Short answer: no, they only work while homing. Another person mentioned it, but the difference is between “hard” and “soft” limits. Hard limits would reset your machine any time the switch is tripped (including jogging the machine), but the switches are very sensitive to noise so hard limits are disabled by default.
Is there a way to programaticly set Easel to remember the homing position and not let you jog past it from the software side of things? Just something built into the jog button logic?
Hey Paul Thanks very much. Just knowing and also knowing my switches and set up is working properly helps. I just need to be more careful! Good thing I bought a 10-pack of switches off amazon last week anticipating this might happen! On a side bar, since these switches are fragile and tend to break, perhaps all three locations should be threaded holes instead of just the one on the z carriage. The way it’s made now if x or y breaks theres really no way to get to the tiny nut behind and between things. (X & Y).
That might actually be a good feature to suggest to the GRBL team. I was playing around with limits last night, and I found the settings to enable and set soft limits, but right now they only let you configure a max. It seems like it wouldn’t take much for them to also allow you to set a min, which would prevent you from hitting your limit switches. I’ll look into that tonight and see what I can turn up.
@Peter & Sketch. I just got a response from Bart Dring as well and they will be doing a post helping with this soon.
Cool, I just played around with the soft limit ability of grbl, and it will in fact protect you from going below zero once you’re homed. If you have a way to access your grbl settings, you’ll want to set variable $20 to 1 to enable soft limits, and then make sure that you have reasonable max values in variables $130-$132 for x, y, and z.
I tested both trying to go past the max and home values, and in both cases it prevented the gcode/jogging from letting the machine go past the limits.
When I attempt to home the xcarve through easel on ‘machine setup’, it begins with the Z axis. Instead of moving up to contact the limit switch, the Z axis moves down into the wasteboard. FWIW, it functions normally up and down during carving. Is there a difference and how would I correct this?
Grbl has a setting for homing direction in the $$ menu. I think it is $23.
@BartDring any progress on this?
I am sorry, but I have not had a chance to work on this yet. It will be a while before I can do it.
You can use the Easel setup walkthrough to change axis direction for homing.
I’m looking into Easel setting soft limits by default, but I’m worried about causing more problems than it solves. I’ll let you know.
Should I be worried about turning on my machine the first time and busting all the switches? There’s quite a few horror stories of smashed switches on the forum. This doesn’t seem as documented as other parts of the machine. Also as a side bar, I’m stuck at fitting all 5 wires in to ground (spindle, fan, limits)—can i wire them all to a piece of zip wire and put that in?
The Z-Axis limit switch is really the only one that’s typically in danger. And I know I didn’t break mine when I was homing, it was when I was jogging the machine around and didn’t notice that I was still in 10x mode when I started jogging on the Z.
You could start your homing sequence, use a pencil or something to tap the Z switch, and if the axis doesn’t stop right away, you should have time to turn off the machine before anything bad happens. Also I think you could attach the Z switch with a single loose-ish screw, then use a pencil to hold it in place for your first attempt so that if it doesn’t stop, it’ll just pivot the switch.
As far as wiring the ground wires, it’s much easier if you do like you suggest and attach them to a common ground wire, then run that to the shield. I ended up just picking up another terminal block, and I use that for my common ground.
Yes you should worry. Or you will end up with a limit switch graveyard like this one.
The advise about the pencil is good, as well as keeping your hand on the off switch. Also, double check your connections before starting the machine each time you use it. Especially the little molex pin connectors for the limit switches, those can easily come loose.
Argh, just killed my first Z-limit switch. Totally my own fault, I double-tapped a 2" Z+ move in UGS instead of sending it just once, and wasn’t across the room fast enough to hit the estop before it slammed to the top. Ordered up a large replacement pack, I figure with the switches set up as they are, damage is more or less inevitable. Ah well.
Nope. You can set up your machine to prevent this.
Read through this thread:
Soft limits are your friend.
It would be nice too if Easel would have a function to manually test the functionality of the switches without moving the axis. Like a function that lets you push the switch with your finger, without moving the axis, and then indicating something like X triggered or Y not triggered.
That would help especially after building the machine when there could be potential wiring issues. Otherwise, you might find out that the wiring doesn’t work when it slams into the switch…
a function that lets you push the switch with your finger
I don’t use Easel, so I can’t help there, but grbl has the function that you want built-in. You would have to access grbl via a terminal program like HyperTerminal or Putty to use it.