opimachine LATHE L28 cnc retrofit. goodbye old siemens!

[Aurelien]

Good morning all. I created this film to show you my work on the retrofit of my Optimachine L28 lathe.
before starting, I want to tell you that I am French, and that I use google translate a lot for this thread, so be a little indulgent if certain words seem strange to you.
This lathe was originally equipped with a Siemens 802S control with which I felt very limited, and especially for which I found very little information on use and in the event of a breakdown, etc.
After a lot of research, I discovered the centroid acorn system, which seemed to me to be a real system that was affordable, functional, and above all with a lot of support.

This machine will serve me enormously in my job which is the preparation of 2-stroke engines.
the work will not be intensive, but repeated. that's the goal, isn't it?

The machine is originally equipped with a nema 34 4.2N/m 6A motor in open loop on the Z axis connected to a leadshine DMD8070 driver

And a nema 23 2.2N/m 3A open loop motor connected to a leadshine DMD5056 driver on the X axis

The original ball screws are HIWIN branded.

I use a 48VDC 5A power supply for the 2 drivers.

A 24VDC that was original in the machine to power the NPN sensors, the lighting, and the power relay for the lub pump

And the original acorn CNC 24VDC power supply which is only used for this one.

So to start, I first disassembled the old control panel, to take the measurements, and designed and 3D printed a support to integrate my asus touch screen.

then I did the same thing for the keyboard support.

[Aurelien]

After doing all this, I was left with the intel NUC integrated pc.
I was able to take advantage of an already existing hole on the side of the desk.
Initially, it was a 220V socket, and an RS232 communication socket for the Siemens console.

I just had to enlarge it a little to be able to pass the pc with its support.

[Aurelien]

after doing this first part, I had to look at the original electrical part, to see what I was going to keep and reuse.

I spotted the operation of the original spindle drive which is driven in 0/5v.
I was able to do a test with a 1.5v battery to validate my location before all disassembled.
I had to buy a KBS240D card in anticipation, but I saw that the latest version of the acorn offered 0/5V or 0/10V.
unfortunately for me the KBSI card had already arrived...

I think the acorn sales site should mention it to avoid the mistake for anyone else.

the original motor seems to be a 2.2kW servomotor

[Aurelien]

After all this, comes the big step of dismantling the electrical part, to replace them all.

I was a little afraid of this part because it was really a big first for me, but I must say that everything went really well thanks to the many electrical diagrams available on the site, I was able to make my own diagrams and I only had wired like my drawings.

first start-up of the electrical cabinet

https://youtube.com/shorts/8zOL8NkV-_w


and finally comes the first axis movement

https://youtube.com/shorts/8cDrMJFNRvw

[Aurelien]

after some research I ordered a new quick tool holder system, so as not to be limited to 4 tools at the same time as with the old system.

I was also able to re-use the spindle encoder that was originally mounted on the machine with the old control.
I would like to thank the people who informed me about this on the facebook group.
I put you pictures of the encoder in question if it can be useful to other people.

and to finish on the installation part, I thought I could reuse the old proximity sensors to do the homing, but I realized that they were PNP instead of other NPN

I therefore ordered 4 new NPN sensors (4 to have one more in case)
I connected 2 for the homing of the X axis and
Z, and added a 3rd that I configured in Z lim+ to avoid getting hit in the tailstock when I use it.
I think it's a safety not to be overlooked.

and I'm pretty happy because it works perfectly, see for yourself:

https://youtube.com/shorts/tdlWAy89sBM

[Aurelien]

I continued with the overall turns ratio settings for the Z and X axes, and the softwear limit.

I'm impressed with how easy it all is.
at first it's very confusing because it's a lot to assimilate, but going slowly and little by little, everything is really good with the different information available here, on the centroid site, and on youtube with the videos of marty franco and on the official centroid channel.

https://youtube.com/shorts/XJB_BBklSWI

I just had to machine the new support for my tool holder.

I made it out of 7075 aluminum.

I am now ready to learn how to use cnc12 and make my first chips

[martyscncgarage]

Outstanding!
Be sure to post a link to a video of it running, pan to the monitor too!
Enjoy!
Marty

[Aurelien]

thank you marty

Now we have to talk about what is wrong with me.

I'm bothering with the European keyboard. I have some keys that are not in the "right place" even though on windows everything works fine.
this is not very serious, but I find it quite annoying to use.

For future potential French customers, who like me would order their system from "D.E.M.I" milling machine, they charge you a notice in French at the price of 50€. I think this is almost theft because it is only a user manual which is also quite old (CNC11).

I expected at least to also have the installation manual. Well no, I had to manage with google trad.
Again, it's not the end of the world, but I think that when you sell this type of service you have to do it until the end, or not at all.

On the other hand, I have another problem which this time bothers me a little more, when I jog on my axes, I sometimes have the button which remains engaged even if I no longer touch it. I had this problem with the arrows on the keyboard, and also on the touch screen.
What do you think would be the problem with that?

[Aurelien]

Hello everyone, and Merry Christmas. I shot a video for my YouTube channel where I present all the evolutions of my digital machine, as well as the centroid acorn cnc card and my CAM software.

[cnckeith]

wow! thanks for posting. very cool to see what you are doing with the Acorn equipped lathe.