Duet 0.8.5 + BLTouch

I'm just finishing up printing brackets for a BLTouch sensor I received. I've been reading through the forum and found a few instances of people considering this sensor. Has anyone had any luck getting it to work on dc42's firmware?

It looks like the sensor has a regular 3-pin servo connector as well as a simple two wire switch. Should I be using the Z-probe connector on the duet or the E0 end stop pins?

Any suggestions are appreciated!



Edited 1 time(s). Last edit at 06/18/2016 05:52PM by darkstargtk.

Hopefully DC42 will chime in on this.

In case he does and needs info on the BLTouch

1) The two wire connector is the end stop signal which I believe should go to E0 end stop
2) The three wire is intended to be connected to an output for a standard R/C servo (no idea how to do this with Duet)

The firmware on the Duet doesn't yet support servos. I don't recall anyone asking for it until about 3 weeks ago, probably because there are so many good contactless Z probe technologies available that nobody wanted to use the old servo-deployed microswitch type.

There is now an open issue about this, see [github.com]. Somebody has managed to get some degree of servo control by using the Fan 1 output and configuring suitable values for the frequency and PWM.

I don't have a BLTouch, and not only is is closed source, the manufacturer has applied for patents to protect it. This is completely the opposite of the spirit of RepRap. So supporting it will be a low priority for me, unless the manufacturer provides me with one for testing with and pays me a development fee. But unlike the BLTouch, RepRapFirmware is open source, so anyone can add support to it.

Edited 1 time(s). Last edit at 06/20/2016 06:04PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

That's a bummer about the BLTouch being closed source, I wasn't aware.

I decided it would be easier go with an IR based solution so I ordered the differential IR sensor from Fillastruder - probably what I should have done in the first place... I'm not super excited about having to tear my PEI off of the glass and paint it.. I wonder if I can get away with painting the underside of the glass?

If there are a lot of guys looking for BLTouch support I'd be willing to send my unit out to you dc42, if you're interested.

The same servo logic required for a servo deployed micro switch will also support the BLTouch. It uses the servo input signal to trigger the deployment of the pin the same way as a r/c servo would be used to raise/lower a micro switch.

It is the M280 G-code in Marlin.

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darkstargtk
I decided it would be easier go with an IR based solution so I ordered the differential IR sensor from Fillastruder - probably what I should have done in the first place... I'm not super excited about having to tear my PEI off of the glass and paint it.. I wonder if I can get away with painting the underside of the glass?

Probably not. It's hard to stick the PEI to the glass without getting small air bubbles in the adhesive layer, which means that the reflectivity and transmissivity of the adhesive layer varies over the sheet. That causes the amount of interference with the weak reflection from the surface of the PEI to vary too, and hence the trigger height.

Hopefully it shouldn't be difficult to separate the PEI from the glass if you heat it to 100 or 150C first. After that you can probably remove the remains of the adhesive with acetone.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

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WZ9V
The same servo logic required for a servo deployed micro switch will also support the BLTouch. It uses the servo input signal to trigger the deployment of the pin the same way as a r/c servo would be used to raise/lower a micro switch.

Yes, that's what I have read. But as I tried to explain before, we have never supported servo deployed probes in RRF because until two weeks ago nobody had expressed a desire to use one. There are too many good contactless types of probe available, as well as solutions that use the nozzle as the probe. Had the BLTouch used a simple deploy/retract signal wire that accepted 3.3V signal levels, the existing M558 or M42 support in RRF would have been sufficient. Which leads to another question: does the BLTouch control input accept 3.3V signal levels?

Edited 1 time(s). Last edit at 06/22/2016 03:11AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

I have not tried it at 3.3V or 5V yet.

I have one but its still in the box until I get my Delta back online. I guess I could try it with a spare RPi I have and let you know.

I've had nothing but trouble with FSR based nozzle probes. Don't know if it was my cursed machine or not. I'm rebuilding it with metal corners/carriages and dumping the FSR's in favor of trying a BLTouch. Thinking of dumping the wheels for linear rails but not sure about that yet.

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WZ9V
I have not tried it at 3.3V or 5V yet.

I have one but its still in the box until I get my Delta back online. I guess I could try it with a spare RPi I have and let you know.

I've had nothing but trouble with FSR based nozzle probes. Don't know if it was my cursed machine or not. I'm rebuilding it with metal corners/carriages and dumping the FSR's in favor of trying a BLTouch. Thinking of dumping the wheels for linear rails but not sure about that yet.

If it's a delta printer, then the most popular options seem to be my IR sensor, and FSRs. Any sensor on a delta that doesn't use the nozzle as the probe needs to be placed as close to the nozzle as possible, so that the relative heights of the nozzle and the probe change as little as possible if the effector tilts slightly as is moves in the XY plane. It's very hard to eliminate such tilt completely. That's why I designed my IR sensor to fit below the heatsink of the E3Dv6 hot end. I don't know how close you can get a BLTouch to the nozzle.

If you want advice on FSRs, several users seem to be getting good results with them, including user mhackney on the Google delta printer group. You might like to ask for advice there.

I have an outline design for an effector with a built-in strain gauge to detect contact between the nozzle and the bed, but before I turn it into a reality I need this hot end [deltaprintr.com] to be available in a 24V version.

As to wheeled carriages vs. linear rails, I have only used wheels and I have good results with them. I have the impression that linear rails may be better, but only if they are of high quality.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

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dc42
...but before I turn it into a reality I need this hot end [deltaprintr.com] to be available in a 24V version.

Hi dc42,

I have thought about using that hotend as well. I too have a 24V system with 0.9 stepper motors. I have recently upgraded the fans on my cyclops and 24V power supply to 12V Noctua fans. The sound reduction is extremely noticeable. Anyway, I think a DC-DC SSR and one of these that I am currently using to power the fans. Will this cause any problems with the hotend PID being routed through an SSR instead of directly controlled via the Duet?

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KeepGettingTexts

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dc42
...but before I turn it into a reality I need this hot end [deltaprintr.com] to be available in a 24V version.

Hi dc42,

I have thought about using that hotend as well. I too have a 24V system with 0.9 stepper motors. I have recently upgraded the fans on my cyclops and 24V power supply to 12V Noctua fans. The sound reduction is extremely noticeable. Anyway, I think a DC-DC SSR and one of these that I am currently using to power the fans. Will this cause any problems with the hotend PID being routed through an SSR instead of directly controlled via the Duet?

As long as the SSR can handle the 500Hz or 1000Hz PWM frequency - and most DC-DC SSRs should have no problem with that - there shouldn't be a problem. But you don't need to use an SSR, just connect the 12V hot end heater between your +12V supply and the E0- hot end heater terminal on the Duet.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Quote
dc42
The firmware on the Duet doesn't yet support servos. I don't recall anyone asking for it until about 3 weeks ago, probably because there are so many good contactless Z probe technologies available that nobody wanted to use the old servo-deployed microswitch type.

There is now an open issue about this, see [github.com]. Somebody has managed to get some degree of servo control by using the Fan 1 output and configuring suitable values for the frequency and PWM.

I don't have a BLTouch, and not only is is closed source, the manufacturer has applied for patents to protect it. This is completely the opposite of the spirit of RepRap. So supporting it will be a low priority for me, unless the manufacturer provides me with one for testing with and pays me a development fee. But unlike the BLTouch, RepRapFirmware is open source, so anyone can add support to it.

Edit/Clarification
Edit: I should stop posting when tired on ipad. I didn't notice the last post is 7 month old, and the state then is not the same as now.
DC42 clarifies in the post below, that BLTouch and servos are now supported.

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I Think that is a very closeminded and detrimental way of approaching new technological developments. You can argue that servo is old technology, but servo in the BLTouch package is a new way to utilize it. Regardless of whether it is open or closed source. I did not know it is closed source. Especially since it's easy to fin diagrams and you can find "copies" of it, which seems identical - I have one of each and can send you one DC42, if that will help supporting it?
The BLTouch is without a doubt the most popular sensor currently on the market. At least in Denmark and the circles I frequent online.

Just because a request haven't been issued before doesn't mean it shouldn't be considered. Seriously ALL the people I know and talk to either use or plan to use BLTouch. Not supporting this is going to keep all of these potential customers away, as they see greater utility in a super nice sensor than in a super nice controller.

I have used dc42 IR sensor, which is great in perfect lightning on some surfaces. When it's dark it doesn't work when LED in printer is on. Had to turn led off to make it work.
When I put on PEI - which can be easily done without bubbles, or by buying a 1 or 2mm PEI sheet to clip on, the IR doesn't work.

PEI is the most popular printsurface. Not just for enthusiasts, but for everyone. Heck. Prusa sells them as default bed now.

Boils down to it being self serving supporting BLTouch now, as it cuts out a huge part (the largest part) of all potential customers from buying Duet WiFi if BLTouch can't be used.
Odds are that some other interesting servo solutions is popping up in the future as well. Not to mention the many servo solution used on various CNC solutions.

I had planned to use BLTouch on my BeTrue3D Printer, where I have Duet WiFi and Duex5, and am sad to see, that it seems that I can't.

Edited 2 time(s). Last edit at 02/17/2017 04:13AM by dintid.

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My Designs on Thingiverse
YouTube channel containing a few 3D printing videos - they are videos for my Instructables, and mostly not standalone.
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dintid, until your post today the last post in this thread was 7 months old. A lot has changed since then. Servos are now supported in RRF, and there is a thread on the forum at duet3d.com on how to use bltouch with Duet.

Edited 2 time(s). Last edit at 02/16/2017 07:17PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

not to mention to whole forum dedicated to the duet.

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dc42
dintid, until your post today the last post in this thread was 7 months old. A lot has changed since then. Servos are now supported in RRF, and there is a thread on the forum at duet3d.com on how to use bltouch with Duet.

Sorry. Guess I should stop posting from ipad when tired! I really didn't notice the timestamp and only found this by googling BLTouch and Duet WiFi

Thank you for not taking it badly

I'll edit my post and make it clear

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dc42
not to mention to whole forum dedicated to the duet.

Yea, I know. It's awesome I just ended up here by googling the combination. I should have done a more thorough "investigation" into the subject!

When using Duex5 so can't use expansion header pins
What to do when using Duex5, so no access to header pins? In my ignorance, I thought we should use the "sensor" plug for the BLTouch (before searching).
I searched the forum and found this post on (among others), but do you know if there is a wiring diagram on how to hook up the servo part? Not just a description, but a diagram/image/photo.
[duet3d.com]

---

My Instructables - both total newbie instructables and some for intermediate users.
My Designs on Thingiverse
YouTube channel containing a few 3D printing videos - they are videos for my Instructables, and mostly not standalone.
Ultius / Tantillus Thingiverse Group