Craftsman/Atlas 618 [page 16]

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Wednesday, Mar 15 2017

As mentioned on the previous page I got a mill. The mill uses ER16 collets. That answers the question of what size collet chuck should I make for the lathe. ER16 is a bit smaller that I’d like for the lathe – max diameter is 10mm – but it will do for now.

I’m going to get enough stock for about 4 parts because I expect to make errors. With that in mind I took some square stock I had on hand and thought I’d attempt to make an ER16 collet block for practice.

Ready for threading

Ready for threading

Ready for threading

At this point I’d turned down the stock to the major diameter to cut M22 x 1.5 threads. I do not have a full set of threading gears. When I went to set up the lathe to cut the threads I found one of the gears I’m missing was called for in the 1.5mm pitch recipe I found. Damn. Oh. I’m an idiot. The missing gear (46 tooth) is being used an an idler. Any gear that will fit can be used as an idler. I’m using the 48 tooth gear. Works fine.

Metric M22 x 1.5 threads

Metric M22 x 1.5 threads

Metric M22 x 1.5 threads
Threads fit

Threads fit

Threads fit

Well, that was painful. The result is fine, but the work getting there was something else. Because the lathe was not designed with metric threads in mind once the half nut is engaged it can not be disengaged until the threads are cut. So how do you move the tool to the end of the piece to make the next cut – you back off the tool and run the lathe in reverse.

When I wired up my motor I didn’t add a switch for reverse. I didn’t think I’d ever need it as you can’t cut with this lathe reversed unless you like watching your chuck unscrew itself from the spindle and bounce off the ways on the way to the floor. It would probably do damage to your toes on the way down. Anyway, with no motorized reverse I had to turn the lathe by hand. I replaced one of the set screws in the countershaft pulley with a socket head cap screw and use an allen wrench in the screw as a lever/handle to turn the lathe. Lots of turns. Never again.

forward and reverse

forward and reverse

forward and reverse

Notice the toggle switch. I need to put it in a box. Later. The important part is I can now put the motor in reverse with a flick of a switch. Much better. Should have done this before cutting the threads.

Next up is an attempt to cut the 8° taper for the collet.

 

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