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Rich Cattell Marlin G30 probe 'shudder'

Posted by ybanrab 
Rich Cattell Marlin G30 probe 'shudder'
June 01, 2015 07:28PM
Hi All, I've got my printer running (thanks in no small part to the help from people here) but it's not quite levelled out or calibrated correctly. I can print small to medium parts in the bed centre but out to the edges things are off. Even in the centre, the dimensions of parts are not quite right.

The plan is to get a hacky probe on the head so that I can get myself into the right area, then print myself out a proper servo-actuated probe. I've zip-tied a microswitch to the print head and connected that to z_min.
My machine has a Z height of 272.2mm more or less but using that height, G30 X0Y0 will get near the bed, then re-home.
Running M666 H300 will allow G30 to make it to the bed. Running G30 X0 Y0 generates the following output:

Bed Z-Height at X:0.00 Y:0.00 = 85.8000
Carriage Positions: [341.40, 332.50, 333.11]

Unfortunately, after reaching the bed and triggering the Z probe, it then moves upwards, very jerkily, then moves back to re-trigger the switch.
I'm not sure how it's arriving at 85.8mm Z height, but that would appear to be about as far as it gets in retracting after the initial probe

Running G30 A generates the following:
Starting Auto Calibration..
	Z-Tower			Endstop Offsets
	167.4001			X:0.00 Y:0.00 Z:0.00
167.4001		167.4001		Tower Position Adjust
	126.6000			A:0.00 B:0.00 C:0.00
167.4001		167.4001		I:0.00 J:0.00 K:0.00
	167.4001			Delta Radius: 127.0000
X-Tower		Y-Tower		Diag Rod: 277.0000
The position of the endstop switches on this printer are not within limits
Adjust endstop switches so that they are within 3mm Z-height of each other
Current Endstop Positions - X: 167.40 Y: 167.40 Z: 167.40
Autocalibration aborted

I've shot a video of the printer running G30 X0Y0 in case this makes sense to anyone?

Here's the probing offsets and positions I'm using:
#define Z_PROBE_OFFSET {10, 5, -2, 0}  // X, Y, Z, E distance between hotend nozzle and deployed bed leveling probe.
#define Z_PROBE_DEPLOY_START_LOCATION {0, 0, 30, 0}   // X, Y, Z, E start location for z-probe deployment sequence
#define Z_PROBE_DEPLOY_END_LOCATION {0, 0, 30, 0} 	  // X, Y, Z, E end location for z-probe deployment sequence
#define Z_PROBE_RETRACT_START_LOCATION {0, 0, 30, 0}  // X, Y, Z, E start location for z-probe retract sequence
#define Z_PROBE_RETRACT_END_LOCATION {0, 0, 30, 0}     // X, Y, Z, E end location for z-probe retract sequence

Any and all input welcome!


Re: Rich Cattell Marlin G30 probe 'shudder'
June 03, 2015 10:49AM
Have you been to the "Delta Robot 3D Printers" Google Group yet?
Here is a VERY long thread on this Marlin branch.

"I like to be, what I like to see, in you and me.
I am the Stallion, Mang."

ISTAR Scope Club
Re: Rich Cattell Marlin G30 probe 'shudder'
June 12, 2015 02:50AM
Thanks very much! I'll get the RichC testing branch and work my way through the thread.


Re: Rich Cattell Marlin G30 probe 'shudder'
June 12, 2015 03:04AM
Is it triggering correctly? I had something similar once when the probe was always triggered. it moves up when getting to the next probing point, senses that it already triggered and immediately moves up to the next point.
Re: Rich Cattell Marlin G30 probe 'shudder'
June 14, 2015 01:11PM
Sungod3k, THANK YOU!!!

Previously when no switch was triggered, M119 reported this:
x_max: open
y_max: open
z_max: open

Flipping Z_MIN_ENDSTOP_INVERTING to false got me all switches reading as open and probing now works!

BoriSpider, I did switch over to RichieC's testing branch, so hopefully I'll get the benefit of a better probing sequence too

Thanks so much

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