Having just bought an HPC laser cutter for use at Make:Bromyard, I found that the existing "handle" was rather annoying. It was basically just a slot cut out the steel lid. You grab it with a finger and lift, and that's fine. However, I found it far too easy to let it pivot over at the top and trap your fingers before it hits the stops. As you can see in the photo, it is basically a slot punched out of the lid before folding, and so I decided to add a simple ergonomic handle.
Step 1: A Block of Wood?
First, we considered just screwing on a block of wood, but thin wood splits easily when you drive a screw into it, and it would be hard to make an exact bit of wood to fit the curved hole. Bonding it on also seemed like a bad idea - glues often fail suddenly and without notice. Putting a screw through from the outside would work, but the self-tapping screws aren't really designed for wood, and it is hard work getting them to go through stuff that is thicker than they were designed for.
So not wood, then.
Step 2: Instamorph?
Second, we considered just using Instamorph, as it is a strong plastic, but not that strong - the
lid is quite heavy, and having the plastic come off or snap would be a Bad Thing - there's no gas strut or cushioning, and the lid slamming down could damage the expensive laser cutter.
Step 3: Reinforced Instamorph!
So, we decided to reinforce the plastic, whether it really needed it or not. A bit of steel should do the trick.
If you've never used self-drilling, self-tapping screws for sheet metal before, you really should try them. As a quick way to assemble anything made of thin sheets it beats riveting by a mile, as you just use a power driver to drill the perfect sized hole with the same screw that will then pull itself in and tap a thread for itself. Very secure for most things, and far stronger than an aluminium pop rivet, plus you only need the screwdriver, not even a drill bit. You won't go back.
Next I heated up the Instamorph. Pop some in a bowl, add boiling water, fish it out with a fork after it has gone clear. By the time you walk to the laser cutter, it will have cooled enough to touch and mould with your fingers.
Step 4: The Finished Handle
I simply used the power drill and a PH2 driver, and ran the screw
through the back of the case, out through the center of the handle hole. I drove it through the back edge of the lid, out through the finger hole. I chose one that was about 10mm longer than the thickness of the lid, so if the plastic somehow came off the screw won't be much of a hazard.
We took the heated the Instamorph and pushed it into the hole, ensuring it went around the edges and into the voids on both sides, as well as encasing the screw entirely. It is never coming out! (Unless you heat it above the melting point of course!) After leaving to cool for ten minutes, it had gone back to the complete white that you see in the photos, and was solid. The resulting handle is tough and easy to grip, sticking out far enough, and is well attached. The screw means it can never really bend, either.
Lots of words for something so simple! But no more trapped fingers, and far easier to grab.