BLTouch working

FrankNPrinter

i noticed my bltouch fires twice at start up. if you are at z home, the probe hits the bed and errors out. no idea if this is what is causing your issue… BTW, i also noticed loose connection on the 50 pin jack causing bltouch to go on and off sometimes during movement. I hope you have better connectors than i do.

To whomever was asking for a copy of my config, sorry but my pc died and i am running on an old xp system at the moment soat a standstill as far as being able to work on the printer. Hope to have resolved soon but definitely intend on sharing as soon as i am back up. I also appear to have a bizarre z movement issue and am wondering if others wired dual motors on y and z of if they are using an expansion of some sort? left y motor never even gets warm but right does.

Miasmictruth

I don't actively have an issue, I am just want to prevent a possible future issue.

The frame of my printer in acrylic and if I had to bet which would give first the steppers or the acrylic I wouldn't bet on the acrylic even though its high quality stuff.

One thing I am thinking of is sending a reset pulse before I start but still that doesn't guarantee anything.

Another thing might be adding some sort of emergency stop on the bed somehow. If it deflects the rods when it hits the hotend I don't think it would hurt much, but it bowed the acrylic a little before I was able to stop it (again this is when I was still setting it up)

In any case while the BLTouch is awesome there is little to no security with it.

iDevelo

What have you guys found the best distance is from the end of the nozzle to the bottom of the bltouch (not the pin)?

Sniffle

the bltouch documentation suggests 1.5mm if i remember correctly

iDevelo

@Sniffle:

the bltouch documentation suggests 1.5mm if i remember correctly

Thanks.

iDevelo

Has anyone had an issue with it going into error state in the middle of a print and dropping the pin? It happened twice now. After the first time I re-wired it but it's just happened again!

Apart from that it does give good first layer results.

iDevelo

Here's a video of what happens. It can happen at any point in the print.

https://youtu.be/kpLTjELdzYQ

Sniffle

You may need to adjust the top grub screw down slightly as that controls teh electromagnet and may help it to stick. Also check the voltage right at the bltouch(you may be having some voltage droop over distance and may require some type of capacitor in-line but that's not my field of expertise, V-Droop is strictly a guess)

I had this issue for a short while but it was due to the connections coming loose. I connected them and put heatshrink tubing on them to make sure they stayed together always. I have also had to adjust the grubscrew in the past, I've never had a voltage droop issue though. and on my corexy it has a about a meter of wire between the board and the bltouch.

iDevelo

@Sniffle:

You may need to adjust the top grub screw down slightly as that controls teh electromagnet and may help it to stick. Also check the voltage right at the bltouch(you may be having some voltage droop over distance and may require some type of capacitor in-line but that's not my field of expertise, V-Droop is strictly a guess)

I had this issue for a short while but it was due to the connections coming loose. I connected them and put heatshrink tubing on them to make sure they stayed together always. I have also had to adjust the grubscrew in the past, I've never had a voltage droop issue though. and on my corexy it has a about a meter of wire between the board and the bltouch.

Thanks. Even disconnected, the pin should hold from what I've seen. With no power to mine the pin just drops, adjusting the grub screw makes no difference. I think it's just defective now.

Sniffle

@iDevelo:

@Sniffle:

You may need to adjust the top grub screw down slightly as that controls teh electromagnet and may help it to stick. Also check the voltage right at the bltouch(you may be having some voltage droop over distance and may require some type of capacitor in-line but that's not my field of expertise, V-Droop is strictly a guess)

I had this issue for a short while but it was due to the connections coming loose. I connected them and put heatshrink tubing on them to make sure they stayed together always. I have also had to adjust the grubscrew in the past, I've never had a voltage droop issue though. and on my corexy it has a about a meter of wire between the board and the bltouch.

Thanks. Even disconnected, the pin should hold from what I've seen. With no power to mine the pin just drops, adjusting the grub screw makes no difference. I think it's just defective now.

talk to the antclabs folks occasionally the magnet will be weak, they will send you a new pin for free, and that usually fixes it.

rlhotrodding

I just wanted to thank everyone for their help on the Bltouch.

I just got it installed and working great. Just something that I discovered during setup, watch out for the config override file.
It seems that it was turning heater 3 back to heater status instead of servo.

claustro

Anyone can confirm this wiring?
I read the wiki and it say to connect only 4 wires coming from bltouch isn't the 3 wires gnd connected?

BLTOUCH DUETWIFI

2wires cable
GND –----------Z probe GND
OUT--------------Z probe IN

3wires cable
+5V–------------+5 (pin1)
GND--------------???????
Control----------Heater3 (pin8)

dc42

Perhaps the ground should be connected to pin 2 of the expansion connector? I don't have a BLtouch, so perhaps someone else can confirm this.

iDevelo

@dc42:

Perhaps the ground should be connected to pin 2 of the expansion connector? I don't have a BLtouch, so perhaps someone else can confirm this.

Correct.

dc42

Thanks, I've updated the wiki.

HenrikM

That wiring is correct.
My bltouch is working perfect and i tried a extreme bed compensation with 1.5 mm high on one side and 1.5 mm low on other side and i got a Perfect first layer

BUT is there a code or something so you can "fade" out the compensation. that compensation makes the Z move around and can make ugly prints.

I had that on marlin with my mks board. 3mm was the compensation Then it dont compensate anymore and the print is level.
I have not tried that gcode that fades out in Marlin on my Duet. And i am not on my computer now so i cant see what that gcode is.

iDevelo

@HenrikM:

That wiring is correct.
My bltouch is working perfect and i tried a extreme bed compensation with 1.5 mm high on one side and 1.5 mm low on other side and i got a Perfect first layer

BUT is there a code or something so you can "fade" out the compensation. that compensation makes the Z move around and can make ugly prints.

I had that on marlin with my mks board. 3mm was the compensation Then it dont compensate anymore and the print is level.
I have not tried that gcode that fades out in Marlin on my Duet. And i am not on my computer now so i cant see what that gcode is.

Sure is M376 http://reprap.org/wiki/G-code#M376:_Set_bed_compensation_taper

HenrikM

Great! Thanks. Will try it later

toshi

Hello,
I wirred my Bltouch yesterday thanks to this thread, it's the new version with something to cut for 3.3V output. I can extend, retract, and simulate the bed contact with my finger with no limit.
But, there is always a problem =), When I launch a G32 with the following code (grid or points), the fourth point is always skipped with the error : ''Error: Z probe already triggered at start of probing move".
Do you have an idea ?

Config:

M558 P5 X0 Y0 Z5 H10 F200 T5000
M307 H3 A-1 C-1 D-1
M574 E0 S0
G31 X-30 Y-5 Z3.15 P25

Bed:

M280 P3 S10 I1
G4 P50

;**Mesh bed leveling
;G28 Z
;M557 X10:190 Y10:190 S36
;G29 S0

;**Point bed leveling
G30 P0 X-12 Y12 Z-99999
G30 P1 X-12 Y190 Z-99999
G30 P2 X170 Y190 Z-99999
G30 P3 X170 Y12 Z-99999 S0

G4 P50
M280 P3 S90 I1

ThePigSlayer

Toshi, you should probably decrease your trigger height. 3.15 is an awfully big trigger height, and since your dive height is only 5 (in m558), your z axis only goes up from 3.15 to 5mm, which is too short of a z-lift after each probe, which makes the probe report that it is already trigger before the travel move.

Your BL touch pin (the very tip) should be 2mm above the tip of your nozzle when retracted, which gives most people a trigger height of around 1.5mm. Your dive height of 5mm is normal, so either you need adjust your mount so you can lower your trigger height (by mounting the probe higher), or you miscalculated your trigger height. 3.15mm would be dangerously close to the height of the nozzle, and could catch during prints, so I think that it is more likely that you made a mistake when calculating the trigger height.