Mini differential IR height sensor board

I am about to make another small batch of my mini differential IR height sensor board. This uses 2 beams of infrared light to detect height above the bed surface. It is designed to work on glass with or without a covering of Kapton tape, ABS juice etc, but works on most surfaces including BuildTak. Not suitable for use on mirror glass.



I can ship to most countries. Prices in GBP including shipping (tracked where possible), for one board paid via PayPal, are:

UK inc. VAT     29.82 
EU VAT paid     37.83
Rest of world   32.52

VAT-registered business customers in the EU but outside the UK may claim the "Rest of world" price, but you must give me your VAT registration number, and if you are in Italy you must be VIES-registered as well.

To order, send me a PM stating how many boards you want, your PayPal email address, and which country you are in. If you are in the EU and claiming the "Rest of world" price, also your VAT registration number. I will send a payment request via PayPal when the boards are imminent. I expect to start shipping this batch on 22 June. Also send me a PM if you would like a price for more than one board.

For further details and fitting instructions see [miscsolutions.wordpress.com]. There is a video showing the board being used to auto-calibrate a delta printer at [www.youtube.com].

Edited 2 time(s). Last edit at 06/11/2015 04:27AM by dc42.

---

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].

The whole of this batch is now allocated to orders. If there is enough interest, I will make another batch next month.

---

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].

Can you set the trigger distance further away so that the board is above the nozzle somewhat to avoid it hitting a print that has lifted or curled?

Quote
jlmccuan
Can you set the trigger distance further away so that the board is above the nozzle somewhat to avoid it hitting a print that has lifted or curled?

Not without making the board bigger and using expensive optics. In my experience, having the sensor 1mm higher than the nozzle is plenty. You can go for 2mm if you like. If you get curl-up by more than this, your print will be ruined or knocked off the bed anyway when the nozzle hits 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].

Some news:

1. SMD component assembly of this batch is complete, so I will send the PayPal requests tonight, with a view to dispatching boards tomorrow and Thursday.

2. I am taking orders for the next batch. Estimated shipment date for that batch is 20 July.

3. I have posted a design for a fan duct with a mounting position for the IR sensor board for a Kossel with a J-head hot end at [www.thingiverse.com]. I will post a version for the E3D v6 soon.

---

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'd like to get one.
glennswest at neuralcloudcomputing dot com

Thanks to continuing high demand and interest from a supplier of 3D printer kits, I am going to have a batch of 160 sensor boards made. The first 16 will be available around 20 July, and the remainder around the end of July. The production volume allows me to make a price reduction, which will apply to all orders from that batch, including orders I have already been given.

I am looking for overseas distributors, especially in the USA, Australia, and Germany.

---

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].

How does your design not fail with heated beds? It seems like the background IR would swamp your sensors. Just curious. I am ready to dump my FSRs.

Edited 1 time(s). Last edit at 06/22/2015 04:34PM by shadowphile.

Quote
shadowphile
How does your design not fail with heated beds? It seems like the background IR would swamp your sensors. Just curious. I am ready to dump my FSRs.

Even at 150C the bed radiates very little at the near IR wavelengths that the sensor uses. Even when there is some background IR such as from halogen lighting, the sensor is reasonably immune to it, because it monitors the relative strengths of two IR beams, not the absolute strength of one reflected beam as other IR sensors do.

I'm curious about why you are ready to dump the FSRs. Are you having problems with them? Do you have one of John's FSR trigger boards?

---

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].

Glad the heat bed isn't an issue. I guess for near-IR the bed would have to be blazing hot.

Yeah, I have John's controller board, even tweaked the code to compensate for preloading so the sensitivity doesn't drop as preload goes up (which works well btw).
The FSRs are mounted on a tiny acrylic disk for back support (because of the border thickness issue), and a fairly hard rubber disk on top to interface with the bed.
But, I just can't seem to get solid repeatable results when the bed is heated, despite 1/4" of acrylic, 1/8" of cork insulation, and the 0.1" rubber disk.
So I want to mount the bed on a more rigid foundation than three rubber disks, which means back to a probe design from the top.
I also have a problem with oozing when I try to cal the bed when the extruder is hot. The ooze gets in the way and I can't stop it unless the hot end is basically empty. I want to leave the filament fully loaded from the previous job. Large retractions also seem to provide an opportunity for heat-break jams. I had to disassemble the entire effector just to clear out the heat-break yesterday.
Then I realized a non-contact approach like the IR sensor would not have an issue with oozes.

David,

can you give a statement to the accuracy of your IR Board?

Whats about repeatable results when probing?
With my mechanical switches I have repeatable results between 0-5 steps on z-height. And thats quite good. But I want a solution without touching the heatbed.
Any information about that?

cheers
Dirk

Edited 1 time(s). Last edit at 06/28/2015 10:33PM by critical_limit.

On my delta, the reproducibility is generally +/- 1 microstep, which is 12.5um on that machine.

---

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
On my delta, the reproducibility is generally +/- 1 microstep, which is 12.5um on that machine.

That´s my target!

Thanx for the info

I now a have a pre-production batch of 16 boards. They are all allocated to existing orders and I have sent out the payment requests. I will have more boards in stock on or around 24 July.

The increased production volume has allowed me to reduce the price. The new prices in GBP, including tracked carriage and VAT where applicable are:

          UK      EU      Rest of world
1 board   27.36   35.27   30.37
2 boards  52.11   60.26   51.30

These prices apply to both new and existing orders. VAT-registered business customers in the EU but outside the UK can use the Rest of World price if they provide me with the company name and VAT number. See the first post in this thread for how to order.

I am seeking distributors, in particular in the USA, Germany, and Australia or New Zealand.

---

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
On my delta, the reproducibility is generally +/- 1 microstep, which is 12.5um on that machine.

As I can see, you are using usual microswitches at tower endstops. Does the quality of microswitches affects quality of autocalibration using this IR sensor? What is the IR spot size on the bed? As I understand the particles of dust on bed and in the air not affect the quality of calibration?

Quote
roboprint

Quote
dc42
On my delta, the reproducibility is generally +/- 1 microstep, which is 12.5um on that machine.

As I can see, you are using usual microswitches at tower endstops. Does the quality of microswitches affects quality of autocalibration using this IR sensor? What is the IR spot size on the bed? As I understand the particles of dust on bed and in the air not affect the quality of calibration?

My microswitches appear to be reproducible to +/- 1 microstep also. However, if you auto calibrate and then print without homing again, then errors of a few microsteps in the microswitches won't matter, because any errors in the last homing will have been calibrated out.

Quote
roboprint
What is the IR spot size on the bed? As I understand the particles of dust on bed and in the air not affect the quality of calibration?

IR spot diameter to half intensity is calculated to be between 2mm and 3mm. Dust should not affect the trigger height significantly. Large changes in the bed surface do affect the trigger height a little, for example going from plain glass to glass covered with Kapton increases the trigger height by about 0.2mm.

---

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 received a new batch of sensor boards yesterday and I will be shipping them from Monday. I have sent payment requests via PayPal to all those who were on the backorder list. If you have placed an order with me and have not received a payment request, please check your spam filter or log on to PayPal, and send me a PM if you still can't find it.

I have about 25 boards remaining. See 3 posts back for latest prices, and the first post in this thread for how to order.

These boards are slightly shorter than the earlier ones. They will now fit below the heatsink of an E3Dv6 hot end, making it possible to get the sensor even closer to the nozzle which is especially useful on delta printers. I have published a new fan duct and IR sensor board mount for the Kossel, see [www.thingiverse.com].

---

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].

how close can you get with the board and not have temperature issues.
also, what temp is the electrolytic rated for?

Quote
innkeeper
how close can you get with the board and not have temperature issues.
also, what temp is the electrolytic rated for?

I've never had temperature issues with this or my previous boards, printing both PLA and ABS at up to 245C. My latest mount for use with the E3D puts the back of the board facing the heater block, partly to help keep the components cool but also to reduce the risk of the optics being contaminated by filament. Ideally, the hot end cooling fan would also cool the board, but I've never bothered to do that. The electrolytic cap is rated at 105C, and is run at no more than 1/5 of its rated voltage.

---

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 sent you a PM for a purchase request for one of the new v1.1 boards to US. Just wanted to make sure you reviewed it and maybe if im on a waiting list, would like to know.

Quote
frodriguez96
I sent you a PM for a purchase request for one of the new v1.1 boards to US. Just wanted to make sure you reviewed it and maybe if im on a waiting list, would like to know.

Looks like I missed your message when I returned from holiday - sorry! I've sent the payment request now. The sensor does work on plain glass (that's what I use), but I recommend you put a black surface under the glass (e.g. black painted aluminium, or black paper) so that reflections from below the glass don't swamp the weak reflection from the top surface.

Edited 1 time(s). Last edit at 07/26/2015 06:06PM by dc42.

---

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].

Just want to say thanks - received one of your new boards (v1.1) and it works really well - finally can use a heated bed

Modified my Kossel J-Head with secondary fan to mount the holder, if anybody is interested: Thingiverse

Quote
Risingphoenix
Just want to say thanks - received one of your new boards (v1.1) and it works really well - finally can use a heated bed

Modified my Kossel J-Head with secondary fan to mount the holder, if anybody is interested: Thingiverse

Thanks for the feedback, I'm glad it is working well for you! I've added a link to your fans+sensor holder design from the instructions page for the sensor.

---

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 now shipped all paid-up orders. There are two orders remaining, all from the USA, for which I have sent the payment request but not received payment. So if you ordered a board but have not received a payment request, please check your spam filter and/or log on to PayPal.

I have plenty of boards in stock for the time being.

---

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].

what is the dimensions of this version of the board? I want to see if it will fit....

Quote
patrickrio
what is the dimensions of this version of the board? I want to see if it will fit....

24mm wide x 17.8mm high x 10mm thick at the thickest point, not counting the connector. The bottom edge needs to be about 1.5mm above the tip of the nozzle. It will just fit below the heatsink of a genuine E3Dv6 hot end.

Edited 2 time(s). Last edit at 07/31/2015 07:17PM by dc42.

---

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].

Defiantly interested in picking one of these up in the future. Will you be continuing to make them?

Quote
Brex480
Defiantly interested in picking one of these up in the future. Will you be continuing to make them?

Yes, and I just had nearly 500 made. Most of them have been shipped already or reserved by kit manufacturers, but I have about 30 left for individual sale. I expect to make another batch in a few months time.

---

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].

can I use it on ramps 1.4?

Quote
mdcompositi
can I use it on ramps 1.4?

Yes you can, see section "Connecting to other electronics" in the instructions at [miscsolutions.wordpress.com].

---

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].