I’m ready to start pulling my hair out. I bought my skr pro board from v1 engineering. It is supposed to have the latest software on it. I can get the machine to move when I go into the move or home buttons. But that’s as far as i can make it. I’m using aspire for my nesting. I got that for the machine running mach3. I installed the marlin.mm post prosser. I think I’ve hit every button on the screen several times. But i still can’t figure out how to set my 0,0,0 to my work piece. I’m trying to do the crown test on a piece of paper. But I’m at a dead end trying to figure out how to get it to work. My gcode should be at .25 safe z. And going down 0.01". I even tried doing an air cut. But when I hit print from home the z goes all the way down and crashes the machine. My lowrider 3 isn’t worth much if i can’t get it to work. What am i missing? I’ve spent hours on the internet trying to figure out how to do it. But i still haven’t solved my problem. I don’t see a probe button or a way to set my starting points. Im using the touch screen is that my issue? Any help would be appreciated. I want to start getting it dirty. Help me.
Since I do not use Marlin I can’t help you (wow, what an idiotic answer, you might think) BUT I know that this problem has been resolved a few times and one of our other, very nice forum members is going to help you shortly. Noone is leaving here without a running machine. 
I would suggest you run through the EstlCAM page and get a crown that way. Then we can make sure that your machine works and are not fighting hardware and software at the same time.
Lots of people here are familiar with Estlcam, but not the Vectric software as much.
Promise your machine will work, stick with us. The last bits are the hardest because you are so excited.
When the Lowrider homes it set x=0 y=0 but z=200.
G92 Z0
sets the current Z position as zero. You can send this to via terminal or include it in the start of your gcode file
G92 x0 y0 z0 sets the current location as zero in all 3 axes.
I figured home was 0,0,0. When I’m using mach3 I’m able to put a project in the middle of my table and change my zeros to there. With the z-0 being the top of my work piece. I don’t find any way to do that in this software. When I watch several YouTube videos there screen never looks like mine. All I want is to be able to put a SD card in the monitor and cut something I designed in aspire. I’m no newby to running a CNC but this is really kicking my anyways. This is supposed to be my retirement fun. Not spending 3 days trying to figure things out. I see others have a button to probe the bit to the top of the work piece. Haven’t figured that one out. Is everyone else using different software on their machines. I’m doing some 2.5D carving so I need to figure out how to put 0 at the top of my work piece.
The easiest solution is to add the G92 code to the start of every gcode file so when you run it from SDCard it will use the current location as 0,0,0 - your CAM program should be able to include it automatically at the start of every file.
A lot of users here use Estlcam http://www.estlcam.de/ which has options to add starting, ending and tool change gcode.
I’m not sure which skr board you have but if it’s the one with the LCD screen you can press and hold the rotary button to change it from marlin to a touchscreen control (not sure what its name is). I used that on my skr as it allowed macros to be set up for things like ‘set zero here’. It also lets you jog in all axes easily.
in marlin with the skr, if you have the LCD, you go to marlin mode (single color, not the touch screen part… if not there, then hold the button for 3 seconds and select marlin mode) navigate to the V1 custom menu and select the menu option to either reset the axis or set home. I forget the exact menu option. This will set all axis to 0 wherever the machine is when you push the button.
CAUTION: the easy option is to move it to where you want it and cycle the power and it will be at home when it starts up, but if it isn’t exactly square at rest, it won’t be square when you turn it on. in the v1 menu you can home just the x and y axis to get them square and then move z and x and y to where you want to be home and use that reset command and you are good to go.
Sounds like you are really close. good luck!
I had to step away from the machine for piece of mind. And to get some other things do around here. I took just a few minutes to look at the machine yesterday. I’ve been in the monitor software. I did find the Marlin software. Runs more like 3D printer software. I did find how to change my zeros position. That was an important. But when I tried to home y1 homed to the limit switch but y2 didn’t. Don’t know what’s going on there. I didn’t have much time to check things out. I’m hoping to be able to get back to the machine after lunch today. You said I should try etslcam. Do I need to put that on my machine? Or do I run it through my laptop? I want to start seeing my machine start doing something on it’s own. Without me pushing buttons.
you use estlcam to make your CAM routing paths. import the dxf or svg cut outlines and then select your cutting tool and click on the holes or part outlines. Indicate where you want your tabs and possibly set the cutting order and then export the gcode to be run with marlin. And marlin is 3D printer firmware that has been stripped down for CNC.
Make sure you test each endstop with M119. The most common error is that the endstops aren’t by the correct motor. So Y1 endstop stops the Y2 motor but Y1 motor still spins. Swapping the Y1 and Y2 endstop cables is the quickest way to test that.
There is a page in the docs about coordinates and it is most applicable to Marlin:
I have made this error with every machine so far (three times), even though I was extra sure to double check… 
I made progress yesterday only to find a new problem. Now that I’m using Marlin software. I moved away from the end stops and set a new zeros position. Using my aspire gcode I did an air cut. Everything was looking good. So I stopped the cut. And loaded up the pen and got things started again. The crow was taking shape. yea. But my points weren’t all connecting. When I noticed I had the paper in the wrong way. I stopped it again and put in a new piece of paper. This time when I tried to get it to go I noticed my motors in E0 & E1 don’t want to play by the rules. The far zero didn’t want to go up. Only down. And the far Y was spotty. I stopped the program. When I tried to home it the Z closest to me went up. The further one went down. I thought I had to change my wires around. But wait when I went to move Z 10 mm they both went up. And when I tried home again everything worked fine. So now I have to figure out why those two motors are acting up. I used notepad++ and was looking at both my code and Marlin. I don’t see what tells the machine to use E0 & E2 as the second Z & Y motors. So today I’ll see if I can download etslcam and try that gcode. And check over my wiring. One step closer but two steps back.
I need to make a correction. I used notepad++ to check out my gcode and the aspire marlin.mmpp. I never checked out the Marlin software. I’m spending so much time trying to figure things out. Things are running together. And I think of things after the fact. Such as this.
It would really help to slow down and not jump to a plot until you have the basic mechanics working.
Just jog the machine around. +X should go right. +Y should go away. +Z should move the tool away from the spoil board. Both ends should move the same distance and the distance should be about the right amount (don’t tune a 10mm move if it is 10.1mm but there is a problem if it moved 12.5mm or 20mm).
M119 lets you check the endstops before homing.
The test crown is a premade gcode file that we know works (and has worked for hundreds of machines). Start with that before trying your own. Once you have all of that working, you know the machine is moving and most problems will be gcode related (which we can also help debug).