Mach4 - Machine Coordinates not Saved

[Goonk]

Well, I finally broke down and got Mach4. I needed a new laptop, so I thought I'd do ti all at once. It has been a bit of an adventure. I have a Standard 2x4 machine with a Bosch 1617, prox sensors, etc. When I setup the machine (Mach3), I made the long axis X and the gantry Y. Why? It just made sense to me. My machine is against a wall, so when I face it, the long axis is to the right. Anyway, I guess when I did that, I just switched wires. Its been so long that I forgot exactly what/how. So, when I installed the Avid Mach 4, I checked the box to swap axis. Oops! I ended up with things quite a mess. Took a while, but I got everything swapped and then swapped sensors (connectors) and then everything was moving as expected. Except that the Z axis was backwards for some reason? I managed to figure that out after some Googling. So, it all works now. There are some other peculiarities, but nothing major.

One thing that really frustrates me though, is that the machine coordinates are not saved on exit like Mach3. I guess the thought is that you should home every time you power up? I can see that, but I have never done that in the three years or so of owning this machine and I don't like having to home each time. I'm not sure if the Avid folks did that or if that is standard Mach4? Not sure if there is a toggle that can be changed? I think one could create a script in the Mach4 "shutoff" script that would save the coordinates and then add something in the screen script to read them on power up. I'm not that good with that stuff yet! I had several custom buttons for Mach3 that I am already missing. I'm working on setting up those. I used my own AutoZero routine, a button that moved the router just off the stop, a park button, bit change, etc. Just a few simple things that made it convenient for the way I work. To qualify, I am a hobbyist.

Funny though, the Mach4 screen was not all unfamiliar. So, after a fixing the issues, I am making parts today.

Oh, I got a new i7 with 12Gb and an SSD. That thing cooks! Wow, what a difference! I run Vcarve Pro, IntelliCAD, and Mach4 and that's about it, but it is fast. Vcarve saves on my old i3 took forever. This thing is so quick, I have to watch to see that it saved!

Attaching a pic of what I am working on now. This is a small mahogany table top. One reason I like to save the homed coordinates is projects like this. It is a two sided project and alignment is critical. I try to make it all in one day, but sometimes.... I'm not sure how accurate the prox sensors are and how accurate the homing routine is. Maybe its plenty good? I may do some testing out of curiosity.

Oh, figuring out how to hold this thing down was quite a challenge! Worked out well though.

Not sure I see any gain by changing to Mach4. Maybe after I use it for a while? Maybe if I don't get anymore ESS ran out of data errors? Gonna take a while to figure out the programming stuff. I knew some Lua already, so that helped. Oh, the AutoZero function that the Avid folks supply is great! They did a nice job with it and the whole install thing. The only issue I had that wasn't my own doing was the Z axis being backwards. And, I'm still not sure that was not my doing as well?

Oh, another stupid mistake...I installed Vcarve Pro on the new laptop. Designed a new part, saved the file, ran the program...the router dove into the work without coming on! Thankfully, the Estop works (I verified it before testing!). I didn't change the profile in Vcarve to Mach3 (not Mach4 entry yet). So, don't be like me! No broken bit though, thankfully.

Similar Threads:

• Mach4 Help Needed: Potentially Paid Mach4 & CNC Consulting
• a full size drawing saved as a vector to machine in plasma, laser or cnc router
• G00 in machine coordinates
• 13 How to delete files saved in machine

[joeavaerage]

Hi,

Not sure if there is a toggle that can be changed? I think one could create a script in the Mach4 "shutoff" script that would save the coordinates and then add something in the screen script to read them on power up.

There is exactly that feature, its called the Screen Unload script. You can for instance put Lua code in there to save the current machine coordinates.
There is also the Screen Load script which can read back previously saved data.

Another possibility is to save the machine coordinates in registers which can be made persistent and therefore be used across startups.

If you are looking for the means to prevent the necessity of referencing (homing) your machine at start up you are going to come up short.....it just
does not work. I have tried, and every new Mach4 user has tried and we all have come to realise that its a fools dream. I did get a solution of sorts,
but it was a trick work-around. If you are interested you will find my posts about on the Mach4 forum page, although I suspect you will come to the same conclusion that
I did....it just doesn't work, or at least, well enough to consider the effort worth it..

The latest servos with multi-turn absolute encoders and battery backups on the other hand can do the business!

Craig

[joeavaerage]

Hi,

One reason I like to save the homed coordinates is projects like this. It is a two sided project and alignment is critical. I try to make it all in one day, but sometimes.... I'm not sure how accurate the prox sensors are and how accurate the homing routine is. Maybe its plenty good? I may do some testing out of curiosity.

That is a very valid reason for saving the machine coordinates and is a prime example of the use of persistent registers.

I use roller plunger snap action microswitches for home switches and achieve at least 0.02mm repeatability. If I come back to a job that I previously saved the work zero,
in persistent registers as is my preference, I can home the machine then drive to the previously work zero and resume work. I do a lot of circuit boards and accuracy
between upper and lower layers needs to be 0.05mm or better, and I can do this no trouble.

Craig

[joeavaerage]

Hi,
saving the machine coordinates of a work zero is rather like re-inventing the wheel, that's what G54, G55, G56 etc are all about, they are persistent.

If you are working on a part and wish to finish for the day, jog to a suitable reference point on the part and 'save' the offsets as a G59 say.
Tomorrow when you start your machine you will reference (home) as normal and then jog to the G59 offsets and you will be back to the
reference point on your part provided you did not shift it in the vice and also that your homing switches and procedures is repeatable and
accurate.

Craig

[Goonk]

Thanks for the help. I'll try that. I have the Avid sensor package and use the built in homing, so I assume it is fairly accurate? Something weird happened today. I was out there working on adding all the buttons I had for Mach3. One of them was to home Z only. I had that one because my Z axis slips after power down sometimes. I got the script working, but right after it homes and backs off, I was hearing a pop. I heard it a few times, but then it quit. Hope its not another bearing! Been there.

Got my park button, Home Z, Safe Z, and Tool Change buttons all working today. Progress! Learned a few things. I've been reading to understand why things worked and/or didn't. I had my own AutoZero routine for Mach3, but the Avid one works great, so I may stick with it. Mine waited to start until it saw a probe hit. I did that because I use a flat plate and it allowed me to click the button, then get the plate in place before it continued. I had another routine and a different setup to find corners. Both pretty crude. I like the spring loaded designs. I may break down and buy the Avid unit. It looks pretty substantial. Hate to spend that much dough, but it is nice.

Tony

[joeavaerage]

H,
Mach4 Mill is pretty well featured and ready to go. Its tempting to believe 'I need a button to do that and I want that operation to be automatic'
but I most cases it is at best a convenience or trying to emulate Mach3 behavior, when in fact Mach3 behavior is a low bar......familiar....but a low
bar none the less.

Creating buttons and scripts is a very good way to learn about Mach4, how its structured and about Lua....but don't lose sight of the fact that
its a CNC program....its meant to control a machine making chips.....if its not making chips and you are still playing with it its wasting your time.

Like you I had a few extra buttons and scripts but the more I use Mach4 the less I rely on them, just about ALL of the features I require are a few
keystrokes away.

One piece of software I do use a lot is MillWizard. Its a standalone conversational Gcode generator. A lot of jobs I do at my machine are just a few
very simple ops, like face that land, then mill a circular pocket followed by drilling three holes. There is no need to use CAC/CAM to do such things
when you can do it standing in front of your machine in a few seconds.

Classic example was yesterday my workmate handed me an cast aluminum automotive speedometer frame. One of the holes for the odometer shaft
was very worn and out of round. What I had to do was make from a scrap of aluminum a jig to clamp the part, then cut a new hole as a circular interpolated
toolpath with a 1.5mm endmill so that he could bush the hole. Took about twenty minutes....never had to walk away from the machine.

I recommend downloading MillWizard from NFS and trying it. I liked it that much I bought it ($75), and I use it if not daily at least several times a week.

Craig

[Goonk]

I was just trying to recreate the buttons I had created for Mach3. I use them alot. There are only 4 or 5. Today, I learned how to check if an axis was homed before using a G53 based move. My park, tool change, and safez all use machine coordinates. I was concerned that since I am not used to homing each power up, I may forget and send the machine to who knows where! Yeah, and if I buy the Avid zero touch tool, I won't need to recreate my AutoZero script. Why bother. Their routine is really nice. I enjoy learning this stuff, but, yes, my real focus is making stuff, I have found it is good to learn at least a bit about the stuff for when things go wrong.