Well heck yeah, learned somethin!
So for the LowRider3 we should, pause, home Z, change the bit, then probe? Normally I move up 10-20mm change the bit then probe. Sounds like the home is key. I home before every job so it can’t be just that, must be just before a probe. Although When I level the gantry I don’t always home I probe a few times before homing.
I need to test that out.
That is key info there.
Thanks Neilp!
To be clear- whenever I have jobs that require a bit change, I break the toolpaths into separate gcode files. So after toolpath 1, it goes back to X0Y0, then Z home. I change bit, z-probe (my macro includes the g92 Z0.5, G0 Z5 F300) then start the next file. That file starts with a G92 X0 Y0 Z5 command.
I’ve never been able to pause and resume a job in progress. I’ve never actually specifically tried that as a bit change method though, so my explanation above might not apply to pauses, only new files.
But whenever if just tried messing around with doing consecutive z-probing to practice my methods, I could only ever do two consecutive tests if I either 1) rehomed the z or 2) the plate was in the exact same place or closer to
The bit. That would indicate that it is expecting the g38.2 to close the circuit within a certain distance, and times out of it doesn’t. Homing the Z resets whatever that expected value is to ‘max’. This is what I think is happening but I don’t know the software side of this
And I home Z essentially because some of my bits are 1/8- 1/4” diameter and 1.5-2.5” long, so I need the full clearance in order to get it in the collet
This is my start Gcode for the LR3:
G90
G92 X0 Y0 Z0
G00 Z5.0000 F500
M00; Attach Z Probe
G38.2 Z0
G92 Z.5
G00 Z5.0000 F500
M00; Remove Probe
M03 S
And tool change Gcode:
M05
G0 Z30 F500
M00 (Change tool: )
G38.2 Z0
G92 Z0.5
G00 Z5.0000 F500
M00
M03
So if i edit the start Gcode to have a G28 Z0 before the G38.2 it should home Z then come all the way down to touch the probe correct?
When i cut my front plate last night i did have a tool change and it probed correctly for that.
Also if i add G0 X0 Y0 Z30 will that move the tool to home to let me change the bit then go back to where ever it needs to start the next part of the cut? Im still trying to learn all of this gcode stuff. I never messed with any of this for my LR2 so im behind the curve lol.
Homing Z for a tool change would defiantly be nicer for getting different bits in and out. I would assume that i can move the spindle to home then home Z before doing the tool change. then have it probe and continue on??
Yes. You can go anywhere on the table with it- for your convenience- and then home Z for the height clearance… this’ll work as long as you don’t do a G92 in the wrong place. If your next file starts with a G0 X0 Y0 Z(#) where # is the Z value you raised the bit up after probing to get the plate out, then it’ll go back to the exact point where it was located at the beginning of run 1
M05
G0 X0 Y0
G28 Z0
M00 (Change tool: )
G38.2 Z0
G92 Z0.5
G00 Z5.0000 F500
M00
M03
So this should work for Tool Change correct??
M05
G0 X0 Y0
G28 Z
M00 (Change tool: )
G38.2 Z0
G92 Z0.5
G00 Z5.0000 F500
M00
M03
I don’t think the 0 is needed. I plan on editing my tool change gcode in a couple of hours to run more YZ plates so I will be testing this soon.
If this fixes the issue I will change the docs to show it (I recently redid the milling basics page, and will edit it again).
This G28 method is the right way anyway. I had a friend doing a giant project as his first one with very few mm to spare and I realized a moving up the Z axis 30mm is not the right step anyway. Homing it up is best. Need a max z switch for the mpcnc so we can do the same.
So once this is proven out, two birds with one stone situation.
I was thinking exactly this as i was reading it. Should be possible to add relatively easy i would think but you are the brains on that one lol. Im still trying to find a 2.5" clear hose adaptor i can print so my dust collection will hook up on the LR3. I cant 3d model to save my life lol.
I will change to this. I wasnt sure why the 0 was there. I remembered seeing it for the leveling part so i thought it was needed.
Missing the F parameter in the first G0 move?
And the second G0 move has an additional 0?
Will that be problematic?
There a 2.5” dust shoe remix by @DougJoseph that i use to directly connect a 2.5” hose (actually, my hose end adapter was 2.25” so I bulked it mount with tape)
https://www.printables.com/model/212623-lowrider-3-cnc-makita-700-series-mount-removable-d
Also, more info on my particular routine here from a couple months ago
Z level question. How close is close enough? i have run it several times and each time it seems i stay the same. Im ending up at .09~ higher on the x+ side.
Well i started typing this then got pulled away. Ended up forgetting i started it and ran the machine. Its definatly higher on the x+ side. So ill have to set it to 0 and run it again. That will have to wait 2 weeks though. My time home has come and gone lol. Time to head back to work for 2 weeks
Yes sir i am running that and your hose hangers. Im using clear spiral dust collection hose so i needed a hard adapter to screw into it and hold better in your mount. I was able to find one on Thingiverse and print it. It fit quite well. Only downfall i have now is using a spindle i have more stick out than a normal router so its a little far from the workpiece and leaves quite a bit behind. It seems to have great suction. If i was any good at modeling i would remix yours and make it just a touch deeper so the bottom was almost even with the bottom of the collet. Right now my collet hangs completely out of the dust shoe.
After running a cut i knew right away we were going to have to add this. it moved SOOOO SLOW back to 0,0
I noticed that but left it alone and i didn’t have any troubles with the movement… other than being slow lol.
I went back and added this:
M05
G0 X0 Y0 F2500
G28 Z
M00 (Change tool: )
G38.2 Z0
G92 Z0.5
G00 Z5.0000 F500
M00
M03
I dont have time to run it again but hopefully that will make it all better when i get back in town.
The one I use is here, Milling Basics - V1 Engineering Documentation.
I have no issues with that. 3 and a half thou over 4’?!
I use this- just wrap a bit of blue tape around the flange part and it fits great in Doug’s shoe
POWERTEC 70191 Screw End Quick Coupler for 2-1/2” Hose – Left-Hand Threaded Adapter, 2-1/4 x 2-1/2", Black https://a.co/d/7WG2HFC
I found a file with all kinds of different ends on thingiverse and the one I printed looked exactly like that one and fit great. I will see if I can get my wife to send me a pic of the other part I was talking about sometime today. I didn’t think to take one before I left.