(Solved) PlasmaC new config Z going up when probing
- phillc54
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I "think" mine is negative but I am not 100% sure. I will check my machine tomorrow.I have bumped this: As the above questions seem to have fallen through the net. Although the machine is working.
I also "think" I have the jumpers set as per Peters suggestion. Again, I will check tomorrow.
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- rodw
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We had to change the THC delay to 0.3 secs
FWIW, in the past they've told me here that a similar time wasn't long enough for the voltage to settle down, and highly recommended I use the default which is 1.5 seconds (I believe).
I think 1.5 seconds comes from me. It comes from lot of halscope plots I did with my Everlast on 2mm and 8mm mild steel. The thicker material made a bit of difference but it was a bit slower settling to cut volts. I reviewed this again when I bought my Thermal Dynamics with more plots but I did not see anything that made me want to change that setting, even on 16mm. I will eventually do some more tests becasue I think that machine acceleration is a factor here. I suspect now my machine can accelerate at 5 m/s^2, that that will significantly shorten this delay period.
Plasma cutters are constant current devices so the inverter changes the voltage to maintain that constant current.
I would suggest you do some tests with halscope to come up with your own delay becasue I think your acceleration settings will influence this delay. As we are all learning as we do this, I think this probably should be part of your initial tuning process.
Re the question about sane values for volts per mm, you should know by now the answer is in the plasma primer! 10 volts per mm has long been accepted as the average but on my Everlast I did some regression analysis and concluded that it was 7.53 volts per mm. IN practice, this number does not need to be precise because the PID loop will converge on the answer.
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- tommylight
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Does not mattaer much as long as it is working.Re this:
Should The encoder count be a -ve number (on mine it is) OR should it be +ve as the problem machine is.
Should encoder position numbers be +ve or -ve
On this machine we had to change the setp hm2_7i96.0.encoder.00.scale -1 to 1
That will change as PCW explained somewhere based on what firmware you are using, what board, how the encoder is wired etc.
In your case you are using the 7i76 with the original firmware, so using one input for the encoder leaves the second input unused, and depending on the state of the second input (encoder B ), the counting will be up or down.
As you noticed, changing the scale fixes that.
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- Clive S
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- phillc54
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I think my delay is 0.5, the voltage settles pretty quickly. What do you mean by P10?Yes its strange the machine above would not work with P10 and delay 1.5 just changing these two things made the machine fly we have just cutout a big control panel using Hypertherms cut parameters in 3mm alli at 7.5M/min without any issues.
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- tommylight
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If there are no pictures or video, it did not happen !Yes its strange the machine above would not work with P10 and delay 1.5 just changing these two things made the machine fly we have just cutout a big control panel using Hypertherms cut parameters in 3mm alli at 7.5M/min without any issues.

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- Clive S
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Ok I will put them both together. Doubting Thomas.
If there are no pictures or video, it did not happen !Yes its strange the machine above would not work with P10 and delay 1.5 just changing these two things made the machine fly we have just cutout a big control panel using Hypertherms cut parameters in 3mm alli at 7.5M/min without any issues.
I was told this same thing by a member here not long ago.
.
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- tommylight
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- snowgoer540
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I’m with Phill, what did you mean by P10?
Side note: other than the linuxcnc doc, is there a YouTube tutorial on how to use halscope (I’ve not found any that really was a bare bones walk through)? There has to be something I’m missing. Everyone seems to use it with ease, I’m not sure what I’m missing. I find it quite confusing to get it to plot.
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- Clive S
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I’m with Phill, what did you mean by P10?
Ok I have had a few sherbets so please excuse me.
P10 is the pid loop whatever in the ini file and the machine in question that I had to help set up was 40 miles away so done with phone and Dropbox. we had to increase the P10 TO 2O to get it to work.
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