JGAurora A5 Infrared Sensor

This video follows my review of the JGaurora A5 and my facepalm give away competition. I wanted to get this printer out to one of the lucky winners with the IR sensor installed. It will help making printing with it a lot easier than I found it.

The project I followed and relevant files by CdRsKuLL are available here: https://www.thingiverse.com/thing:2750505

The sensor information here: http://www.escher3d.com/pages/order/products/product1.php

And some additional info if you intent to install this on some other printers or control boards: https://miscsolutions.wordpress.com/mini-height-sensor-board/


I’m going to try quickly the IR sensor and flash the firmware so this printers ready to be sent to one of the lucky winners. I’ve already got the A3s in a box on the floor, and the parcel has been sealed and I’ve forgot to put any stickers in there as I couldn’t find them. So I didn’t forget, I just couldn’t find them. I’m going to try do this quickly and get this out. So well done to the lucky winners, vickie and connie.

And I should also mention the project file have been kindly uploaded onto thingiverse by CdRsKull – I’m not sure how I’m meant to pronounce that and the project is called JGaurora A5 infrared autobed level. So I so wouldn’t have been able to do that with this information been made available.

So this is the IR sensor. And I’ll turn this on.

I’m going to need slightly longer machine screws. They’re good.

Ok, I’m just pushing the circlips down and that’s what it’s meant to look like. The nozzle is further down than the bottom of this piece here. In anycase if this were to push down this would lift up.

I’ll give myself a quick read of the instructions on Thingiverse and make sure I don’t bugger this up. Ok I don’t have any tiny machine screws to fix this on like here, so I think what I’m going to have to do… I’m going to try force a M3 nut in, and is it long enough, we’ll find out. Yep I think it is, fek it, lets get it on the front of that.

So these machine screws are 10mm. And the other ones I used are 5mm maybe, and if I need to I can adjust that, woh shit. unbelievable.  This is bit of plastic scratches onto the the terminals. I’m just going to bend the pins up I think.

Ok I’ve got my wires, and will solder this directly onto the terminals.

I put my heat shrink here.

So I need to make sure I have plenty of wire. It says in the instruction that you need about 1 meter, but I’ll do it a bit longer, say 1.5 meters.

Just feeding it through into this trunking. Probably should have twisted the wires. Ok I’ve done the wiring up to this point here and I need to work out how to get it into the enclosure. Again that’s not really clear from the instructions that I’ve found, so I’m thinking I might use this aviation panel mount and put a connection point somewhere.  But what I need to do first is open up enclosure and have a look at whats inside and familiarise myself with where the wires are going to go and what I need to do.

So I’m just going to move this up, while I start to open this and then I’ll unplug it. I think this goes… so I’m going to take the z-minimum out and… I think I might use these connector terminals instead. Just to split the wires so I can do one side and connect to outside the box. I think I can pass them through right in here. The wiring is not great on this machine. I don’t find it easy to use or access.

I’m just going to write a not for myself to help me remember what the wiring is… so out is brown, ground is white, and vcc is yellow. And the control board – voltage ground signal.

Someone wrote to me telling me I was doing this wrong and I said to him, why don’t you put a video up coz I’ve not seen anyone really share how to do this. But I think the way I’m doing it works. Get the dupont connector into the appropriate jaws, so it doesn’t move around, actually that’s a little bit too long so I’m going to snip it down a bit. So 3-4mm of wire exposed, pop that in with a little bit of the rubber of PVC sheaving. And the first one need to be voltage, and that’s going to be yellow, I heard a click that good. Then ground, which is white, no click so I’ve done that one badly, and brown and that ones ok. Pop these on there.

Ok there was a flashing light there, that’s a good sign.

Ok I’m just going to flash the firmware on this now. In the file or collection of files you downloaded from thingiverse with the STL templates and description, there’s also a marlin1.1.8c file. And if you go to… so this particular board on the JGaurora A5 you want to go to tools, to board and change that to Arduino Genuino – Arduino Mega 2560. Make sure you select the right com port and it’s done uploading – that’s nice and simple. So the next thing to do is test.

The first thing to do now is to home the machine and check that either side of the z axis is the same height. I did this with my Vernier caliper.

That 86.14 and 86.20, so that’s pretty good. I’m not going to mess with that.

You now need to level your bed manually as best you can. But you can’t use the assisted bed levelling. The reason is if the IR probe detects the bed say 3mm below the nozzle in the first sector, raising the bed to 0.2mm below the nozzle and moving to the next will still result in the bed being detected by the IR sensor still at 3mm. This will skew the bed levelling. You have to instead move the nozzle manually in the X and Y axis, using a piece of paper between the nozzle and bed, until you are happy it is as good as you can get it.

You now need to work out the new offset for the Z axis.

Unfortunately, you can’t do this in Cura, so I opened Repetier Host connected to the 3d printer using a USB cable and used the gcode input terminal to do the following: M503 which displays the current eeprom setting. M851 Z-0.5 set the offset (this should leave enough gap to start with) M500 (save the settings to eeprom) M503 (read the eeprom and check the new settings has saved)

I’m going to change the ofset by writing M851z-2.0 – I had it at -2.5 before and save that to the eeprom by writing M500 and check that by writing M503. I can see it’s changed on the screen.

I then check the z offset by moving the gantry down by writing G1 Z0. I check the distance between the space heatbed and the nozzle with a 0.2mm feeler gauge. If I need to adjust the offset I repeat M851 changing the measurement (closer to 0 is higher and further into the minus numbers moves the offset lower), M500 to save to the Eeprom, and M503 to check that it has saved.

I also checked the step for the extruder by placing a bit of tape around the PLA at the stepper motor opening and retracting the filament 100mm. I then measured how much had actually moved, and put it into an equation to work out the new steps. I divided what I asked it to move by what it actually moved and times that by the number of steps in the firmware. I rewrote the new steps into the firmware the re-flashed the Arduino using the IDE.

Ok that’s done. I can close that and reconnect on Repetier Host, and home this with G28. I’m not sure if flashing the firmware effects the Eeprom. G1Z0. And no I don’t think it does. I’m going to put some PLA in there and do a test print.

Ok I just found a video by Da Hai Zhu – I think what I did when I opened this up, I accidentally moved this in the wrong place and what I need to do is turn that around and pop it in like that.  Hopefully that’s going to be ok now.

I then edited my start code in Cura. This will include a G29 command which will perform a bed levelling grid which the print will reference. This information is also available to see after the M503 command – but not in cura. You have to use the serial terminal in the Arduino IDE or the Repetire Host.

I definitely feel like you still need a tweezers to pull filament away at certain points. This sort of design there’s so much stuff around the nozzle it makes hard to do that and see what you are doing. But it is sticking. Ok something’s gone wrong. The printer is not responding. That wasn’t doing too bad in the scale of things. I’ve had a little google and it might be the USB pen itself so I might suggest that they use a different one but anyway this is what’s going to be sent out along with the A3s. So good luck in your new life, I hope they don’t scrap you and use you for parts. It might be what you deserve.


Edit start code appropriately:

G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
G28 ;Home
M851 Z-2.08 ; Z Offset
M500 ; Save to Eeprom
G28 ; Home
G92 E0 ;Prime the extruder
G1 F200 E-3 ;retract 3mm of feed stock
G92 E0 ;zero the extruded length again
G29 ; Level bed
M500 ; Save to Eeprom
M 117

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