BLTouch working
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M98 Pdeployprobe.g can be M401
M98 Pretractprobe.g can be M402What does G29 S2 do ? I just use G29.
This is what I run on bed.g
G1 Z20 F6000 ; Making sure we're not going to hit the side of glass
M400 ;Wait for move to finish
M401 ;Deploy probe
G29 ;probe grid
M402 ;Retract probeThanks,
Jeff
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G29 S2 clears the current heightmap in case you are trying to probe with the heightmap already loaded. also your start Gcode needs to have G29 S1 to load the heightmap or it wont compensate at all.
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G29 S2 clears the current heightmap in case you are trying to probe with the heightmap already loaded. also your start Gcode needs to have G29 S1 to load the heightmap or it wont compensate at all.
Wow, ok this is news. I've been under the impression G29 does a new probe, creates a new map and uses it. Looking at the code seams to support that theory. Perhaps we can have some kind words from the coder ? In the mean time I'll change my bed.g to use the extra commands.
Thanks,
Jeff
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I ended up with the BLTouch because the gantry on my HackenForge Creator Pro bows in the middle from a past life of having dual extruders on it. Using an 8mm sense inductive sensor worked well with the grid mode through glass to the aluminum bed, it however weighed more then I wanted. I've done soo much to reduce weight and get a solid 120mm/s print speed and far more accuracy that I wasn't willing to keep the weight on. The BLTouch and the IR sensor are good options. I liked the IR…it just wasn't the right fit for me as I swap from Blue to Black to Glass to Glue to Spray..etc..etc. The BLTouch just works..and works well.
Ohh if anyone cares you can run a short NEMA 17 motor on the X Axis of the Creator Pro to cut down on weight. Granted it runs pretty warm at 1 amp...but who cares. It cuts off the ounces. I'll have to post some pics of the Hackenforge.
Ok I hijacked it back
Jeff
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I am working on adding a BLTouch to my printer. I have the Duet 0.8.5 and see where you can set the probe type to use either the E0, E1, or the Probe header. Since I will be using +5 and a PWM from the expansion header, I was hoping I could map the BL Touch to one of the end stops on there so I can get all the connections from the expansion header. This would allow me to create a board I could plug in that the BL Touch could connect to.
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Do I have to have a Duet 2/5 in order for the BLTouch to work?
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Do I have to have a Duet 2/5 in order for the BLTouch to work?
For the Duet WiFi the BLTouch works without any expansion board and with the Z-Probe pin already on the board. The 5 volts can come from the expansion header and control signal comes from the Heater 3 pin on the 50 pin expansion connector. The z-probe can be feed via the BLTouch with a 240 (or 220) ohm resistor in parallel with the output from the BLTouch, this drops the voltage down from the 5 volts from the BLTouch to something a bit more friendly for the 3.3v logic levels the processor expects. We'll have to get a wiring diagram together for the various models of Duet boards. It's a pretty easy install and it works great.
Jeff
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Thanks. That's good then! Yes a diagram would help but I understand it's early days. I have it setup currently on my Bigbox (Rumba) so looking forward to switching.
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If anyone could knock up a quick diagram of connecting the BLTOUCH to a duet wifi I would appreciate it. I am getting everything ready to change over on Saturday evening.
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I have set my BL Touch up, but I am having a lot of repeatability issues that I am hoping someone could help me with. I have followed all the instructions in this thread as best as I could. I am using the resistor, plugging into the z probe pins, pin 1 and 2 on the expansion, and heater3 pin. I have tried changing the trigger value a bit which didnt do anything. All my connections seem fine as they are crimped and the resistor is soldered.
Here are the results (just the Z coordinate) from four 5-point auto bed compensations that I did in a row, without the heated bed or anything turned on.
[ 0.000] [-0.190] [0.425] [0.112] [0.158]
[ 0.082] [-0.170] [0.540] [0.503] [0.285]
[ 0.010] [-0.522] [0.780] [0.635] [0.293]
[-0.122] [-0.637] [0.322] [0.115] [0.197]As you can see there is a big difference between each new probe sequence. Here are some relevant config files and my bed file.
; BL Touch
M558 P5 X0 Y0 Z1 H4 F450 T4000
G31 P25 X36 Y0 Z1.5; Auto Bed Compensation
M561
M98 Pdeployprobe.g
; Probe the bed at 5 points
G30 P0 X15 Y15 H0 Z-99999
G30 P1 X15 Y175 H0 Z-99999
G30 P2 X185 Y175 H0 Z-99999
G30 P3 X185 Y15 H0 Z-99999
G30 P4 X100 Y100 H0 Z-99999 S
M98 Pretractprobe.gThanks in advance for any help.
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Few things to check,
Make sure your config_override.g isn't changing the value of the G31 P25…command.
I'm actually running G31 P1 (vs P25) and have been. My theory is that the even shorter pulse detection gives the Z axis less time to move once triggered. I've had really consistent results. Granted if the z axis overshoots the same each time it shouldn't matter. But still perhaps worth a try.
Edit: Not that it matters but M401 can be used to call the deploy.g and M402 to call the retract. Just a bit cleaner.
Jeff
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So your not wanting to run the grid based compensation , G29 ?
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I remember I used to have a config override file but after updating a few times it seems to have disappeared. Is this a problem?
I tried a lower trigger value but haven't had any better results. I also decreased my Z acceleration as it was set pretty high. Also ironically shortly after I posted, I set up a macro for grid compensation. The probe points produce different values each time.
Any other suggestions? Thanks a lot for the help. I read your previous post about M401/2, but just forgot to change it, thanks though!
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I remember I used to have a config override file but after updating a few times it seems to have disappeared. Is this a problem?
I tried a lower trigger value but haven't had any better results. I also decreased my Z acceleration as it was set pretty high. Also ironically shortly after I posted, I set up a macro for grid compensation. The probe points produce different values each time.
Any other suggestions? Thanks a lot for the help. I read your previous post about M401/2, but just forgot to change it, thanks though!
Hmm, mechanically sound printer ? In other words do you feel it's nice and solid and should be producing the same results each time ? For the grid what's the map look like, is it random junk ? Did you try changing the height of the BLTouch based on the docs that came with it ? 8m gap from bottom of BLtouch shell to bed.
Jeff
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Yep my printer is pretty solid and prints consistently. I took it apart to make sure nothing got loose, tightened a few things, didn't help sadly. I am still getting deviations of 0.5mm maximum.
The grid is pretty random, I can upload the map if you want but I dont think it will help much.
I actually didnt get any docs with my BLTouch,, although it looked legit. I got it from spool3d.com. I modelled my own mount, and the distance from probe (retracted) to tip of nozzle is just 1.61mm. I read a distance of 2mm is optimal, so I don't think my mount height is causing any issues. Honestly at this point im thinking the probe is defective.
Thanks a lot for the help, I really appreciate it.
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I thought the probe I got was defective at one point as well. It turned out my config override was causing the issues. You've ruled that out already. See if you can get it to probe the same exact spot over and over to P0 P1, P2, etc and see how much the values vary.
Jeff
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If you are not getting consistent results from a Z probe, using a lower probing speed may help. It's the F parameter in the M558 command.
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I probed the same spot 20 times and I ended up getting a standard deviation of 0.054.
Hopefully we can get this solved, I am losing hope though lol.
EDIT: Thanks for the input dc42. I dropped the probing speed to 100. I had already tried that with bad results, but this time I got a standard deviation of 0.026.
I will lower the speed again.I dropped the speed again to 50. Standard deviation is 0.032.
Any other ideas?
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If the BL touch is genuine then contact the manufacturer and ask what repeatability they expect. Could be a hardware fault.
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I just ran a bed probe:
This was on a dirty piece of glass with some left over print residue.
35 points probed, mean error -0.125, deviation 0.055On a different piece of semi clean glass:
35 points probed, mean error -0.050, deviation 0.076and again on the same peice:
35 points probed, mean error -0.170, deviation 0.073What command did you run to get the multi point probe ? I can try that.
Edit: Whatever my results I'm getting really nice flat first layers with even widths. Probes were done at F300.
Jeff
