Author Topic: Lathe build project  (Read 2142 times)

Offline PK

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Re: Lathe build project
« Reply #25 on: May 15, 2018, 11:09:14 PM »
Thinking...thinking... That's actually a really clever way to do it.
99% of my thread turning is either 1.25mm/1mm/0.75mm pitch and I always leave the half nuts locked and run backwards.... I could just have three reference screws. It's a lot simpler than a gearbox...

Thanks for the post!

Offline awemawson

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Re: Lathe build project
« Reply #26 on: May 16, 2018, 02:33:32 AM »
Yes Denis Chaddock described a follower for grinding threads on the shanks of end mills on the Quorn T&C grinder
Andrew Mawson
East Sussex

Offline Fergus OMore

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Re: Lathe build project
« Reply #27 on: May 16, 2018, 02:36:56 AM »
Steve

Fascinating stuff- thank you.

I'm desperately trying to get my aged head around a new U2 Asiatic clone of a Deckel tool and cutter grinder to counter senile dementia.

Kind regards

Norman

Again- thanks Andy. The grey matter isn't as addled as I imagined

N

Offline NormanV

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Re: Lathe build project
« Reply #28 on: May 16, 2018, 04:21:48 PM »
I've had a boring afternoon. :D
I have been given a tailstock ram for a Myford lathe (thank you so much Kayzed1) that is slightly larger than the one that I was making. Which meant that I had to bore out my tailstock casting to fit. As I am rotating the lathe by hand it took a long time, especially where the split cotter is situated. That took a bit of effort to turn the mandrel as the cotter is steel and the tailstock is aluminium.
Anyway, it is done and I didn't go oversize as I had feared. All I need to do now is to hone the hole to make it a perfect fit.
Here is my boring set up, I've shown it before but this is from the other end and shows my temporary tailstock. I used the saddle to push the tailstock along. Steve, (VTsteam) will recognise the method as it is how Dave Gingery showed to do it to build his lathe.

Offline vtsteam

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Re: Lathe build project
« Reply #29 on: May 16, 2018, 08:54:52 PM »
You're welcome PK. I can't tell you how many times I've looked at that photograph -- copied off the internet 15 years ago -- I don't remember where. It took a long time to figure out what was what. I'm still tempted to add it to my old Gingery lathe.  :coffee:

But for now, working on the new lathe.  :dremel:

And Norman(s) here's one more possible method for thread cutting without change gears... uh I guess you'd call it the pantograph method:



Slightly more information here:

http://www.jacquesmaurel.com/machining

I found a copy of the referenced Model Engineer (4270, April 2006) on ebay and sent for it. But it will apparently be two weeks or more getting here from UK shores. I'd appreciate it if someone could send me a copy of the article before that. -- though I had worked out and tested an electronic change gear system for my new lathe, I think I would prefer the mechanical simplification of something like this. Plus I think it's really cool.  :dremel:

Norman (Fergus) sounds like a good use of time to me! :beer:

Norman (lathe builder) Yes indeedy, that boring method is familiar -- bored my Gingery headstock and tailstock that way, and will do it again on the new lathe. With the weird reversal that I already have a tailstock bore and will use that to bore the headstock. Either way, they come out the same Z and Y axis position on the ways, parallel and concentric, which is the point!  :ddb:
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline NormanV

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Re: Lathe build project
« Reply #30 on: May 17, 2018, 01:29:27 PM »
Thank you for the suggestions. I don't think that it is worth my while making one of the linkages for thread following as my requirements are very rare and I am more interested in fitting it with a fine feed to save me from having to wind the handle all the time. If I have fine feed it is just a step away from thread cutting abilities. The Knaell device is enough information for me, it is practical to do it with timing belts.
I need to do some measuring and sit over a list of timing pulleys to see if I can fit it all in. I also want to incorporate a dog clutch on the end of the leadscrew, this lathe does not have half-nuts to disengage the drive.

Offline NormanV

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Re: Lathe build project
« Reply #31 on: May 17, 2018, 02:42:24 PM »
I've had a look at it and it appears that I could set up to cut .75, 1, 1.5mm threads and a fine feed of .1mm per rev. This would need six pulleys and four belts and cost just under 50. That doesn't sound too bad.
I will file away the sketches for a later date.

Offline NormanV

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Re: Lathe build project
« Reply #32 on: June 08, 2018, 09:20:24 AM »
Work has come to a halt on my lathe. I am moving house shortly and will not have a workshop for a few months, but when it is built I will be back to work!

Offline vtsteam

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Re: Lathe build project
« Reply #33 on: June 08, 2018, 09:28:06 PM »
I know the feeling, Norman. Looking forward to when you resume. :dremel:
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline gerritv

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Re: Lathe build project
« Reply #34 on: June 09, 2018, 07:33:23 AM »
There is a simpler threading method using the follower principle: http://cartertools.blogspot.com/2011/01/monty-remons-taig-lathe-mods-part-2.html

This works very well on small lathes. I have used this on both my Unimat and Taig.

Offline nel2lar

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Re: Lathe build project
« Reply #35 on: September 18, 2018, 09:09:58 PM »
Norman
Been gone for a while trying to catch up. What a beautiful project and you are making the old girl look good. I will be following when you resume. Sorry to hear that you will not have the shop to play in. I do not know what I would do without mine, I guess go insane. Looking for the finally.
Good Job
Nelson