Nozzle Probing comes to BEACON

[mvdveer]

Thanks to @Pappy3831 for alerting me to this. All credit where it is due. 

Very exiting - nozzle probing coming to beacon probes - all software driven and backwards compatible with all beacon models. Much less force than TAP and basically auto-z functionality. It is apply named BEACON CONTACT and will be available early May through a software firmware update. Read press release here.

This might be enough reason for me to change to Beacon form cartographer. (But most likely cartographer might follow suite, unless their chip is not compatible. 

 

[claudermilk]

Well, that's very interesting.

[GabrielZ]

This is awesome.

[VoronManiac]

For me, the original Beacon is a non-starter because I use an FR4 surface for smooth surface prints, and I don't feel good about trying to guarantee the thickness variation of the FR4 sheet or the adhesive attach.

But this contact Beacon sounds very exciting!  The promo video shows the nozzle touching the object, and the release text says:

..." Our TrueZero technology is a low-force touch probing system that enables precise physical detection of the bed directly from the 3D printer’s nozzle. No moving parts, strain gauges, or switches required. 

Beacon Contact leverages Beacon’s ultra-high resolution induction measurements to precisely determine the exact point of contact between the nozzle and the bed, ensuring unparalleled accuracy."

Seems to me that something has to move or deflect.  Anybody have more insight as to what they are doing?

My latest 2.4 is using TAP, but I think I still prefer my oldest 2.4 which is using a Klicky because of the probe force and temperature restrictions of the TAP. 

Would have really been impressive if they probed the bacon in the video...

 

 

[Michel]

 

I am using the Cartographer because it can be connected to the CAN bus and it's half the price.

For hardware support, the Cartographer doesn't use the ADXL345. Instead, it uses an STM LIS2DW accelerometer, which includes the same feature called "tap detection" that triggers a hardware interrupt.

Tap detection is configurable for each axis, allowing you to set a threshold that determines when it triggers.

Beacon hasn't released the code yet, but I suspect tap detection is enabled with a threshold set slightly above the homing acceleration to achieve the desired 30g tap.

On the CAN bus, the threshold will likely be slightly higher due to the increased delay (less than 15ms) associated with multi-MCU homing.

 

edit:
On the other hand, in the video they're probing an egg BUT the egg is next to a pack of delicious kerriegold butter, the butter is wrapped in metallic foil and both times the probe is over it - that could mean they're actually using the eddy current sensor to somehow detect the tap

 

https://www.st.com/resource/en/application_note/an5038-lis2dw12-alwayson-3axis-accelerometer-stmicroelectronics.pdf

 

Edited April 17 by Michel

[GabrielZ]

@VoronManiac 

I also use a fr4 sheet. Isn't it flat enough? Have you ever had such issues with a sensor like this?

[VoronManiac]

@GabrielZ Seeing PCB FR4 thickness tolerances from board shops of +/-10%.   I am not seeing any specs for variation across the panel which is the problem.

I sourced my 0.3mm 350x350 FR4 from AliExpress ($10) and used 468MP (12"x12") adhesive that I had to splice.  Wish I could find bigger pieces, because the film tends to bunch up around the edges creating a small wave.  BTW the 0.3mm is on the thin side but have had good results with 0.8mm in the past.

Did you buy a pre-fabbed FR4 steel plate?  Last I checked, couldn't find a 350x350 pre-fabbed FR4. 

Do you use the FR4 bare?  I coat with Vision Miner Nano Polymer - amazing stuff if you get it hot enough.

 

[VoronManiac]

@Michel Welcome to the Forum!

The datasheet for the STM LIS2DW looks interesting.  Thanks for the heads up.  Digikey shows 16,792 in stock.  Cheap.  Min single tap trigger threshold is FS/32.

Max sample rate is 1.6kHz or 625usec.  It does not generate an event trigger until it passes the trigger threshold and then returns to baseline, so that is 2-3 samples min.  With printer.cfg:second_homing_speed 3mm/sec, that should put us in the 0.6um resolution range (single sample variation) similar to TAP (CAN bus latency variation aside which could be an over travel issue).

I've often wondered how long it takes Klipper to stop movement; or how much over travel it has once a probe event occurs.  What is max Z de-acceleration for probing?  For Voron TAP,there is beaucoup over travel so not an issue. Same with Klicky Probe.   In this case we have many msec of delay before movement is stopped and the probe is touching the bed surface which could be problematic.

Data sheet for this chip show it is only +85C which starts to be concern if it is mounted anywhere near a +120C bed.  (but so is the rest of the ABS head assembly).

One neat thing I guess you get with this chip is 3-axis end stop controls, and could replace sensorless homing for X and Y.

 

[GabrielZ]

@VoronManiac

This guy sells up to 500x500, assorted thickness. I got my 300x300x1.5 from them. The thickness was about 1.7, YMMV, but I got part of my money back. 

I use it raw with no issues! (pla and petg). No fancy colors tho.

Edited April 18 by GabrielZ

[Dirk]

16 hours ago, mvdveer said:

But most likely cartographer might follow suite, unless their chip is not compatible. 

All the eddy current sensors we have been talking about (beacon / idm / cartographer / BTT Eddy / Mellow Fly V3 / ForgotName-CANFD-RRF-Probe) have the same sensor. The one that measures the eddy current.

BTT Eddy and Mellow Fly v3 use Klippers software / firmware to function, while Beacon and Cartographer/IDM use their own firmware / software.

I have heard from the Cartographer people that they have been working on an auto-z already for a while and who knows their version even might be out before may. Still 2 weeks left, not?

[claudermilk]

17 hours ago, VoronManiac said:

Would have really been impressive if they probed the bacon in the video...

Right? I was waiting the entire video for them to probe the bacon. But no, it was just a tease. I guess they know everything is better with bacon, so it was just there to lend support and improve the whole thing.  Or maybe it was the videographer's lunch.

[VoronManiac]

For ANY direct contact nozzle probe, if there was a contact event signal that was instantaneously sent back to the MCU or even the PI, is there enough time for Klipper to shut down the Z stepper movement to prevent damage to the print surface? i.e. have to contend with the angular momentum of the steppers; Is there enough compliance in the Z belts?

@GabrielZ This is the FR4 Vendor I used; lots of different thicknesses.  You're at 300x300 so you can get by with readily available 12"x12" adhesive sheets .  But for me, the 350x350 is problematic because I only see 24" wide rolls for like $500. 

@Michel There's probably a companion micro interfacing to STM LIS2DW so we don't have to rely on the internal contact trigger functions of the sensor.

@Dirk The eddy current is not going to help us for direct contact? it gotta be something else - no?

[Dirk]

10 hours ago, VoronManiac said:

eddy current is not going to help us for direct contact? it gotta be something else - no?

No.

As I understand, the tap causes the z motor to slip, like with sensorless homing. And this slipping causes a disturbance in the current. Which is picked up by Eddy.

[mvdveer]

22 hours ago, claudermilk said:

to probe the bacon.

It's a beacon........ they forgot the e -  bacon 

[Pappy3831]

Good catch on the butter Michel. I’ll have to go back and watch it again.  And I think mvdeer is right about the missing e. Or when they started up they accidentally added an e to the name. Auto correct can be such a pain. 

[Penatr8tor]

I'm sooo tempted to buy another beacon probe and install it on my 2.4 I'm in the middle of refurbishing.

Decisions...

[TitusADuxass]

15 minutes ago, Penatr8tor said:

I'm sooo tempted to buy another beacon probe and install it on my 2.4 I'm in the middle of refurbishing.

Decisions...

So am I, but I want to try the microprobe first.

But, I also think my CNC TAP set up will take some beating.  Since I installed it and configured  KAMP, I never looked back.

[Penatr8tor]

59 minutes ago, TitusADuxass said:

So am I, but I want to try the microprobe first.

But, I also think my CNC TAP set up will take some beating.  Since I installed it and configured  KAMP, I never looked back.

As much as I want to get another Beacon... I'm too far along with my 2.4 toolhead upgrade. I'm using a Mellow CNC TAP on it and it will perform just as well as a Becon, just not as fast. And that's totally fine.

On your VzBoT build... I would 100% add a Beacon H to it. @mvdveer and I are both running Beacons and can attest to their performance. 

[claudermilk]

Yeah, I'm not in any hurry to replace Tap on the Trident. But if this could be somehow shoehorned into a Dragon Burner on a V0... 

[TitusADuxass]

7 minutes ago, Penatr8tor said:

On your VzBoT build... I would 100% add a Beacon H to it. @mvdveer and I are both running Beacons and can attest to their performance. 

Thanks, I'll add one to the shopping list.

[Penatr8tor]

29 minutes ago, TitusADuxass said:

Thanks, I'll add one to the shopping list.

I have an optimized cooling duct with Beacon mount you can download in my VZ330 build diary. 

[TitusADuxass]

17 minutes ago, Penatr8tor said:

I have an optimized cooling duct with Beacon mount you can download in my VZ330 build diary. 

Thanks I'll do that.

My biggest problem is getting one over here in Europe, there doesn't appear to be any dealers. I suppose Beacon will send me one and I'll have to pay the import duty.

[mvdveer]

7 hours ago, TitusADuxass said:

My biggest problem is getting one over here in Europe,

Same her in Australia - the locally available probes are double the price than those of the US ones including postage. All it needs is patience. So I normally order "hobby bulk" to save on postage - but then I am fortunate to do that, not everyone is.

[Dirk]

8 hours ago, TitusADuxass said:

there doesn't appear to be any dealers.

If you are really convinced in what these old people say about 'American-muscle' being the best in the world, please go ahead and order an all American made (yea, sure - Alles made in China) Beacon H for about twice, and in the case of an import to the EU, for three times the price of a Cartographer, with the same functionality. -Sorry... Carto has a probe accuracy of 0.003 against 0.001 of Beacon. 

There is a EU reseller,(from Delft-NL) where you do not have to pay import costs, for only 100 euros... I bought my first fully functional printer (Sidewinder X2 for 250 euros).

If you want to give Cartographer a try, you can get it from MeltBro. A German online shop. You can also check out the Carto site which now also has the version 4, with the ADXL chip. I think the price will be less than Meltbro, but it will take a week longer.

 

 

[TitusADuxass]

10 hours ago, Dirk said:

If you are really convinced in what these old people say about 'American-muscle' being the best in the world, please go ahead and order an all American made (yea, sure - Alles made in China) Beacon H for about twice, and in the case of an import to the EU, for three times the price of a Cartographer, with the same functionality. -Sorry... Carto has a probe accuracy of 0.003 against 0.001 of Beacon. 

There is a EU reseller,(from Delft-NL) where you do not have to pay import costs, for only 100 euros... I bought my first fully functional printer (Sidewinder X2 for 250 euros).

If you want to give Cartographer a try, you can get it from MeltBro. A German online shop. You can also check out the Carto site which now also has the version 4, with the ADXL chip. I think the price will be less than Meltbro, but it will take a week longer.

Thanks for the links @Dirk

I ordered one from the Carto site, I won't order anything further from MeltBro. I tried them once for some printed TAP parts and the quality was Scheiß.

Edited April 20 by TitusADuxass