The FR-1 Challenge[1]

Originally posted in the CircuitMaker blog.

Brought to you by Bantam Tools and Altium

We’re very excited to announce another awesome design competition, open the the whole CircuitMaker, Upverter and Altium design community.

 

Competition Details:

Imagine all the cool projects you could do with a Bantam Tools Desktop PCB Mill. This amazingly high quality prototyping CNC mill is ridiculously accurate – with a resolution that allows accurate milling down to 6 mil trace and space. What’s more, you’ll notice if you have been following my own Sausage Factory project that this mill is not just great for PCB prototyping, but also brass, aluminum, acrylic, wood, craft foam and a host of other materials that can nicely top off your designs.

Over the coming weeks, I’ll be working on a few more blogs and articles showing how to do things like milling an aluminum front panel, or prototyping accurate microwave / RF PCB components. Just to whet your appetite!

The best news is that Bantam Tools have partnered with us to GIVE AWAY one of these to one of our users! And there’s more chances to get awesome runner-up prizes as well. Read on for details.

Grand Prize

Grand Prize: A brand-new Bantam Tools Desktop PCB milling machine valued at $3199 USD. We will ship it worldwide and cover all shipping, taxes and all other costs associated with you having this machine on your desk totally free of any charge for you.

First Runner-Up

One person will be selected for this prize, 50% off a Bantam Tools Desktop PCB mill in the Bantam Tools Online Store. (Valued at up to $1600).

Second Runner-Up

Five (5) people will be selected as second runners-up to the Grand Prize. Each of the five will receive $500 worth of Concierge component credits

Third Runner-Up

Ten (10) people will be selected as third runners-up to the Grand Prize. Each of the ten will be given coupons for PCB manufacturing services from one of our manufacturing partners: PCB:NG, OSH Park, OSH Stencils, CircuitHub, Seeed Fusion, PCBWay. The winner will choose which of these to issue credits for.

Project submission requirements

Only open source projects created in  Altium CircuitMaker,  CircuitStudio,  Upverter and Designer/Nexus can participate. There is no requirement for the design to be a brand-new project, it can be one you started earlier but needed to finish. Designs that are imported from other PCB design software are not allowed. Designs that are recreations of existing open source projects are not allowed either. Be creative, make something new and share it with others!

To “submit” your design, you must:

  • Create a project page for it with complete documentation about the project at:
  • If your project was created and shared on Upverter or done using CircuitStudio or Altium Designer, you must create the project write-up (documentation explaining what it does, why you created it etc.) and include links to the original source files. Using Upverter you can even embed the design in an iframe if you wish. The write-up can be on your own blog site or Instructables, Hackaday, Hackster or Github in this case.
  • Connect with us on Instagram, Facebook, or Twitter with the hashtag #FR1Challenge

That’s it! Make something, write about it, catch us on social. We’ll automatically enter you with the email address on file with your login.

Judging Criteria

Each design will be judged based on 4 simple criteria, sames as last time. Each criteria has certain weight allocated as explained below.

Idea 20%

Collaboration 5%

Sharing 50%

Delivery 25%

Idea

The community has its own voice. 20% of the pie.

Members of the community can cast votes and express their opinion about the design idea behind the project. As a community member you can follow particular design, comment on it, fork it, share it on facebook or Instagramtweet about it so people can come and visit your project page and we can see number of views. Remember to use the hashtag #FR1Challenge! We will look at all those metrics for each project and will compare them to other designs. The more people engage with your project, the more we think this is a good idea!

Collaboration

Let’s make together! 5% of the pie.

Open Source Hardware design is not only about being locked in a garage and making things on your own. It’s also about collaborating with others and solving problems and making stuff together! Create a team and work on the design together. To gain points in this category you will have to demonstrate that your team was using collaboration features in CircuitMaker, Upverter etc., with comments showing how you approached design issues and how you collaborated to solve them. Also you can use the project page to engage with others or the CircuitMaker forums if you need help with something. For example, if your project involves a microcontroller, invite a friend to work on software. Do you need enclosure? Invite a friend to work with the step output for designing the enclosure. Maybe you have a friend that can do a 3D model for some component that you use in your project? He/she’s your team member as well. Just keep in mind that there’s a single machine for the prize that will go to the project owner or team. Maybe you should win it for your school 🙂

Sharing

Show how you made this project and explain how it works. 50% of the pie.

The project write-up. It’s that simple. As you go with your design, document your progress with photos, videos, and explanation of problems you are going through and the solutions you came up with. Share the knowledge and experience with others. Share how you make things and how things work so others can learn from you and innovate on their own! Go into details and become an educator. Explain everything, leave nothing behind! A good write-up and demo videos embedded will go a long way here. As I mentioned above, we love write-ups to be done in CircuitMaker project pages, but if you’re using Upverter, CircuitStudio, or Altium Designer, feel free to use Hackaday, Hackster, Instructables, Github or your own web page or blog for the write-up. Just make 100% certain that we have the links so we can read all about it and see the goodness!

Delivery

The PCB Design project quality. 25% of the pie.

This is the PCB project in CircuitMaker, Upverter, CircuitStudio or Altium Designer. Here are guidelines on how we would like to see things done:

  1. As much as possible, components are linked to Octopart (this is mostly automatic in Upverter and CircuitMaker).
  2. Components are real and easy to get via standard online suppliers. Since we may build the top 3 designs, we need to be able to source those components online. Hence they need to be linked to Octopart correctly so we can use the Octopart BOM tool.
  3. All components have 3D bodies so we can look at it in 3D view. We may want to 3D print them or do enclosure designs.
  4. Schematics are easy to read. Group components based on functionality. Make it dead easy to understand what is going on there. Leave notes, important calculations etc.
  5. Project compiles / passes design rule checks, with Design Rules enabled.
  6. Project is released and public (you are free to use any open source hardware license).
  7. PCB document includes an outline layer with proper board outline. Everything else has to go onto their own dedicated layers – yes 3D bodies as well.
  8. PCB document includes the keep-out layer.
  9. All designators and artwork on the silkscreen (Top Overlay) are easy to read, meaningful and not overlapping with pads.

Basically, follow good design practices. If you’re not sure, and you are working on something then jump on the forums and ask for help – there are plenty of knowledgeable users there and we will also jump in and help as much as we are able.

Altium staff and their family members are not allowed to participate in this competition.


 

[1]Why “FR1 Challenge”? Because the Bantam Tools mill ships with a bunch of FR-1 pre-clad PCB sheets! What is FR-1? FR-1 stands for “Flame Retardant 1” and is the original mass-produced PCB material made with copper foil,  paper sheets and phenolic resin. It is practically interchangeable with FR-4 which is now the most common PCB material, but has no glass fibers and therefore much safer for milling when making prototypes.

Bantam Tools, the BantamTools Desktop PCB Mill and their associated logos are all trademarks or registered trademarks of OMC2 LLC.

Sausage Factory Finale – Milling a Hammond Stomp Box Enclosure

Hi everyone!

With the holiday season behind us it’s time I give you the last installment regarding my Sausage Factory overdrive/distortion project.  I’m from Australia originally, so I grew up with Christmas and New Year’s Day holidays in the sweltering heat of summertime. For most of the readers of this blog, you’re in the Northern Hemisphere so just imagine having Christmas or Hanukkah in July, trying to stay cool in 35 to 40°C (95 – 104°F) in high humidity. Oddly enough we had Christmas trees and watched American Christmas movies wondering what it must be like to have all that soft powdery snow!

These days I live in America, and I’ve come to love the holidays when it’s cold outside. Why? More time for staying indoors doing electronics projects of course!

So these few days out of the office have given me a chance to get some stuff finished with the Sausage Factory project. And thanks to our friends at Bantam Tools, I’ve been able to do some neat things with the Bantam Tools Desktop PCB Mill. In this final project blog for the Sausage Factory I want to show you how to use the PCB mill for something every project needs – a good quality enclosure to mount it in.

A variation of this blog with more machine setup details will be shared from the Bantam Tools site soon – so be sure to subscribe to their blog as well. I’ll come back here and provide the link when it’s ready.

I can’t thank Bantam Tools’ pro’s Zach and Kim enough for their help and guidance – I found little to no information on the web about how to mill a metal or plastic project box with this device, and I know very little about CAM, so this was a first for me and probably will be for many electronics engineers and hobbyists out there.

I broke a couple of bits while getting this right, so read this so you won’t have to!

Here goes…

Designing the PCB for a Hammond 1590BB metal box enclosure

From the start I planned to use a Hammond 1590BB aluminium (that’s Aussie for “aluminum”) project enclosure. These boxes are probably the most popular on the planet when it comes to guitar effects building – even many commercial pedal manufacturers use these because they’re very strong, have a great finish, are available pre-painted, and can easily withstand being stepped on by brutal guitar players.

I chose the 1590BB which is about a double-width of the more frequently used 1590B because I’m essentially putting two stomp-boxes (an overdrive and a graphic EQ) into a single unit:

20181023_145551

Here’s the datasheet: https://www.hammfg.com/files/parts/pdf/1590BB.pdf

Hammond documentation is really good – their data sheets even have a spinning 3D model of the enclosure and lid alongside the 2D dimension drawings. I used those drawing dimensions to set the size of the PCB outline in the Upverter “Mechanical Details” layer, using the dimension tool to make sure I got it right. Most users of course would normally have a DXF/DWG file from 2D CAD as a PCB outline drawing, but I am starting in the PCB and deriving all my data for construction from that.

Since this project was done in Upverter it was quick and easy enough just to draw it based on the datasheet dimensions, but next time I’ll download the DXF from Hammond (they make those available too!)

2019-01-14 14_08_45-SausageFactory (public design) - Opera.png

What you see here is a screenshot from Upverter with just the Mechanical Details, Top Package Outline, and Holes layers enabled. All the slider pots when I created the footprints in Upverter I used the Top Package Outline to accurately place the necessary rectangular slots and 2mm holes for the development of just such a drawing, and slot pattern for CAM in any panels they may be mounted to.

Just a not about the jack portion and room for the footswitches: you can see in the image above, that I placed slots in the PCB between the main circuitry (to the left) and the audio and power jacks (to the right). The design intent was to be able to test the board after initial assembly (which I did in my sound test video in the last blog) and then separate the jack board with a Dremel and connect it with wires for final mounting in the box – there are photos of this below, so read on.

I used the 3D model with the component detail layers exported from Upverter, and those in turn allowed me to make a 2D dimensioning drawing in MCAD:

2019-01-14 14_25_52-Sausage Factory 3D Model from Upverter - Alibre Design Expert.png

I use a few different MCAD tools at different times, but since all the Bantam Tools help blogs and documentation centers around Fusion 360, and since Fusion 360 also includes CAM tools for generating the gcode for CNC milling, I caved in a decided to use it for this project. The tool is nice with a modern UI but doesn’t follow paradigms I’m more familiar with from my experience with Solidworks or Alibre, so it was a bit of a learning curve, but before too long I had imported the STEP model of the 1590BB enclosure, and generated an extrusion for milling the top of the box. Later on I added the larger holes as well for the footswitches. Here’s the screenshot of the enclosure model ready for generating CAM toolpaths for the Bantam Tools Desktop CNC Mill:

2019-01-14 15_24_27-Autodesk Fusion 360 (Startup License).png

Not be glib – I’ll elaborate in a future post as a guest on the Bantam Tools site as to the process, but to summarize, here’s how I made this model:

  • Imported the 1590BB STEP model, downloaded from Hammond Manufacturing’s website.
  • Created three sketches, aligned with the plane of the box surface:
    • One for the slots and potentiometer holes, drawn from my 2D dimensions diagram (above) – this method is very precise because the positions come directly from the PCb components.
    • Another for the footswitch mounting holes (they are not PCB mounted, so these are positioned aligned with box centerline).
    • And the last for the text.
  • Extruded all the holes and slots through the box surface (the top of the actual stompbox pedal is actually considered the “bottom” of the mechanical model for some reason, so I had to re-orient it by flipping the assembly in Fusion 360).
  • Extruded all the text to a shallow depth (1mm or so) from the surface – this is for using the CNC mill to engrave the text into the box surface.

After creating the model, I switched Fusion 360 into CAM mode, and created three separate tool paths for milling.

  • The larger holes are all milled with a 1/8” flat end-mill, to save time. This is setup as a 2D Adaptive cut with the spindle at 16,500 RPM and 150mm/min plunge rate – because we’re using a larger bit we can be a little more aggressive to speed things up.
  • The slots are very fine, as are the 2mm holes for the sliders, so these needed to be done with a 1/16” flat end-mill, using a 2D Contour cut. At first pass I used the 1/32” end mill which was working great and making a very precise rectangle – until it got to the 2mm hole breakthrough and the excess material left in the center of the hole broke the bit! Moving to the 1/16” tool saved that problem because the tool path overlapped enough to not leave any loose materials in the holes or slots. Similar feeds and speeds were used.
  • The text was hard to figure out in Fusion 360. Somehow I figured a 1/32” flat end mill would be able to make nice 3D engraved markings on the box, but no matter what I did it refused to generate a tool path. Then after many attempts and trying different cut types, I used a 2D Contour cut with the engraving bit, and it successfully generated a tool path for the text. This still needs some tweaking – on the first non-painted 150BB box, the tool path was too deep. The text is legible, but looks a bit rough. But by setting the depth of cut shallower by about 0.5mm and milling the pre-painted enclosure, the engraving bit follows the letter outlines and it looks very nice.

Here’s a screenshot of the text engraving toolpath in Fusion 360:

2019-01-14 15_44_11-Autodesk Fusion 360 (Startup License).png

Then, it’s just a matter of post-processing the tool paths into GCODE files for the mill. I mounted the box including it’s base attached with the four screws, using the double stick tape that came with the Bantam Tools setup, to the front-left (lower left) corner of the spoilboard. Aligning this was easy, because the machine is highly accurate and zeros itself whenever you power up.

I created a new mill plan in the Bantam Tools software (formerly known as “OtherPlan”), and set the material to “generic” with the material dimensions just big enough to exactly fit the space of the box plus the mounting tape. Each GCODE pass was loaded into the plan and the tools specified to run them one at a time. Here’s a video I put together to show the process once I had the GCODE ready to go:

The end result looks like a professional, boutique guitar pedal which, well, hey that’s precisely what it is!

 

Sausage Factory – Sound check

Hi everyone,

It’s been a few weeks with a lot going on, not the least of which are some neat Halloween electronics projects.

But as many know I’ve been working on my own start-to-finish build of a high gain overdrive guitar pedal with a graphic EQ section called “sausage factory”. Some folks have told me I should probably call it something different, but for the record the idea did come to me while enjoying a bratwurst with sauerkraut, and it occurred to me a high gain pedal is a bit like a meat grinder… hence the name.

Anyway, a few friends emailed me after my first blog about the project and requested a sound demo. I didn’t have the actual boards from the fab at the time, let alone the assembled prototypes, but now thanks to Altium’s corporate management I have a small lab space, and I’ve been able to get together the parts and do this!

In my last blog post I showed part of the assembly process – using a laser cut solder paste stencil and hand pick-and-place actually didn’t take too long.

In the process however I discovered I had one incorrect footprint – so I did have to cut a couple of traces around the 9V DC input jack and rewire those.

I also found one design flaw (a very minor but nonethelese important one) in the EQ circuit which I have since been able to easily fix with the addition of a single resistor.

In this process I discovered the neat “Notes and Issues” feature in Upverter (CircuitMaker has something very similar called “Comments”) where I can basically highlight a part of the schematic or PCB and write a task, assigned to a specific user, with a description of the change needed. These all go into the issues list and as I address those for the final design revision I check them off:

This was developed for team collaboration on designs, but it is equally useful for an individual designer like me, just to keep a list of changes I need to make when I have time to get back to the next rev. Also, this is useful because I’ll keep the notes and the design as-is while assembling the first 5 prototypes, which I’ll hand modify like the first so as not to waste the PCBs and paste stencil. Once those are together I’ll go ahead and modify the design and check off the issues as done.

Watch this video for the initial sound test, and discovery of the EQ section bug.

Please subscribe, like, share and comment on this video! I need your support to make this better and make more project and technical walk-throughs like this.

I’d like to even do this with you! If you have a cool design and want to share and do a video interview, please email me and we’ll arrange it!

ben dot jordan at altium dot com.

And final PostScript: Here’s a track I was working on after a few more small mods to the Sausage Factory – my take on a classic 80’s pop song:

Sausage Factory Project Update – SMD Reflow (or, 10 steps to a nice prototyping experience)

Well, many of my friends in the Upverter and CircuitMaker world have requested more details about my first project start to finish done in Upverter.

So here’s a quick update. Since I finally got a corner of our office and was given the blessing to use it for making stuff, and since I’ve finally got all the parts, I can show the next phase of the project.

But talk about a wait!! The slider pots took 12 weeks to arrive! I should have checked the supply chain for them in Octopart before designing them into my pedal!

I’m still not ready for final testing yet – stay tuned, but at least here’s an update on my progress with hand assembly of the prototype.

Now, you may not have access to a desktop reflow oven, but if you can afford to get one of the cheaper units, or build one using a toaster oven, then I highly recommend the investment. Believe me, you’re worth the time it saves when building stuff with SMT devices. Even hand pick and place is not too painful once you’re organized – as my video demonstrates here.

But this process, though you may spend a few hours on it, is so much better and faster than it used to be. For a good flow, like what I did in the video, here’s what I recommend to anyone building prototype quantities:

      1. Find a decent workspace with enough bench area to spread out your project. Mine is about 15 ft2 but you don’t need that much, 7-10 ft2 should do the job.
      2. Get a compact desktop reflow oven, or build one, or use the hot plate method if you’re doing SMT parts just on one side of the PCB.
      3. Get some anti-static component trays, with enough 2 in2 compartments to hold your “popcorn components”.
      4. From your Bill of Materials, print out the manufacturer and reference designator columns, and cut them out as labels for each component bin or compartment.
      5. When ordering parts from DigiKey, Mouser, Arrow, or whomever, make sure that you add your reference designators to each component line item so when they ship to you, each bag, tube or tray holding the parts is labeled with the reference designator.
      6. One by one sort the components into their labeled compartments in the quantity needed for your production run.
      7. Print out the top (and bottom) assembly drawings on large (A3 or 11×17) format paper and stick them to the wall in front of your assembly area. I find it helpful to also print out the schematics in case I need to verify a part against the engineered design.
      8. Order the solder paste stencil with your boards, or get them from a good stencil shop such as OSH Stencils. If you have access to a CNC or laser cutter and you know how, you can make them yourself from polyimide or acrylic film. Usually they should be very thin! No more than 1-2 Mils. Make a jig with other scrap PCB material for aligning the stencil over your project PCB. Don’t try to use the stencil without this scrap board jig! If you do, you’ll bend it and the holes will not align correctly with your board.
      9. Pick and place the parts with tweezers or if you have one, a vacuum nozzle. Pay careful attention to the orientation of polarized capacitors, diodes, transistors and ICs. The magic blue smoke can’t be put back in if you insert them wrong!
      10. Carefully put the board into your reflow oven, or on the hotplate. If you can control the temperature you need to – this is the difficulty with using the hotplate approach, you have to watch it closely and remove the heat once you see the solder fillets fully formed. Excessive heat will damage devices and your board may be DOA if you’re not careful. If you have an oven, select a solder heating profile that is suitable for the paste you’re using. Lead free pastes need a higher temperature than tin-lead pastes.

     

Finish up by hand-soldering any through-hole parts you may have, then your board is ready for testing!

 

OSHWA and Altium Live: Done.

Well it’s been a crazy few weeks since my last Upverter and CircuitMaker blog post. There’s a lot going on with the Open Source Hardware Summit at MIT in Boston, and then the very next week I had the privilege of presenting once again at the AltiumLive Summit in San Diego. As a result I’ve been kept from updating the community but… here we are!

OSH – Summit 2018

OSHWA summit was extraordinary as ever. Sponsored by several companies in the open source hardware / hacker / maker community, Octopart, Upverter and CircuitMaker brands were represented. Why do we even care about this event? Because the Open Hardware Summit and the CircuitMaker and Upverter communities share the same spirit – information wants to be free, and we can’t build and improve our electronics unless the work of those who went before us is available to build upon. For this reason, and for the social aspect, I’ve always loved attending these events – to find out what’s new in the community, promote CircuitMaker and Upverter designs, meet old friends, and discuss cool projects people are working on.

There were a lot of excellent talks about the state of OSHW and it’s future, exciting innovations that can only occur because open source collaborators band together to achieve amazing things out of sheer enthusiasm, and improvements at the community level with a new version of the open source hardware certification program.

Up-close view of the OSHWA 2018 badge.
Up-close view of the OSHWA 2018 badge.
Registration Table at OSHWA 2018 – Drew Fustini was rapidly programming everyone’s name into their badge.

Drew Fustini of OSH Park posted video recordings of the main presentations which you can catch up on over at the OSH Park blog: http://blog.oshpark.com/2018/10/07/open-hardware-summit-live-stream/

New Open Hardware Certification V2.0

So what does the new OSHWA certification process mean? It comes down to the Community Definition of what Open Source Hardware actually is. Let me explain it in my words – I’m sure you’ll relate to this story:

I got excited when I discovered “open source” single board computers were made cheaply available to makers. The first of these $30-ish single board computers most people think of in this sense is the Raspberry Pi. It’s a great tool, and the fact that it runs a useful Linux distro with Python makes it especially so. With this information, there are many websites and marketing material out there since it’s release talking about open source development and waving the “open source” flag, but the day I tried finding the schematic and PCB files so I could learn (not even copy, but learn, mind) about the PCB design of the Raspberry Pi, was they day I learned that not all the people out there marketing a product as open source are telling the whole truth. I was angered by this, as I’m sure some of you may have been as well. I’m not knocking the Raspberry Pi designers or even Broadcom for the product – we all agree it’s great – but there is an incongruence to all this which I personally find distasteful. I’m all for commercial, closed and open designs for different things, but if you call something open in your marketing, you should make it truly open.

What I love about the new Open Hardware Certification is that you can’t just slap the official logo on your design unless it does meet the true community definition of open hardware. And what that boils down to is a short list of important characteristics, my personal favorites of which are:

  • Original CAD format files are made available.
    • This has to be the most important criteria. Just putting the schematics in to a PDF or even making gerber files available for download is considered not acceptable to the community definition (I’m looking at YOU, PI clones!)
  • No restrictions on Use:
    • For an open source design to be certified, its use cannot be restricted to any people group, country, industry or business. It’s truly available and useful to all.
  • Software to operate hardware:
    • Any software needed to make the hardware carry out its function either:
      • Has to be also available under a similar open source license, or,
      • Documented enough that suitable software/firmware can be written by anyone with the skills to do it.
  • Does not restrict external hardware or software:
    • Including the requirement that external software working with it be open source. In other words, you don’t have to use KiCAD to draw your schematics, just because you want the design to be open. You can use any CAD tool you prefer.
    • This also means you can write your own custom software or firmware, or design other non-open source hardware, that interoperates WITH this open hardware product. This is an important requirement for open hardware to be able to form a legitimate play in the electronics economy. Without this, we’d not have such a great competitive environment for 3D printers, laser cutters, single board computers, and many consumer devices.

But I cannot do justice to the certification program here. I highly recommend you read about it and follow it through for your own projects as Michael Weinberg, OSHWA President, suggested in his talk at the 2018 Summit. It costs you nothing but a little extra time and attention to details, and it’s definitely worth it.

To learn more, check out the OSHWA Certification Page: https://certification.oshwa.org/

More Summit Highlights

I did get to sneak in a couple of video interviews. So stay tuned for more. This first one was with Jasmine Brackett from Tindie – a maker oriented marketplace where any of us can sell hardware products we designed in Upverter or CircuitMaker!

Altium Live 2018

Old School Altium Live badges - no paperwhites or microcontrollers here!

…Then on to AltiumLive! Me, Camaryn and Christian building camaraderie by attaching lanyards to “old school” badges. Perhaps we can learn from the OSHWA crowd and get on the electronic badge bandwagon for AltiumLive next year – it would sure make prepping the badges more fun!!

Upverter Meetup Oakland – User Interviews

Hi everyone!

CM version of this blog was already posted here: https://circuitmaker.com/blog/oakland-meetup-user-interviews-oshwa-summit

It’s great to see so many new projects all the time. With almost no input from Altium to this Upverter community it speaks volumes to see the momentum here. This is in spite of some people that would cast doubt over the future of this product.

We announced earlier that CircuitMaker is going to be renamed “Upverter Desktop”. We are working to merge the communities and data together – so Altium R&D and Upverter R&D teams have become a single unit collaborating across Kiev, La Jolla, and Toronto offices. These fine factories are feverishly coding to ensure data and user accounts can be brought together without loss of fidelity. As technical folks, you’re no doubt aware this is not trivial. Naturally it will take a bit of time, but so far our R&D team tells me it’s pressing forward, and later this year or early next we’ll have our sites merged and hope to have some beta testing going on well before that.

Meanwhile Upverter is here en force, and we want to keep the ball rolling on all the cool designs and community content being produced. So keep up the great work. There’s more info coming soon, but I’ll give you a tip – we’re rolling out a user generated content incentive program this month. I’ll blog separately about that soon.

In other news, we just had our Oakland meetup event, graciously hosted by Circuit Launch by Oakland airport. These guys have a really big nice workspace for startups to come in and get some serious robotics and 3D printing done, among other things. While we were there I was privileged to get some neat interviews with a few people, working on interesting projects. Check these out below…

https://youtu.be/3kc2MztsxFk

Karlis Veilands shares his build of BlueSaab 6.1 – designed in CircuitMaker by Seth Evans – and explains the movement of “Saab addicts” who needed a solution for integrating Bluetooth audio connectivity into their 1990s-2000s Saab 93 and 95 models, replacing the old factory CD changer with this module to provide all modern conveniences of phone connectivity in the high-end audio system of these luxury vehicles. There are now quite a few BlueSaab users and a vibrant forum and community support the product. It’s for communities of collaborators like this that we wanted to make sure the open source community had access not just to PCB tools, but the most productive.

https://youtu.be/LdzsFXcNKYE

Alex Wayne is a software developer by day, and an LED kinetic sculpture artist by night. What do you need when your normal line of work is not doing hardware, but you need to do hardware efficiently for your side projects? You turn the the most productive tools with the simplest user interface that’s what! And in Alex’s case, he switched from EAGLE and KiCAD in his earlier attempts to Upverter. Now he’s designing boards for some pretty amazing APA102 LED based kinetic art sculpture work – commissioned by the city of Santa Rosa CA. See his  interview to discover more about this interesting project.

Our next meetup isn’t actually ours!! Our next meetup will be the Open Source Hardware Summit – this Thursday at MIT in Boston. We’ll be emailing the CircuitMaker and Upverter Bostonians in a day or two with more details. We would certainly love to see you there! But even if you can’t get the day off for Thursday, perhaps we could catch up Wednesday evening at a pub in Cambridge? Either way, I hope to see you there or at our next meetup which will be in the Los Angeles CA area. Keep designing cool stuff and I’ll report back here again soon!

 

About the Sausage Factory Project

My First “UPVERTED” Design

In my earlier post about taking the plunge and forcing myself to learn how to use Upverter, I mentioned the project I was working on was a new guitar overdrive / distortion pedal I named “Sausage Factory”.

Well, some friends got back to me and requested to see what was in it – just out of curiosity, so although my original intention was to keep this a private project, I figured it would do no harm to share and describe more about it.

Every design should begin with a design specification. Mine was very simple:

  • Marshall style high-gain front-end.
  • Fender/Vox/Marshall passive tone stack (Bass, Mid, Treble)
  • 7-band Graphic Equalizer similar to the Mesa/Boogie Mark IIC
  • Individual footswitching for the OD section and Graphic
  • Fit in a single hammond 1590BB metal box
  • As low noise as possible.

I used an opamp based graphic. I knew I could probably do all this in DSP based on Eli Hughes’ Monkey Jam, but since I’m learning Upverter at the same time I figured this design would stay in the analog realm so I could have more going on with the PCB. This will be harder and take longer to assemble my prototypes by a long way, since there’s a lot of 0603 parts in a graphic EQ!

This one was done first as a module in Upverter so that I could place this graphic EQ into any future designs very easily. I like the the physical design reuse aspects of Upverter – this is not just a device sheet or sheet symbol but a full hierarchical reuse block which includes the pre-routed PCB layout for it.

I’m specifying LM4562MAX/NOPB parts in this project because they are the best low-noise opamps right now which are affordable and useful at lower gains (such as in the EQ section where the gain may be 0dB or up to +/-12dB)

GraphicEQ_Schematichttps://upverter.com/eda/embed/#designId=1bbbd2511f352cc9,actionId=

The opamp gyrators were set to have Q factors and frequency bands similar to the MESA/Boogie Mark II head’s graphic, but there’s no way to get it exactly the same because it’s not the same circuit. The target center frequencies are 84Hz, 240Hz, 400Hz, 1KHz, 2KHz, 4KHz and 8KHz. The Boogie was designed a long time ago, before opamps were cheap enough or low noise enough to be used as gyrators, so that circuit uses tank circuits with real inductors and caps and resistors in series. There’s no end to the audible nuance in such things, but for my intents this is enough to make great tone, and finding the right inductors to use to faithfully copy the Boogie EQ circuit would render this project prohibitively expensive.

I created a new project after the GEQ7 re-usable module for the main overdrive pedal. This is the Sausage Factory – I named it this because it’s meant to be a meat-grinding face-melting distortion capable unit.

SausageFactoryPCBhttps://upverter.com/eda/embed/#designId=59034a1ef51ae755,actionId=

As with the EQ modules, I’ve used LM4562MAX/NOPB opamps throughout. I’ve used those before in other high-gain designs like the “Screamin’ Dolly” and they sound amazing, yet have extremely low noise. The Screamin’ Dolly next to a TS-808 will give the same tone but way less hiss because of these opamps. Similar to the TS-808 and TS-9 in this design I’m using an input buffer with a 2N5088 transistor configured as an emitter follower.

You can see the gain stage is followed by a higher voltage clipping circuit as used in Marshall Preamps, where they used a diode rectifier bridge, shorted with an additional rectifier (Silicon) diode between them. This provides a clipping voltage of about 1.5-2V as opposed to many overdrives using a single pair of back-to-back signal diodes which will clip hard at about 0.6V. The circuit here is better for a more natural head-like overdrive, and for driving the following passive tone stage. After the tone stack is a buffer with a small amount of additional voltage gain (6dB), a Master volume control pot, and then into the EQ.

Both sections – the preamp/overdrive and the graphic EQ, have pin-headers for ribbon cables to go off the board and be soldered to the 3-pole double-throw try bypass footswitches. I have a big bag of these footswitches from China ready to go…

I keep hearing about more and more PCB prototyping fab services, one of which is PCBWay. They seemed to be fairly low cost and promised a very fast turnaround time, so I went ahead and ordered the bare boards to be made there. I had them back in 2.5 weeks which was pretty fast for an off shore fab.

The quality seems good, though my silkscreen coudn’t easily be edited to show all the graphic EQ reference designators properly – so I’m just going to have to use Upverter interactively while I put these prototypes together, as a “living” assembly drawing.

20180726_153156

The boards were vacuum packed well, and I ordered their minimum prototype run of 5. I also ordered the stainless steel solder paste stencil – I’ll do another post and video when I use it to show how to use a stencil and desktop reflow oven for soldering the parts onto the boards.

20180726_153435

So, this is an honest quirk of Upverter when you use re-usable modules like I did for this EQ section – it prefixes each module reference designator with the hierarchical parent designator of the module instance. So all these reference designators begin with GQ: that’s not a bad way to handle this hierarchy. However I was not able to move the silkscreen texts in the main board, so many of them ended up cropped by the solder mask openings…

Oh well, one more thing we will improve with Upverter I guess!

Stay tuned for more posts when I put these together and do some testing.