Centroid Community CNC Support Forum

Thanks that worked I still can't get my head wrapped around the table coordinates and the job coordinates.

The great user "disservice" of ShopBot. Table coordinates (machine coordinates), if you have prox sensors working and auto home set up, never changes once the machine is homed. Job coordinates (WCS 1-6 or G54-G59) are your working coordinates that you can set anywhere on the table. You can switch between any of them with Alt-1 through Alt-6. They are saved in the WCS origin table. Job coordinates on a router are typically set at the corner of your part/material or the center, depending on where set in your design program.

As an example, once the machine is homed, you move out from machine coordinates home to the location that you want your working coordinates set at (WCS #1 G54), and hit the SET WCS XY0 button to set your working coordinates there. Set your Z0 with the Auto Z to plate, or with the SET WCS Z0 button. At that point, your job coordinates are set, but your machine coordinates (table coordinates) are unchanged.

The great user "disservice" of ShopBot.

ShopBot was my "first love", but to boast that they have created 10,000+ CNC operators, when in fact very few, if any, were taught anything that could be used in the real world to acquire employment in the commercial CNC world is a shame. For a CNC company firmly vested (possibly leading) in the home CNC revolution to avoid using any code, terminology or operator screen similarities with commercial machines was a huge disservice to it's user base.

As you go forward and explore the differences between the two controls, remember that ShopBot control remembers nothing and doesn't care if you have homed or set work coordinates or travel limits. With Centroid, EVERYTHING matters. So, my advice is that you "learn good habits".

Gary Campbell wrote: ↑Fri Mar 10, 2023 1:53 pm

The great user "disservice" of ShopBot.

ShopBot was my "first love", but to boast that they have created 10,000+ CNC operators, when in fact very few, if any, were taught anything that could be used in the real world to acquire employment in the commercial CNC world is a shame. For a CNC company firmly vested (possibly leading) in the home CNC revolution to avoid using any code, terminology or operator screen similarities with commercial machines was a huge disservice to it's user base.

As you go forward and explore the differences between the two controls, remember that ShopBot control remembers nothing and doesn't care if you have homed or set work coordinates or travel limits. With Centroid, EVERYTHING matters. So, my advice is that you "learn good habits".

similar to how mach combines and electronic constant 'steps per rev' with a mechanical constant 'overall turns ratio" to create steps per inch...a bizarre way to do things. awesome that mach got so many home shop users into CNC but, this trained a whole bunch of folks to mix these items up causing machines to not be configured properly and therefore providing less than stellar results. Why make it easy when it can be hard?

I just ended up with a PRS standard to replace the PRT that I had sold it and the old control box to help cover the PRS. It was pretty much a wash as the PRS didn't have a control box and missing the spindle. I had an old router that I sold with the PRT and kept my spindle and VFD. Now I have to start fresh. I did save my settings.

I got almost everything set up on the new Shopbot. I did run 6 jobs on it and other then cutting a little to deep I have it right on in the X Y. I just have to adjust the depth. The other thing is the GO TO X Y Z it drops down to Z0 before it starts going home.

Do you have a proximity sensor on the Z axis, and use it to set machine home for the Z axis upon start up (all the way up)? If not, I'm assuming that you have set your Z axis machine home with the Z axis low and then set your working Z axis coordinates above that at some point. Go To XY zero will move the Z axis to machine coordinate Z0 first before moving the XY.

If you're going to stick to the old ShopBot ways of no machine coordinates/working coordinates, then you'll have to set CNC12 to not use homing at all, but you'll need to pay attention to the Z axis.

I do have a switch on the Z but not hooked up. I will try that It is just a mechanical switch though

That would be better than nothing. Your other best option, if you have working X and Y prox sensors (SB PRS's had them as standard), would be a custom homing routine that would tell you to drive the Z axis up until it just stops and that would be Z machine home, then after that, X and Y would be automatically set with the prox sensors. That and software limits would keep you in cooordinates, unless you loose steps with your open loop system. In case of that event, you should then re-home.

The loosing the steps is why I wanted the table coordinates to be at the corner of the table. I like to double check that the job is cutting right after I stop and restart it.