Centroid Community CNC Support Forum

Hello from the UK!

I am finally getting around to installing an Acorn in a Harrison M300 lathe that was originally running an Anilam Crusader control. I am planning on using an IMO i-drive2 VFD and AASD 240v servos (from BST automation in China). This is my first re-fit so I will have plenty of questions....

Starting with the home and limit setup - the machine has 6 x switches, (4 limits and 2 home). I was thinking of setting these as 3 strings of 2 switches in series as per the attached diagram, input 1 set as homeall and inputs 2 and 3 as X and Z limits. First question - will this work? Second question - do I need to install a manual overide on the limits as per the second diagram? I don't really want to add the limits switches to the e-stop circuit so am looking for ways to do this with 3 or 4 inputs. I have read the other threads on limit switches but to be honest can't quite convince myself that I understand the series method!
BTW - I have been using a free wiring layout CAD program called proficad - seems easy to use and you can make up standard symbols (like the acorn one shown). If anyone wants a copy of the acorn symbol let me know and I'll post it.

Pete

Answering your second question, I'm not quite sure yet, have not installed Limits Switches on my project.
But I believe the Bypass or manual override its not necessary, if you have a look at the VCP there is bottom close to the E- stop, its label as Limit switch defeater. I believe its serves same purpose.

Please just let me know if its works.

Max.

You shouldn't need a limit defeat switch if your switches are not in series with the estop

Hello Pete
I have been wondering about this myself , and I think you have great idea. It would be very helpful if you were to share that Acorn template , I myself would like to try it out as well as the program is there a link to the CAD program you are using.

Just to close this off in case any other novices read the thread; I have wired things now and option 1 works fine, no physical defeat switches are required.

When you approach the limit from the direction that you have set on your input menu you can jog away without any other action, but if you hit the opposite limit you just need to press the limit defeat button first.....or at least that seems to be how it's operating!

I have not tried it yet, but I assume that exactly the same will work if you string teogether mixed axes?

Thanks for the help guys!

I too am interested in the Acorn symbol you made.

I tooo am interested in the Acorn symbol you made.

Thanks
Bill

Question for the community:

I had my limit switch wired in series with estop, but the system would not differentiate between a estop condition and a homing sequence.

So I wired them independently. Homing works and estop works. Now my problem, I can run right through the switches in manual or when I did a probe routine. I did had my soft limit set at zero, same as the limit switch. So far I've smashed 2 switches.

Before I add more switches, is there a parameter setting that the machine should stop on limit switch, no matter what? If not, my next step is to add separate limit switches in series with estop and have still have independent homing switches.

Thanks in advance,

Nick

Nick, please post a report.zip file of your current configuration.
for soft limits to work you must have BOTH sides of the soft limit set. just setting them to 0 is the same as no soft limit at all.

Hi Keith,

Thanks for the suggestion, it worked, I did not have the other side of the soft limit set, so that's why the machine was able to go past the physical limit.

Thanks, Nick