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Precision Piezo Z-probe Now available.

Posted by DjDemonD 
Re: Precision Piezo Z-probe Now available.
February 09, 2019 04:48AM
I don't have a drawing for the Orion at the moment.

The hole is currently 6mm, I know it can be enlarged to 6.5mm but anything more that that and I think you'll cut the traces between the piezos.

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
February 09, 2019 01:10PM
Anyone have any issues with the plastic parts provided with the Orion Kit? I ordered some time ago and am just getting around to installing it now. The part that clamps around the hotend heatsink doesn't close fully so the holes don't line up with the the holes in the pcb or the top piece.
Re: Precision Piezo Z-probe Now available.
February 09, 2019 02:51PM
Wonderful idea and addition to any 3D printer !

Will definately be adding it as soon as we've built our printer. I think it's a much better and simpler solution than most any
movable/retractable armed touch sensor or capacitive/inductive sensor etc, especially as surface type makes no difference.

Just a suggestion, but you could simplify the circuit whilst retaining current functionality if you wanted with something like the attached
schematic (little 8-pin Atmel mcu would of cause simplify further) ..

Pippy

Edited 1 time(s). Last edit at 02/09/2019 02:51PM by Pippy.
Attachments:
open | download - Piezo_Z_Probe.jpg (162.2 KB)
Re: Precision Piezo Z-probe Now available.
February 10, 2019 12:51PM
Quote
FA-MAS
Anyone have any issues with the plastic parts provided with the Orion Kit? I ordered some time ago and am just getting around to installing it now. The part that clamps around the hotend heatsink doesn't close fully so the holes don't line up with the the holes in the pcb or the top piece.

Figured it out. Looking at the step file I got from Moriquendi a while back, the diameter of the clamp that is supposed to go around the top and bottom of the groovemount (nominal 16 mm) is way too small. It is 15.8 mm and then when you have material shrinkage, it's even less in real life. Those should actually be modeled a little bit larger than 16 mm, say 16.2 mm. Reprinting a new part with updates now.

Edit: Adjusted parts worked.

Edited 1 time(s). Last edit at 02/10/2019 04:07PM by FA-MAS.
Re: Precision Piezo Z-probe Now available.
February 12, 2019 10:37AM
Got it all assembled and hooked up. What kind of tap does it require. I'm finding that I have to give it a fairly good tap with my finger to activate. I've tried turning the pot 180 degrees clockwise and it had little effect.
Re: Precision Piezo Z-probe Now available.
February 12, 2019 12:36PM
Try loosening the 4 screws in the mount a half-turn at a time. If they are too tight there is no flex in the system which is required.
Re: Precision Piezo Z-probe Now available.
February 13, 2019 10:03PM
I've loosened them 1/4 turn and it seems to be working normally. I do have a question about probing speed. The documentation for the Orion says to probe between 4-7 mm/s. Seems that makes it super slow if you issue G30 from homed position on an 800mm tall delta. Is there a way to speed up that initial dive and still perform the probing slowly? Or is it advisable to get the nozzle close to the bed with regular movement commands then issue G30?

Running Reprap Firmware 2.02

; Z-Probe
M574 Z2 S2                                         ; Set endstops controlled by probe
M558 P8 R0.4 H5 F300 I1 T7200        ; Set Z probe type to effector and the dive height + speeds
G31 P500 X0 Y0 Z0                             ; Set Z probe trigger value, offset and trigger height
M557 R106.066 S20                            ; Define mesh grid

Edited 1 time(s). Last edit at 02/13/2019 10:10PM by FA-MAS.
Re: Precision Piezo Z-probe Now available.
February 14, 2019 05:54AM
That would make it very slow on a large delta. I have not used the Duet on a delta so this is from a cartesian viewpoint. I've put code into all my home.g files that decreases acceleration and jerk before probing and increases again after, perhaps you could do the same for Z-speed? You could also put in code so that before probing it always homes to the top (Z-max?) and then moves down 790mm before calling G30.

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
February 14, 2019 12:06PM
I'd say my regular movement speeds are ok

I do see the need for changing acceleration and jerk when probing
I don't quite understand how the homing files come into effect when you probe
Like the home files (homeall.g, homex.g, homey.g, homez.g) or homedelta.g on a delta are only called when you home all or individual axis using G28

I could see homing, then changing changing acceleration and jerk, and then probing
But there would be nothing to change acceleration and jerk back, I mean running G28 would just do it all over again

Are you using a macro to probe?

Then it wouldn't be issuing a straight G30, it'd be G30 called from within a macro.

I could set up a macro to home my printer, then drop down to Z10, change acceleration and jerk, G30, then reset acceleration and jerk.

I haven't run G32 yet, but I'd assume it would act the same way since all it is is a bunch of G30 in the bed.g
If it acts the same way, at least I could edit bed.g and add the drop to Z10 before the probes.

Edit: Also looks like I need a Z offset of -0.1 or so on my G31 command too.

Edited 1 time(s). Last edit at 02/14/2019 12:07PM by FA-MAS.
Re: Precision Piezo Z-probe Now available.
February 14, 2019 01:10PM
Yes, essentially my home.g files look like this;

; Reduce Z jerk and acceleration
M201 Z5
M566 Z0

//////// Probe stuff///////

;Reset Z jerk and acceleration
M201 Z50
M566 Z5

As I understand it, the home.g files are macros.

Isn't the function of G28 to call homeall/homedelta? What does the homedelta.g file look like? Could it be changed to do this?

Move up to hit top endstops:
Move down 790mm
reduce speed/acc/jerk
probe bed (G30)
reset speed/acc/jerk

Or am I missing something? I'm not used to deltas anymore.

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
February 14, 2019 01:46PM
I guess the question is, why would i want it to probe every time I homed?
Re: Precision Piezo Z-probe Now available.
February 14, 2019 01:49PM
Ahh, of course...

For me, homing Z means using the probe, for you on a delta it doesn't.

In which case you only use the speed reduction code around the parts of the files that use G30.

Idris


{Precision Piezo} Accurate, repeatable, versatile z-probe plus piezo discs, endstop cables, pt100, 50w heaters.
Re: Precision Piezo Z-probe Now available.
February 14, 2019 02:18PM
Oh yeah, it just dawned on me too that they're different. I suppose if I want to do an individual probe with G30, I'll either make a macro for G30 or remember to lower the nozzle closer to the bed. Later I'll try G32 from endstops and see how it acts and tweak my bed.g if I need to.
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