Yes the basic idea is that you could have an array of DW660s with different bits installed, or even two. I had thought you could use the electrical connection for steper enable to activate a solid state relay to enable power on each DW660. That way a single electrical connection is multiplexed to enable N routers.
I measured the tool offsets and hard-coded work offsets into the tool-change g-code. I installed the black pen, and just touched a surface, and reset G92 X0 Y0 Z0. Then I installed the red pen, and jogged (only a bit) so that it was just touching the same place. Then M114 tells me the offset. Then I installed the router, jogged to that it was touching the same place, and M114 again tells me the offset.
Then this is where work offsets M54, M55, M56, M57 come into play. When I home the machine, I set M54 work coordinates to be machine relative. I physically hold against X Y hard stops and home Z, and this is M54 G92. Then when I touch off the workpiece, I perform this:
G92 X-5 Y3.4 Z1.1 ; Router position relative to pen 1
G92 X0 Y0 Z0 ; Pen 1 numbers zero by definition
G92 X-1 Y-1 Z-0.7 ; Pen 2 position relative to pen 1
; Change back to machine coordinates
Then after that, picking up the router for example is this:
; Pickup router sequence
G1 Z185 F1000
G1 X577 Y39 F3000
G1 Z30.4 F1000
G1 X587.8 Y28.7 F300
M280 P0 S160 ; Latch
G1 Z185 F1000
G55 ; Switch to router work offset
So it uses machine coordinate space to pick up or park the tools, and switches to the per-tool work offsets to perform the work. Then it will switch back to M54 to put it back and pick up the next tool.
As for Z height, yes it is a disadvantage, but I think it’s necessary for the gantry rails to clear the tops of the parked tools.
To mitigate the Z height, I was thinking I would put a tall “box” to provide an elevated work surface, and stiffen the side rails with boards. Or alternatively you could put holes in the deck and reach down through the deck to get the tools.
The twisting cleat has somewhat of a cam on it’s working surface, and there is a similar cam surface on the movable mount. This allows it to grab, even when it it a couple mm out of position, and pulls it into place. But in the latched position the surface is flat so that it doesn’t “want” to unscrew itself and there is some allowance in the amount of rotation. The servo is driven to a fixed position so it’s not really possible to grab with a given force. I think this means that errors in the print do matter. Being plastic, the pieces can deflect somewhat, and I think this flexing is having to accommodate all the imperfections in the dimensions.
Once the electrical connections allow driving steppers, It’s really sky’s the limit.