about my 48" X 48" X 5" Techno/ISEL woodworking router build

17 Feb 2021 10:43 #199142 by travis036
I have uploaded my LCNC configs to my GitHub ( github.com/travis-farmer/linuxcnc ) if anyone is interested. unfortunately, i did not save a backup before my recent changes, and i have not tested the recent changes, yet. but i will try and remember to keep it up to date, for troubleshooting things. so there may be tons of errors, at least until i am able to test it, and make the corrections. though if anyone finds blatant errors, feel free to let me know how to correct them.

there is, i hope, config values for two spindles, if i copy-and-pasted correctly. spindle 0 is controlled via a HY VFD over Modbus, and spindle 1 is a PWM controlled laser for cutting and burning. hopefully i have configured those somewhat correctly.


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20 Feb 2021 19:16 #199550 by travis036
worked on some config changes today to get my HY VFD to communicate over RS485. first i had to add the current user to the "dialout" group to be able to init communication.
i ended up commenting out the PWM for Laser configs, as apparently i do not know how to add a second spindle, or maybe i was doing it wrong. i will attack that when i know more.
anyway, i pushed the latest configs to the Github above.

I am waiting on delivery of more wire to finish connecting things up, so wiring progress is slow.
major todo's are:
finish power supply connections.
install and connect stepper drivers.
connect home switches.
connect relay to control Z-axis stepper brake.

then i should be able to see some first moves. i really should lube the machine axis again too. been sitting awhile.
after i get in some first moves, i need to fine tune some parameters regarding stepper direction, homing direction, tie back in my tool probe and 3D probe.

when i go to make first moves, i will try to remember to drag out my video camera, and pop a video on my YouTube. could either be boring (if everything goes right the first time), or entertaining when it all goes to heck.


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06 Mar 2021 21:05 #201215 by travis036
i connected the machine up today with temporary power, and signal wires, and didn't have anything worth posting the video of. in fact, i deleted the video...
X-axis: very slow, but responds to LCNC control, though direction was inverted (fixed by inverting direction in HAL).
Y-axis: nothing.
z-axis: nothing.

observations: the 5V logic to 24V logic opto converters i bought off eBay have diagnostic LEDs.

LCNC machine OFF, stepper amp enable signals
X: input LED HIGH, output HIGH
Y: same as above
Z: same as above

LCNC machine ON, stepper amp enable signals
X: in LOW, out LOW
Y: in LOW, out HIGH (about 1.79V)
Z: in LOW, out HIGH (same volts)

those are just examples of similar activity across the different signals. my stepper drivers are active when enable is low. my interpretation is that the Mesa 7i80HD-16 is not outputting true LOW signals (not tested with meter), so the opto level converters output high all the time. or, and this is more likely, the opto level converters are defective. i checked the stepper drivers inputs for current leakage through the internal optos, and found none, as i suspected. so the drivers are not inducing voltage. i don't know where the power could be coming from. i used shielded twisted-pair cable (CAT5e) for the stepper driver signals, with the shield drain tied to the shielding on the control board. the dark colors were used for the signals, and the light colors tied to ground.
admittedly, the control board shielding is not yet tied to anything, so it could be inducing something on the signal wires...

if i can't figure out the issue (i stopped for the day due to a headache) sometime tomorrow, i may eliminate the 24V level converters for the stepper drivers, and connect directly from the Mesa card to the stepper drivers. the inputs have optos already, and the signal wire length is short (18 - 20 inches), so with the shielded twisted-pair signal wires, there shouldn't be too much error. first i will try grounding the shielding, and test the wiring some more, but it is getting to the point where i want this machine usable again.

just a little frustrated, is all.


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06 Mar 2021 21:48 #201221 by tommylight
Disconnect the "enable" from the drives, set the machine up properly, later on you can set up enable if you need it.

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07 Mar 2021 16:20 #201308 by travis036
ok, i unplugged the enable, and to my surprise, the LED on the voltage level shifters went out. i unplugged all the signal wires, and all the LEDs went out, or rather, they responded to the output of the 7i80HD-16. so, something about the drivers is driving the LEDs on, though this should not be, as the drivers inputs are just LEDs, with a weak current limit resistor set for 5V input. i added resistors for 24V... oh, wait. i added 3.3Kohms, should be 2Kohms... i can't imagine it would be that big a difference, but maybe. waiting for my scope/meter to recharge, so i will head back out in a few minutes to see if changing the 3.3K to 2K solves everything.
i suspect it won't change anything... but what do i know? (less than i thought, apparently)

as far as "set the machine up properly", this is a little vague. but then, my opening statement could have been misinterpreted. the power wires are temporarily installed, but the signal wires were done proper, i assume. i have since grounded the shielding on the control board, and it didn't have any change, but it is done.

i have some sort of plan for moving forward. i will change out one current limiting resistor, and test for effect. if it solves, i will change out them all.
i think my biggest brain-fart is that i disregarded the other end of the twisted-pair light colored wires. one end is tied to ground, the other is floating, with a separate ground... and yes, i see the flaw in this (as i said, brain-fart). so that will have to be fixed. i think i was regarding it as a shield, but as a twisted-pair, it needs current flow to be effective. sometimes my mind gets doing stuff without thinking about exactly what needs to be done, correctly.

but anyway, when i unplugged the enable signal, the other axis were able to move, but it also got me thinking, and more critical of my wiring job. once the signals are straightened out and working, i will solidify my power wires.

as far as non-stepper signals between the control box and machine, i am going to mount a junction box under the machine (side accessible) with a DB25 breakout board, and another in the control box. that way i can use a parallel port cable to route signals to and from the machine, and be able to disconnect the cable easily when i move the machine from the trailer to the to-be-built shed. it will also tidy up the wires quite a bit too.


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07 Mar 2021 19:57 #201345 by travis036
We have motion on all 3 axis!!!
i eliminated the 24V step-up logic opto converters for only the stepper signals. so the stepper drivers are receiving 5V from the 7i80HD. other signals, when connected, will use opto converters, so the homing switches, and probing will be at 24V. i honestly wasn't expecting it to move all three, so i forgot to video the moment.
at present, i don't have the homing switches connected, so i setup the machine INI for instant homing. the signal wires are attached, but not immobilized yet (to keep wires from breaking).

so, with the wiring in a known moving state, i can focus on solidifying power. when the DB25 breakout boards arrive (generic, for custom wire-planning), i can start to clean up the non-stepper wiring. i rigged in the power for the brake on the Z-axis, but that will be routed through the DB25 cable. i just needed it powered to move the Z-axis.

one thing i noticed, my USB XHC (wired) pendant functions, but will not jog, so i will need to look into that. machine is pretty slow, but i can work on that when the wiring and all sensors are complete.

The following user(s) said Thank You: tommylight

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07 Mar 2021 21:25 #201363 by tommylight

travis036 wrote: We have motion on all 3 axis!!!

Nice ! :)

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