Analog Computer

Build an analog computer reminiscent of those from the 1960s.

Here's a video about how it works: https://youtu.be/_3VhXvwV18Y

December 1961 issue of Popular Electronics describing analog computers: https://www.worldradiohistory.com/Archive-Poptronics/60s/61/Pop-1961-12.pdf

I printed the base from PLA with a 0.4 nozzle, 0.20 layer height, 3 perimeters, 20% gyroid infill. These settings are not critical , so use what you like.

I printed the knobs from ASA and vapor smoothed them so they look cool. PLA would work too. Do a final size on the center hole with a 1/4 inch drill. Drill it slowly and carefully ( I did mine by hand with a pin vise) so the hole is not oversized and slips on the pot shaft. Superglue the cursor to the knob; the cursor will self center on the boss of the knob.

When installing the pots into the base, be sure to install the spacers as shown in the video. These ensure that the protrusion is correct on the front side so everything fits properly. Clock the pots so they are all aligned at the same angular position.

Print the scales in the pdf on your computer printer. They are scaled correctly. Cut them out and tape them to the front of the base as shown in the photo. Position them carefully.

When installing the knob/cursor assemblies on the pot shafts, turn the pot shafts all the way counterclockwise. Gently press the knob/cursor onto each shaft so the cursor line is just above the zero mark on the dial. Once the knob is all the way down, turn the knob so it slips on the shaft and the cursor lines up with the zero mark on the dial. If the knob slips, use a tiny dab of blue tack on the pot shaft to hold the knob securely.

Purchase the components below. Solder the connections as shown on the schematic in the YouTube video.

Here are the purchased parts:
50 Ohm Pot: https://www.digikey.com/en/products/detail/cts-electrocomponents/026TB32R500B1A1/203774
1k Ohm Pot: https://www.digikey.com/en/products/detail/cts-electrocomponents/026TB32R102B1A1/203778
Cursors: https://setworksdesigns.com/products/laser-etched-cursor-for-analog-computer
Battery Holder: https://www.amazon.com/dp/B08NFQDNYG?ref=ppx_yo2ov_dt_b_fed_asin_title When I bought these, 2 of the 3 holders didn’t work. Test them before installation.

If you need an Analog MultiTester, do search for “Micronta 27 range multitester” on ebay. Any multimeter will work, but an analog meter preserves the analog feel of the computer.

Banana Plug Sockets: https://www.amazon.com/dp/B07BZZK4WN?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_4

If you don’t already have banana cables to connect the computer to your multimeter:
https://www.amazon.com/dp/B07179VF5J?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1