Fulfilling a project BOM

J

jchristof

New member
New forum member, new hobbyist.

Just built a Stew Mac tape op from a kit. When I found PedalPCB I initially thought I was going to find a similar "all components" included experience, but now I've spent some time reading posts and understand the process a bit better.

I am looking for the most straight-forward way of fulfilling the entire BOM of a project since I haven't accumulated spare parts yet.
Is the easiest way to hand enter each component sku and add to cart on a site like Tayda, or is there an easier approach? I also see a BOM merger script which I haven't set up yet, so I'm thinking the answer is manual component selection. Am I missing something?
 
jchristof said:
hand enter each component sku and add to cart on a site like Tayda
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That's how I do it. If you're going to build a lot of pedals and want to keep costs down I think that's where you'll end up. It probably doesn't take as long as you think. I do take the extra step of entering the BOM contents into an excel sheet so I can sum parts for ordering multiple projects at once.

If you don't mind paying extra for the convenience of single-click ordering, there are some places that will put kits together for you.

StompBoxParts has a few PPCB kits. Small Bear Electronics has a bunch of MadBean kits. There are probably other places too.
 
Welcome!

Sourcing parts can be a chore. But after a few times, you can get a lot faster at navigating the site, and you’ll have more parts on hand, reducing what you need to order to finish a build.

I’d recommend getting a feel for doing it manually before adding automation. If the automation doesn’t 100% work, fixing the order will be less frustrating with some experience.

For resistors, Tayda does have a single page with all the values on it (link). I recommend using ctrl+f to type in the value (33k, 2.2m, etc) to quickly navigate. For other components, you can search something like “10nf” for capacitors, “B100K” for potentiometers, etc.
 
Thanks for the replies, that is really helpful information. I've been browsing around for components and tools. Bundles of components similar to this seem like an economical and quick way to build up my components on hand for common items. Is there a reason to avoid these? This is on Temu
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I’d recommend just buying components you actually need for a project. For cheap components like resistors I’ll round up the totals so I have a few extras on hand.

If you’re interested in extra parts for breadboarding, just print out or save the BOMs for those too, and combine those with your pcb BOMs for ordering.

There’s also a benefit to standardizing your component sourcing. It’s harder to visually verify all your resistor values on a board that’s not working right if they’re different sizes and colors. Face them all the same direction while you’re at it.

Trying to get cheap assortments and stock every value you could potentially need doesn’t really work. There’s always going to be something you don’t have, which means every pcb requires an order anyway, and trying to not buy things you already have means you need to take inventory of your stock before every order which will take longer than just check-listing through the BOM and ordering all the parts.

Just doing it the hard way is actually the secret shortcut.
 
Second what some others have said - just dig in and enter into a cart at your preferred vendor. Here are some of the things that I do:

I have an ever-growing Component Inventory Spreadsheet. I track all my components, grouped by kind (i.e. Resistor, Capacitor, Diode, Transistor, IC) with sub-groups (i.e. film vs electrolytic. Within the sheet I have a column for each specific PCB I've built or ordered to track the use in that PCB.
When I order a PCB, I just start a Mouser cart with what I am going to need that I don't already have, but in larger quantities - I assume I'll use the same value down the road and can afford to accumulate a small inventory. Mouser orders take 2 days to arrive for me, so I tend to be a bit less planned with these, although I do try to batch into a larger order to save money.
  • For most components (except potentiometers, knobs, and jacks) I tend to buy from Mouser first. I am, however, pretty comfortable with the filter tools that you need to use to narrow down your search from the infinite numbers of flavors.
  • I typically buy 10, 25, 50, or 100 of resistors. I've decided (no special reason, but they are well known and reliable) that KOA Speer is my brand choice, with Yageo as my backup, and 1%/100ppm is my standard grade. Resistors are cheap enough that basically the first time I see a new value in my builds, I buy 25 of that value.
  • I typically buy 10 or 20 of a capacitor ($2-$5 worth). Mostly either WIMA or Kemet films, TDK or Murata MLCCs and Panasonic, Rubycon, or Nichicon electrolytics. These seem to be trusted brands
  • I typically buy $2-$10 of diode, transistors or IC.
  • For potentiometers, knobs, and cases I tend to buy from Tayda. You can buy a lot of other stuff, but these items are distinctly cheaper at Tayda and the lead time is not terrible. I try to batch maybe one order a quarter to Tayda, at the most.
This said, I have placed a couple of component orders with LCSC.com, the component side of JLCPCB. I haven't had any bad components from them, and am teting ordering Yageo resistors in 100's. You can also get ICs for a lower price, and experiment with Asian Brands if you are price sensitive. I have only used the lowest cost delivery (not default) and have not (yet) had issues with tariffs and shipping these to the US.
 
All good stuff. Another thing to consider while sourcing- the photo may not depict the exact component. Check things like voltage for capacitors, and lead spacing so you don’t accidentally get some huge component that doesn’t fit on the pcb. There are a number of times I didn’t look carefully enough and ordered not-quite what I needed.
 
Along the lines of component selection, it did occur to me that it might be difficult for me to nail the part sizing with my current knowledge-level. Multiple components on my Stew Mac board were crowded due to changes in part sizing since the pcb had been printed where several of the electrolytic caps needed to be extended to "float" above previously installed components due to their larger size. Same happened with several box-shaped capacitors. Also since I didn't notice any comment about orienting the high-side of the resistors (the were all too large to mount flush on the pcb) away from the ics, I ended up not having enough room for the sockets and opted to solder them directly to the board rather than unsolder everything. I didn't cook them thankfully. Lot of good takeaways from that first project.
 
When I first started, I bought spares of anything, especially the way some are priced. Resistors are 1.5 cents each, you need 8, don't get 10 buy 50.

Stuff breaks, gets lost, catches on fire or just dies and without backups you’re dead in the water. Having extras also makes future builds way easier.

One thing that got me was SMD vs hole through IC's. I needed a 2399 for a build, the photos make them look the same size, didn't really notice the legs were different, not sure if the SMD was cheaper or more expensive and I thought I was buying the "better" ones.

Needless to say, I have a half dozen PT2399 SMD.



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I almost don't want to post it here, because going through it is just a great way to learn... like buying a 250V or 500V capacitor and then having them arrive and being too big to fit or trying to hyper optimize to reduce on shipping only to have bought 2 knobs instead of 3, so back to another order/shipping charge again, etc

But I have been using this a bit and like it a lot https://forum.pedalpcb.com/threads/bom-merger-and-tayda-quick-order-generator.27321/

I still have had some mishaps/missing parts/etc due to quirks, but it is a nice way to start a cart perhaps

I tend to make tayda wishlists per-project, and then once I have 2 to 4 ready to go, I add all to cart (and ignore if I get 40 10k resistors and only needed 1 per-project) and then build what I can, and then place the mouser/digikey order for the specialty parts that weren't on tayda + whatever I missed from the original order
 
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