SG Drill collision mesh is too large
I was trying to add drills on hinges, when I noticed the hinges wouldn't go to 90 degrees. At first, I thought they were hitting the cockpit, but after testing (see attached video) they are hitting the conveyor tube (first example). This gets worse with a conveyor junction rather than a tube (second example). You can increase the torque on the hinge and they will close further, but then the grid starts to move from phantom force.
Putting drills on 90 conveyor tubes in this scenario obviously works, but the drills will still be colliding with the conveyor tubes at 90 degrees.
As you can see in the third example in the video, replacing the drill with 2 blocks (left) folds to 90 degrees just fine. On the right, the hinge is now supported from behind and it will actually go past straight a few degrees before colliding with the cockpit. In other testing, I turned the drills 90 degrees, so they are flat relative to the miner, but had the same issues.
I believe these examples show that the rear/connecting portion of the small grid drill has a collision mesh that doesn't match it's visual appearance.