Best Sensor for ABL

Quote
dc42

What sort of printer do you have? If it's a delta, you need a sensor that has low mass and can be placed very close to the nozzle.

Yes, it's a delta (Kossel mini).

Very well, what do you suggest, bearing in mind that I can't use your sensor due to not wanting to remove the existing PEI sheet on my bed?

Quote
nebbian

Quote
dc42

What sort of printer do you have? If it's a delta, you need a sensor that has low mass and can be placed very close to the nozzle.

Yes, it's a delta (Kossel mini).

Very well, what do you suggest, bearing in mind that I can't use your sensor due to not wanting to remove the existing PEI sheet on my bed?

I suggest you do remove the PEI sheet. If you heat the bed up then I suspect you will be able to prise the PEI off without damaging it, using a palette knife or similar tool, but you will need a new sheet of adhesive.

Other types of sensor that are popular deltas are FSRs under the bed mounts, or an FSR in the nozzle mount. Using the nozzle itself as the probe eliminates the effect of effector tilt on the probe trigger height, which is a good thing. The disadvantage is that probing with the nozzle hot may damage the bed surface. I believe PEI is claimed to be heat resistant to 200C, so you could preheat the bed, preheat the nozzle to 180C or so, then probe, then continue heating the nozzle to printing temperature.

I haven't used FSRs myself, but from what I have read:

1. If using FSRs under the bed mounts, you need to protect the FSRs from the bed heat. There are FSR mount designs that achieve this.

2. It's best to use JohnSL's trinket board to interface the FSRs to the electronics - although if using electronics with an analog Z probe input such as the Duet, this may be less important.

---

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].

Ah right. Correct me if I'm wrong, but all those solutions aren't easy to retrofit to a production printer with minimal downtime.

A BLTouch it is then! Thanks for confirming it

Quote
nebbian
Ah right. Correct me if I'm wrong, but all those solutions aren't easy to retrofit to a production printer with minimal downtime.

A BLTouch it is then! Thanks for confirming it

I would have thought that something as large as the bltouch would not be easy to retrofit to a delta printer - but I don't know your printer. Anyway, good luck with it!

---

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].

[plus.google.com]

As you can see, there are several examples shown of BLTOUCH on Kossel printers.

Here is where you can get them on EBay > [www.ebay.com]

You can also send Charles $33 via PayPal, as I did, along with a simple letter which he outlines and you'll have it in about 2 weeks.

''Hello, everyone who are interested in BLTouch!

Now, we can sell 100 items per a month on e-Bay
But it still always sold out quickly.

If you want to order through PayPal, please send us an e-mail including 1.quantity, 2.shipping type, 3.your name, 4.address, 5.zip code, and 6.phone number.

BLTouch Price : $28 / ea
Shipping Price : Standard Int'l Shipping - $5 (5 - 20 days)
or Expedited Int'l Shipping - $23 (1-4 business days)

E-mail & PayPal Account : antclabs@gmail.com

Also you can track your package on this site!
→ [www.17track.net]

Thank you!
ANTCLABS (A&T - BLTouch Team)''

from > [plus.google.com]

---

Folger Tech 2020 i3 and FT-5 as well as modified JGAurora A5 with direct drive E3D/Titan. All running the BLTOUCH.
Great kits. Having fun and running the heck out of them.
Running Marlin 1.1.0 RC8 on the i3 and FT5. Custom firmware on A5.
Folger Tech Wiki board >[folgertech.wikia.com]

I just asked the seller how heavy the BLTouch is, and the reply was 10 grams.

For interest's sake, I weighed my kossel mini's useless Z probe, including allen key, switch and mounting bolts. 13 grams. And that's for something that is difficult to set up, has poor repeatability, and never really seemed to work properly.

I ordered my BlTouch off of Ebay. After it showed shipped I get a email from ebay/seller saying that they have refunded me $5 since they changed the price. I've NEVER HAD THAT HAPPEN BEFORE!!!

Kudos to those guys. I got mine in about 2 weeks, maybe less as well. I will be ordering a backup. I love it!!


Ernie

Quote
nebbian
I just asked the seller how heavy the BLTouch is, and the reply was 10 grams.

For interest's sake, I weighed my kossel mini's useless Z probe, including allen key, switch and mounting bolts. 13 grams. And that's for something that is difficult to set up, has poor repeatability, and never really seemed to work properly.

AND the BLTOUCH is tiny compared to those proximity sensors.

---

Folger Tech 2020 i3 and FT-5 as well as modified JGAurora A5 with direct drive E3D/Titan. All running the BLTOUCH.
Great kits. Having fun and running the heck out of them.
Running Marlin 1.1.0 RC8 on the i3 and FT5. Custom firmware on A5.
Folger Tech Wiki board >[folgertech.wikia.com]

I received my BLTouch recently, and have been setting it up. It seems to draw a bit of current when drawing the rod upwards after sensing a touch, it almost overloads the tiny little 5V regulator on the RAMPS board. I might add the recommended separate regulator for the servo lines, it won't be hard to do.
As I just wanted to get it working last night, I added a 220 uF cap across the 5V and ground terminals near the BLTouch, and it seems to be working really well. Repeatability is within 0.02mm, which is way more than I need for the first layer.

Thanks to all for the advice, I'm really happy with this sensor. What a nice piece of kit

Edited 1 time(s). Last edit at 04/15/2016 12:22AM by nebbian.

I wouldn't use any system which touches the bed with the hot nozzle. These systems are unsuitable for some print surfaces and also for a dual nozzle setup. Capacitve proximity switches may depend on (bed) temperatures and humidity.
BLTouch is not directly supported by my controller board.
I have a similiar optical sensor like the one from PiBot except I get a direct value for a height instead of an on/ off signal. However this system is very bad and differs in height readings nearly every time. It is dependant from the bed surface and temperature for example. If the bed is not preleveled well ABL does not work good with this sensor.
I changed to the Mini height sensor from dc42. This is very accurate and I got similiar settings like a system with direct nozzle touch, but it is touchfree which I prefer.
I will also use one of these boards for my own printer design. However the biggest disadvantage is the price for this part, but at least it is the best option in my eyes.

---

Slicer: Simplify3D 4.0; sometimes CraftWare 1.14 or Cura 2.7
Delta with Duet-WiFi, FW: 1.20.1RC2; mini-sensor board by dc42 for auto-leveling
Ormerod common modifications: Mini-sensor board by dc42, aluminum X-arm, 0.4 mm nozzle E3D like, 2nd fan, Z stepper nut M5 x 15, Herringbone gears, Z-axis bearing at top, spring loaded extruder with pneumatic fitting, Y belt axis tensioner
Ormerod 2: FW: 1.19-dc42 on Duet-WiFi. own build, modifications: GT2-belts, silicone heat-bed, different motors and so on. Printed parts: bed support, (PSU holder) and Y-feet.
Ormerod 1: FW: 1.15c-dc42 on 1k Duet-Board. Modifications: Aluminium bed-support, (nearly) all parts reprinted in PLA/ ABS, and so on.

Quote

I wouldn't use any system which touches the bed with the hot nozzle. These systems are unsuitable for some print surfaces and also for a dual nozzle setup.

Hi Treito, what issue do you see with dual nozzles for nozzle-bed contact? The advantage of a direct contact system is that you don't need any additional setup to allow for the nozzle to probe offset. I change hotends a lot so I plan on using a piezo based nozzle-bed contact system specifically so that I don't have to manually re-check my Z=0 calibration after each change, but it's a dual extruder setup and you have me wondering if I have overlooked something.

Quote
Treito
I wouldn't use any system which touches the bed with the hot nozzle. These systems are unsuitable for some print surfaces and also for a dual nozzle setup. Capacitve proximity switches may depend on (bed) temperatures and humidity.
BLTouch is not directly supported by my controller board.
I have a similiar optical sensor like the one from PiBot except I get a direct value for a height instead of an on/ off signal. However this system is very bad and differs in height readings nearly every time. It is dependant from the bed surface and temperature for example. If the bed is not preleveled well ABL does not work good with this sensor.
I changed to the Mini height sensor from dc42. This is very accurate and I got similiar settings like a system with direct nozzle touch, but it is touchfree which I prefer.
I will also use one of these boards for my own printer design. However the biggest disadvantage is the price for this part, but at least it is the best option in my eyes.

If your board supports a servo style ABL, then it supports the BLTOUCH.

NOTE:: If you go to ANTCLABS on Google +, you will see that they have layouts on how to hook up the BLTOUCH to just about every board! [plus.google.com]

Also, For those of us using a BLTOUCH for ABL, if you get a red flashing light on the sensor when you first start up, put the following lines at the very beginning of your Start GCode in your slicer:

M280 P0 S160
G4 P5000 : wait for alarm reset to clear
M280 P0 S90 ;pin up

This will reset your BLTOUCH and give it time to do it. It wouldn't work for me without the G4 command. 5 Seconds seems too long but it works! The pin up command makes sure it's up before making the first move anywhere.

Edited 2 time(s). Last edit at 04/15/2016 04:40PM by tjnamtiw.

---

Folger Tech 2020 i3 and FT-5 as well as modified JGAurora A5 with direct drive E3D/Titan. All running the BLTOUCH.
Great kits. Having fun and running the heck out of them.
Running Marlin 1.1.0 RC8 on the i3 and FT5. Custom firmware on A5.
Folger Tech Wiki board >[folgertech.wikia.com]

Quote
JamesK
Hi Treito, what issue do you see with dual nozzles for nozzle-bed contact? The advantage of a direct contact system is that you don't need any additional setup to allow for the nozzle to probe offset. I change hotends a lot so I plan on using a piezo based nozzle-bed contact system specifically so that I don't have to manually re-check my Z=0 calibration after each change, but it's a dual extruder setup and you have me wondering if I have overlooked something.

Very simply. Regarding the kind of wrong leveling one nozzle will touch the board first, but you will never know for sure which one until you tested it. My current design for my new printer has a nozzle offset of 26mm so an accurate leveling would be impossible. The only option would be BLTouch, which is incompatible with the standard-firmware of my Duet-Board.

Quote
tjnamtiw
If your board supports a servo style ABL, then it supports the BLTOUCH.

There is no support with the firmware of the Duet 0.6 and 0.85. As far as I know there is even a problem with the Pin-headers for the 0.6-version.

But that's no problem. The Mini-height-sensor-board from dc42 is accurate enough that I decided to use this. I compared this board to a mechanical direct bed touching system with a good microswitch and the result where the same except that the wire of the heater cartridge broke because of the small movement of <1.5mm with every touch. So for me there would be no advantage in accuracy.
The BLTouch is not very cheap. For that price model I would expect a small microcontroller which costs less than 1$. This MC could provide the desired signals so you could nearly use it for every printer board.
But why? I am very happy with that touchless system. dc42 uses a design which allows him very high accuracy with a non-standard optical sensor setup and a microcontroller itself. So his board really works with every board, regardless is the board needs an analog or digital signal. I often resisted against this board especially because of the price, but now I am really happy with it.

---

Slicer: Simplify3D 4.0; sometimes CraftWare 1.14 or Cura 2.7
Delta with Duet-WiFi, FW: 1.20.1RC2; mini-sensor board by dc42 for auto-leveling
Ormerod common modifications: Mini-sensor board by dc42, aluminum X-arm, 0.4 mm nozzle E3D like, 2nd fan, Z stepper nut M5 x 15, Herringbone gears, Z-axis bearing at top, spring loaded extruder with pneumatic fitting, Y belt axis tensioner
Ormerod 2: FW: 1.19-dc42 on Duet-WiFi. own build, modifications: GT2-belts, silicone heat-bed, different motors and so on. Printed parts: bed support, (PSU holder) and Y-feet.
Ormerod 1: FW: 1.15c-dc42 on 1k Duet-Board. Modifications: Aluminium bed-support, (nearly) all parts reprinted in PLA/ ABS, and so on.