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Pimp my mini-lathe
I converted a 7x12 Mini-lathe to TurboCNC years ago, when there was no space in the apartment for a machine shop, other than a corner of the inner city balcony.
http://wrathall.com/Images/My%20Shed.jpg
Since moving to a house with a basement, and getting a real lathe, the minilathe just lurked in a corner. There were a number of aspects of my previous conversion which were pretty half-arsed.
- 1 per rev spindle encoder for threading. Done with a optical gate and Schmitt trigger, the wiring was very messy.
- never installed the ball screw on X
- the plastic back gears broke, and the DC motor burnt out, so it was converted to 3ph 3/4 /hp induction motor and VFD with toothed belt drive to the spindle. Loosing the back gear meant it had little torque at low rpm.
- The bed grinder appeared okay, but the fit of the slides, and tail stock were horrible, with tiny contact points.
Figured it was time to learn to scrape in a whole machine, and the tiny size of the 7x12 mini-lathe means it is not too daunting a task.
There is a Mesa 7i96 inbound, to give this a LinuxCNC connection. I have a tiny gigabyte SBC and 10" touch screen to make a controller of matching scale to the lathe. It will take a while before I get to that part of the build.
This will be my first attempt at a multiple video series.
https://www.youtube.com/watch?v=NVBC9Vzixtk
Mark
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Re: Pimp my mini-lathe
Thanks for the video! I'll be watching as you go along. I think these lathes get a lot of grief, but they are certainly fun and capable enough. I think as a CNC machine, these could be pretty great for making fasteners.
Have you swapped out the headstock bearings to angular contact or tapered roller bearings? I'm actually going to do that in the next week or so and change out my gears to metal. I'm also installing a 5C collet.
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Re: Pimp my mini-lathe
Hi. Thanks. I wouldn't recommend the 7x to anyone, unless they really had no space for anything larger. Any lathe is better than no lathe. Out of the box, the fit and finish of these (and it seems all chinese machines up to about €3000), is pretty terrible.
Years ago I replaced the chinese bearings with SKF ball bearings. Now a set of SKF tapered roller bearings have gone in. I made an ER32 collet chuck for mine. 5C chucks build pretty long on a spindle with a small bore. The next video will be finishing the bed, and moving on to the headstock.
Mark
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Re: Pimp my mini-lathe
I kind of expected to be done scraping the bed, and move on to fitting the headstock, but the scraping of the underside of the rear way took longer than expected. And maybe my standards are also developing.
I've uploaded the second episode of this rebuild and mod project to youtube here.
https://www.youtube.com/playlist?lis...wys-tTM3wKMOGW
One of my friends has gotten really good at scraping, and he popped around on Saturady and gave me some valuable tips to improve the accuracy of printing and scraping such narrow ways. There is now just one more way to scrap, and the clamping surface for the tail stock will need to be machined as well.
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Re: Pimp my mini-lathe
I have to admit to not owning such a lathe, but I am impressed by the dedication shown to improving it and I hope it inspires others to learn the skills to upgrade their own lathes.I am looking forward to seeing how the implementation of LinuxCNC and a SBC goes as I would like to win back some workshop space myself and losing the old desktop computer would be one way of doing so.
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Re: Pimp my mini-lathe
Thanks Routalot. I guess I'm going way over the top here, but it makes for an interesting way to learn a new skill.
Mark
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Re: Pimp my mini-lathe
This weekend the bed was completed. Here is Episode 3.
https://youtu.be/7MTHWuS5S8A
Scraping in a whole bed (even a little one) is more of a challenge than I expected. Especially using µm digital micrometers on scraped surfaces, you get a far bit of scatter in the measurements.
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Re: Pimp my mini-lathe
Now that the bed is finished, it is time to move on to the head stock. Sorry this one is a little more disjointed, but features a little Lathe and Mill machining, and a little CAD and 3D printing.
https://www.youtube.com/watch?v=7MTHWuS5S8A
Mark
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Re: Pimp my mini-lathe
Link the same video as before?
How about this one??
https://youtu.be/-xdPNk6Fluw
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Re: Pimp my mini-lathe
Oops. Thanks for picking that up.
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Re: Pimp my mini-lathe
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Re: Pimp my mini-lathe
Since the bed was so flexible, I did a quick and dirty reinforcement...
https://youtu.be/iplxnimaFSI
Mark
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Re: Pimp my mini-lathe
Given the increase need for entertainment at this time, I hurried up a little and got episode 8 out early. Hope you enjoy...
https://youtu.be/AFfDfmhfTTs
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Re: Pimp my mini-lathe
Great videos. I've watched them all. Has me thinking about my lathe.
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Re: Pimp my mini-lathe
Thanks for the feedback. What lathe do you have?
Mark
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Re: Pimp my mini-lathe
I've just uploaded episode 10 your enjoyment...
https://youtu.be/QdJcBxymCRM
Mark
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Re: Pimp my mini-lathe
The lathe I have is a TS-210. 8x16.
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Re: Pimp my mini-lathe
Those have a lot more iron in the bed. Should be a lot stiffer.
Mark
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Re: Pimp my mini-lathe
The book shown is Edward Connelly 'Machine Tool Reconditioning' ? Did you find a reprint at a fair price ?
Are you using any other reference material ?
I'm enjoying the videos and getting tempted to 'turd-polish' a mini-mill.
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Re: Pimp my mini-lathe
Thanks for the feedback. I look forward to see you polish your Mini-mill as well.
Yes, that is the book. My thoughtful wife gave me a copy as a birthday present years ago. I guess the other reference material I used were youtube videos by Müllernick and Stefan Gotteswinter.
I just uploaded episode 11, on making a close fitting gib for the cross slide.
https://youtu.be/1tqLHFMwqx0
Mark