Well, I think that the spine tester is pretty much finished:
The mechanics are finished, electronics are permanently fitted, the wires are properly secured and the software is good enough. Even the DIN socket has been flipped over so it's the right way up.
It's hugely over-engineered but at least I know it'll survive an apocalypse. Maybe the descendants of the cockroaches will have fun trying to figure out what it is.
To take a reading you press the arrow down onto the central pillar and read the spine from the display:
It reads the modern 1.94lb at 28" spine as listed on most modern arrows by default:
But will also give the older 2lb at 26" centres reading (without adjusting any of the mechanics; it's an arithmetic transformation):
although I don't know if anyone is really interested in this older standard of spine reading.
It'll also do the poundage reading for old-school guys:
I have to admit that I don't really know how accurate this reading is.
At the press of a button it'll average the last six readings and tell you the direction of the maximum:
The code assumes that the last six readings were taken on the same arrow 60 degrees apart (ie on the vanes and half way between them). All my fancy ideas of taking a small number of readings and the software magically working out all this stuff itself came to nothing. But hey, at least it saves you hunting for a biro and a notepad.
It'll also weigh an arrow:
although only to gram precision so I'm not really sure how valuable that is. I suppose given that it knows the front and rear weights separately it could do a FOC calculation too. There's a project for the next time that I throw my back out.
Being a homebrew item the gauges need calibrated:
It's not too big a deal to do; it's really just a case of putting a known weight on the gauges; it just takes a few minutes. Once it's done it saves the calibrations in EEPROM so in theory it's a one time only thing but in practice you need to re-do this whenever you fiddle with the mechanics. And let's be honest - this is a fiddling with project. Nobody's going to trust their arrows to my shonky software and worse electronics.
The height of the centre pillar needs adjusted after it's been apart too:
This is done with my trusty (and cheap) 1/2" ball bearing. At 99p it may be the only bit of this project that made financial sense.