Now that I've got a useful dual-spool holder and a sound events upgrade, I was thinking of what to do about that rectangular hole in the back of the printer. I guess I'm being a little ambitious with the available space allowed on that pass-through but at the moment I'm trying to kill four birds with one stone: 1. do something useful with that hole 2. move the speaker to the outside of the printer where it will be louder (powering it from the external USB) 3. allow the Nikon camera to be remotely controlled via the printer (via an MC-DC2 cable) 4. have somewhere to mount the second bowden stepper The big piece will be on the back of the printer and hold the bowden. All the cabling (one 4-pin and two stereo 1/8") will go through the middle of the pass-through. The mid-piece allows both front/back to be mounted together with #6-32 bolts and the front piece holds it in place just behind the z-screws on the inside of the printer. Not having the stepper motor in meant that I put in the wrong depth for that so I'll need to redesign the big piece. It just went in for a test fit and everything seems good so far.