This month, we talked with Daniel Cleveland from OtO Inc. where he works on an impressive piece of equipment that saves time and money with automatic lawn treatments and irrigation. OtO makes a smart sprinkler setup that allows you to designate the boundaries of your lawn and only water those areas, rather than watering your sidewalk as well.
Daniel has been using the LumenPnP to produce prototypes, and make batches of boards needed for testing and production. Check out how the LumenPnP is helping bring the OtO hardware to life in this Community Spotlight.
Tell us a bit about yourself and what you make.
My name is Daniel Cleveland, I'm the electrical engineer at OtO Inc. I primarily design the PCBs for the company but also handle manufacturing at scale. On the side, I play the saxophone :)
What are you building with your LumenPnP?
The machine technically belongs to the company I work for, OtO Inc., so it's not my machine per se. But I use it the most. We're making mostly our devices' two main boards. We use it to make prototypes and small runs of variants of our main boards.
When I'm in prototyping mode I'll set the Lumen up with the BOM lines that have the most quantity and are likely to not change between versions, so this allows me to reuse the same setup for different but similar designs.
We've also done a variant of our main board in 100 qty runs that includes a specific temp humidity sense that we don't typically include on our device. We stick these special boards in units of interest.
Did you build or buy a LumenPnP? Have you made any modifications from the original build?
I bought it as the kit, then slapped on the feeder harness when it became available. Now it has about 20-ish feeders. I'm planning on getting some more. I'm definitely going to print those stands I see on your website now so that my tape doesn't get jammed on the table anymore.
I'd really dig putting on the linear rails mod from Stargirl. Why? I'm pretty good at putting mechanical things together that break fast! I'd prefer just to focus on what I'm good at, which is designing PCBs.
At the end of the day, I'm more interested in the machine doing the job and staying operational than trying to mod it and potentially put it out of commission. Modding it could risk timelines (if I break it), and the thought of tightening up already tight timelines gives me a headache.
How many boards a month do you produce with your machines?
Depends on the month. Each prototype I do will be 10-20 boards as singles. Hopefully not doing more than one prototype a month during these times. So far, I've only gone up to X.4 with each of our major revisions. So that'll be about 40-80 boards over the course of 4 months.
When I'm making boards to go into production units it'll be in batches of 100. Usually, that'll be every 4-6 months. I'm cooking up the latest and greatest version of the main board right now, and I plan to start building those boards in early 2024.
How were you building these boards before the LumenPnP?
Either buying from small-run assembly houses or hand placing. We did one full hand-place job, and that was the last one. We tried a few budget Chinese places like PCBWay for assembly, but often the turnaround times were too long. We used a few places in America that do small run assembly, but if you want boards in a hurry, it's top dollar for those while still taking 2-3 weeks to get a PCBA.
Now, if I'm really in a grind, I can order a PCB and parts on Monday morning, do my file prep, and dust off the PNP in the afternoon. On Tuesday morning, I'll get my PCB and parts and set up the job. By the afternoon, I run the job. I could have PCBA in hand to start testing as early as Wednesday. Now that's fast!
What is the single most important piece of advice for running an SMT line?
Make sure your files are in order and your PNP is set up beautifully. The better the digital and physical setup, the fewer mistakes will be made when the job is underway. Oh, and check your paste before you start the job. I've been burnt by pads with no paste, which is so annoying to catch after everything is placed and cooked.
What's your solder paste of choice? Any advice for others?
I saw this question when reading your other spotlights, and it made me a little self-conscious. I've never really thought too much about it.
I'm currently using CHIPQUIK SMDLTLFP250T4 and SMD291AX250T4.
We have some connectors that don't like high heat, and our rubbish reflow oven temperature control is a mystery and makes them into mush, hence the low temp stuff.
It looks like the Loctite 1993881 is a hit among the other community spotlight members. I might give that a try!
please feel free to check it out on Oto's website.