Mini differential IR height sensor board

Quote
Fpex
Are they compatible with the duet 0.85 and can be used in a larger effector mounting a kraken?

Yes, they are compatible with Duet 0.8.5, Duet 0.6, Arduino/RAMPS, and most other electronics. For Smoothieboard you need to change a resistor, or add a pulldown resistor.

It would be up to you to design a mount for use with a Kraken.

Quote
Fpex
Do you know if it works on carbon fiber also?

I have just tried it on a carbon fibre sheet, and it works. However, the sheet I have has a distinct pattern, and the trigger height varies slightly (maybe by 0.1mm, it's hard to say) depending on which part of the pattern the sensor is over.

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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].

Mmmm .... maybe i should just get a round plate instead of the carbon fibre for my kossel.

For the effector, the question is more about the fact that the sensor will be somewhat more on the side than in, let's say, a riprap head. Not by much, but a little bit as the effector will be somewhat larger than a traditional one (more like the SeeMECNC one).

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Quote
Fpex
For the effector, the question is more about the fact that the sensor will be somewhat more on the side than in, let's say, a riprap head. Not by much, but a little bit as the effector will be somewhat larger than a traditional one (more like the SeeMECNC one).

The farther the sensor is from the effector, the more the trigger height will be affected by any tilting of the effector as it moved in the XY plane. But with a Kraken, you will already have a big problem if there is even a tiny amount of tilt, because the non-printing nozzles will foul the print.

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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 know I know.

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----- Making the world smarter @ www.xetal.eu
----- Helping entrepreneurs @ www.fralke.com

Forgive me for asking, and slap me if I'm missing something obvious here...

I'm using a Cartesian style printer with Repeater firmware on Ramps. The IR probe is mounted -35mm to the left of the nozzle on the X and inline on the Y. With the nozzle paper height above the glass bed, the bottom of the board is 1mm about the bed (rested it on a 1mm spacer and tightened up the mount). After sending the G92 Z0 to capture the 0 position, the LED turns off after raising the Z 1.75mm.

So parameters plugged into firmware are offsets of -35X, 0Y and probe height of 1.75mm.

Run the auto level map and everything looks good, start a print and nozzle starts about 1.5-2mm (eyeballed...) above the glass. What am I missing here? Feel like it's something obvious that I just am not seeing.

Startup Gcode is:

G28; home all axes
G1 Z5 F5000; Raise nozzle
G32 S2; run z-proble
M109 S208; Heat to first layer temp
G1 F5000 X200 Y169 Z1; Move print head to center and lower to first layer height

Thanks!

- Chris

Edited 2 time(s). Last edit at 09/09/2015 02:39AM by crussty.

Hi Chris, it sounds to me that your firmware isn't recognising when the sensor is and isn't triggered. Some suggestions:

1. Check that you have the output wire connected correctly. For RAMPS/Marlin of a delta it is typically connected to the Z_MIN endstop connector, although if you have a real Z min endstop switch on your Cartesian printer then I guess it goes somewhere else. See Z_PROBE_PIN in [www.repetier.com].

2. Check that after power up, the LED flashes twice. If it flashes four times, then either the output is connected to the wrong pin, or you don't have the pullup resistor enabled for that pin. See Z_PROBE_PULLUP.

3. Use the M116 command to check that the firmware sees the Z probe as triggered when the LED is on, and not triggered when it is off.

4. For best accuracy, measure the trigger height with the probe descending, not rising.

HTH David

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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].

Hi David,
1 & 2 verified as correct (wiring wise and 2 flashes at least). I am wired into the Z-min end stop and the end stop has been disabled in firmware. My understanding is the probe acts as/replaces the end Stop?

3. Assuming you mean M119? Verified that with M119 the probe shows L when raised and H when at triggered height (1.75mm).

4. Are you suggesting after finding paper height off the bed, flagging this as 0, running probe up to 5mm or so so it disengages then bringing back down to find trigger height?

Thanks for the help!

3. Sorry, yes I did mean M119.

4. Yes.

My guess is that when you run G28, the firmware is assuming that you have a Z min switch that triggers at Z=0. Is there a way to configure Repetier to tell it that you are using a Z probe and no Z min switch? If not, is there a way to tell it that the Z min switch triggers at 1.75mm height?

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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 agree and think that is what is going on. I have it set now so that Repeater thinks that there is no Z Min so it's defaulting to using the Probe. I'm trying to figure out a way to get it to offset the Z Min height to -1.75. To It's credit, the probe triggers spot on every time...

I may end up having to move the probe to Z Max pins and put the Z Min back on but shouldn't have to do that. Never easy this journey of ours...

- Chris

I found this question [forum.repetier.com] which seems to describe a related issue (Z homing using a Z probe).

Edited 1 time(s). Last edit at 09/09/2015 01:58PM 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 sounds similar. I think this is either a bug in Repetier or I'm missing something obvious. Watching the logs doing dry runs, I have been able to confirm that when it moves to the center to start print, the head stops dropping when the probe triggers and not at the probe + offset level. But back to the day job for now, this will have to wait until this evening I'm afraid.

I will throw a post up on the Repetier forum this evening to see if they can offer some insight and let you know what turns up. Man, I cannot wait for Christmas so I can move on to a Duet or Smoothie board...

David, I do appreciate you help on getting this working! If anyone ever says you don't support you products, send them my way and I'll put them straight!

- Chris

Thanks for your kind comments.

Just a thought: what does Repetier do when you send G30? In RepRapFirmware it lowers the probe until it triggers, then sets the Z height to the probe trigger height. If Repetier does the same, you could use it to set the Z height at the start of a print.

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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].

Hi David, this is a pretty clever little sensor you've created! I have equivalent parts on hand and was looking to play around with this on my perpetually-under-construction corexy bot. Would it be too much to ask for you to share the spacing of your IR emitters? Just eyeballing it, it looks like D2 is 0.05" lower and 0.15" to the right of D1? If you don't want this to be public knowledge I can delete the content of this post.

I've been enjoying this a great deal.

I'd like to try and run the repeatibility test but can't seem to figure out how to trigger the g-code command: M48

[reprap.org]

Can anyone give some advise on why I can't run this? I'm running a slightly older version of marlin.

Also at what point is the "sense" point? IE for the probe offset, is it between the IR sensors and the led's or at the IR sensor?

Not that a few mm makes a huge difference, just curious if that was known.

The sense point is approximately below the large capacitor, and inline with the lenses on the IR LEDs and phototransistor.

When using the sensor to calibrate a delta printer, the probe offset is not relevant, because the calibration model needs to know the position of the head and it assumes that the bed is flat.

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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].

First a Duet 0.8.5 and now this... curse it all! Ordered from Filastruder since it's a bit closer than the Isles... thanks!

Finally got to the point where I could Mount and test one of my mini heigh sensors on my custom-fan-shroud for my UM2 clone Carriage
First test of Mini height sensor on UM2 clone

Good evening.
I use mega2560, RAMPS1.4 and Marlin1.1RC

For me - enabling / disabling of pullup resistor in firmware for Z endstop does not work - all the time LED is flashing 4 times, when powered by ATX or by USB
though, it has not a real problem because firmware recognize that sensor triggered.

But I have a problem:
About 50%(approximately) times the sensor has fails: the LED lights very very dim and the sensor is not triggered at all.

Earlier, when I used the servo for bed leveling it happened something like that, but servo jitter. The solution was in firmware option:
------
// With this option servos are powered only during movement, then turned off to prevent jitter.
// # define DEACTIVATE_SERVOS_AFTER_MOVE
------

but the IR sensor required 4 seconds to initialize, so that solution it is not possible, how to fix it?
Maybe 5V from ATX power supply helps?

I'm sorry to hear you are having problems getting the sensor to work correctly.

If the LED is lighting up very dimly, that suggests that there is no 5V power to the board and the LED is being lit by the current through the pullup resistor. So I think there is an intermittent connection in the 5V power. I suggest you start by checking the crimp pin connections at both ends of the wire carrying 5V power from the RAMPS to the sensor. With the sensor low enough so that the LED is lit, see if you can make it go dim by wiggling the cable. Also check that you have properly soldered the 3-pin connector to the board and you don't have a dry joint on the Vcc pin.

If none of the above resolves the problem, send me a PM and I will arrange to replace the sensor.

If the LED flashes four times but the pullup resistor is definitely enabled in your firmware, that suggests that the Arduino is taking longer than 4 seconds to initialize and enable the pullup resistor, or that the 5V power is rising very slowly. I have only one other report of this happening. A possible fix is to add a permanent pullup resistor between the Out pin of the sensor and +5V. Any value resistor in the range 10K to 120K will do.

HTH David

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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].

After replacing wires and connectors, cleaning pins with sandpaper, etc - the problem seems to be solved. I will test sensor 1-2 weeks and reply if some problem appear.
Thank you for advices.


ps
I also checked that when sensor is connected to the already loaded Arduino - the LED blinks twice. Maybe you can take this into account in the next revisions of your wonderful sensor.

Quote
abuharsky
After replacing wires and connectors, cleaning pins with sandpaper, etc - the problem seems to be solved. I will test sensor 1-2 weeks and reply if some problem appear.
Thank you for advices.


ps
I also checked that when sensor is connected to the already loaded Arduino - the LED blinks twice. Maybe you can take this into account in the next revisions of your wonderful sensor.

I'm glad you got it working. If you have a multimeter, what would be really helpful to me is if you could disconnect the sensor, and connect your multimeter in place of the sensor Out and Gnd connections. Then turn on the power, and time how long it takes before the meter reading stops being zero. That will tell me how long the sensor needs to wait before checking whether the pullup is enabled. In my tests with RAMPS/Marlin, 4 seconds was enough, but evidently your configuration takes longer.

Edited 1 time(s). Last edit at 01/06/2016 07:37PM 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].

Quote
dc42
I'm glad you got it working. If you have a multimeter, what would be really helpful to me is if you could disconnect the sensor, and connect your multimeter in place of the sensor Out and Gnd connections. Then turn on the power, and time how long it takes before the meter reading stops being zero. That will tell me how long the sensor needs to wait before checking whether the pullup is enabled. In my tests with RAMPS/Marlin, 4 seconds was enough, but evidently your configuration takes longer.

I am so sorry, but it is not possible to make for you any checks at this moment: I am on working trip. when I am go back to home, I will make for you this work.

Hi David,
I am installing one of your sensors on my mini kossel, with a ramps 1.4 board. Is there any thing I need to do in the software other than checking if the pullups are enabled? I was wondering if I have to tell the software to use the endstop for the sensor, or if it does that anyway. The printer is one from think3d which is where I got your sensor from. Sorry but not that familiar with arduino code other than calibrating the printer
Thanks.

Edited 2 time(s). Last edit at 01/09/2016 05:35AM by Wavy Davy.

If it's a R1 or R2 Mini Kossel from T3P3, then the firmware they provide for Arduino/RAMPS is already configured to support the normally-closed microswitch Z-probe they supplied with the kit. You don't need to change the configuration from that, other than to adjust the Z probe trigger height and XY offset from the nozzle.

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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].

Thanks David, yes its a R1.

Hi David,

I'm about to buy the sensor. It would work well in a classic black (not red) pcb heat bed with a 3mm glass ?

Thankyou!

Yes, it should work fine with 3mm glass on top of a black PCB. Please place your order here [escher3d.com].

Edited 1 time(s). Last edit at 01/14/2016 03:47AM 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].

hello david i'm just about to buy one of your sensors to go with a duet 0.6, ive got a 3dr with a purple pcb heat bed with 3mm glass will it work fine with that or is there sth else i need to do like paint the glass?

i did send a pm to you but ive seen where to buy it from (im in the uk) now so forget the reply to the pm thanks

Hi forest, it should work OK with the purple PCB backing. What it really doesn't like is a bright white or shiny aluminium backing.

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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].