2016 POTD Thread Archive

[British Steel]

Simple answer: leave the half-nuts engaged. Threading to a shoulder, thread away from it instead: run the whole lathe in reverse (don't touch the tumbler gears! leave it set for the right-hand thread you want!) with the threading tool starting in your run-out groove and turned upside-down[1] (still with the cutting edge on centre!), turn the topslide to 29 degrees the other way ( ---/--- instead of ---\---) so you're feeding and cutting on the leading edge of the tool, returning to the start you can turn the chuck forwards by hand for the last bit just passing the groove then reverse by hand a little to get the tool into the run-out groove and take out slack in the leadscrew / geartrain.
If you have a threaded spindle and chuck, be sure to take it slow and take VERY light cuts to prevent it coming adrift...

Dave H. (the other one)

[1] or right side up from the far side of the spindle and work - if so leave the topslide at the usual angle ---\--- (and wind OUT to put the cut on) or spun through a full 180 degrees ---\--- with the handwheel away from you, kind of awkward! (winding IN for cut), depending whether you can get it around the other side?

 

[savarin]

This is a pretty good explanation for metric threading
http://www.conradhoffman.com/metricthreading.htm
down the bottom he gives a method of using the thread dial so you can release the half nuts.
I haven't tried it yet as I said I just keep it engaged. So far I haven't had to thread to a shoulder and the small amount of run out I cut has been sufficient for the lathe to come to a stop.

 

[boostin53]

For some reason I've been in a knob making mood recently. Didn't spend much time in the shop today, but I managed to make another knob haha. This time it's a knob for one of my reloading presses. 2.25" aluminum with four accent grooves .120" deep, spaced .300" apart. I also ordered some brass in various diameters for a bunch of other handles/knobs I want to make.

 

[Mark_f]

I re made the collet chuck today. It came out perfect. I left the half nuts engaged, but am going to experiment with engaging on the same number all the time. It worked yesterday but was it a fluke? We shall find out.

 

[British Steel]

Looks really good, Mark - have you chucked a piece of turned + ground in it and measured the runout yet?
I'm planning on an ER chuck for mine some day, but with a camlock spindle nose it could be a lot more complicated (and needs a piece of 6" round to start from...) - and I already have native collets* and drawtube for up to 7/8" by sixteenths, anything bigger goes in one of the 4-jaws...
Dave H. (the other one)

* rare as rocking horse droppings, Holbrook collets

 

[Charles Spencer]

Thank goodness I don't have to cut any metric threads (America - Yay!).

Today I did gang milling for the first time on my little Garvin horizontal mill. I'd previously made an arbor and some bushings for this purpose.

Yeah I know - the bushings should be hardened and ground:

http://www.use-enco.com/1/1/32282-hardened-ground-arbor-bushings-spacers-nuts-212-4265.html

These were cut from a piece of pipe. bored out, milled flat, and the key ways cut.



Hey, they worked for me.

 

[chevydyl]

British, just start with a backplate of what you need, then turn the chuck nose rough and Bolt and maybe pin it to the back plate from the backside, the mount it and turn to final and thread, that way your not wasting material
If you do it that way make sure you turn a boss and recess for more rigidity

Friend of mine has a d1-6 with a 5c nose bolted from the front to a backplate

 

[jbolt]

Made some more parts for the high school robotics team.

 

[NCjeeper]

Discovered this when I opened the breaker box on my new to me Doall saw.

I guess I am going fuse shopping.

 

[dave_r_1]

you don't think that fuse will blow with too high a current?