Machsupport Forum

Mach Discussion => Mach4 General Discussion => Topic started by: dogluvr on January 12, 2021, 09:48:48 AM

Title: Nooby in need of help!
Post by: dogluvr on January 12, 2021, 09:48:48 AM
Help needed with Mach4 Setup
I am a nooby to cnc plasma. I built my own CNC. I am transitioning from Mach3 demo to Mach4. I Attempted to get help from New Fangled Solutions without any success. Hopefully someone with more experience than me can help me get this set up. I installed home and limit switches along with Mach4, but have since disconnected the switches out of pure frustration. My guess is that I had something wrong in the I/O settings. NFS was no help at all and refused to even look at the spreadsheet they provide to transition from M3 to M4 and advise on settings. So much for support.

So I now have the CNC Plasma running G code snippets, but when I attempt to run one of the included G code examples, it runs about three lines of code and I get the error message “Z axis commanded over soft min”. I had this CNC running code and cutting using Mach3, but I did not have any limits, soft or hard, setup at the time. I have tried different settings in Homing and Limits configuration, but still get the same message. I have the z axis soft limits set to the following: neg dir; home offset 0.5; speed 20%; Home in Place enabled; soft enable checked; soft min -1.0; soft max 3.0.

I am running Win7, 32 bit, using a UC100 controller, running the most current ver of mach4 (licensed) with three axes. JK02 BOB, TB1-H drivers.
I/O settings as follows:
Inputs
X axis Limit:    port 1 pin 10 Input1
Y axis Limit:    port 1 pin 11 Input2
Z axis Limit:    port 1 pin 12 Input3
E-Stop:   Port 1 pin 15 Input5

Outputs
Pin1 enable signal
Pin2 X axis step
Pin3 Y axis dir
Pin4 B axis step
Pin5 A axis dir
Pin6 A axis step
Pin7 Z axis step
Pin8 Z axis dir
Pin9 Spindle motor
Pin14 x axis dir
Pin16 Y axis step
Pin17 B axis dir

Hope I supplied the needed info. Thanks for any help!
Title: Re: Nooby in need of help!
Post by: joeaverage on January 13, 2021, 04:23:04 AM
Hi,
you can't really use SoftLimits without Homing your machine first, and by that I mean Homing to some defined and repeatable position,
which means you can't HomeInPLace.

When you have HomeInPlace enabled for an axis the moment the axis is homed it just sets the machine coordinates to zero (or the offset if you
have programmed it) right where it is. Therefore your SoftLimits for that axis are meaningless. SoftMin and SoftMax are distances to the
the axis limits from the Home position.

Lets say today you Home your axis, using the HomeInPlace facility, with the axis exactly halfway. Your SoftMax and SoftMin would then be +nnn inches
and -nnn inches say.

Tomorrow you turnd the machine on and Homed in place but this time the axis is near to one end. With the same SoftMax and SoftMin from yesterday the
machine will happily sail off the end of travel in one direction and fail ExceedSoftLimit in the other.

SoftLimits work only if you Home your machine to exactly the same place every time. Other than that you just have to turn SoftLimits off altogether.

Craig
Title: Re: Nooby in need of help!
Post by: joeaverage on January 13, 2021, 04:33:47 AM
Hi,
if you are trying to make a plasma then I think you may struggle with the UC100. It is USB connected and very prone
to electrical interference. Keep the USB cable as short as possible.

The UC100 does not support any hardware THC controller.

Ethernet connected controllers are much better for plasma tables. The Ethernet SmoothStepper is Ethernet connected but in addition
supports the TMC3in1 hardware THC controller.

At tis time I believe the Ethernet SmoothStepper and the Hicon Integra are the only Mach4 ready controllers that support high
dynamic range hardware THC controllers. In absence of hardware THC support you'll have to rely on the Mach4 THC script solution,
albeit at much less dynamic range. Even there your UC100 will struggle as it has no analogue input with which to monitor the arc voltage.

Craig
Title: Re: Nooby in need of help!
Post by: Brian Barker on January 13, 2021, 09:09:24 AM
Home to the top with the Z axis and you will have to take care on how you command your moves . Use G53 when you would like to pick up the axis so you can stay away from the home switch.
Title: Re: Nooby in need of help!
Post by: dogluvr on January 13, 2021, 09:50:25 AM
Thank you for the response. That explains why I was unable to get my Proma 150 THC to work correctly. I just purchased shielded cable to rewire my CNC steppers and limit switches. Hopefully that will eliminate any interference issues. I assume the controller you are referring to is the Warp9 smooth stepper? I will look into changing out the UC100 controller. I really do appreciate the help. It is difficult getting this sorted out when you have a DIY machine. I will no doubt be back with additional questions. Thanks again.
Title: Re: Nooby in need of help!
Post by: Brian Barker on January 13, 2021, 10:22:10 AM
USB uses a shared ground where as Ethernet uses transformer coupled communication (no direct path to ground). So you will not get the noise issues with Ethernet. Also why you don't get a ground loop from PC to PC when you connect two computers. Don't know if you wanted to know a bit more of why USB is bad for this but I hope it helps others that may read this.
Title: Re: Nooby in need of help!
Post by: Steve Stallings on January 13, 2021, 11:17:29 AM
Not all USB devices use a shared ground. The PMDX-424 has an isolated USB interface.
Title: Re: Nooby in need of help!
Post by: joeaverage on January 13, 2021, 12:34:30 PM
Hi Steve,
the  PMDX-424 sounds like a fair choice, does it support hardware THC controllers?

Craig
Title: Re: Nooby in need of help!
Post by: Steve Stallings on January 26, 2021, 01:02:10 PM
As of January 2021, PMDX has not yet verified operation with THC controllers running with the Plasma profiles and LUA code supplied by Mach4. Operation with controllers that supply hardware generated step and direction control, such as the PromaSD are known to work. We hope to work on testing with the Mach4 plasma profiles after we get settled into our new offices.

Steve Stallings
PMDX