My Newb Plasma Table Attempted Build

also if you set the servo thread period to 2000000
the P terms should all be set to 500 instead of 1000

I just ran across a thread on cnczone where a guy had what seems to be a similar issue on a cnc router. Turned out his stepper motors were too big (high inductance). He got smaller ones and his machine ran great. Does this make any sense to anyone?

P.S.
Still replacing the PC regardless.

did anybody address possible electrical noise issues? there is way to much discussion here for me to go back and read through everything here.

plasma can be a noisy electrical environment so good grounding and even separating the the motion control from all the plasma controls i've seen people have to do.
seems some people are able to get away with it and there always seems to be one unlucky guy the has nothing but troubles with no matter what..

i don't know what the controls look like or what you built so far i just know your moving along a break neck speeds and could have overlooked something not so obvious.

Start here forum.linuxcnc.org/plasma-laser/36734-le...ring-and-emi?start=0

machinedude wrote:

did anybody address possible electrical noise issues? there is way to much discussion here for me to go back and read through everything here.

plasma can be a noisy electrical environment so good grounding and even separating the the motion control from all the plasma controls i've seen people have to do.
seems some people are able to get away with it and there always seems to be one unlucky guy the has nothing but troubles with no matter what..

i don't know what the controls look like or what you built so far i just know your moving along a break neck speeds and could have overlooked something not so obvious.

It's doing the same thing with the plasma completely removed from it (not even plugged into power). It was one of my first guesses. It's strange because I worked fine for a bit and then didn't, with only two seemingly unrelated things done to the table in between (software update and consumable change).

Picking up a monitor for the new-to-me Dell Optiplex. My laptop has poor latency so maybe this will be the cure.

Too big motor and high inductance - >
Not able to turn fast enough as conter voltage too high and or
Not able to accelerate fast enough.
If that is a problem dro and teal measurable distance differ. And probably you would not come back to the same point. Results woud differ by speed settings.
Mike
Your error seems for me somehow "commanded" and fullfilled correctly by your mechanic. I would try to run the sample with the feed slider near to zero and watch by eye if you get the same jump/deviation. I expect that you will see it.
Mike

Mike_Eitel wrote:

Too big motor and high inductance - >
Not able to turn fast enough as conter voltage too high and or
Not able to accelerate fast enough.
If that is a problem dro and teal measurable distance differ. And probably you would not come back to the same point. Results woud differ by speed settings.
Mike
Your error seems for me somehow "commanded" and fullfilled correctly by your mechanic. I would try to run the sample with the feed slider near to zero and watch by eye if you get the same jump/deviation. I expect that you will see it.
Mike

Slowing down feed is a good idea. I'll try that.

I did finally get the PC and a couple of monitors for $75. I don't need 2 monitors, but it was an all-or-nothing deal and it doesn't hurt to have a backup.

Going to get the software installed and all that fun stuff and try something tomorrow. It's over 100F right now so I don't feel like roasting in the shop.

I've been struggling this weekend with getting my USB WiFi adapter to work on this PC, but finally got that situated. I've installed Linuxcnc master branch on the new machine. Question...can I use my config files from the laptop (ini, hal, etc)? I haven't gotten to running plasmac on this yet.

dvn4life1972 wrote:

I've been struggling this weekend with getting my USB WiFi adapter to work on this PC, but finally got that situated. I've installed Linuxcnc master branch on the new machine. Question...can I use my config files from the laptop (ini, hal, etc)? I haven't gotten to running plasmac on this yet.

Generally Yes just copy the config folder across

I finally was able to get the WiFi adapter to work (that was a horror-show). Anyway, I don't know if this is how I "SHOULD" have done it...but I got master branch onto the new PC, and connected it to the table. I can't just run my ini and hal files and all the rest, because plasmac isn't added to it yet. I set up another base config and tested it, and the machine homed and moved properly. I noticed some slack in the belts, they're new so they need one retightening, and when I went to add plasmac and use my old config files, it would not work. Linuxcnc would try to boot up and time out.

So, I removed all of those config files to start from scratch again and now when I make a base machine config, it won't home. I'm getting "home switch inactive before start of backoff.." errors on joints 0, 1, and 2 (0 = X, 1 & 2 are Y1 & Y2). The only thing I did to the machine was tighten 2 belts.

Is there a way I can just throw plasmac onto it without a base config, then use my previous config files? The limits and everything worked fine before.