PART 2, SCREAMING CIRCUITS AND THE MAKER COMMUNITY

My last post mused on the affordability of assembly at Screaming Circuits for the maker/very small business/kickstarter community. My hypothetical Arduino-compatible dual motor driver Kickstarter came out to $9.81 per board at a quantity of 250. That's probably more than a cheap off-shore assembler, but we'll get you 100% yield. They probably won't.

TI TPS62601 front and backIt's more than just cost though. Many of the budget manufacturers won't do the most complex parts. For example, I could shave about a square inch off of the board size - maybe two - by using 0402 or 0201 passive parts. That's about $.50 - $.75 less per board for the blank PC board. Most discount assembly shops won't assemble 0201 parts. Many won't assemble 0402 parts. Screaming Circuits will assemble 0201s, and your little micro BGAs too!

The part on the right is a tiny wafer scale BGA next to the edge of a U.S. dime. We can build that.

If you're just designing the board and not hand assembling, putting in 0402 or 0201 parts is no big deal. You just design it and let the robots build it. If your assembly house can't deal with those small parts, you're stuck. You've lost some freedom of choice.

Now, you would expect me to be biased, because I work here, but more than bias, it's a matter of picking the right tool for the job.

If time is your key driver and cost isn't an issue, you'd want quick-turn Full-Proto; our Short-Run production would be the wrong tool.

If cost is your key driver, you have more time, you need predictability, and need good yields, our 24 hour Full-Proto service might be overkill, but our 20 day Short-Run can do all of the hard work for you, and you'd know exactly what you're getting, and when: 250 working boards in 20 days, for a decent price.

Here's a Kickstarter project we built earlier this year.

Duane Benson
Don't use a Marten64 0-dot-19 Freembulator when you really need a Model B Mitchel Warbler brand size 32.125 green Sackcombobulator.

 

Part 1, Screaming Circuits and the Maker community

Yes, a Maker can get 250 custom-design Arduino-compatible boards built for about $10.00 each at Screaming Circuits.

How can Screaming Circuits, a full-service assembly provider, compete with a low-cost assembly house?

Upon first thought, it might seem like Screaming Circuits, would be too expensive for anything but well-funded big-business and big-education. In reality, that may not at all be the case. Like so many other things in life, there are trade-offs between time, effort, and money. The nice thing about Screaming Circuits is that, unlike the low-cost small volume manufacturers, we can cover both ends of the spectrum.

Our least expensive service is not as cheap as the lowest-cost assemblers. We don’t sell on price, but when you start to add in reality and practicality, the cost difference gets much smaller.

OpenHardware logoIf you need that maximum performance, “I need it now, now, now!” service, there’s no question that you need a premium manufacturer, like Screaming Circuits. But let’s do some compare and contrast on the other end of the spectrum. Can Screaming Circuits be a good deal for a maker?

I’ve got an open source Arduino-compatible robot motor board that I designed a while back. I’ve hand-built a few, because I enjoy soldering, but for this exercise, we’ll pretend I’m a maker with a Kickstarter and I need more built up.

I’ll need 250 for the hypothetical Kickstarter project. The 1.5” x 3.5" board uses an ATMEGA32U4 processor with the Arduino Leonardo bootloader. From a software perspective, it looks just like a Leonardo. It uses a different hardware form-factor than the standard Arduino to better fit a mobile robot.

1-DSC_0001It’s got 26 different components (26 line items in the Bill of Materials). Due to some part types being used in multiple places, that’s a total of 48 surface mount (SMT) placements. I’ll ignore the few thru-hole parts. As a Kickstarter, I would supply the board with all of the SMT parts installed and let the customer solder in the thru-hole parts. That’s pretty common practice in the hobby, maker and Open Source world.

You can quote the assembly on the Screaming Circuits website without registering, so let’s do just that. It’s got:

  • 250 desired board quantity
  • 26 unique parts (BOM line items)
  • SMT on 2 sides? Yes
  • Lead-Free? No (If you’re shipping into Europe, you’ll need lead-free)
  • Class III? No
  • ITAR? No
  • 48 SMT parts
  • 0 thru-hole
  • 0 BGA/QFN

For 20 day, Short-Run production service, this comes out to $9.81 per board - less than $10.00 each.

Soldering by hand, I can do about two an hour. Some folks are faster than me, but some are slower. At two per hour, I’d spend 12 ten-hour days hand soldering the 250 boards. Ouch!

You can most likely find a cheap overseas manufacturer that would build 250 them for less, but they may not want such a small job. You may end up with concerns about intellectual property theft, and you may not get the yields you need.

At Screaming Circuits, we treat every job as proprietary, we’re happy with a run of 250 without any commitments for more, and we promise 100% assembly yield. Finally, a job like this, that totals out to $2,452.48, gets the same process and care as does a $10,000 quick-turn complex prototype.

Food for thought.

Duane Benson
Here's a Kickstarter we built back in 2012