What Your Old Graphing Calculator Says About Technology

Assuming that's one of those '3D printers'. I doubt it has the resolution to make something like this. The pinions are about 3mm overall diameter and have perhaps 10 or 12 leaves (teeth to the rest of you ;-)) In any cae, i find press-fitted plastic parts do tend to fail with time. I would prefer to make a metal replacement pinion and fit it with Loctite or similar. [Modified Radio Shack PC2 serial box] Exaclty... I also have the HP3221 unit (HPIL-controleld data logger, bascially) which I use with my HP41 and HP71 machines, although it's a little large to be easily portable (it's a 2U rack unit, albeit a plastic case). I also have a home-made I2C interface for my HP48 with 8 and 12 bit ADC add-ons. I've always htought that there should be a combined programmable calcualtor (RPN of course...) and DMM. Preferably with control outputs too. It would be very useful. -tony