MIMF

Bit the bullet
Did some touch up paint work, but apparently, very hard to make that non-obvious, so now I have varying areas of high gloss, and matte areas, and some lines.... Only on the top though, so I'll flatten that, and then respray just the whole top, leave it and then polish it.

Was keen on assembling it, so I made the recess for the nut, and fitted everything else. As imagined, finding out the right strings and tuning is a bit of a puzzle. Right now it has a 5-string set made for the Ibanez Mikro 5, but tuned E-A-D-G-C (as are all of my other regular 5-strings). But the two lowest strings require a lot of string on the capstan of the tuning machine, not ideal. Also, the strings are obviously thick and stiff, so that is noticable. The plan was to tune this an octave higher, as is the Mayones Cali and Mub Miezo, might still end up doing that.
Given low string tension, the tesnion does not pull the neck into some relief, maybe that'll come over the coming days. Luckily, I fitted a two way trussrod, so I already gave it some preload in the "other" direction. It is quite a substantial neck, given the size of the instrument (wide, it is pretty flat).
Haven't fitted the electronics, might do that this evening. Will post some pictures in a minute (they are on my phone). Biggest and the smallest (in our house anyway)

The rear:

Can you cut the strings shorter so they don’t bunch up on the tuner post?

For three out of five, yes, certainly, but the lowest two strings are to thick to fit on the tuners (those have a taper on the end to fit in the tuner). The original plan was always to tune it an octave up from a regular bass. Might do that, because the thick and stiff strings also don't play as comfortable as I'd like.

"too thick"

Done, for now anyway.
I put in a preamp of my design (clone of a pre-EB Musicman Stingray 2eq preamp), and it works great.
Not too much treble, probably due to mode cancellation in the relatively wide coils, I can tap it for single coil operation, probably will do that.
Also, tuning, pretty sure it is going to go up 1 octave.

Looks good to me! It'll be interesting to see your next bass.

Thanks!
In the meantime, coiltap helps to get a bit more "air" in the sound, and it now has the lowest 5 strings out of a Fender Bass VI set of strings from labella (roundwounds), tuned E-C an octave up from a bass.
It is better, but the strings still are a bit taut. That's what you get for building something quite different , it's all good though, currently a really fun instrument to play and easy to take along.

Correction, have used the highest 5 out of a labella BassVI set, and as mentioned, string tension was a bit high.
Tried regular bass tuning with a set of Pyramid strings for mini bass (23"), but that doesn't work, very floppy, as expected, and the E-string kept going flat. Can't imagine this working, even on a 23" scale instrument, very disappointing.
Went back to octave up tuning, with a slightly lighter Bass VI set, combined with a string from a heavy electric guitar set.
So we now have 20(wound)-30-42-54-62 (E-C tuning, an octave higher than regular bass, on a 21" scale length).

Fantastic little instrument, think I will need to make a proper nut for it, adjusted to the actual string gauges, but for now it is fine. Bought a bag for it, for 16 euros (for a tenor ukelele, I think).

Hey Jarno,

Mind sharing more pictures of your fret slotting jig?
If I continue building, I'll probably be slotting my own fretboards to save money.

Hello Matthew,

I posted it here in tools&jigs: https://www.mimf.com/phpbb/viewtopic.php?t=6891

But I will say that in the meantime, I've made something else because I am working on a multiscale instrument: You can get a set of rails and T-nuts etc. on Amazon for I think 30 euros or so, and so I used that, a piece of MDF as a base and a few pieces of beech for the guides, fitted with 20mm neodymium magnets.
Works really well.
The right angle guide still has too much slop to use it without checking for square though, figured that by making a reference edge it would always be square, but that is not the case. Both of the guides are bombproof, no wiggle at all.

Whoa!

Thanks for sharing.

One of these days, I was gonna attempt a multiscale...but was afraid of the cost of a fretboard.

Anyways, would love your thoughts on how the bass turned out.

I checked the other day, and the fretboard material was 3.50euro at Maderas Barber in Spain. Not exactly going to be a bass though, or, actually, also a bass (and also a guitar)
It's weird three bass strings and three guitar strings 28"-25" scale lengths, tuned GCF on the bass side and CFBflat on treble side. Wonder if I'll manage to learn how to play it. (See Charlie Hunter to learn what is possible with an instrument like this)