This may be a stupid question, I'm just making sure I can transfer over to something like this without trouble, but I know on a double bass etc the scales are all different and change position because of the note changes. This wouldn't be the case here correct?
I am not sure why you would think this. Are you thinking a double bass is tuned in fifths like a violin?
Doublebass has the same notes and intervals as electric bass, there's just more space between each note on the board.
This is correct, the double bass is unlike the other instruments in the violin family. It is tuned in fourths, EADG, just like an electric bass guitar. Or rather the BG is tuned in fourths just like the DB because the BG was meant as a replacement for the DB. When the BG was invented bands were struggling with the problems of transporting a DB and with dealing with its bulk on stage. Bands were getting louder and the DB was not. It could be amplified but there are a lot of problems with feedback when a DB is amplified. Guitarists who could not find work as guitarists were trying to convert to bass to get work yet the learning curve of a DB is pretty steep. So Leo Fender found a pot of gold when he addressed all these issues with the Precision Bass....
Now, if you like you can tune any BG in fifths, CGDA like a cello for instance. Some of us do that because we like the tuning and in fact some DB players do that too. You start just a half step above the low B of a five string bass and you end a whole step above its high G string. Thus you get the range of a fourths tuned fiver plus a half step from four strings. But you do have to re-learn your fingerboard and you may have to rework your bass lines and your approach to bass lines because some things get harder to do while others get easier. I switched to fifths a few years ago and I really enjoy playing in that tuning. It is not for everyone however and you do not have to tune in fifths to have a bowable BG.
Last I knew Ergo Instruments would make 34 inch scale upright basses. He did not recommend that, he feels that cello and DB strings bow better than BG strings but he was giving in to demand for 34 inch instruments using BG strings. A cello has a scale of about 27 inches (similar to a baritone guitar) and a DB is around 41 to 43 inches, btw.
I've played around with bowing occasionally. I bought a dirt cheap violin bow from eBay, or rather asked for and got one for Christmas one year. The rosin is messy but it causes no problems with a BG. I've got an eBow which I don't find to work very well for any of my basses including the high strings on my Squier VI. I don't know what the secret is. Some people do marvelous work with them, I just don't get it. The Gizmotron looks very interesting, in fact my failure with the eBow and the problems of using a real bow had me thinking about building something similar. It's nice to see that someone has done it and it works. If they were around a hundred bucks I would buy one in a heartbeat. At three hundred sixty some and more I will put it on my list of things I would like to try some day if I get the money. Hmmm, I wonder if I could buy some of their BG bowing wheels and make a hand held, single string, electric bow???
If you want to just test out the concept of the electric upright bass (EUB) you could undoubtedly make one yourself. It might not look pretty, it might not last long, but it should be fairly cheap to do using spare bass parts you have, a nice straight 2x4, and spare parts you can buy from places like Rondo Music. A split Precision pickup would work fine, you can just angle the two halves so each covers two strings. You can do piezo pickups too but that is a bit more work. It probably won't play real well but it will play well enough to give you a taste of what you could do with one. It will give you something to practice with while you build, or save up the money to buy, a better one. If that is the sort of thing you like to do just go for it!
BTW, I love the idea of using zip ties to make frets! The spirit of the viola de gamba lives on!! Opinions are divided as to whether the DB is a descendant of the de gamba family, an extension of the violin family, or a hybrid of both.