I programmed my HP- something to calculate spoke length, using an algorithm from Brandt. This was of course well before internet toys or excel was available in our pockets. I used it to calculate spoke lengths for a couple of sets of wheels I built. One set of training sew-ups, a radial spoked front and my set of C-record hubbed MA40's. Every spoke was the perfect length. That was cool. But, I had to create my own database of values to work from. Getting the rim measurement right is a trick. I did it by using two spokes and a caliper. I was never fast, so building as a profession would be dumb. Though I would not get fat. The usual method of building wheels back then was to go to the pro-shop, (real bicycle shop run by an old European ex-racer) who would hand you the hubs you desired, rims spokes and nipples, then berate you for screwing it up a few days later when you came back with the rear wheel laced backwards. oser But, then patiently demonstrate how to re-lace it correctly and send you on your way. Then every time you walked in to buy some tubes, tires or just hang out, he'd ask if you broke those wheels yet. Good times. And yes, I've laced a wheel up completely backwards and mounted the tire and as I put into the frame noticed my error. It was 10:30-ish PM. There were a few raw words expended at somewhat elevated levels. The neighbors may have noticed. By, 1AM I had it corrected. That has been long enough ago to not remember much more than that and which wheel that was, I think first rims on those old 36H Campy hubs, or maybe it was the second. Yeah, probably the second. Back when I could hear I could tune my spoke by ear. I even managed that with old airhead wheels from the 60's and 70's. I still prefer the look of those old spoke rims from the 1974 R90S to most cast wheels.