The solution for my issue is in this post.

https://forum.duet3d.com/topic/29608/the-problem-of-restoring-z-height-after-toolchanger-tool-change

2 commands in the tpost#.g.

I'm using this external mosfet. If I use a different one, will the noise go away?
With Q50 the annoying sound is almost silent. Can I use it or will something break?

I want to test the F25 and became this message.

Fehler in Startdatei macro Zeile 69: exactly one of EFHJPSR must be given

M950 H0 C"bed" T0 F25

That sounds good, what I have to change it?

M307 H0 R0.475 K0.931:0.000 D7.84 E1.35 S1.00 B0

M308 S0 P"e0temp" Y"thermistor" T100000 B3950 C7.06e-8           	; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bed" T0                                        			; create bed heater output on bedheat and map it to sensor 0
M140 H0                                                  			; map heated bed to heater 0
M143 H0 S100								             			; set temperature limit for heater 0 to 100C 

ok. I'll order an inductive one and try it out and then report back.

Unfortunately, I have a problem with my Keenovo heating pad. I've just installed it. When I want to heat the bed to 60 degrees, everything is quiet up to 55 degrees. From 55 degrees onwards the heating pad makes noise. A humming noise that only stops when it's turned off.

Do you have any ideas? The heating pad is new.

For me, it is definitely the magnet. The BLTouch measures 4 positions perfectly. Then the magnet comes and the pin is not retracted and flashes blue and red. There are also neodymium magnets which are embedded in the plate from below.

Hi oliof,

I have the BLTouch in V3.1, so with a nylon pin. I think the mechanism doesn't work with the strong magnets.

Can you tell me a good inductive/scanning probe?

Hi everyone, I bought a new hotbed with magnets on the bottom. Unfortunately, the BLTouch doesn't measure properly. When it's over a magnet, it doesn't have enough power to pull the pin back and gives a message that the probe is in use.

What is a perfect alternative that works perfectly with magnets?

Thanks, for the first time it looks really better.

@rechrtb Do you give me the 2.1 beta7, please? I have terrible issues with my connection. That is so bad, that I have to restart the printer on every time.

The bed can be adjusted with screws and Z has a stepper. Leveling via a 4 point macro, which doesn't work when I check it with paper. The 2 screws in the front are ok, only at the back both screws are too far away from the nozzle. If I manually level the heightmap comes from above.

4 point macro

M140 S70
M190 S70

M671 x43:214:214:43 y43:43:214:214 P0.7                             ; The location of the four bed securing screws

;M558 P0												            ; Uncomment this if you don't have a Z Probe

G28 X Y Z                                                           ; Home Z


G30 P0 X43  Y43 Z-99999 ; probe near an adjusting screw             ; Front left screw
G30 P1 X214 Y43 Z-99999 ; probe near an adjusting screw             ; Front right screw
G30 P2 X214 Y214 Z-99999 ; probe near an adjusting screw            ; Rear right screw
G30 P3 X43  Y214 Z-99999 S4 ; probe near an adjusting screw         ; Rear left screw

G28 Z                                                               ; Home Z

;M140 S0

bed mesh

M140 S70
M190 S70
M98 P"homeall.g"
G29
M140 S0