Monday, December 13, 2010

EAGLE settings for milled PCBs

Edit this post to contain info pertaining to best practices for EAGLE milled PCBs (tracewidths, hole widths, etc).


Friday, December 10, 2010

Oakley TM3030 Build

I'm building an Oakley TM3030 for myself and a friend.

Here's the link to the product page:
Oakley TM3030. From there get the board, PIC, and 2k tempco resistor.

Here's my frontpanel design:

Here's the BOM, almost ready to ship on Mouser. Mouser BOM. You just need to source a few easy to find parts that have sold out since my order.

After that you also need to get dual 50k linear pot for resonance control and some rare parts:
2SC1583 | 2/each
2SK30-Y | 1/each

Instead of the 2SC1583s you could use the other part as suggested in the build manual, I believe they are SSM2010s. I happen to have the vintage part on hand.


Wednesday, December 8, 2010

Modules to start making in EAGLE

Seems like a good idea would be to make software that could convert from PDF/GIF/JPEG to drill plans.

Also look here for cheap parts

For panel engraving with CNC

This Page seems to have a ridiculous number of modules.

Minimoog and dual-MS20 filters from this site:

Maybe more details here for minimoog vcf:

Scott Stites' page has details re: HP output on the MS20 filter.

VCO-1 would be great but has no saw output. No good. Maybe can waveshape it?
TH SN synth looks really fun as a synth or module. I think I will do that eventually but not first. First I want warm vintage-sounding VCO.

  • JH Living VCO
    • 3 VCOs, 27e for board, not 12v, saw & pulse out
    • Good choice, cheap board for 3 VCOs (27e), but big panel needed
  • Teezer
    • 1 VCO, $35 for board, 12v,
    • Good unique sound but more expensive at $35/OSC

  • Sheboygan
    • TH design, 12v?, Sine, Triangle, Square, Pulse, Ramp, -1 suboctave, and -2 suboctave
  • Ken Stone VCO
    • This site shows another take on this without the waveshapers. I'd want the waveshapers.

  • TH 566 VCO
    • This mentions using a tri->saw converter. Could add that to the VCO-1?

Need ADSR (PAIA dual?) Need LFO - MFOS VCLFO Need VCAs - MFOS VCA - Decide VCAs based on info found here. Need mixer S&H Need slew generator 808/909 BD/SD? Maybe MFB?

To use up my parts I have:

BA6110 based VCA? Apparently I can get plans for this from tony allgood (oakley modular) for a few $

PTC2399 VC echo?

Labels: ,

Tuesday, December 7, 2010

Paia Fatman

Just recorded a little demo of a Paia Fatman. I'm selling this unit. Hit me up in the commments.


Cheapest/best kit available?

Another option is to get a kit from Zen Toolworks. They seem to be the best option for DIY kits in the size and price range I want (small and affordable).

Cost would be:
Kit - $329
Spindle - $70 - not the best but I think a good start and the benefit is it's built to fit. Could replace motor afterwards maybe?

Still needs power supply and controller board.

Zen sells a controller board for $130 but I think I could DIY one for a lot cheaper. The part used by the Mantis is unfortunately SMD-only. Other options?

Looks like total cost then of ~$500. Not great, but better than $350 + endless time.


More on (Stepper) Motors

So, I will fully admit. I know next to nothing about machining. I know even less about gears, collets, shafts. The only bearings I've ever used were on a skateboard. Most of the reading I do on CNC-ZONE could be summarized as one big "that's what she said". I'm working on it, so bear with me.

"Hey, lets build a CNC"
"Ok cool, let's get some motors on ebay"
"This auction is for a new Applied Motion Products NEMA 17 sized precision stepper motor, part number 4017-871. This double-ended stepper motor has a 303 stainless steel shaft with a 19 tooth, 120 pitch, 20° pressure angle, pinion machined into one end of the shaft. The other end of the precision 5.000 mm diameter shaft extends 11 mm (0.433 inch) beyond the motor housing."
photo by Kristian D.

Lets work through that step by step shall we?

"NEMA 17" - Describes a standard for the size of the mount for the motor. Mounting holes for the motor are 1.7" apart, looks like this.

"double-ended stepper motor" - the axle sticks out the back.
"303 stainless steel shaft" - 303 is a grade of stainless steel.
"19 tooth, 120 pitch, 20° pressure angle, pinion" - A pinion is a small round gear. The pitch and pressure angle of a gear are a bit more complex:

I asked an architect friend about this and he said:
- P=N/PD for diametric pitch.
- circular pitch = 3.1416 / diametral pitch

I couldn't get the math to work that well but I'm sure I'm doing something wrong. Not sure what though :). The key things to know is that the pitch and pressure angle must match for any gears which work together.

"machined into one end of the shaft" - Thats what she said.


CNC Electronics: Choices

Some random facts I've learnt about CNC electronics:

- there is math involved with deciding optimal voltage for motors, and subsequently deciding a large enough power supply and drivers. A lot of the "kits" on ebay are of badly matched components that would not work optimally.

The most important thing with a CNC build is apparently you need to understand this is an entire hobby in itself: the learning, building, maintaining of a CNC. It's not just purchasing a tool that will then output parts.

The upside is great though, a CNC would be an excellent start to many home fabrication business (tons of art options, hobbiest support, synth building, pedal building, etc, etc)

This website seems like a great resource for starters, walking through a lot of the terminology and choices involved in a CNC build. The rest of this post is a lot of summarized info stolen from that crevicereamer link. (what a name)


For PCB milling around 60-80 oz./inch NEMA 17 motors should be more than sufficient. Trying to find numbers for wood and thin aluminum.

"BIPOLAR PARALLEL" wired steppers are the best design for CNC as they maintain their torque at high speeds.

"Stepper motors need around 20 times their rated voltage to perform at their best."

"For the EXACT Max/Best power needed for a stepper motor the formula is 32 times the square root of motor inductance in mH. EXAMPLE: A motor with 4 mH inductance would need a 64 Volt PSU. The PSU must be sized for the lowest voltage motor--So a 64 Volt motor combined with an 85V motor would need a 64V PSU. You would then pick the PSU that is at or as closely below 65V."

"AMPERAGE: To determine the PSU amperage required the formula is 0.6 times total motor amps. EXAMPLE: Ampere rating for three 3 Amp motors would be (3+3+3) times .60 = 5.4 Amp PSU. Some apply a safety margin and use 0.67 as a factor instead. You only consider the Amps for ONE phase of a 2 phase motor. A motor rated at 3A per phase will count as 3A in the calculation--NOT 6A."

From Amazon, this looks like a decent deal: Zen Toolworks CNC Carving Machine


Monday, December 6, 2010

PCBs & Panels: CNC vs Etching

EDIT: I decided to get a DIY CNC kit! Read about me putting it together I'm trying to decide for my next generation of synth building what to do.

On one hand there is the Mantis mini-CNC which costs around $200-$300 to build.

On the other hand, do I need to go that far around to get to a closer goal? I'm considering using stickers on aluminum panels + drilling them, and etching circuit boards using chemicals. It would save the otherwise relatively large task of building, maintaining, and learning to use a CNC and I could get to modular synth building immediately. It'd also keep my startup costs down to almost nothing, selling one or two of my current DIY synths would be more than enough to cover the startup costs involved.

It's not as exciting but I'd have the starts of a modular finished within months instead of a year.

link summarizing PCB making:


Sunday, December 5, 2010

MFOS Soundlab

Just about finished this synth project. More info on the Music From Outer Space Soundlab can be found here. Yes it's a ratsnest inside but there was no real alternative to get this synth into this small a case. There's a ton of point to point wiring you have to do on the panel components, and for that reason I'd never build another one of these.

Still need to find and fix squarewave LFO problem and noise problem. It's probably the same problem the way they're interacting.

The sub-oscillator doesn't work. I thought I could just feed the squarewave output to the 4024 but apparently I'm missing something. Will know when my oscilloscope probes arrive.

My goal here is to move past these toys and start a modular. It's the end-all synth if I'm working on analogs. Having the ability to swap filters is too exciting compared to what I'm working with on these minisynths.

That being said my next project is a pair of Oakley TM3030's for myself and a producer friend.

Labels: , ,


slower by Gravitronic


Living in the cloud

Well my hosting ran out today so time to move to the cloud.

Here's some music I've made in the last year: