Front Panel Engraving

After quite a time of experimentation, my cnc-engraved front panels are starting to work out really well.

The last few days I've been trying to clear some of the backlog of pcb projects picked up including:::
Fonik's SSM2044 LowPassFilter









Two Thomas Henry UD1 DrumSynths with PCBs from sMs Electronics









Thomas Henry Super Controller with PCB from Fonik
- this circuit comes from TH's Build a Better Music Synthesizer book (good book!)









PT2399 delay project - previous versions have had some niggling problems to iron out.










The technique is now relatively smooth though it still takes a while for the machining:
Front panels designed in FrontDesigner
Exported as .hpgl engraving files
Loaded into EasyCam to generate the machine files for Mach3 - set the engraving depth etc
Mach3 drives the CNC engraving. These are the first uses of custom blank panels I got made up locally (at about 1/4 of the cost of blanks from Paia!) - simple Frac sized black-anodized panels. The engraving cuts through the black surface to expose raw aluminium. The only tricky bit is to make sure you engrave deep enough, but not too deep (literally a difference of fractions of a mm)
Once engraved, the holes are drilled
..& the project is put together.

BugBrand RingModulator

Here's a new BugBox - I was asked to make a custom ringmod for someone recently.. I figured it would be worthwhile making a couple as I'd got the parts. So here's details of the box::::

Built with modular techniques, this is a two input all analogue ring mod built with the powerful AD633 multiplier chip for quality operation.

You can either ring modulated two input signals (or feed the same signal to both inputs for great & wierd octave-up effect) or one input with an internal varispeed oscillator.

- 2 input preamps - independent gain, mono inputs accepting mic or line levels
-- internal varishape oscillator with triangle and square waveforms and speed variable from slow tremelo up to hyper freqs (three way speed switch plus rate dial). The waveshape changes the triangle from ramp-down through triangle to saw wave (ie changes the harmonic content greatly) and squarewave is changed from narrow pulses through to pure square
--- ringmodulation of either In1 vs In2 (don't see that so often?!) or In1 vs Osc. The Osc setting allows so many sounds ranging from smooth or hyperharsh tremolo up into screamy pure noise ringmods - the varishape and varispeed give so many different sounds.
---- output mix to blend the ringmod output with dry1 and dry2 signals
----- modular expansion connectors on the back -> direct 4mm banana outputs from the two preamps and from the oscillator allowing hookup to other modular devices. Standardised output levels ideal for most modular systems.
------ chunky metal case, engraved faceplates, big-assed nicey knobs.
------- AC power (supplied)

So, the 1st box has now gone to the original instigator and the 2nd one is being offered to people on the Bug-mailing list.

New Weevil Prototype

So, finally, here's the new Weevil07 prototype. This proto is a bit of an experiment to try a few new techniques. I've not scheduled proper production yet, but will be doing a couple more prototypes shortly - these'll certainly be a little bit bigger as this design is a little too cramped - bigger touchplates, better knobs and spread a bit further apart. Must add the internal speaker too...

The New Stuff:::
Front Panel - this tries out some CNC ideas. Its made from an engraved PCB (tinned) with 9 contact plates and dial engraving around the knobs. I've chosen not to add labels for the controls.

Oscillators - again, like previous Weevils, you get two oscillators that are ring-modulated together for a bunch of audio chaos. There's a switch for low or hi freq and there's a new pulse width control for each osc - ranging from 50% sqr wave up to a very narrow pulse. The low power circuitry is a bit different too - again this just starves the oscillators, but behaves quite differently from the old designs.

Filter - this is much more powerful than other Weevil filters. Actually, its similar to what I used on the one-off Weevil Knievel - a 2pole resonant low pass filter - pretty gnarly with the resonance turned up.

Touchpoints - there's 3 points for each osc (two pitching and one pulse width) - the outside sets of touchpoints. The central 3 are - ringmod output, ground and filter mod (touch this to open up the filter)

So, as I say, general production is still a way off, especially with a bunch of projects coming up for me... Stay informed with updates via the BugBrand mailing list

& here's a new YouTube demo of it:

Broken Bits - CNC Update

The CNC router work is really coming together now. As always, learning involves making mistakes so I've busted a good few router bits figuring out the limits!

The first picture is an engraved name-plate badge (to wear on my labcoat for live shows - yes, tongue-in-cheek) using sheet aluminium. This is a good test for making front panels - I've been using Abacom's FrontDesigner software (good value!) which exports .plt files which are then imported into Lazycam which comes with the Mach3 routing software. Initial tests had had the scaling all wrong, but I've now figured how to set things up in Lazycam and its all working good.

The 2nd image shows PCB isolation routing - automated circuit board manufacturing or at least semi-automated. Using Eagle and PCB-GCode (available from Cadsoft) you generate two files - one with routing info to route out the tracks and then a 2nd with drill info - change over the bit and set it to run drilling all the holes. Having used Press'n'Peel, ferric chloride and a mini-drill for pcb making for the last few years, there's great joy in seeing the CNC machine working its ways with the copper clad board!

1st pics of my DIY CNC Router

-----computer controlled cutting machine!

The last month or so I've been gradually putting together my own CNC (Computer Numeric Control) router machine and last night I finally got to do some testing / cutting (though things didn't quite work out straight away)

I've wanted to explore CNC for a while, but even going the DIY route its not cheap to get into. I purchased a router kit from CNC Kits & Bits (wooden kit with a large travel area) and then got the driver boards and stepper motors from Routout CNC. Both of these companies are UK based - I'm sure there are options for people elsewhere in the world.

So, after building the machine, adjusting the bearings, fixing on the stepper motors and wiring them all up..... time to try to figure the Mach3 routing software (a pretty complex program) and how to get my circuit designs from Eagle into the required GCode for Mach3. The first attempts got things working a bit (along with also things going a bit out of control - I broke a router bit by rushing ahead without thinking -- moral -> go slow!). A program called PCB-Gcode, run from within Eagle is used to generate routing data (and also will provide drilling data -- auto drilling of all the pcb holes! No more hunching over the dremel drill).

Well, as you can see, I got the settings a bit wrong - routes were cut but I certainly need to tweak the PCB G-code settings some more. Once I'd returned home from the workshop I looked more at the software -- the router needs to do several passes over the board, routing out a little more each time it goes over and running at a very fine resolution. I could see where I'd gone wrong when I started figuring out the path viewer in Mach3. Hopefully I get to try the process out again today...