As I’ve been working sporadically on monocle, I’ve left the lid propped open against the wall. That meant I didn’t install the wheels, so that it wouldn’t roll away from the wall and break the lid falling backwards.
But now that I’m installing the enclosure and getting closer to turning this thing on, it’s getting more and more inconvenient to not have wheels to move it around for easy access. I used nothing more than imagination to choose a pair of 150N / 33lb gas struts with 3.63 inches of travel and hoped they would work.
Because the monocle doesn’t have an inner and outer frame, there’s no good place to install the gas lifts inside. I have installed them on the outside (warning: pinch hazard but if you can’t deal with a pinch hazard you probably shouldn’t be playing with lasers either), and ultimately they seem to be working.
Mounting them was a bit of a challenge. They were intended to mount in cabinet doors and box lids, so the mounting hardware needed to be adapted somewhat.
One end had slots that would have been fine for 4mm screws, but of course I have 5mm t-nuts, so I drilled out the ends of the slots slightly for 5mm screws. That was the easy part.
The other end was a challenge. I made some quick blocks out of POM to mount the ball ends on the top of the lid. I cut a 20mm thick chunk, 40mm tall, and about 40mm long, and ran 45mm screws through it into roll-in t-nuts, aligned to be able to screw the three screws in the mounting plate without screws running into each other:
The other end is connected to the frame, so on each end of the enclosure it looks like this when it is closed:
However, when I actually tried to close the lid like that, the 2020 extrusion on the lid that the block is mounted on twisted too much. I needed to stiffen it, which was when I discovered that I’d run out of OpenBuilds 90° joining plates for this purpose. So I went to rummage through the scrapyard remanents and found a couple plates that had holes about 10mm in from each of three corners, plus some irrelevant other holes. I opened them up to 5.1mm and put some m5x10 screws into t-nuts and that took the twist right out.
I could have put them on the bandsaw to remove unnecessary metal, but it didn’t seem worth it. Maybe later.
I had to play around with the location of the block in order to have it both hold the lid open and be able to close all the way. My first attempt had the lid pivot too far from the hinges and required more travel than the gas structs supported. Fortunately, with about 65mm total distance from the back of the lid to the pivot, the gas struts hold the lid up vertically at full extension, and can still close.
When I close the lid, I don’t have to pull it very far before it starts to come down on its own. These are not soft-close gas struts. But all I want is for the lid to stay up when I’m working, so it’s good.
These were inexpensive. If they break, I’ll probably replace them with slightly stronger struts, but not twice as strong.
With the gas struts installed, I was finally able to install the wheels. That should help me move it around as I work on finishing the enclosure.