Future project

Here's an instrument which I'd like to make some day:

• Three string blues slide guitar
• For playing seated
• Sliding nut
• No strap
• Spine: 30 X 12 mm aluminium rectangular beam - freely vibrating
  
• Piezo pickup on aluminium beam
• Sliding pickup under strings- probably an ultra flat one with few primary windings and a current transformer.
• Plunger tuners (this principle)
• Minimalistic ergonomic body - the first version would probably be made from heat-bent acrylic plate

To-do list

Nothing much has happened on my T-beam-bass lately. I've replaced the jack connector since the old one didn't work and clamped the connecting cable going from the jack more securely to the sliding bracket. Plus, I've borrowed a friend's bass to do some comparisons of sound, feel and ergonomics.

His is a 34" bass, and though the picture doesn't really show it, mine, with its 30" scale length, is much smaller and lighter.

My bass still isn't exactly pretty, but I do intend it to be so one day. But until now (and probably some time ahead as well), most of my focus is on experimentation rather than looks.

Nevertheless, in an attempt to convey an idea of what I expect it to become some day, here's a list of some of the things, I'd like to do next:

• Make the saddles lengthwise adjustable for intonation, i.e. making slots for the saddles and fastening them with nuts.
• Shape the neck as shown on the image . I have to modify the sole plate of my jigsaw to be able to do that.
• Make a prettier and more ergonomic shield in 5 mm acrylic (that's approximately 0.2"). The current one is just 3 mm thick, and it's too fragile and flimsy looking.
  
• Make mahogany sides rather than the current spruce ones. What's keeping me back here is that I'm not quite sure yet where the holes for the shield are going to be, and I'd rather keep the mahogany intact and experiment on the spruce.
• Decide whether I like the sound of the vertical pickup. If so, I'll tidy up the bracket. If not, I'll buy a P-bass-pickup and use one half of that in a new bracket.

A slightly prettier sliding bracket

I've made a sliding bracket for the small pickup. It slides with little effort and easily picks up the different antinodes of the strings. Unfortunately, the pickup itself doesn't sound that good, so one of the next steps might be mounting one half of a P-bass pickup in a similar bracket - or perhaps have two sliding brackets and the usual switching arrangement.

Trying a good, well-known pickup should give me an idea of what the instrument sounds like and make it easier to find out its particular characteristics.

The system of cable and female jack on the body also works fine. I plan to add tone and volume pots down by the jack at some point.

A sliding pickup

There has been several attempts - by for example Westone and more recently Norton Guitars - to make a pickup that can be moved to the areas of the strings where different antinodes and their corresponding overtones are located. This gives you the sound of a neck pickup, a bridge pickup and everything in between. Though only one at a time.

The T-beam bass and the bracket for the humbucker pickup were too obvious a candidate to not trying something like this. And since I allow myself an impulsive and unstructured approach to my hobbies, I gave it a try.

The pickup bracket has nylon cable clips screwed to it. The clips grip the edge of the T-beam top flange and allows the whole thing to be slid easily along the beam. It was necessary to isolate the pickup from the vibrations of the guitar body (hence the rubber bands and foam padding). If not, the vibration characteristics of the string on the pickup's location would be hardly audible compared to the much stronger body vibrations also received by the pickup. Isolating the pickup also significantly reduced the noise of the nylon clips sliding along the T-beam... nice, because now it is possible to slide the pickup "in-tone" and hear the subtle changes of the timbre of the string.

The bracket and pickup is big and heavy, so one of the next steps will be making a sliding bracket for the much smaller between-strings pickup, which I made earlier. The small pickup should also be better at sensing a small section of the string, where the humbucker due to its length picks up a lot of vibrations - including the unwanted ones. With the big pickup, you can easily hear the difference up and down the strings, but the effect isn't exactly striking. I hope and believe that the small one will do a better job.

I had to rout a channel in the wooden sides for the nylon clips. With everything on, in the afternoon sun, it looks like this: