That was silly. I only need about 1 meter for the horizontal arrangement, because it can be connected from the middle of the back. However, there’s another problem. No matter what, if it reach one front corner, it needs extra room on the back. I tried it out. Here it is reaching to the front corner:
And moved back to the corresponding back corner:
Additionally, the bracket interferes with the cable at the rearmost end:
My edge-to-edge design strikes again!
I put it back the way it was before. I thought about running a vertical chain to get the air from the back to the gantry, but decided to try horizontal instead first. I can always change later if I need to, but it looks like this will work. I can play with preload as required.
I bought silicone 8mm ID / 5mm ID hose for air assist because it is relatively large ID (low impedance) and bends easily, and because I thought that the fitting for the air nozzle was ⅝" / 8mm. Reader, it was not. But it turns out that it is either 6mm or ¼" and that ¼" vinyl tube fits in it, and the silicone tubing fits securely over the vinyl tube.
I wrapped the air tube around the nozzle, which works both at maximum extension (for 100mm lenses):
…and at minimum extension:
Then I looked at running drag chain to wire up the X servo. While I had earlier thought of running it horizontally in the side, above the extrusion holding the Y linear rail on the left side, I instead tried mounting this one horizontally as well:
I’m not sure if I’ll leave that this way, but it is at least worth trying. I’ll have to design another part that connects to the gantry mount if I want to run it vertically between extrusion members on the side.