Beacon Contact

[mvdveer]

9 hours ago, Penatr8tor said:

My final thoughts are... Total game changer!

Great explanation and I agree - a Game changer. Have not looked back since using this on the VZBot and Micron. Now only to get the time to fit the others.

[Penatr8tor]

10 hours ago, mvdveer said:

Great explanation and I agree - a Game changer. Have not looked back since using this on the VZBot and Micron. Now only to get the time to fit the others.

Agree back at ya! 

I just don't see anything thing trumping this tech anytime soon and things like TAP and inductive probes are rendered obsolete. Who wants to poke the plate with a clunky electro/mechanical switch on a heavy slide when you can float over the entire bed surface at ~500mm/s, and it has an ADXL on it. No heavy moving parts, no attaching an ADXL and running a cable to resonance test with a board and cable you're going to remove as soon as you're done. It's all combined on a little wing shaped PCB that only weighs a couple grams. What was it that Elon said... The best part is no part.

In a way I feel sorry for the guys that did all the work on Voron TAP. I remember the hype and the live stream they did... it wasn't that long ago. So, again... A real game changer. Now we need a CAN/toolhead board that you can plug the Beacon into instead of running a long cable. Probably by the end of the year, the people in Asia react pretty quickly to shifts in technology.

[TitusADuxass]

So I had a play with Beacon Contact today, wow!!

I get a few "Sample spread too large" errors, so I need to do some research on that.

But here's how good it is on my VzBot, 100 x 20x20 0.25 thick first layer patches.

The ones at the front look strange but its just down to the light. They're all near perfect.

[Penatr8tor]

20 hours ago, TitusADuxass said:

So I had a play with Beacon Contact today, wow!!

I get a few "Sample spread too large" errors, so I need to do some research on that.

But here's how good it is on my VzBot, 100 x 20x20 0.25 thick first layer patches.

The ones at the front look strange but its just down to the light. They're all near perfect.

They look beautiful. Game changer 100%.

[TitusADuxass]

23 hours ago, Penatr8tor said:

They look beautiful. Game changer 100%.

Unfortunately, repeating that print, in fact trying to print anything is impossible at the moment.

Beacon keeps returing Sample spread too large (sometimes it's down to 0.001 but it's a no go).

I cleaned and regreased everything. 

What I have seen is that when beacon is being calibrated, the bed overshoots and pushes the toolhead up. It's a very small amount but it does move the toolhead.

This movement probably accounts for the spread of errors, through the 3-4 probing attempts it can range from 0,0081 to 0.034 - 0.008 is the cutoff - this is stupidly fine.

[Penatr8tor]

55 minutes ago, TitusADuxass said:

Beacon keeps returing Sample spread too large (sometimes it's down to 0.001 but it's a no go).

The only thing I can think of checking would be the height of the beacon from the surface of the bed. There's not a really big range of functionality for the unit, 2.6mm to 3mm from board to the tip of the nozzle.

Unlike other toolheads, the Vzbot cooling horns position is dependent on where you decided it should be during the build. I was unsure when I built mine, so I did a check on the CAD model and set mine so that the bottom of the horns was 1mm - 1.5mm from the tip. My thinking is that since the Beacon is mounted to the horns... it's possible to mount it too far away from the nozzle tip to get accurate readings. I'm just thinking out loud here because this is an issue that hasn't come up yet and trying to fish for a potential solution for you so, lightly pinch a 123 block between the nozzle and bed and measure the distance from the Beacon PCB to the 123 block. I'm totally guessing here but, maybe you're just out of range and moving the horns down 0.5mm is all it needs.

 

 

 

[TitusADuxass]

13 hours ago, Penatr8tor said:

The only thing I can think of checking would be the height of the beacon from the surface of the bed. There's not a really big range of functionality for the unit, 2.6mm to 3mm from board to the tip of the nozzle.

Unlike other toolheads, the Vzbot cooling horns position is dependent on where you decided it should be during the build. I was unsure when I built mine, so I did a check on the CAD model and set mine so that the bottom of the horns was 1mm - 1.5mm from the tip. My thinking is that since the Beacon is mounted to the horns... it's possible to mount it too far away from the nozzle tip to get accurate readings. I'm just thinking out loud here because this is an issue that hasn't come up yet and trying to fish for a potential solution for you so, lightly pinch a 123 block between the nozzle and bed and measure the distance from the Beacon PCB to the 123 block. I'm totally guessing here but, maybe you're just out of range and moving the horns down 0.5mm is all it needs.

That's probably where the problem is, I'm sure that it's over 5 mm from bed to Beacon.

[TitusADuxass]

Well that was a serious Senior Moment - I've been looking at the ducts and nozzle and thinking that's not right!

Dropped the duct to approx 1 mm above the nozzle (thanks @Penatr8tor and everything is working again.

 

[Penatr8tor]

3 hours ago, TitusADuxass said:

Well that was a serious Senior Moment - I've been looking at the ducts and nozzle and thinking that's not right!

Dropped the duct to approx 1 mm above the nozzle (thanks @Penatr8tor and everything is working again.

You are most welcome @TitusADuxass. I'm glad it was a problem that was easily solved. I wonder if that was also the problem you had with the Cartographer probe.

[TitusADuxass]

25 minutes ago, Penatr8tor said:

I wonder if that was also the problem you had with the Cartographer probe.

It could have been, I'm not about to swap out the Beacon to find out.

What I do need is a nozzle wiper, any ooze and you get false readings from Beacon. I have some of the silicone  rollers from Bambulab. But I quite like the look of the those silicon pads.

[TitusADuxass]

I've ordered some of those silicone pads and am going to adapt this - https://www.printables.com/model/327641-vzbot-nozzle-brush-and-purge-bucket

[Penatr8tor]

16 minutes ago, TitusADuxass said:

What I do need is a nozzle wiper, any ooze and you get false readings from Beacon.

Definitely a valid concern. I'm super anal about making sure the tip has no ooze before printing.

I learned something very interesting on the RatRig RatOS 2.0 install I did last week. With RatOS, everything is pretty much what they've implemented and there's not a lot of changing you can do, if any at all. Sounds like you're locked in I know but, they've done an excellent job of eliminating most of the issues and have some very clever solutions. For example, the prime blob is one of them, which I felt was worth adapting to my VzBot. So, when I did my first few test prints on the RatRig... in the startup sequence there is a step that I noticed and later realize was pretty clever. Startup is as follows:

1. Home XY. Z is homed using the proximity method.

2. Move Z to 2mm. Heat bed to printing temp, heat nozzle to 150c. This lets the Beacon heat soak a little per the Beacon recommendations.

3. Move to wipe location. X5 Y5 Z5

4. Home Z using contact method.

5. Move Z to 0.1mm above bed and move along X to wipe any ooze from the tip.

6. Move back to center of bed and home Z with contact method again.

7. Scan bed

8. Prime

9. Print

Interesting right?

Here's some of their code fragments to help understand how they do it.

This is the move to wipe location code

[gcode_macro _START_PRINT_AFTER_HEATING_BED_PROBE_FOR_WIPE]
gcode:
	# config
	{% set speed = printer["gcode_macro RatOS"].macro_travel_speed|float * 60 %}
	{% set z_speed = printer["gcode_macro RatOS"].macro_z_speed|float * 60 %}

	# move to wipe position
	G0 Z5 F{z_speed}
	G0 X5 Y5 F{speed}

	# probe at wipe position
	PROBE PROBE_METHOD=contact SAMPLES=1
	BEACON_QUERY

To create your own "Wipe" macro. Just use the move and probe sections. The BEACON_QUERY I'm guessing, is to check that the probing didn't fail so you don't dig a groove into your PEI sheet.

This next section is the wipe

# wipe before z-calibration
	{% if beacon_contact_wipe_before_calibrate %}
		{% if printer.beacon.last_probe_result|lower == "ok" %}
			{% set last_z_offset = printer.beacon.last_z_result %}
			RATOS_ECHO MSG="Auto calibration nozzle wipe with probe result {last_z_offset}..."
			G0 Z{(0.1 + last_z_offset)} F{z_speed}
			G0 X20 F300
		{% else %}
			RATOS_ECHO MSG="Skipping auto calibration nozzle wipe because probing failed!"
		{% endif %}
	{% endif %}

Here you only need the G0 Z{(0.1 + last_z_offset)} F{z_speed} and the G0 X20 F300 lines. Obviously, there's a good amount of error detection/mitigation in their code but, since we're adapting it for a single printer... we can just hard code the offset distance (for thermal expansion) and speed for the G0 Z line.

They also have a new faster prime blob but, that's another post. 

So, Yeah... The RatRig guys are wiping by skimming over the bed surface to knock off any ooze. And I'm assuming that the 150c tip temp is warm enough to soften the plastic enough to overcome the probing force, allowing the melt to push up into the nozzle as long as the bulk of the ooze has been knocked off. I haven't tried printing something with dried ooze on the tip to test if this works yet. I guess I'll try that today and let you know.

[Penatr8tor]

OK so, I did an experiment... And like most experiments, the result is not quite what I expected.  But also not bad.

Here's the test setup... Cold nozzle and bed with ooze from last print with a good 30mm protruding from the tip.

 

The rest of the test I recorded. This will let you examine the RatOS startup procedure. I only paused the recording once, so we don't have to wait for the bed to heat up.

As you can see from the video... the long strand of ooze remained on the nozzle all the way up to the prime blob which pretty much trapped all of the ooze. 

But what about the 1st layer?

I pulled the skirt and measured the thickness... 0.21mm all the way around. Prime blob grabbed all the ooze and the bottom surface of the cube looks good. Everything was still stuck nicely after cooling to ~45c. At ambient it would pop off easily. Bed had no glue or Magigoo, just soap & water wash a few days ago and a quick alcohol wipe prior to running the print. I did get a little strand of ooze that diagonally crossed under the part that might be an issue if you're using the 1st layer as a cosmetic surface but overall... while not perfect it did print as expected even with 30mm of ooze hanging. I suspect that a small curl might pop off completely but ya really never know what half melted plastic ooze is going to do.

I will probably try to create some sort of RatOS like wipe for the Vzbot and I also would like to refine the startup sequence and implement the new faster prime blob on the old VZ.

[TitusADuxass]

This just another big thumbs up for Beacon.

I have a new build plate and wanted to test it out.

I printed once on the carbon fibre pattern side and once on the textured side.

I didn't do any tuning or recalibrating I just put the plate on, printed, flipped the plate and printed again.

Carbon Fibre

(my thumb's there to mask the LED.

Textured

There is a tiny bit of elephant's footing that I could tune out.