!. I am reusing Roy's template onto my base till I get that section all worked out in my mind.
here is how it should all go together for facing cuts.
Grant
one thing is, with all this assembled stuff. we need to worry about square and straight. everything will be doweled and bolted together for strength and rigidity. the stylus rides along the template, but with only a few ounces of pressure, but we don't want this moving or wiggling, or vibrating around!
this is what I have in mind for turning set up.
the long bar running up along the tailstock clears it. and it will hold long templates for longer shafts.
just working the way through! all in the head, no prints! but one other important thing in this kind of work, keep all your bolt and dowel patterns the same and to standard dimension's, like 2 inch centers. easy to remember, and easy to move modular parts that way. if you just keep repeating the same patterns everything can move around, or be used in other set ups. you will see down the line.
Grant