Z-Axis rod issues

[aetherianlabs]

Hello and good morning!

I have printed out all the parts to make a MPCNC and MP3DP.
Started assembly on the 3D printer first so that I could get it up and running more parts to start a MPLaser engraver. Everything so far has been going together quite well as far as hardware is concerned. However, the Z-axis has been giving me some issues. The threaded rod that came with the kit ordered here does not clamp well in the pineapple coupling (neither 5/16 or 8mm coupler) With the coupler fully clamped shut with the screws, there is still a very slight amount of play in the rod that causes it to sag; also, it is relatively easy to pull the rod out from the coupling.

I measured the rod with a micrometer and it measured out to be 0.290"-0.292". If it were a 5/16 or 8mm shouldn’t it be closer to 0.312"-0.315". If so I am about 0.020" off which would be enough to create a fair amount of play. However, I have been assured that my rod’s diameter is correct at 0.292"

I doubt it being an issue with my printer printing holes too large. Usually slicers have an issue with printing too small. Slicer is Simplify 3D

[vicious1 (Ryan)]

You bought that rod from me? It is still with in the right size range but I buy hundreds of them at a time and thread the nut on by hand if it was too small I think I would have noticed it. Maybe not. The pic below is from the batch I bought a few months ago, that I have been selling since.

Either way the coupler should still fit. If not there are a ton of parametric ones on everything just make one a bit smaller on the 5/16 end. I have to thread the rod in on the couplers I sell before I put a screw in there. They are very snug.