J2 Motor M4x45 Screw too Short

Yes no problem on using a 50mm long screw but I'm curious why the 45mm is not reaching all the way through. Can you send me a side or profile view. I'm curious if the motor flange is not fully seating in the printed motor mount, or if the split collar has build material or not completely flush to each other.

Looks like you are working on MK3 version and you have already removed the motor cap and installed the J2 motor mount - so the spacer you have is fine and no need to take it back apart and use the MK4 split spacer. Im not certain why the 45mm screws are coming up a little short though.

I am seeing 40.5mm here. I can make the spacer file narrower. Given you have already installed your motor mount it would probably be alot less trouble to use the 50mm screws as you suggested. If anyone else is having this issue please let me know.

I went to the store and didn't realize I bought 50mm shoulder bolts.... Anyways I'm just gonna reprint the spacer, here's the stl I made to accommodate my specific case - the original model is 10.5mm, mine is 8.63mm https://drive.google.com/file/d/1qMLo4gdakC0XdlT6BGr19x92Do7THrkm/view?usp=sharing

OK thank you. the extra distance should not hurt anything. Let me know if you have any issues.

I've run into the same problem but for a different reason. Today my 50mm screws arrived so I took another try at mounting the AR3 J2 motor into the redesigned AR4_MK4 type mount.
Turns out when I milled the U shaped slot my tolerances were a bit tight and I had to remount it on the mill and use a boring tool to enlarge the hole by about 0.4mm as otherwise it was too tight on the planetary body.
I'm still using the washers to move the motor out so that the face of the planetary drive doesn't touch the set screws used to adjust play out of the tapered roller bearings.
Man that AR3 J2 gear box has a lot of backlash. I can see why it was changed over to a better one. Too bad it sells individually for so much or I'd replace it.
Anyway. Slowly replacing the 3D printed bits with metal bits. Notice in the top right corner a split pattern for casting the body of the J2 Turret Housing. However had Cataract surgery so not allowed to lift anything heavy for two weeks so no sand casting for a bit. Time to mill out the arm as the 3D printed one is too flexible to be able to reasonably tighten the toothed belt.

I 3D printed four 4.5mm spacers which puts the motor just clear of the sets screws on the J2 Tension Ring. I still had to use 50mm screws.
For now I've inserted brash 3mm inserts into the J2 Arm so that I could clamp things better. Hopefully this weekend I'll be able to mill out the J2 Arm from a piece of scrap aluminum plate donated to this project.

I connected up my Electronic Lead Screw project to the J2 motor and now have it moving nicely. Here's a 32 second video of that. Clearly show's I'm not one of those YouTube creators intent on generating income from tediously long videos.
https://youtu.be/zTwx1Fkdp-w?si=HWv-_kpeZkuOMRIE

Here's a photo of it. And to just be clear. The two pulleys for the J3 mechanism had to be keyed and a set screw drilled. Without dimension from drawings to go from I screwed that up big time. The key slots were in the wrong location and I though that a 4mm screw for the 3mm key was the right choice. Not!

I've ordered new pulleys. They come with flanges and are wider. I've had to clamp them in the lathe and cut off the flanges along with broaching the key slots and then adding the set screws. Looking again at the assembly manual I see I should have use 3mm screws for both and set up the slots so they are in the pulley valleys.

Meanwhile I can turn the J3 stepper motor shaft and see the second arm move. So things are good.