Jules,
I have used your guide many times in the past year and recommended it to other so first let me say thanks!
I wanted to ask a question I was just thinking about now. In the guide you say to set your width to 0.4mm, and I always have, and then set it back to 0.48 for printing as recommended by most sources. I was just wondering why it is generally recommended to use a 0.48 width on a 0.4 nozzle especially after I just calibrated it with 0.4 width.
Thanks!
How To: Calibrate the Z-Offset
Re: How To: Calibrate the Z-Offset
Well, I leave mine at 0.40 mm generally.
It depends on the layer height you are using...if you use a 0.20 mm layer height, leave the extruded width at 0.40 mm.
If you are going to a 0.25 mm layer height, you can set your width to 0.48 mm.
Just depends on the layer height you are running.
It depends on the layer height you are using...if you use a 0.20 mm layer height, leave the extruded width at 0.40 mm.
If you are going to a 0.25 mm layer height, you can set your width to 0.48 mm.
Just depends on the layer height you are running.
Re: How To: Calibrate the Z-Offset
So there's no confusion, I have a Rev D machine with a V4 extruder.
I saw the posting that strongly recommended running calibration squares & adjust parameters on every filament change. (I am only printing PLA right now.) Which I have been doing. And its been quite interesting. Changing the extrusion multiplier I get. But something that I haven't reasoned through, is the radical change in the Z-height adjustment when switching filaments. I've been running into changing the g-code z height a couple of tenths of mm when swapping filaments. But I make the configuration changes in S3D, and the calibration square comes out as expected, ie. 2.00 mm so I'm reading the calipers correctly and making the right change in the software.
Something else that makes me wonder if I'm not following procedures correctly, is that when I re-assemble and re-calibrate after an extruder jam, I consistently end up .2 mm or more off on the z height, even though I use the feeler gauge in the recommended range and allow the hot end nozzle to rest on the gauge as I tighten the screw on the extruder housing. Is the hot end rising up when I tighten the screw? Is that what's happening? If my reading is correct, I'm supposed to reset the gap with everything hot (Ex 215C/ HBP 70C) which is what I've been doing.
I saw the posting that strongly recommended running calibration squares & adjust parameters on every filament change. (I am only printing PLA right now.) Which I have been doing. And its been quite interesting. Changing the extrusion multiplier I get. But something that I haven't reasoned through, is the radical change in the Z-height adjustment when switching filaments. I've been running into changing the g-code z height a couple of tenths of mm when swapping filaments. But I make the configuration changes in S3D, and the calibration square comes out as expected, ie. 2.00 mm so I'm reading the calipers correctly and making the right change in the software.
Something else that makes me wonder if I'm not following procedures correctly, is that when I re-assemble and re-calibrate after an extruder jam, I consistently end up .2 mm or more off on the z height, even though I use the feeler gauge in the recommended range and allow the hot end nozzle to rest on the gauge as I tighten the screw on the extruder housing. Is the hot end rising up when I tighten the screw? Is that what's happening? If my reading is correct, I'm supposed to reset the gap with everything hot (Ex 215C/ HBP 70C) which is what I've been doing.
Re: How To: Calibrate the Z-Offset
The tolerance on the initial Z-axis home position is so tight that, IMO, you cannot set it correctly with a mechanical adjustment. You can get close, but there's no way to tighten a setscrew without nudging the position one way or the other.ajmadison wrote:consistently end up .2 mm or more off on the z height
So I get close mechanically, then tweak the position using an offset in my startup G-Code: print a calibration square, measure the actual height produced during normal printing conditions, adjust the software offset to compensate, maybe iterate a few times, and it's perfect.
That seems to be Not The Way It's Done nowadays, what with user-friendly programs that hide all the details you desperately need to know in order to understand how the thing works, but that's progress.
In any event, don't be surprised if you get marginal & inconsistent results from mechanical Z-axis adjustments, because being off by ±0.1 mm with a 0.2 mm layer makes the difference between "works great" and "rubbish"...