Centroid Community CNC Support Forum

Hey

I am in the process of fitting a previously manual lathe with a Centroid Acorn board and Clearpath motors.

This kind of lathe manufactured by Linz, and a smaller model by Haulin, are made of a welded sheetmetal frame, while the slide rides on ground and nitrided 65mm rods. This setup is known for accuracy, stiffness and very small footprint, which I need above all.

Here are a couple of videos - in french though. If this thread shows interest I'll make some english videos.

Thanks,

yellow_submarin wrote: ↑Mon Nov 04, 2019 7:57 am Hey

I am in the process of fitting a previously manual lathe with a Centroid Acorn board and Clearpath motors.

This kind of lathe manufactured by Linz, and a smaller model by Haulin, are made of a welded sheetmetal frame, while the slide rides on ground and nitrided 65mm rods. This setup is known for accuracy, stiffness and very small footprint, which I need above all.

Here are a couple of videos - in french though. If this thread shows interest I'll make some english videos.

Thanks,

https://youtu.be/IoOl3AU43us

https://youtu.be/1X3O1HY0gWU

It shows! Very neat! Thank you for sharing and yes, if you can give an overview in English that would be appreciated.
Look forward to seeing it run!

nice! thanks for sharing...

fyi.. CNC12 has language support for French. (along with other languages) Change CNC12 parameter 9 = 2 and save.

this will change CNC12 language from English to French (but not the VCP)

also interesting is that you can edit the language.msg text file ( located in the cncm or cnct directory) if you wish to change a word or phrase. Let us know if you have any improvements to our translation!

Hey guys,

Thanks for the comments.

I like using the controls in english but i can have a look at the french version if it helps improving the product, though.

I'll make that english tour of the machine when all the axis are in motion.

Hi to the knowledgeable folks,

I have a couple of questions for you regarding this build, regarding the capabilities of the Acorn.

First, I would like to operate a C axis. I was taking that for granted, but seeing the hefty pricetag for the option on the Oak, I am not even sure anymore that the Acorn can handle it.

Here is how I see it. I have a Nema 34 Clearpath servo collecting dust (got a combo of 4). I would have it drive the spindle with a timing belt in possibly 2 stages to get decent torque, since I would like to do some light milling with that C axis (no Y axis planned, just C interpolation).
To toggle between C and lathe mode, I would use the same belt arrangement I saw on Fanucs through a forum (sorry, can't find the picture). A pneumatic cylinder actuates the idler to engage the belt. When the idler is retracted, the belt springs back in a housing, where it is disengaged. Dead simple ! On the Fanuc, it is used as a 2-speed redrive (2 parallel belts where only one is engaged at any given time). On my lathe I would only engage the C when needed, without disengaging the V-belt of the spindle motor.

Now I could either actuate that "clutch" manually or through the control.

So will the Acorn support C axis, and can an output be configured to engage the C drive ?

Second, I have a last Clearpath SDSK on the shelf. I hear they are decent motors for the size, and self-contained. This makes want to turn into a live tool motor. On my BXA toolpost, I could very simply use the "heavy duty" boring bar holder, fit a pair of angular ball bearings in there with a straight shank ER colled holder used as spindle. That would leave me with a belt drive going to the Clearpath somewhere. That all sounds lovely, but being an SDSK I cannot turn on that motor with a switch. It needs a step/dir pulse from the control.

So the question here is, can the Acorn 4th axis be configured as a live tool spindle, where it outputs a signal giving continuous speed to that motor ? Could it ... rigid tap ?
If this can't be made to work, I will just work out a simple pulse generator controlled with a pot.

Many thanks,

You have 4 axis, a 0-10vdc analog signal and a spindle encoder to work with. How you engineer your machine, what drives and motors you choose are up to you. I know DMM DYN4 drives can do both position and spindle mode, but not sure it's totally refined yet. I have limited testing.

Sounds like your wish list is way up there.....good luck with your project.
Marty

Well, the majority of parts I turn, or will need to turn with this machine, involve radial or axial hole patterns.

I don't have a large mill so drilling those holes can get very complicated for me. Besides, it's always better done in the same setup.

Worst case scenario, I'll manage to index manually based on the encoder and use a spindle brake. But this is a CNC after all, so if I can do it with the software with a reasonable build cost and time, I will.

Now my questions were mostly about the capacity of the Acorn / CNC12 software to handle that kind of code. Is the Acorn license meant to use C axis on a lathe, will CNC12 allow it ? Is it "just" a matter of finding the proper parameters in the software to get that kind of action ?

thanks

Hey guys.

I haven't posted here in a long while but things have moved forward.

The lathe is fully operational in turning as I just finished mounting the encoder and got a lathe pro licence. Toolpost spindle is ready. I'll be dealing with the C axis very soon. At first I was set on a double stage pulley redrive, but while making the video it became obvious that a planetary gearhead then single stage belt would produce better results. I did not want chinese gearheads and just settled on a used 40:1 Parker PS series low backlash unit for $120.

I'll be posting a video on the encoder, CSS and threading during the weekend, so stay tuned on the tube.

Very nice, thanks for sharing your outcome!