Axis Motor Based ATC for Mill on Acornsix

[jedmill67]

Hello everyone. I hope I haven't created an insurmountable challenge for myself. You see, I have built an axis motor based ATC carousel (closed loop stepper on a worm drive gear box), and I'm trying to get it working for a MILL on Acornsix.

I like the idea of a fast tool retrieval an axis motor-based ATC can provide and it's so much easier to build. I saw the various ATC options that are supported by Centroid and have seen videos of axis based carousels working, so figured it was possible with some modifications to the existing macros. However, it seems I haven't counted the cost ahead of time and now I'm starting to realize the challenge of controlling the tool change process without code readymade like there is for say a Geneva wheel mechanism. I could really use some guidance.

Here's what I have:
ATC is fully built, 11 tools held in plastic forks. Tool platter is mounted to a worm drive gear box driven by closed-loop stepper with home switch, labeled U axis. Carousel slides in and out by pneumatic cylinder connected to one solenoid, "CarouselIn", and has limit switches for carousel in and out. Spindle orients no problem and has a limit switch. Power drawbar has Tool unclamped switch. VFD reports "VFDZeroSpeed" to the Acornsix board. I think all the ingredients are present.

Here's what I get running the stock M6 for CNC12 V5.22 :
Head raises up to Z0.0, lowers to tool change height, spindle orients, carousel slides over but then right back out. Then it sits "Waiting for Carousel In".

I've tried disconnecting the carousel air cylinder and moved it by hand and I get farther. It releases the tool and raises the Z up to 0.0 and then waits for the carousel to move. That is what I'd expect from the stock M6 macro considering its set as a sliding carousel in the wizard and at that point is waiting for the separate PLC on the tool changer to do its thing and report back to CNC12 it's in position.

How hard is this going to be for someone with minimal coding experience? Was this a bad idea to go this route? I have a lot of work in it, hope it is salvageable, please help!

[jedmill67]

Found this thread (linked below) and I think this is my problem with the carousel going right back out as soon as it comes in. I have a single coil solenoid valve that drives my air cylinder and only have “CarouselIn” defined in outputs. When the output toggles, the carousel goes in and out. The solution in the thread was a modified PLC program. That was many versions of CNC12 ago. So I doubt that PLC would be currently useful.
Is there a reasonable way to get around this without modifying the PLC? I have an extra output and single coil solenoid available if that would help. Seems like that would work but the thing that concerns me about that solution is the carousel sitting there with nothing really holding it out. With the vibration of machining, it could slowly wander into the head of the machine.
Any ideas on running it from a single output and single coil solenoid without PLC mods? If not, what mod would need to be made? Thanks always for your time, it’s the most valuable commodity you have after all.

https://centroidcncforum.com/viewtopic.php?p=48415#p48415

[cnckeith]

got some photos of your machine? video? would help alot.

[jedmill67]

Hi Kieth, yes, I’m sorry I wasn’t able to get any pictures or videos posted yet, I’m working on that actually. The Google photo album is a good idea and I’ll get that going somehow but I’m an iPhone user and learning Google photos doesn’t play very nice with Apple. The only way it will allow me to use it is to allow it to access all my pictures and I’m not wanting to allow that. I’m going to try an old phone that has no other pictures on it to see if that works. I’ll figure out some way that works.

In the mean time, I’m in the process of switching to a two coil solenoid valve for the carousel in/out cylinder. Really hoping that’s going to solve my retreating carousel issue. If that works, then it’s on to the coding side of things.

[jedmill67]

Ok, I got the carousel moving. Thank you for the help on that. The issue was that I only had a single coil solenoid connected to the in/out cylinder. I put a 2-coil solenoid on and added another input (ATCcarouselin & ATCcarouselout instead of just toggling the ATCcarouselin on and off to move it with a single coil solenoid) and now it cycles as expected.

I've finally got the Google photo album set up, I used my wife's account as she is an Android user, my apologies for the delay. Are these the photos that would be helpful? Let me know specific ones that could be useful to add. As you can see in the video, with direct commands, the mill is capable of going through the motions of a tool change, see attached M101 program that it was running. Obviously by the code its clear this is only a test of the physical movement and alignment of the ATC, and the video isn't showing a true tool change. The control/M6 as is doesn't have the ability to ask for a specific tool, rotate the carousel, keep track of the tool in the spindle, home the carousel (U axis) to the bin number to match the tool in the spindle, etc.

Thats where my question begins, how complicated is creating a macro that replaces what the ATC PLC and tool counter would do? Any guidance would be very much appreciated. However, if this feature, (axis-based carousel ATC for mill) is in the works and coming to the wizard sometime soon, I may just put this on the back burner and wait for the readymade solution. Centroids solution always works best, you guys at Centroid are awesome!

Google Photos Link:
https://photos.app.goo.gl/5P6FFa6nAqP5ss8g9

[Ken Rychlik]

I would suggest doing a custom m6 tool change macro that has variables in the same folder. All tool locations are in the variables of the one file, and when you ask for a certain tool, it goes to the variable location of that tool. I put one of my m6 macro's up just to show what I mean. You can change it to the rotary location of whatever number is designed for rotation of the tool rack. Read through the notes on each line and you can follow it to see what changes you would use.

You start with unload
Go to variable location of the tool currently in the spindle (empty fork)
then spindle to tool change fork height
then activate the slide, unlock the tool holder, raise spindle along with any safety's you want to add
Then rotate to the variable of desired tool
and proceed from there.

Hope this helps.

[jedmill67]

I would suggest doing a custom m6 tool change macro that has variables in the same folder. All tool locations are in the variables of the one file, and when you ask for a certain tool, it goes to the variable location of that tool. I put one of my m6 macro's up just to show what I mean. You can change it to the rotary location of whatever number is designed for rotation of the tool rack. Read through the notes on each line and you can follow it to see what changes you would use.

You start with unload
Go to variable location of the tool currently in the spindle (empty fork)
then spindle to tool change fork height
then activate the slide, unlock the tool holder, raise spindle along with any safety's you want to add
Then rotate to the variable of desired tool
and proceed from there.

Hope this helps.

Ken,

Thank you for your quick response and included code. I am using that and getting started on a custom M6 macro of my own!

[jedmill67]

Update:
Success! Thank you for the help on this one. My axis based ATC is up and running. I took your advice Ken and embedded the tool locations as subprograms within the mfunc6. Works like a charm. I have to say I am very pleased with the speed of the tool change. With the Acornsix, I still have 2 axis left for my future project of a 4th axis and eventually a 5th axis.

I've also created a homing program that moves the carousel to the fork location of the tool in the spindle. That way after homing the carousel is in the right spot to accept the tool. The M6 macro also has a call for moving the carousel to the right fork as part of the putback routine if for some reason it was jogged out of position by mistake or something. So, there's only the chance of crashing if somehow the homing is lost at some point. However, it's a closed loop stepper so it can't lose steps, and I have the "axis 6 ok" set up so if there is some crazy event with it CNC12 will know about it and error out. I also have it set to force rehoming in the event of an E-stop. Seems pretty robust to me at this point. Time will tell.

I will post the mfunc6 and homing macro when I get back to the shop.

[spikee]

Thanks for sharing!