Linz lathe with Clearpath and Acorn = toolroom workhorse

Post your completed retrofits for the world to see.

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yellow_submarin
Posts: 16
Joined: Mon Apr 22, 2019 4:54 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: C120826

Linz lathe with Clearpath and Acorn = toolroom workhorse

Post by yellow_submarin »

Hey guys,

Here I'm sharing a CNC conversion that starter last summer when I picked up an old gunky lathe for the price of steel in July. It is a French design produced in the 70s and 80s where the slide rests on 65mm chromed steel rods supported only on both ends. The base is a sheetmetal weldment with cast iron saddles and stocks. While the design looks very unusual, it is extremely compact, quite stiff, and "open" in the way that everything is very accessible to mess with. The old machinist who sold it to me had it as spares, he was restoring another one. I got a very good deal letting him "gut" the machine for any mechanical part useful to him, and useless to me. So he stripped it from the motor, any kind of gear, gearbox or screw and the compound slide. That was fine with me, as all of that would be rendered obsolete with the CNC conversion.

I only brought it home 2 months after my initial visit so that left me with plenty of time to search for parts. Having time ahead of you is the very best way to make the best deals ! Just wait for the good one.

This way, I picked up 4 Clearpath servos + power supply for under $1K, while they are very rare in Europe. That was beyond my wildest dreams. Also picked up a 4-phase 3KW AC motor and VFD. A US teammate sold me on the Acorn, I was lucky he made me aware of its existence otherwise I would be stuck with Mach3 again. D'oh !

Then it started with a good cleanup and paint job. Nevermind the French, my last videos are in plain English.

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Then I installed Isel ballscrews. I like them quite a lot. They are German made, at a good price point. The 16mm has a pitch as low as 2.5mm which is convenient for an axis on which you want good resolution (X) without reduction redrive. Well, I had to redrive anyway to make it compact. That's my only regret so far. The very good thing with those ballscrews, is that the preload can be adjusted on a single nut, which is slightly pressed on the screw by a set screw on the side.

Everything wet quite smoothly although a bit lengthy. Fitting the ballscrews and motors was no big deal, except for the X axis which was very, very tight to fit a ballnut. But adding a lube pump and piping, wiring, ... took me a fair amount of time. It was all worth it in the end.

By the way, I moved to a new house in the meantime.

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I threw at it a 4 jaw chuck and my BXA knock-off tool post. It works like a charm, I just finished mounting the encoder. A C-axis is coming together and I already have a toolpost spindle ready.

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I'm quite pleased with the performance of the Acorn and CNC12 in the end. I use them on a Dell Vostro 330 with I5 proc which just passes the CPU rating recommended by Centroid for a lathe. All touchscreen, no keyboard. It's a bit large, though.

CNC12 is quite stable and the interface is certainly better than Mach3. I do see some room for improvement in Intercon. Some modules like the simple turning block are convenient, some are not. I would like to be able to make a chamfer without outputting a profile or manually typing lines. It would certainly benefit from a fresh looking Pathpilot-style "help" drawing.

Anyway, I'll be converting a travelling column toolroom mill soon, with Acorn again. I'll try to keep sharing videos and pictures of the parts I made with this lathe.
yellow_submarin
Posts: 16
Joined: Mon Apr 22, 2019 4:54 am
Acorn CNC Controller: Yes
Allin1DC CNC Controller: No
Oak CNC controller: No
MPU11 & GPIO4D -w/ 3rd Party Drives: No
DC3IOB: No
CNC12: Yes
CNC11: No
CPU10 or CPU7: No
CNC Control System Serial Number: C120826

Re: Linz lathe with Clearpath and Acorn = toolroom workhorse

Post by yellow_submarin »

BTW I've been chamfering and threading ORB-8 ports yesterday, meant for AN-8 oring boss adapters. It went very smoothly.

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