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Cheers Mark.

I don't get to do as much ally as I'd like.

Bit of a progress update from the last couple weeks:

Control panel is at the powder coaters. I choose a dark matt charcoal. Mainly as my coater runs this Dulux colour often and Im impatient at the best of times! Should have this back on Tuesday.

The custom control panel buttons are now 3d printed, along with the MX switch carriers. All wired up. These run into a DB25 breakout board and then will travel back the Mesa cards in the cabinet. I appreciate this isn't the nicest way to execute it, but I only require the 7i97t and 7i84u for all IO, and most IO terminates in the cabinet. I got cold feet on flashing the 7i97.... Pics below.

PC has been setup with linuxcnc. I chose a Coofun CK41 miniPC, which The Feral Engineer made some tests on YouTube with seemingly good results. Fingers crossed it works out. It's very compact and so was the price tag. Took me a few nights to get MesaCT and an updated Mesaflash running correctly to recognise the 7i97T. This is honestly due to my lack of unix (or IT in general!) skills. We got there in the end - I'm now able to run a draft linuxcnc config and toggle a coolant assigned output on the 7i97t with no dramas. I'll take that as a win. Yet to hook up the 7i84u.

Have to thank JT for the great MesaCT package!
I was and still am very daunted by the task of editing lines in the Hal/ini files.

The servo drives are currently on their way from China. I went with Leadshine EL7 drives in the end. The price was decent and they're offered in 380-400v 3ph. Opted for analog/pulse control as these control methods appear to be well documented here, especially by Tommylight's guide. Ethercat looked appealing, but given my lack of IT skills I thought it safe to stick with the aforementioned.

This weekend I started drafting the wiring diagrams between the Mesa boards, original Bridgeport control/distrubution board and new servo drives. The free schematic cad on DigiKey.com ist great btw! Would recommend.
Which brings me to my next question:

I assume I can run the enable controls from the 7i97t to drives without a relay? I believe I've drawn this with the correct polarity directions, but any insight are most appreciated.

More updates to come!

Cheers,

j

 
 
 
 



 

I have EtherCAT AC Servos with 23-bit multi-turn absolute encoders. I am trying to configure my "home" position. Is there a definitive documentation on using absolute encoders?

My absolute location is not where I want G53 "home" to be, in the case of the below and the provided INI sniplet, it's 7.3033 inches from the zero location I want.  Reading the documentation, it states to set HOME_OFFSET, and I also see a forum posts to set HOME. I feel like I am just guessing.  I have tried both, and neither works.  Also, I should never have to "home" the axis, correct?

I would try the steps A,B,C of example 1 I posted earlier

ok that makes sense, and after spending some more time working on it, including taking the scale back to 10, i have it now in a pretty good spot where i would consider it time to start tuning.

does the halscope guide tommy put together also work for tuning torque mode PIDs? otherwise im currently hunting out an equally well put together guide so i dont resort to just changing numbers and seeing what happens.

Thanks langdos, I did a similar fix

I have absolute encoders, so I just set the soft limits.

Maybe there is an issue with hard limits? Should I report this? GitHub issues?

You can also have a look at the EasyCAT:
www.bausano.net/shop/gb/home/1-arduino-ethercat.html

you can hook encoder pretty easily to that for much cheaper. And it is also quite flexible.
Encoder counting happens on arduino and current count is sent over EtherCAT to LinuxCNC, which saves you some hal configuration.

RE: EL1819 vs EL1809 response time - i think it includes signal debuncing, so 3ms does not necessarily have to be bad, because it's slower than 10us.

100 mA is a typical value for 5V, at say 24V the current is much less for most contacts (closer to 10 mA)
A small capacitor across the contacts can provide the wetting current without a large constant load.

If the relay does not show closed at 24V, its likely faulty...
 

This should be it.  

Yeh, my post must have broke. If you look a bit harder on eBay you will find better priced moduled for around $130. Some want stupid money. Don;t be frightened of buying from other countries...

Failed again to leave my workshop early.
Sorry i am blessed with writing jam at the moment, but good luck for recovery from the injury

version 2.9.4 did not get the change, only master branch.
You will need to save over the camview_widget with the supplied version again.

hey @rodw, was there something you wanted to add? looks like you just quoted my original post.... I know you have a lot of experience in this area, i have read more than a few of your posts so would love your input.

Thanks

The pierce delay starts from the beginning of arcOK so the delay turning the torch on makes no difference.
The internal relay will need a minimum current of 100 mA and the Mesa board generally can't deliver this. You need to add a pull down resistor as discussed in the qtplasmac docs.

bassti wrote:

At the moment, rotorhoming starts when i power on the machine.
The problem is that i want to home the z-axis first.

HOME_SEQUENCE in ini

Aforementioned docs references:

Reed relay:

linuxcnc.org/docs/devel/html/plasma/qtpl...l#plasma:reed-arc-ok

Contact loading schematic:

linuxcnc.org/docs/devel/html/plasma/qtpl...tact-load-schematics

Calculations:

linuxcnc.org/docs/devel/html/plasma/qtpl...asma:qt-contact-load