Author Topic: Building a New Lathe  (Read 144394 times)

Offline vtsteam

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Re: Building a New Lathe
« Reply #750 on: August 06, 2018, 10:52:27 PM »
I went through a repeat of the lathe threading routine on the Craftsman -- a lot easier with the lathe already set up, and the earlier experience under my belt. I was able to use the old tap, as well to do the final thread sizing. Since the tap is made of the same screw material I will be using, the clearance is very close, with almost no backlash.

It was also at about this time that I figured out that the slightly eccentric and relatively close relief bore was probably the cause of my earlier problems.

Of course since this insert wasn't in the ram, the tap couldn't jam. And the threading was easily accomplished.

I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

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Re: Building a New Lathe
« Reply #751 on: August 06, 2018, 10:57:22 PM »
And finally a trial fit -- it does seem to be a slight interference fit. I didn't drive it home, because I want to clear out the relief bore -- no sense having the jack screw binding. I guess I'll have to make up a longer boring bar to do it. Might take a while because of springing, but at least this part of the process will be finished.

I love it when a Plan B comes together!
Steve
www.sredmond.com

Online awemawson

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Re: Building a New Lathe
« Reply #752 on: August 07, 2018, 02:00:57 AM »
Persistence pays off, well done Steve  :thumbup:

Andrew Mawson
East Sussex

Offline PekkaNF

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Re: Building a New Lathe
« Reply #753 on: August 07, 2018, 02:57:18 AM »
Good Job. Pretty confident that the insert works out better than the original plan!

Pekka

Offline Neubert1975

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Re: Building a New Lathe
« Reply #754 on: August 07, 2018, 07:34:36 AM »
Nice work, as always ;-)
Good to see that you managed to make it work  :thumbup: :beer:

And now i will go out i my HOT workshop and continue with project mill power feeder.

Offline vtsteam

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Re: Building a New Lathe
« Reply #755 on: August 08, 2018, 09:27:13 PM »
Thanks Andrew, Pekka, Neubert!  :beer: :beer: :beer:

I bored the recess wider, and it was definitely slow going with such a thin long bar, but it did cut, and after a trial fit with a piece of acme all-thread, there was enough clearance to press the insert home.

Next step was to start on the jack screw. I cut off a 6" length of Acme rod, chucked it in the 3 jaw, and began turning the threads off of a 2-1/2" section. That will be the part that passes trough the tailstock end cap, and will accept the handwheel.

I had the tailstock itself apart, so couldn't use it as a support center for turning off the threads. So I had to take light cuits.

I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

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Re: Building a New Lathe
« Reply #756 on: August 08, 2018, 09:32:08 PM »
But I got there eventually, and it was nice to have the three tailstock ram pieces together and functional.



I still need to make up thrust bearings for the jack screw, and mill a groove along the ram to complete these components. But not today. :beer:
I love it when a Plan B comes together!
Steve
www.sredmond.com