tapered bore

KD
The last picture shows a brass tube? Air blast to clear chips?
Pierre
 
Its finished.
I cut the slots with an angle grinder and a thin disk, thats why they are a bit skewed.

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and in place, not a problem.

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Once I had the wheel in place I used it to cut an 8mm 1.25 pitch thread.

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My first thread cut on a lathe but at least the nut screws on ok even if the finish is appallingly rough.
The first pic is as it was cut, the second is after wire brushing the thread to attempt a clean up.

thread-2_zpscd17c289.jpg

However, lets list the horror story, the graunched bit at the end is where the tip of the bit broke of after approx three passes.
I was very surprised at how small a feed had to be used at each pass but even so I think I've cut the thread way too thin.
I managed to re-sharpen the carbide on my 400 grit diamond lapidary wheel and add the rounded end. This time I only used 0.075mm per pass feed.
I will be very interested in seeing how the finish ends up in some real quality steel and this hot rolled rod always leaves a poor finish by me so far.
Aluminium on the other hand leaves an excellent finish.

pulley-3_zps4d8f915f.jpg

pulley-4_zps30ad4c4c.jpg

thread-1_zps866d5be6.jpg

thread-2_zpscd17c289.jpg
 
That is a tryco mist coolant. Keeps every thing cool and doesn't make a mess

Ok, that makes sense. I was using the cylindrical grinder today and I do not like the new coolant. Makes me cough and headache for a couple hours after only a few minutes at the machine to setup and gage a few times. Next time I will setup a small fan to blow outside air towards me.
Pierre
 
Well I finished my ER40 collet chuck have less than .001 runout I am happy with it.

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Terminating in a 8mm hole seems a mite small, but not too small a ending. Not only small bar/tool size but bar flex while cutting would be wild. While your compound is still set, grab a piece of drill rod and turn a copy of your shaft. Then over to the mill and cut some grooves to fab yourself a reamer. A little shot with a torch to heat treat, and it should last to cut one hole and many holes if you are a hidden tool maker. Good luck. Always cool to make the tool that makes the tool! :whistle:
 
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