The project was coming together now, with the cabinet assembled, wood stain applied, and the dial faces ready. However I wasn’t done with it yet. There were three more things to consider. Firstly, fitting all the electronic bits and pieces into the cabinet. Secondly, fitting the motors (driving the dial pointer needles) into the two dial cases (and coding the program to drive these). Last but not least, decorating the cabinet a little to add some finishing touches!
Buying a few bits and pieces
After thinking about what may be needed to do the above, I visited a hardware store to pick up a few little things. The assistant at Bretts Hardware, Windsor (Brisbane) was very helpful. Here’s what I bought:
- 6 small brass bolts for the dial cases (2 were missing on the original cases). These were imperial size 5/32″ bolts – only one length was available, so I would need to cut them down to fit
- a box of short brass screws to use for fixing panels, blocks, aerial, etc
- a couple of metal strips with holes in them, to use for mounting the motors and fixing the power pack
- two brass cupboard handles to look like ‘ears’ and a small brass knob for a ‘nose’
Keeping an eye on budget
The bill for these items was $32, bringing my total spend to $87. I had an old power pack at home, so there was no extra cost for that. The breadboard, Microbit, wires and motors were from the Makers Kit I got from the university, so I haven’t included the cost for those at this stage.
Mounting the electronic bits
Next step was to mount the electronic bits – the breadboard with Microbit and wiring, my power bank and a battery pack – onto the back panel. I added an extra piece of wood beside the power bank to provide a surface to fit a bracket onto. I had previously drilled a hole in the back panel to allow the power bank’s switch to be accessed from the outside.
For the battery pack, I used an old bracket sawn in half to fit, which held it in snugly (and could be unscrewed when it was time to change batteries).
Mounting the servo motors onto the dial cases proved trickier. I tried to use a metal bracket, but this meant the centre of the motor didn’t protrude enough for the needle to spin. After a bit of thought and experimenting (and a fair bit of help from my ever-patient partner) we decided the best method was a piece of plywood with a slot cut in it to fit the exact size of the motor. This allowed us to drill a couple of holes in the back of the brass dial cases and screw the plywood onto those.
Mounting in this way meant I couldn’t used an off-centre needle for one of the gauges as originally planned, so I re-did the gauge face artwork. I also made the dial pointer needles slightly wider so they would cover up the white plastic arm on the central shaft of the servo motor.
That was most of the hard stuff done, and here’s what the little fella looked like now:
I had a bit more decorating to do – like fixing the aerial on properly, adding some steampunk cogs for decoration, and affixing the acrylic dials, but at least my Steampunk Data Monitor was starting to take on a personality!
The final stage was to program the Microbit to get the dial pointers moving…
Next > Practical project step 6: Coding the Microbit
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