Right. I thought this might be worth documenting in case anyone else is interested. As you'll see, my approach is based on overthinking and overengineering everything I can.
I am rather fond of my Line6 Helix, but having previously used a pedalboard with a Headrush the need to switch to a different screen to control the looper is somewhat irksome, particularly as I'm used to leaving the looper in overdub mode and changing sounds to play each component part. On the Helix that means a lot of flipping between screens and therefore a loss of "flow". Not that I'm particularly great at it.
The Helix manual lists the MIDI CC messages to control the looper. I know which end of a soldering iron not to pick up. It therefore didn't seem a Herculean task to build a discrete control pedal for the looper so that I can leave the Helix in normal control mode but work the looper from a separate set of buttons.
At the same time, the lack of MIDI clock functionality in the Helix was limiting what I could do with my Source Audio Reflex. Only a little, but still limiting, so some way of incorporating MIDI clock seemed a good idea. Ha ha. More on that later.
A few stages first before anything gets built:
- I used MIDI-OX (jolly useful bit of free software) to test that the Helix does respond to those MIDI CCs when not in Looper control mode. Turns out it does. Good start.
- I checked that I could get the Helix Tap Tempo footswitch to send a MIDI CC every time it's pressed. Yup. Plan forming; send a message whenever the footswitch is pressed, and have something downstream time the pulses and generate MIDI clock in time. This has some limitations but it'll be good enough until (hopefully) MIDI clock is added to the Helix.
- Research. There are a load of MIDI controller boards out there - MIDICPU is well supported and will definitely do all the looper control stuff, but won't do the clock stuff (as far as I can work out). I could homebrew something with Arduino but that's another rabbit-hole to get stuck in. I ended up finding MIDI-Kits and a couple of emails later had a MIDunio with breakout board and software all built up. It took a few more versions of the software to get it working correctly (MIDI clock still isn't quite there but progress being made) but all ready now.
So the build begins. I couldn't easily find a sensibly sized enclosure for the footswitch, but there are plenty of cheap amp footswitches out there - the bonus being that they have the switches already inside too. After a few things went for more than I fancied on eBay I bought myself a TC Electronic Switch-6 - preloaded with six momentary footswitches on a nice PCB that links earth across them all. A few cheeky mods to the PCB, enlargement of the jack hole to take a Cliff 7-way socket, some light sanding & a lick of spray paint and all looked good. I had some vinyl lettering done (at www.vinylletteringonline.co.uk - no affiliation but it was quick and good quality). Also came up with a name; FIGLA. FIGLA is a helix-loop-helix protein. See what I did there?
Finished footswitch bit - the brains will be in a separate enclosure:
http://www.monkeyfx.co.uk/pictures/builds/FIGLA/FIGLAtop-sm.jpg
http://www.monkeyfx.co.uk/pictures/builds/FIGLA/FIGLAback-sm.jpg
"[Sporky] brings a certain vibe and dignity to the forum."
Comments
Because of the sizes and shapes of the various bits (and because I needed some CAD practice) I decided to model all the bits in Rhino3D to make sure they'd fit around each other; I can then print off drilling templates to make sure everything lines up neatly (particularly the MIDunio board, which will sit on 5mm standoffs screwed through the lid, but also has connectors that need to go through the side). Skip a few hours of measuring things with verniers and making models of connectors and such and we have this:
http://www.monkeyfx.co.uk/pictures/builds/FIGLA/brainsrenderFL-sm.jpg
http://www.monkeyfx.co.uk/pictures/builds/FIGLA/brainsrenderRR-sm.jpg
Those transparent orange cylinders show where the wires will come away from the connectors, so I can be sure they won't foul the board.
That lets me plot the hole positions:
http://www.monkeyfx.co.uk/pictures/builds/FIGLA/brainsencFL-sm.jpg
So next I'll extract the surfaces, mark the centres of the holes and print that onto a bit of paper so I can transfer the positions reasonably accurately to the enclosure. Alternatively I could make up drilling templates on on of the CNC machines, but I'm only making one of these and experience from making the ValveSporkers tells me that a paper template is accurate enough for this work.
http://www.monkeyfx.co.uk/pictures/builds/FIGLA/brainsdrill-sm.jpg
http://www.monkeyfx.co.uk/pictures/builds/FIGLA/papertemplate-sm.jpg
http://www.monkeyfx.co.uk/pictures/builds/FIGLA/brainsencFL-sm.jpg
That'll do, pig, that'll do. Next step is to centre-punch all of those holes, remove the template and write the sizes next to each punch point.
So enclosure punched and marked:
http://monkeyfx.co.uk/pictures/builds/FIGLA/encmarked-sm.jpg
Drill the top first; all 3mm (which is also a decent pilot size for the bigger holes). A little drop of cutting fluid on each or the swarf tends to stick to the drill bit. Also, kids, remember to wear barrier cream, eye protection and ear defenders for this sort of work.
http://monkeyfx.co.uk/pictures/builds/FIGLA/topholes-sm.jpg
Then same deal for the side and end holes, but using a vice for stability and safety. For the bigger holes I use a step drill, nice clean holes and the same bit will go up to 24mm. Cutting fluid is even more important for the bigger holes as they're cut at a lower speed.
http://monkeyfx.co.uk/pictures/builds/FIGLA/stepdrill-sm.jpg
Then a quick go with a 220 grit foam sanding block and a spray and wipe down with isopropanol. I'm not going to bother painting this as it'll sit out of the way.
http://monkeyfx.co.uk/pictures/builds/FIGLA/drilled-sm.jpg
On a ValveSporker I'd countersink the PCB mounting holes so that the heads sit below the surface slightly, then fill the screw heads with liquid metal epoxy, sanding it down flat. Again, this doesn't need to be so pretty so next step is assembly and wiring.
:-O is that what Lady bMcH means? I always thought Sporky was married to a dyslexic Lady McBeth.
Surely that'd make me the dyslexic one?
Terrific job, well done!
Not sure I can work a camera and a guitar and this all at the same time. Let alone make the results be on the inferweb without any fires.