I am not positive if you can run without it.  It would be a quick experiment for you to remove the cable and see if it works.

My Jr had 2 'sensors' at the extruder ( feeder)  One is a small optical sensor detecting the small 'blade' that detects forward and backward movement of the filament.  I assume it was to help keep track of filament used.  I removed this and did not use it.  The other sensor is an optical filament sensor.  It is used to tell the printer when you are out of filament at the feed end.  I did put that back.  My solution was to mount my Raspberry Pi ( uses it to host the files, Threedub, etc ) and also the filament sensor.  Here is the 'thing I made for it.  https://www.thingiverse.com/thing:2482409

That would make sense. Are you saying that it's possible to just leave the sensors disconnected and the printer still works ok? That would be very helpful if true, as I could hijack the sensors to feed the Pi some diagnostic data.

Not sure what sensor or printer you are talking about. The picture above is from a JR.

This entire thread is about the XYZ Da Vinci Junior...

Not sure what sensor or printer you are talking about. The picture above is from a JR.

His sig says it is a JR 1.0 but I assume nothing.

Since the OP won't share his project. I am trying to do the same as him I bought this of Amazon:
https://www.amazon.com/gp/product/B011Q … &psc=1

now I just need the fitting the 4mm tube goes into and an adapter that fits the circuit board of the Davinci. What is the plug called that feeds into the Davinci circuit board where the factory motor is located?

To start with you are expecting the OP to respond to a thread that is a year and a half old? I'm sure if you read through enough of these threads you would be able to find the information you need. I have done a similar thing with my JR except I place my new feeder in the same place the orginal one was. There was no need to run a wire all the way to the mother board. Just wire the motor to the existing plug the orginal one was plugged into. I used some testing wires and soldered the onto the new wires. Then I plugged the pins into the orginal plug and it has worked fine for a year now. My stepper motor cam with all of the fittings and a new tube, which I never used.

now I just need the fitting the 4mm tube goes into and an adapter that fits the circuit board of the Davinci. What is the plug called that feeds into the Davinci circuit board where the factory motor is located?

To make sure everything kept cool I fitted a 12v 50mm fan above the extruder to blow cooling air down on to it. I connected the fan in parallel with the main exhaust fan at the rear of the cabinet.

No structural mods involved and I get perfect prints every time with print times over 14 hours presenting no problems. The extruder works perfectly and the filament used indicator still works as well - my last reel let me print a small part with only 5 m indicated on the reel !

Because of the many jams I had prior to this I had resorted to drilling out the blockages in the hot end  so if there was a PTFE lining it has well gone .  I noticed that Maplin were selling a replacement item but when I asked they said it only fitted the Wifi Jr and not the basic model I have.
I took a chance and purchased one - it is the exact replacement but has the addition of the auto calibrate function - you can remove this with one screw or if you are using XYZ firmware  use the function now on the latest menu.

Sorry it's been a bit of a long story but this has really transformed my machine into the item I had expected it to be before reality took over.

For those interested:   the extruder Mk8 frame mod was £6.99 using eBay item 121805539946
                                 Mounting bracket could use Thingiverse/thing 1720214  ( sensor ring can be removed)
                                 Maplin Code for replacement hotend is A10YZ  price £86.99

Hope all this helps and will offer an easy solution to the XYZ Junior woes.

Hi sorry about delay replying.

I am about to mod another davinci JR the same way.
I will take photos and post the whole process which is pretty easy.

I used a new stepper motor from amazon $16 that came with a LONG CABLE!
I just had to wire it to the davinci with 4 jumpers.... hard to screw up... worse that can happen is it runs backwards.

ever since I did this I have had ZERO feeding problems. The feeder that comes with the unit is a very POOR design, you cant see inside it, so you end up having to take it apart and eventually break something in the process.

Chas

@charleshyman. Can you post pics on how to wire it to Da Vinci? I'm up for doing this but I don't know how the wiring setup goes.

In other words, subscribing for interest!

I am about to mod another davinci JR the same way.
I will take photos and post the whole process which is pretty easy.

I used a new stepper motor from amazon $16 that came with a LONG CABLE!
I just had to wire it to the davinci with 4 jumpers.... hard to screw up... worse that can happen is it runs backwards.

ever since I did this I have had ZERO feeding problems. The feeder that comes with the unit is a very POOR design, you cant see inside it, so you end up having to take it apart and eventually break something in the process.

Chas