Getting rather confused

[G-Thomp]

Hi All, this is my first post as generaly I have been able to figure most things out, this time however I have bitten off more than I can manage to chew..!

Hope this post is in the right place as I am unfamilliar with this sort of thing.


I built a milling machine with, origionaly 3 axis and am using Mach3 with the following "cheap" Chinese breakout board and it all works fine, 3 axis X,Y & Z as well as "A" which I used as a stepper to controll power drawbar.

ebay item:
https://www.ebay.co.uk/itm/5-Axis-CN...72.m2749.l2649

The above board is marketed as a 5 axis board, however I found it's only 4 if you use the on board relay.

On deciding to add a trunnion (yet to build) I realised I needed another x2 axis, so bought this item:
https://www.ebay.co.uk/itm/New-CNC-M...72.m2749.l2649

described as 6 axis breakout board, however I was sorely dissapointed when it arrived as it is clearly marked for X,Y,Z,A & B, apparently its a 5 axis with a relay and not a 6 axis, I could use it as is X,Y,Z with A powering drawbar and just add a 4th axis "B" as rotary or forget about the power drawbar, and at this point I was going to just give up and do that, then I saw this item:

https://www.ebay.co.uk/itm/CNC-6-Axi...72.m2749.l2649


Described as a 6 Axis breakout board with 3 relays that has 12 outputs and can simultaneously drive 6 steppers, so I tried again, only to be dissapointed again as it is a 4 axis with 3 relays, or a 5 axis with 2 relays or a 6 with 1 relay..! I need to power external relays (motor,coolant) so there is another axis gone....whichever way I look at it.

No documentation whatsoever (as usual) but I did manage to find an "Instructable" on it, though it's rather vague and does not show any use or Mach3 settings for the relays..
I realise I could use more than one breakout board and will most likely have to do that, but I would like to "squeeze" as much as possible from the last one I bought, If I end up using 2 boards , I may as well build an ATC and utilise the rest of the unused ports.

Thinking about it I would need the following from one or 2 of the above boards and would like advice on the best way to proceed:

X,Y,Z axis
A axis or "relay" Means of powering drawbar ( have all equipment to do it with pneumatic solenoid or stepper).

B and C axis for Trunion

2 More axis for linear come rotary ATC

Any and all advice would be greatly appreciated

Hope I havent gone overboard
regards
Robert

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[skrubol]

You'll probably need to go to using 2 ports with 2 breakout boards. A parallel port only has so many IO's.. 12 out and 5 in normally.
What are you using for a control? Mach 3?
The single parallel port USB controllers will probably have issues trying to use more than one in the same system. You'll probably want to go with a Pokeys or smoothstepper interface which has more I/O points from a single USB/Ethernet connector.

[ger21]

Not to many options for controlling 8 axis. Most low cost controls only allow 6.

[skrubol]

Sounds like only 5 need to be synchronized though, depending upon your budget and how adventurous you are you could try adding some sort of accessory controller (like an Arduino with GRBL or something.)

[G-Thomp]

Hi Guys and thank you for the replies, I quickly realised the NC200 USB thing was just going to complicate matters as it would only controll the relays on x64 (everything else was fine on 32bit win) so I would either have to buy another of those for x64 win or just get another paralel port pci card, which is what I have done, to use first board I listed and leave it as is and add the 6 axis one as port 2 in mach 3 (ver 2).
skrubol I thought only 5 needed steppers but I think I need another to controll carousel for ATC.
I figure I can use some of the pinouts for the stepers I will need which wont be a problem and use whats left for relays for pneumatic cylinders which wont be a problem to wire ,but most likely I will have difficulty figuring out how to automaticaly configure them to activate on/off at the correct time in mach 3 for the ATC (when I get it built).
I have Uno's and with cnc drive boards etc but other than use them with grbl I am clueless as to getting them to activate when commanded by Mach3.
I had a quick look at the M codes in mach and seem to only see coolant ,mist and spindle for triggering relays, nothing specific for powerr drawbar or ATC, maybe I need to study it a bit more.
Probably an obvious answer but how do I upload a photo of it on here, am quite OLD school lol
thanks again guys
Robert

[wizard]

why are you actuating the power draw bar with a CNC axis. That should need nothing more than a single bit. That bit would drive a vale to actuate an air cylinder or hydraulic cylinder if you want to go that way.

This would immediately free up one axis for you. It will also save you from having to program in the proper draw bar movements into every program you generate.

By the way the draw bar can remain motorized if you really want too. The single bit would either indicate open or closed. That I/O line would go to an indexing drive, Arduino or similar device to handle actual motor positioning.

Frankly the same approach can be take with an ATC carousel controller where a word in this case indicates the desired too to be installed in the spindle. Again an Arduino can do this or you can go the PLC route. You could communicate with the ATC controller via discreet I/O lines, via RS232, or a combination of methods.

By the way I personally believe one is better off having discreet controllers for the various subsystems of a machine. That is delegate control of an ATC to an independent controller programmed to work with the G-Code processor driving the CNC axis. Effectively it separates the code bodies so that development can go on in parallel. Considering the cost these days of Micro controllers it adds very little to the final cost of implementation.

[G-Thomp]

Hi Wizzard, the power drawbar stepper thing was just a stop gap and seems to work ok, though I cant have the belevilles too tight, so its limited.Im waiting on delivery of pneumatic cylinders as I state in my first post, I have everything else and a rough idea how.
I totaly agree, having been in engineering for 38 yrs subsystems are easier to diagnose and can be altered independantly etc, I have done lots of design and developement of machines for the food /packaging industry, but my background is not electronic controll systems ,( I know virtualy nothing besides a little electronics knowlege) the company used to get an automation guy in for that, I'm more mechanical and in the past replaced electronic timers for pneumatics with things like cams to get the job done so to speak.
I would be very interested in turning this uno or a pi I also have to the sole task of an ATC, but am totaly clueless as to how to accomplish that, I imagine I would have to write C or code for the arduino specific to what I'm doing, probably a simple task to someone who knows what they are doing, but def beyond myself, cost isnt a big problem, I 'm just trying to get a ballance between industrialisation and a hobby machine, its work envelope is not very large though it is structuraly very sound being made mostly from steel.

Thanks again
Robert

[TTalma]

I messed around with using modbus with an arduino to control some subsystems via mach 3 a while ago.

There is a lot of info on the mach forums. There are a few people who have their entire rotary tray ATC running off an arduino communicating via modbus. They just have the tool number selection in their G-code and then the magic happens, The way it should be.

[wizard]

Hi Robert;

If you have learned mechanical engineering learning electronics isnt that much of a jump. For whatever reason some people do have a hard time with programming. Im not sure why programming baffles so many (maybe it is the debugging) but you will not really know how it will be without trying to learn a bit of programming.

The good thing with programming is that there are many free or low cost sites on the internet to get you up to speed. Just be aware that you need to allocate some time to get the basics down. After the basics you need to learn a bit about embedded techniques. Ideally you would get involved in a program that covers the first two years of a computer science degree so that the basics of computer architecture is covered.

Spending a lot of time with education is great in the perfect world. There are alternatives, one of which would be to find an open source project that already implements an ATC. Like everything else somebody has likely done this already and posted their project to the net. Id do some searching and would be shocked if nothing was found. If nothing on an ATC is found look for simpler embedded projects.

As for hardware Arduino was mentioned because it is extremely popular. Keep in mind though that there is likely close to a hundred different embedded board solutions out there. First off the microprocessor development companies all have boards (development hardware) for their chips. Then you have various third party board developers selling boards for mass production. If you get past the microcontroller world there are boards of the Raspberry PI class that are often used in the embedded world. What im trying to point out here is that Ardino is being used collectively here for all the potential ways you can find to do an embedded controller.

As far as software goes you have the following to consider:

1.
Arduino is programmed in their version of C++. Nothing wrong with that but the "C" languages can have a learning curve.

2.
Many boards, especially ARM based boards are supported with more mainstream C or C++ programming environments. Usually this means a GCC or LLVM/CLang compiler supported be the chip designer or board maker. You still have the C / C++ learning curve to deal with but a more complete environment.

3.
One alternative solution is microcontrollers running MicroPython as their programming environment. The range of boards where MicroPython runs is limited but you do end up with a cleaner language to program in. In a similar manner you can still find companies selling controllers with BASIC built in. I would suggest though that BASICs time has gone while MicroPython is very interesting.

4.
More capable boards, running Linux, means that you have an almost unlimited number of programming languages to choose from.

It might seem like i dwelled on languages and hardware here but i didnt want you to think Arduino is the only solution. Rather Arduino and Raspberry PI like hardware make up a good portion of "maker" supported hardware out there. That doesn't make them the best and in fact there is a huge gap between an Arduino and a Raspberry PI filled by all sorts of boards.

Now for writing that ATC software; the ultimate answer lies in the details about the hardware and software you are using. In general terms you send the ACT controller a tool number and it is then directed to do a tool change based on that tool number. Sometimes controls engineers refer to that sending of a tool number as strobing in data (there are many terms and techniques) and then sending a trigger to do a tool change.

I should note that i didn't even mention PLC's here. This is a completely different way to do an ATC controller. PLC's are commonly programmed in ladder logic and are built around electronics hardened for the industrial environment. PLC's have their own learning curve and likewise their own advantages and disadvantages. They can be somewhat more expensive but also offer up ease of use and installation in return.

Hi Wizzard, the power drawbar stepper thing was just a stop gap and seems to work ok, though I cant have the belevilles too tight, so its limited.Im waiting on delivery of pneumatic cylinders as I state in my first post, I have everything else and a rough idea how.
I totaly agree, having been in engineering for 38 yrs subsystems are easier to diagnose and can be altered independantly etc, I have done lots of design and developement of machines for the food /packaging industry, but my background is not electronic controll systems ,( I know virtualy nothing besides a little electronics knowlege) the company used to get an automation guy in for that, I'm more mechanical and in the past replaced electronic timers for pneumatics with things like cams to get the job done so to speak.
I would be very interested in turning this uno or a pi I also have to the sole task of an ATC, but am totaly clueless as to how to accomplish that, I imagine I would have to write C or code for the arduino specific to what I'm doing, probably a simple task to someone who knows what they are doing, but def beyond myself, cost isnt a big problem, I 'm just trying to get a ballance between industrialisation and a hobby machine, its work envelope is not very large though it is structuraly very sound being made mostly from steel.

Thanks again
Robert