Fixing v3 Z opto sensor in place

[drfoop]

I'm assembling my v3 kit and have a problem fixing the Z opto sensor in place.

The sensor locates in a slot on the Z-axis lift part. The instructions (step 70) say to fix it in place with two 2.2x9mm small screws. The sensor fits in the slot. The screws aren't long enough to grip the holes at the bottom of the slot, and the width of the screw heads prevents them from moving further into the slot.

A couple of pictures will hopefully show what I mean:




One possible problem is: the screws in my box of screws and bolts are labelled 2.2x8.0mm, not 2.2x9mm. Is that missing mm making all the difference?

EDIT: The 8mm screws are also a little short for going through the M4 nut to fix the Y-axis sensor in place.

Or am I doing something else wrong?

Also: Is the problem I read about with incorrect voltages and/or wire colours for the opto sensors fixed in the v3, or do I also have to worry about that?

[andrewsi]

My recollection was that these were self-tapping screws in my v3 kit and therefore length was not critical, they shouldn't protrude all the way out the bottom. If the holes are stripped such that they won't hold in place, you could probably fix that with some CA glue and the end of a toothpick glued into the hole to give the screw something to grip again.

[andrewsi]

Oh, and I had no issue with proper functioning of the sensors either- go with it and see if it works.

[drfoop]

Yes, they're self-tapping screws but they don't reach the holes they're supposed to self tap into. Only the taper of the screw reaches the hole and it's not enough to gain purchase on the plastic.

I'm going to tape the sensor in place for the moment because it's mostly held in place by gravity. I need a more permanent solution, though. I shall look through my box of assorted screws.

[b3dvisuals]

I assembled a few 3.0 printers, and had no issue fixing the sensors.

[seaton]

the problem Ive had is updating from v2 to v3, the sensor is different as its mounted on a small PCB, I've mounted it underneath the current mount and drilled 2 extra holes, seems to work well

[j_redbeard]

I can confirm this issue, I'm assembling the 3.0 right now and just ran into this.

The assembly instructions call for 2.2 x 9mm, the box of parts has 2.2 x 8mm screws, but the 8mm screws don't reach the plastic in order to get a bite. This happend on the z mount as well as one hole on the y mount for me.

Going to try some 10mm screws, will let you know the result.

[kerog]

I had the same problem. Since I live in the US, I had trouble finding metric alternative screws. But I went to an electronics supply store and found some non-metric screws that were slightly longer and seem to do the trick.

I also had trouble on this step with the wire routing when I finally got the sensor screwed in place. Trying to get the wires to lie flat as in the instructions just didn't work. In bending this way and that trying to get it to go, I ended up breaking the connection on the middle wire, which appears to be just soldered on. I'm going to try re-soldering tomorrow. If anyone has a better idea, I'd love to hear it.

Finally, I noticed that the very next step (for the 3rd sensor) calls out a pair of thin nuts, but the picture shows the sensor on nuts stacked two high, which would use four total. Anyone know which is right?

[olce]

I had the same issue also :
- assembly manual instructs to use 2.2x9mm screws, but they are not in the box
- the existing 2.2x8mm are just .. a mm too short to "grab"
- I used a bit longer screws from my stock, and they work

[Eli-Audio]

I too came to the conclusion that there were no screws in the kit to fasten this sensor, but just used the thicker screws that were in the same part of the screws box! There's way to many parts in this box anyway...

These screws don't reach the bottom either, but because they are thicker they end up doing the same, stick the sensor!