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Gallery, Projects and General => Project Logs => Topic started by: RotarySMP on January 26, 2020, 10:48:37 AM

Title: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on January 26, 2020, 10:48:37 AM
I got a mini-lathe from Artec (a German brand), about 10-15 years ago. It is the generic lathe made by SIEG,  but branded and sold by every man and his dog. it was the only machine tool I had as we had an inner city apartment, and the lathe in the corner of the balcony was the machine shop.
http://wrathall.com/Interests/machining/My_shed.htm (http://wrathall.com/Interests/machining/My_shed.htm)
 I did a lot of modding on it. Starting with the typical little stuff like swarf guard on the apron gears, and adding a carriage lock.
http://wrathall.com/Interests/machining/Carriage_lock.htm  (http://wrathall.com/Interests/machining/Carriage_lock.htm)

Then on to some more extensive mods like the T-Slotted cross slide, which was very handy.
http://wrathall.com/Interests/machining/Carriage_lock.htm (http://wrathall.com/Interests/machining/Carriage_lock.htm)

It was quite quickly converted it to TurboCNC, which worked quite well. The canned cycles were really quite handy.

Since moving into a house with a basement machine shop, the 7x Minilathe has just lurked in the corner, except for being abused into turning wood on a couple of occasions. 

I was never that happy with some of the harlf-arsed mods I did, and also got interested in doing a scraping project, so figured the little mini-lathe would be the perfect practice piece as it is nice and small and shouldnt take for ever.

Here is the first installment of the video log of re-modding it...

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on February 16, 2020, 04:11:38 PM
I have made a fair bit of progress on the Minilathe.

Episode 2 - Still scraping
&t=1s

Episode 3 - Finishing the bed


Episode 4 -
&feature=youtu.be

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: Joules on February 17, 2020, 02:42:04 AM
Great series of videos, I particularly like the 3D printed lathe dog, look forward to seeing how that works out for you.
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on February 17, 2020, 05:11:48 AM
Thanks Joules. My first thoughts were machining a steel lathe dog on the MAHO, but the 3D printer provides a way faster solution, for a one off problem.  On another forum someone was wondering whether that Lap would work 3D printed as well.
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: Joules on February 17, 2020, 05:46:16 AM
Mmmm, many times I have used wooden internal laps, not sure I would trust the printed plastic direct, especially if it warmed up a bit.  I have small bending rolls and would consider rolling a thin wall tube for cutting up, then epoxy the pieces to a 3D printed lap carrier.  Get the best of both worlds, must give it a try.   I recently started laser cutting fine emory paper and adding that to 3D printed profiles for polishing.

Regardless of all that, very much enjoying your journey with the Mini lathe.
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on February 17, 2020, 07:50:07 AM
Thanks fo the encouragement. The whole video thing is much harder than I thought. Especially once you record yourself you find out how scatterbrained your thoughts are, and that rather than sounding like a TV announcer, you sound like a stoner :)

I need to make another lap for that test bar, and think it'll be a 3d print one and see if it is a complete or partial failure. Good point on the heat effects.
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: Joules on February 17, 2020, 09:02:41 AM
My major worry on a printed lap is not getting the scraper action a metal lap will have to clear slurry.  Find out in a few hours when the first test lap comes off the printer.

Well being stoned explains how you can keep scraping for so long  :ddb:
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on February 17, 2020, 09:34:18 AM
Scraping is kind of addictive. When is enough? when do you stop? it is all subjective, so you do "just one more pass" and then "just one more". Soon enough you arms and back are aching.
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on February 17, 2020, 02:12:33 PM
Just tried out the plastic lathe dog. Worked very well.
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: Joules on February 17, 2020, 05:03:58 PM
 :thumbup:

Good news, another accessory added to the list of prints here.
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on February 23, 2020, 05:23:15 AM
The fifth episode of this series is now up.


Mostly it covers making the #3 Morse test bar. Hope you enjoy it.
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on March 07, 2020, 05:33:30 PM
I was out on a business trip and missed a week, but here is the 6th episode. Scraping in the head casting to align it to the bed. Went better than I expected, with one hiccup.
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on March 15, 2020, 09:38:39 AM
Since the lathe bed was only as stiff as a wet noodle, I did a quick and dirty reinforcement.



Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: Joules on March 17, 2020, 05:14:33 AM
Interesting video Mark, do you plan to add a cover where the gap in the carriage exposes the ways.  I see a path way for fine swarf getting under the saddle, but don't know how much clearance you have with the modified nut.
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: Brass_Machine on March 17, 2020, 09:42:14 AM
I'm late to the show... Now I have videos to binge watch!

Eric
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: Chuck in E. TN on March 17, 2020, 12:10:48 PM
Thanks Joules. My first thoughts were machining a steel lathe dog on the MAHO, but the 3D printer provides a way faster solution, for a one off problem. 
Mark
Can you share the stl for the late dog, or post a picture, please?


Chuck
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on March 19, 2020, 03:53:50 AM
Glad you are enjoying the series. I have attached the STL of the 20mm dog. The forum does not accept the extension .stl, so I renamed it to .txt, just save it and rename it back. The extra drive tab broke off when I used it.

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: nrml on March 19, 2020, 07:41:25 AM
Why don't you add a third leg between the base plate and the lathe bed to improve stiffness?
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on March 19, 2020, 04:34:32 PM
Thanks for watching the video. It would still need a stiff base plate. Making and fitting a third leg would be a lot of work. If I was going to do a lot more work on bed stiffness I would be more likely to bury it in a big block of epoxy granite.
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: nrml on March 19, 2020, 07:05:15 PM
I was thinking on the lines of a simple block of steel or cast iron of suitable height bolted to the base plate and the gap between the bottom of the bed and the new leg filled with JB-weld or similar. A bit crude, but there will be some additional support to that thin span of bed without increasing the weight of the bed itself.

Epoxy granite would be good but you might be venturing into the zone where the minilathe is compromising your design rather than being a convenient skeleton for re-fleshing.   
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: WeldingRod on March 20, 2020, 10:49:35 AM
Epoxy granite will get you in trouble with mis-matched thermal expansion!
Adding structure underneath and tying in with jb weld floated pads is a much better plan.

Sent from my SM-G892A using Tapatalk

Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on March 20, 2020, 06:06:30 PM
I am not going to do anything more than bolt it down to that slab of steel. E/G was just theory for this one. Looking at the theory, differential expansion is not  really an issue in my basement. The temp range is very limited.

I just uploaded episode 8.

Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on March 26, 2020, 11:21:02 AM
Here is episode 9...


I am trying to up the frequency and the quality at the same time. Hope you enjoy it.
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on April 07, 2020, 06:14:51 AM
Here is episode 10 of this continuing saga... enjoy.


Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on April 12, 2020, 12:18:50 PM
Continuing to polish this turd, episode 11 covers the close fitting gib I made for it.


Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on April 19, 2020, 08:39:29 AM
In Episode 12, I'm using the LinuxCNC converted MAHO 400E to convert to tapered gibs on the saddle.

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on April 26, 2020, 06:09:55 AM
Just uploaded episode 13...

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on May 03, 2020, 06:04:42 AM
Now that the geometry of the main components has been corrected, we can move on to the motion hardware...


Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on May 17, 2020, 06:07:41 AM
Epispde 15 is now up, which covers the spindle motor, and has a bit of Maho slotting head action.
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on June 07, 2020, 06:00:55 AM
I was too embarrassed by last weeks screw up to post a link to Episode 17...


but Episode 18 is back to normal.


Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on June 14, 2020, 07:25:28 AM
Hi guys. Episode 19 is up...



Happy fathers day in Austria,
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on June 21, 2020, 06:20:23 AM
Hi All,

I just uploaded episode 20.


Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on June 28, 2020, 12:39:17 PM
Episode 21 is in Youtube,

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on July 05, 2020, 06:36:04 AM
Episode 22 is now up.


Enjoy,
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on July 12, 2020, 06:05:47 AM
Episode 23 is my challenge getting this old Gigabyte brix PC to load linux..


Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on July 19, 2020, 10:36:52 AM
Episode 24 deal with configuring the Mesa 7i96 ...


Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on August 02, 2020, 01:35:31 PM
Since my camera can do 4K video, I thought it would be good to celebrate the 25th episode in UHD. Bad mistake with a Gen 1 Zbook, and pretty slow DSL line. I took 8 hours to render the video, and another three to upload it. Back to HD 1080P for me.

Enjoy,
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on August 09, 2020, 07:21:12 AM
Hi Guys, Here is episode 26. First motion is a nice milestone...


Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on August 16, 2020, 06:28:49 AM
Episode 27 is up...


Enjoy,
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on August 30, 2020, 06:35:42 AM
Episode 28 is not up:


Enjoy,
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on September 06, 2020, 06:49:35 AM
This week it is again more playing around with the Maho Mill...

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on September 13, 2020, 06:03:58 AM
E30 is up. The first time I used tool offsets, including a crash due to my lack of uderstanding.


Enjoy,
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on October 04, 2020, 06:22:38 AM
Episode 31 is up.

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on October 25, 2020, 07:47:29 AM
I just noticed I forgot to link Episode 32:
&

I also just uploaded E33.

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on November 01, 2020, 06:10:17 AM
This weeks effort contains more MAHO CNC work...

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on November 15, 2020, 06:07:01 AM
Episode 35 again has a little Maho action...

Ark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on November 22, 2020, 06:28:38 AM
Episode 36 is now up...

Enjoy,
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on November 29, 2020, 06:20:09 AM
The end in coming into sight...


Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: hermetic on November 29, 2020, 08:53:52 AM
Hi Mark, love the build, I have in the past been able to do temporary repairs on older ribbon cables using the cores from solid conductor cat 5 cable . Soften the cable with a warm air gun, use a pin to create a hole above the conductor, and push the wire in with tweezers, however, this does not work on the newer super thin ribbon cables, but could you buy a ribbon cable connector, cut the cable right through, install it on the cut ends, and plug it back together?
Phil
UK
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on December 06, 2020, 10:54:21 AM
 Thanks Phil. It is a really tiny skinny cable. I have contacted Sunfounder about replacing the touch overlay, ribbin cable and all. They responded to ask for my order number, so I am awaiting a further response.

This weeks video is now up....

Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: philf on December 06, 2020, 03:41:28 PM
Another super video Mark - showing that it's not only me who can cock things up!
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on December 07, 2020, 01:59:40 AM
Hi Phil, I was pretty disappointed with my performance on that part for sure. Oh well, gives everyone a good laugh, and me something to learn from.
Mark
Title: Re: Re-Pimping the 7x12 minlathe.
Post by: RotarySMP on December 13, 2020, 07:36:17 AM
I couldn't leave it as
Humanity 0 : Robot 1


Enjoy!