I have built my LR4, but none of my limit switches are working. I even took my z axis high enough to break the little tabs above the rail. All of my limit switch lights are lit and when I manually press them, the light on the jackpot controller goes out. Additionally, when I ran “$Limits/show” I was able to test all of the switches successfully.
How do I get the limit switches to actually limit movement?
They don’t limit movement. They are endstops to square your machine.
For X type $HX
For Y type $HY
For Z type $HZ in the terminal. There is also a button in the webui to home each axis.
oh, I see that now. Thanks.
Have you been able to home and make sure your CNC is square? Maybe try some air cuts.
I had to delay because I do not have a level bench. Since you asked, is there a way to manually offset z0 vs z1? As the picture shows below there is an inch and a half difference between z0 and Z1. I need to see and see to cut a couple parts for the bench that I’m building.
This is covered in the docs LowRider CNC V4 - V1 Engineering Documentation
You’re just inputting a very big offset 
Yes there is, but I’m not sure about the Lowrider. I have a MPCNC. Doesn’t the Lowrider home up on the Z axis?
That is a YUUUGE difference. The offset is meant to adjust for minor (<2mm) differences between the two limit switches, not to compensate for large differences due to individual build decisions.
You are also losing over 1/3 of your available travel if you do that.
Much better (IMO) to shim up the Y rail holders so that they are at the same height as the non-rail side.
That is what I ended up doing. This is just temporary and didn’t want to go through all of that if I didn’t have to
Yeah, 1-1/2" difference doesn’t sound right, maybe I’m misunderstanding. Are the leadscrews well lubed before you home Z axis?
Consider sharing close up pics so we can help get your machine closer to just needing couple mm pulloff offset between Z0 and Z1.
The YZ sub-assembly on X Max pipe rail side rides higher, so, that’s something to consider when figuring out where to measure from.
As you’ve already found out, you have to have the bottom of the Y rail level with the top of the non-rail surface that the opposite side YZ plate rides on. That’s how the LR4 design works.
My first impression is that the Y1 plate rides on the Y rail, and is therefore higher, however the XZ plate on that side holds the gantry lower than the other side in order to compensate for this. As a result the gantry should be level (or close to it) it may appear to be very different but should not actually be.
The whole thing is supposed to sit on the same level surface as mentioned above. Looks like you built half of the opposite of a drop table.
Yes. I learned that it needs to be level. As I mentioned earlier, this was suppose to be a temporary setup. Set up just enough to cut a few parts, then I would put proper rails.
The challenge I am facing is that I want to cut full 48"x96 sheets. So the bench needs to be wider and longer to have a cutting area. I have shimmed up the y rail and got it level enough to finish building the cnc.
Thanks for all of your help and insight.
