Prototype frame is in from the laser cutters! Time to start testing stuff!
First impressions: things look good. 10mm thick acrylic is ridiculously thick. Edge finish is really, really clean. I’m so glad I didn’t decide to go the route of buying a cheap laser cutter and cutting this myself – I’m sure I wouldn’t have ended up with a finish like this.
As with the MK1 kits, I plan on having the MK2 frames cut from black acrylic – but I had the test frame made of clear acrylic so I can see through it for fit / tolerances, and see any cracks if they develop.
One of the first things I did was to try and assemble the x-carriage. The x-carriage, along with a few other pieces, are made of 4.5mm acrylic instead of 10mm – this is to keep weight down on the moving axes. Immediately I realised I’d left a part off of the sheet I sent to the laser cutters – not the best start!
Fortunately, the missing part was small, and I have a 3D printer on hand – easy to fix! 20 minutes later, I had the x-carriage put together:
The next thing I noticed is that I’d mis-judged the size of the T-slot nut traps – the M3 nuts, which should be held in place, are able to spin freely. This really annoyed me at first – initially I thought I wouldn’t be able to assemble the frame without the nuts fixed in place. After a few minutes of fiddling with it, I realised it wasn’t that big a problem – holding the nut in place with pliers does the job, although assembly would have been easier without it.
Anyway, thanks to the aforementioned text-file of variables, fixing this problem was only a quick change to one line in a text file – not too bad!
The 10mm thick acrylic made it difficult to grab the M3 nuts with a pair of pliers – but eventually the frame came together. Things are looking good!
Screws are only hand-tight and everything is already feeling really square and sturdy. I’m tempted to try and stand on top of the frame – I think it could take it, but if I’m wrong (and I’m probably will be) I’ll be set back a few weeks.
Still… maybe once I have the next prototype in.
After working with it for a while, I’m starting to really like the clear acrylic look – I might try and carry kits in both black and clear, I think being able to choose a colour would be really cool.
Great. Now I want to find out if my laser cutter stocks hot-rod red – that could be fun!