Community Spotlight: Paul James, Co-Founder of Water ReNu

Paul James is a wonderful human being with a lot of passion and co-founder of a company called Water ReNu. He believes in a "work hard, play hard" life, as evident when he reached out to us from the boat he was working from. The LumenPnP is helping Water Renu improve the world by utilizing what would typically be wasted water, called graywater. 

Starting at the onset of COVID, Paul saw what could happen if it became difficult to get PCBs manufactured from overseas, and when he co-founded Water ReNu, he wanted to make sure that was never a problem for them. The LumenPnP is helping Water ReNu bring their manufacturing in-house and take more control over their product. We hope you enjoy learning about Paul and Water ReNu as we did.

Tell us a bit about yourself and what you make.

Hi! My name is Paul James. I am the VP of Research & Product Development and a founder of Water ReNu LLC, which manufactures smart water reuse systems for landscape irrigation. The system reuses graywater (water from showers, tubs, and laundry) and other alternate water sources such as foundation water, rainwater, and more.


The IrriGRAY system substantially reduces the consumption of potable (city) water while still protecting valuable landscapes during drought and water restrictions.

Our clients include residential properties, multi-family facilities, and hotel laundries. Residential ROI is usually less than 3 years, while multi-family instances are value-positive from day 1 of operation.

I have been designing graywater re-use systems since 2000 in Australia and the US. I moved to the US in 2011. IrriGRAY has been developed over 25 years and is now a complete outdoor water use management, monitoring, and control system, utilizing water reuse first when possible and uses best practice commercial irrigation practices to use the least amount of water possible while maintaining a healthy landscape.

What are you building with your LumenPnP? 

IrriGRAY includes three boards:

- A 40-channel digital and 16-channel analog edge board, providing the interface between the controlling RPI 3b+ and various electric motorized valves, solenoids, pressure sensors, temperature sensors, servos, 110v pumps, audio, and visual indicators. The board is four layers, double-sided.

- A 16-channel front panel (daughter) board for ease of wiring irrigation zone solenoids, plus additional sensor inputs.

- A dedicated daughter board with current sensing circuitry for 3.2v DC, 5v DC, and 24v AC. The edge board also contains current sensing for 100v equipment.

The three boards, along with the RPI 3b+, 7" touchscreen, and DC, and AC power supplies, are contained within a plastic irrigation-style controller box.

Equipment communicating with the PCBs is connected via control cables (DB HD and DB ports at the controller to M12 patch/connector panels. Individual cables to the devices are color-coded, and all have stainless steel m12 connectors.)

We also have additional products in development - shhh!

Did you build or buy a LumenPnP? Have you made any modifications from the original build?

The IrriGRAY system has been in development for decades - we purposely stayed low-key for the last 10 years while we fully explored market niches, testing and improving our control logic.

From January 2020 (the onset of COVID), we decided to take the foreseeable downtime and port our previous Android control system to RPI, which is much better for 24 x 7 industrial control purposes.

In March of this year (2024), despite still being low-key, very significant market opportunities opened up that clearly would outstrip our manufacturing capabilities opened up. This is when we decided to look for a PNP.

I chose the Lumen system for being relatively recent, not too expensive, and adaptable while we felt our way into PNP.

We modified the board bases to fit 1.5 bases, to enable the PCB mounts to fit our needs. We also installed under base supports to prevent downward movement of the base with placement pressure.

 

What is your favorite feature of the LumenPnP?

Adaptability - because the design is open source, and replacement parts are easily found, we had the freedom to modify as best suits our needs, and as we learnt how to improve more over time.

I am glad we made this choice, as I felt much more freedom to adapt and modify than I would have with an entire metal machine.

How many boards a month do you produce with your machines?

Across the three boards, there are more than 300 PNP placeable components per saleable product. We also have additional manual soldering of power relays, sockets, and more.

We can now produce 15 board sets daily, or about 4,500 placeable components. Our current CPH is ~ 610, although we could increase this by about 50% (especially with the new Lumen 4), but 610 is comfortable. It is fast enough without introducing component momentum issues for larger components, and all these boards still have to be pasted, baked, inspected before and after baking, etc.

How were you building these boards before the LumenPnP?

Painfully!

Edge PCBs with many digital and analog IO channels have many signal conditioning caps, protection diodes, transistors, and more. We have over 20 components that are only used once. Even though most of the passives we use are 0805, these passives are still too small to visually identify.

If a wrong component is placed, an error will be detected during PCB testing, but identifying the incorrect component is still very difficult and time-consuming. With over $300 of components within our boards, trashing a bad board is still very expensive.

We developed a component management and placing system where we used pill box-style containers for storing components broken out of reel tape. Each box also had a drawing of a particular region of the PCB to be placed, with color codes to show where each component storage location was to be placed.

With practice and care, this was a very robust system. Our mistake rate was less than 2% of boards, which means about 0.02/300 on a per-component basis. BUT - so painful and slow!
 

What has the LumenPnP enabled you to do that you previously couldn't?

We no longer have to break components off tape into an intermediate manual storage and manual pick method.

With the LumenPNP, we have a controlled reel management system that never changes. When a reel is empty, it is cross-checked, and the replacement is put in place.

So, in summary, for mass production, the Lumen removes ALL potential human error inherent with manual placement.

What is the single most important piece of advice for people who are trying to get into PCBA production?

Don't be put off. I am approaching 60; if I can do it, you can too.

While I have always had a hobby interest in basic electronics, my first experience with ADC SPI, digital multiplexers, and so on was only 4 1/2 years ago, with my first prototype development for the RPI transition. Along the way, I still had existing customers to support, the previous generation technology to keep functional, etc.

As an entrepreneur, you just have to roll up your sleeves and get your hands dirty. Once you get the process down, you now have the ability to concentrate on marketing and start to receive the rewards for all that hard work.

Cost savings should be a driver for your decision as well. Our boards are relatively complex, and the cost per set to have them populated in China was over $260 per set. Our cost today is about $60 per set, with US labor. And, of course, this was for relatively high volume production runs, which just eats up capital and also limits product innovation.

Another significant reason is self-reliance, particularly in terms of supply chain vulnerability. We have had to make several minor design and component changes over the last 2 years just to cope with component price and availability fluctuations.
  

What's your solder paste of choice? What do you use for a reflow oven?

We haven't really explored different pastes. We just settled on Chipquik SMD291AX50T3, mainly because it is readily available. Leftover resin from manual lead-free soldering of our larger components is a bigger issue for us, resolved by using a good quality ultrasonic cleaner.

We purchased a Puhui T-962C oven from China about four years ago. It works well, but it must be vented to the outside!