Transmutascope: Structure and Fabrication
Transmutascope cases are made of 1/2" shop plywood (left) which is glued and nailed together. They are then sanded and painted.
The main mechanical assembly bolts into the case, as does a plate with all the electrical components.
LEDs are mounted onto 4 plates (2 are shown above). These plates are mounted in the case corners on standoffs with the LED side down. The viewer thus can't directly see the LEDs, and the objects get illuminated from 8 points.
Here we see the revised mechanical sytem which uses a DC motor and urethane belt to achieve a 10:1 ratio. As opposed to using a gearmotor (ealier version in above right photo), this strategy is very quiet.
The main axis is ball bearing supported 1/2" diameter stainless steel shaft. The platter accepts 23" diameter media disks.
To the left of the motor is the slot sensor which detects pins passing by as the media disk (not installed here) rotates above.
"Media Disks" (left) hold the media, which in this case are the red objects. Media Disks are intended to be interchangeable and quickly mount onto a Transmutascope.
These disks are random sanded acrylic, 23" in diameter and 3/8" thick.
LASER CUTTING EXPERIENCE: These disks were my first experience with subcontracting to a laser cutting shop. The disks were too big to easily handle on available equipment and needed to be accurate, so seemed like a good candidate for computerized laser cutting. I chose Pololu, and submitted a .DXF file.
2 disks cost $175 including everything, and arrived on time looking nice. When mounted and spun it was obvious that there were major geometric inaccuracies, the edge and hole lines wobbled up to 50 mils (should be within 1 or 2 mils). Pololu said they couldn't guarantee accuracy, which is odd since that's the whole point.
But despite this, it is clear that laser cutting is a very powerful tool, allowing easy creation of 2D forms which would be extremely difficult to fabricate by traditional methods.
Once media is attached, the disk must be balanced if if will be used in a verticle orientation. The brass weights and washers serve this purpose.