test of touch probe
Marlin has a M or G code that can test how reliable the probe is, it does so by raising and lower the probe at the same spot, but moving 10 mm away from the spot between each probe
does repetier have the same option?
No we haven't but you can repeatedly test with G30. Only the move away is not there if z probe offset is 0. Otherwise G30 will also move between extruder and z probe position.
edited November 2015
hmm... i think its swinging to much... or am i just to "picky"?
21:57:50.931 : Z-probe:20.16 X:31.37 Y:28.80
21:58:06.841 : Z-probe:19.31 X:31.36 Y:28.80
21:58:21.851 : Z-probe:19.29 X:31.36 Y:28.80
21:58:37.111 : Z-probe:19.29 X:31.36 Y:28.80
21:58:52.173 : Z-probe:19.31 X:31.36 Y:28.80
21:59:06.402 : Z-probe:19.34 X:31.36 Y:28.80
21:59:20.413 : Z-probe:19.32 X:31.36 Y:28.80
21:59:33.942 : Z-probe:19.33 X:31.36 Y:28.80
21:59:47.902 : Z-probe:19.29 X:31.36 Y:28.80
22:00:01.782 : Z-probe:19.30 X:31.36 Y:28.80
22:00:15.647 : Z-probe:19.37 X:31.36 Y:28.80
22:00:29.522 : Z-probe:19.30 X:31.36 Y:28.80
22:00:43.342 : Z-probe:19.30 X:31.36 Y:28.80
22:00:57.564 : Z-probe:19.46 X:31.36 Y:28.80
22:01:12.573 : Z-probe:19.32 X:31.36 Y:28.80
22:01:27.288 : Z-probe:19.29 X:31.36 Y:28.80
22:01:41.113 : Z-probe:19.31 X:31.36 Y:28.80
22:01:55.036 : Z-probe:19.30 X:31.36 Y:28.80
22:02:09.744 : Z-probe:19.32 X:31.36 Y:28.80
22:02:23.664 : Z-probe:19.29 X:31.36 Y:28.80
22:02:37.984 : Z-probe:19.29 X:31.36 Y:28.80
22:02:52.038 : Z-probe:19.29 X:31.36 Y:28.80
22:03:06.224 : Z-probe:19.31 X:31.36 Y:28.80
checked everything again for looseness... can it be any better than this?
22:51:21.193 : Z-probe:19.22 X:30.00 Y:30.00
22:51:35.104 : Z-probe:19.20 X:30.00 Y:30.00
22:51:48.633 : Z-probe:19.19 X:30.00 Y:30.00
22:52:02.343 : Z-probe:19.19 X:30.00 Y:30.00
22:52:16.169 : Z-probe:19.19 X:30.00 Y:30.00
22:52:29.933 : Z-probe:19.18 X:30.00 Y:30.00
22:52:43.704 : Z-probe:19.19 X:30.00 Y:30.00
22:52:57.435 : Z-probe:19.19 X:30.00 Y:30.00
22:53:11.453 : Z-probe:19.17 X:30.00 Y:30.00
22:53:25.174 : Z-probe:19.17 X:30.00 Y:30.00
22:53:38.793 : Z-probe:19.17 X:30.00 Y:30.00
22:53:52.444 : Z-probe:19.16 X:30.00 Y:30.00
22:54:06.233 : Z-probe:19.16 X:30.00 Y:30.00
22:54:20.254 : Z-probe:19.15 X:30.00 Y:30.00
22:54:33.983 : Z-probe:19.16 X:30.00 Y:30.00
22:54:47.804 : Z-probe:19.15 X:30.00 Y:30.00
22:55:01.424 : Z-probe:19.15 X:30.00 Y:30.00
22:55:15.252 : Z-probe:19.15 X:30.00 Y:30.00
22:55:28.867 : Z-probe:19.14 X:30.00 Y:30.00
22:55:42.484 : Z-probe:19.15 X:30.00 Y:30.00
22:55:56.105 : Z-probe:19.17 X:30.00 Y:30.00
22:56:09.934 : Z-probe:19.17 X:30.00 Y:30.00
22:56:23.754 : Z-probe:19.16 X:30.00 Y:30.00
I guess it depends on the type and how you fixed it. If it is on a servo it will vary more then fixed sensors. With a fixed sensor and hal endstop I get a range of 0.03mm. You can also set how many repetitions you make per measurement. Then it does several short moves (must be long enough to untrigger, not more). This averages the height and reduces the error a bit.
the sensor is a FSR sensor and the nozzle itself act as the probe...
got the idea from a russian forum:
FSR sensor needs force, so your extruder carriage will bend. So you have precision of FSR sensor + variance in bending to create force. Have no personal experience with this, so I can not say if 0,05mm range is good or not. Since you only probe with empty bed I guess you can set sensitivity quite high to reduce required force. If it triggers while printing nothing will happen if you use it only for z probing and not for z min.
i did some test prints to see if bed is level and to get my first layer height right.... no issue there