Cheap enclosures ?

Been searching for plastic and aluminium extrusion for constructing my horizontal "Capacitive ribbon" sensor prototypes, and came across a load of "Dado" "Chamfered" trunking, designed for fitting on walls to house sockets etc.

These come in all sorts of styles. and are of this general form:

End pieces are available, one can get them with RA or angled "bottoms" and "tops" and they can have independant or combined covers as this:

from here.

Only bummer is I havent found them available in less than 3M length, at about £10 / Metre, end pieces at about £2 each..

But my thinking is thar with a bit of wood re-inforcement on the base and inside, it will serve my purposes as a prototype housing for the control box of my C-ribbon (I need 1 metre length, and theres no available enclusures for this) but that it may also be useful for anyone wanting cheap enclosures for prototype theremins.. the angled section could be ideal for mounting pots / displays etc.

I havent got this stuff yet - highly doubt it will be a good idea for any serious home brew or product designed to last (have no idea how tough it is) so I ma looking at it just as something to use for proof-of-concept - much easier to get someone who knows about fabrication or woodworking to implement a sensible construction and quote for a bespoke part if you can show them a model of what you need..

Fred.

I thought about this with respect to theremin enclosures a while ago and have a suggestion.

My line of thinking went like this...

Who makes the theremin enclosures I like most? Dominik Bednarz.

What does he do? Uses long thin enclosures.

Why? They provide the physical separation required between the pitch rod and volume loop.

What restrictions does this impose? Long, thin circuit boards.

Are there any advantages to that? At a guess, physical separation of different parts of the circuit reduces RF interference, parasitic capacitance?

Who else has a hobbyist requirement for long thin boxes? My mum did. Bingo!

http://www.sewandso.co.uk/Products/Wooden-Knitting-Needle-Box---Large__SEW-31-fslsh-115-fslsh-1.aspx

>> "Thank you Gordon!"

I have to agree here... Dominik makes the most aesthetically pleasing theremins out there! I love mine, still play it frequently and enjoy it tremendously!

Ha! I hadn't seen your knitting needle box theremins. :-) 

My sister played flute in high school and I always envied that small instrument case for portability.  Something like a plastic hard-shell flute case, maybe with hinges that allow the lid to be removed, would be nice for a Theremin.  I also keep looking at double walled plastic blow-mold cases made for long wrenches.  But going air-core means these kinds of options are probably out.

Amey, always a pleasure :)

I suppose some of this as a contest between function and style - The best would be if there were no contest and one had both - But I have little artistic sense of style so function wins! ;-) [ absolutely no disrespect meant, Dominik - but I find nothing appealing about the knitting boxes! 8-]

For me, sloped access to the controls is essential - and here the Theremini IMO wins.. I would prefer a plastic enclosure which facilitates this to a wooden one which doesnt - but a wooden enclosure with a sloped control panel is my idea of function and style being combined.

I suppose that for "usual" theremins, particularly simple ones (few user controls) a sloped control panel isnt that important - for what I want, its essential - both for theremins and for theremin / tannerin related instruments.. My designs (even the simple ones) have lots of controls - my H1 pitch only had 5 controls just for tone shaping.

My new "tannerin like" instrument (a theremin with a horizontal pitch "antenna" that behaves a bit like a ribbon - as in, senses horizontal position not hand distance from it) is absolutely packed with knobs - its one meter long, and a sloping 1m control panel with a single row of knobs along it is my ideal implementation.. I was really looking for an aluminium extrusion for this - something shaped like this or similar:

Anyone knowing of any extrusions in any material, which is similar shape and available in lengths of more than 60cm (ideally available up to 1.5m - I dont want less than 80cm for my horizontal products and could want more than 1m, but 1m is about right - but am also interested in shorter lengths for theremins), please let me know!

(at present I am thinking about prototyping with plastic extrusion having alluminium tape unside to emulate the electrical charactaristics, then getting either extrusion made, or having aluminium sheet bent, or a wooden casing of that form with inner conductive coating - I think bespoke extrusion will be too expensive unless I made about a km of the stuff.. Possible if I was to produce and sell enclusures for other purposes as well, but too much for the theremin market!)

Fred.

Gordon: i simply hadn't documented them online. Not too much space inside those, so your idea might be the better one to work with. Though the lady and the cat are missing..

The price of those knitting boxes certainly is good - and the size also.. Great idea for DIY.. Its one of the things about electronics, particularly theremins.. You cant really do an optimal design without first deciding what box its going in.. Everything from the PCB size to the antenna (particularly loop) is impacted by your box choice.

Dewsters square sewer-pipe ideas were extremely tempting - and I may yet go that route and angle the pipe at 45 degrees in some structure to get a sloping control panel.. But it would be a bit more awkward to assemble.

One other great enclosure I have used for one theremin was a hard case for pool cues.. These came in at about £30, but I have seen some cheaper ones... I used this for one loop-less theremin (the volume antenna was built in using copper of the FR4 board I used for the panel)

Fred.