Hello I've just bought a Openbuilds mini-mill that I'm trying to set up with limit switches. I'v set them up as NC-wired switches as I'm trying to eliminate interference from the motors. To test out if they work correctly I want to home each axis separate, but I see in open control that its disabled, you can only home all axis together. Can I write some g-code in the serial control tab for homing each axis separate? Terje
Only if you recompile Grbl: gnea/grbl just test them using the Troubleshooting tab, then go for it. Interference would cause False Hard Limits issues, no matter which axis is homing. Use Xtension Limits and BlackBox: Built In Noise filtering.
I'm lost here. So I got my limit switch mounted and working as NC: my limit switch for Z is on top, my limit switch for X is at my right(seen from front of machine), X-plus side I think and my limit switch for y is at the front, Y-minus side I think. I want to home at my right front so I can easily get my part taken on and off, so I've set $23 to 2 as I understand that will home to that posisjon, right? When I jog the motors: my Z+ goes down, should this not go up? my X+ goes to the left, I think this is correct? my Y+ goes to the back, should this not go to the front? So if the inverted posisjons in the grbl settings is correct, I guess I will have to change my wiring? Please se my attached picture Thank you so much
No, your Z and X movements when you jog are not right, and you have to get that correct first - all cam software will assume that ;- X +ve = right Y +ve = back Z +ve = up Alex.
@Alex Chambers , you may want to clarify that your post to make clear that the moves are "Relative movement of TOOL to STOCK" - as the MiniMill is a moving-bed design... Don't look at the direction the bed moves, visualise the direction the Bit is moving, relative to the stock
Which puts the Endmill, on the BACK RIGHT corner of the "stock" on the bed right? That is indeed inverted
thanks My understanding is that: X plus is to the right Y plus is to the back X plus is up So jogging with the plus sign on the controller should bring X and Y to the opposite direction, as it's the relative movement to the spindle(so this would be the X-bed moving to the left and the y-bed to the front, right)? But when jogging the Z+ it should always go up as the column does not move, right?
gnea/grbl is a worthy read on homing positions. Use the Backup Settings button to get a much easier to read Txt file (; then you can just copy paste the settings in here. In your settings you have X = not inverted, Y = inverted and Z= not inverted Default (not inverted) is if the switch is at the Maximum end of travel (where the DRO shows the biggest number, that side) - if you INVERT an axis you are telling Grbl you put the switch on the Minimum (side with lowest DRO number) instead On the minimill you should home with Y toward the max (not inverted) so the "bed" comes forward for easy stock loading X homing can be either direction, doesn't make much difference, just tell Grbl where you did put the switch (Invert on if its not at axis max) Z must never be inverted, and always have the switch at the top of travel (bit moves away from stock to home) Current wiring order is 1234, swop it around to 4321 (all 4 wires) You could do 2134 or 1243 too (swop wires of one pair) but swopping the whole row around is easier to visualize
So now I really got confused. I do really regret buying this mill as a demo version from the Danish Openbuilds store, I've expected it to just work out of the box, now I have to backtrack everything insted. So I removed the wire sleeves to get a closer look at the wires, and I find that there is 8 wires, not 4. So two pair of wires are crimped together and four single ones are going to the control board. Does this mean that this is not an Openbuilds motor, and why does it have 8 wires, and is it really for my purseres? What wires would correspond to AA+ and BB+? You mention wire-order 1234, what colour does that translate to?
Definately not: See ours: NEMA 23 Stepper Motor Wanted to look up the specs on your motor, no model number? Just company name and URL? 8 wires: You can choose to use only two of the 4 coils, or wire the 2 coils together - but its tricky - they exist for people who need to rewire the motor to fit specific torque or speed requirements, by changing whether you use all the coils, and serial vs parallel wiring if you do, etc. Ideally though the unused cables should NOT be crimped together! Yikes! That would make the motor fight the shorted out coil - was it working well? I'd imagine you would stall out quite low. See the 8-wire section of Difference Between 4-Wire, 6-Wire and 8-Wire Stepper Motors - National Instruments 1 = first wire you had on the plug, 2 = second wire, etc as you look at the plug. Swopping then to 4321 = reversing them from left to right. Instead of numbers, if : 1 = red 2 = blue 3 = purple 4 = orange Then 4321 would be 1=4 = orange 2=3 = purple 3=3 = blue 4=1 = red as an example. How to identify: docs:blackbox:faq-identify-motor-coils [OpenBuilds Documentation]
Yes but he not used a black box, so there are not any plugs. The controller is xpro v3. He crimped together red and yellow + orange and black, they are all now only about 10 cm long. I see from his website that he specifies that +A Blue, -A Green and +B Brown, -B White. So Z should be wired this way and XY should be inverted or do I wire them all the same way, and invert XY in the control software? NEMA 23 - 0.9Nm - 1/4" shaft Hybrid Stepper Motor
BlackBox, xPro, whatever. Stepper theory and wiring order on almost all bipolar drivers are just about the same. Xtension Connector, crimp housing, whatever, still counts as a plug Choosing whether to fix wiring or flip it in settings boils down to whether someday when you reload the profile you want to remember what to flip, or just have it work with the stock profile without modifications
Yes I agree, but this is very strange as I loaded all defaults, and only changed the homing posisjon the $23. Is there a way to get all the default settings back?
Thanks for all the help, got it working! What I don't understand is that it reports x 295, y 175 and z-15 when I home all axis. Is it just a number or does it really belive that's where it is? Is it because I've not set any of the axis to Zero machine coordinate yet ? How do I do that, are there some threads I can read for setting machine and works coordinate? I have the Openbuilds probe if that's help?
Hover over the DROs to see Machine coordinates. Work coordinates is an Offset from Machine Coordinates, of whatever you last zeroed on (or set with G10 L20 commands) - watch the Hello World to learn how to Zero out the DROs: docs:blackbox:hello-world [OpenBuilds Documentation]
