Different ways to get a decent  stockpile of electronic parts - Page 1
Forum section: electronics / projects

author: Jesset1996.5
author_rank: Regular Contributor
timestamp: October 18, 2015, 09:41:26 pm
content: I usually go to ham swaps for parts but what other ways are there other than digakey, mouser,exc. I mainly buy offline since here in Michigan we have a tax on everything we buy online. Stuff can get way to pricey real fast. Any ideas?

author: alexanderbrevig
author_rank: Frequent Contributor
timestamp: October 18, 2015, 10:34:28 pm
content: There's this threadFrom no parts to decent stockpile; best approach

author: KL27x
author_rank: Super Contributor
timestamp: October 19, 2015, 02:08:19 am
content: What kinda components do you want to stockpile? And what for?I have a suspicion that hoarding components are interest in redundant ham radio and test gears are related mental illnesses.

author: nctnico
author_rank: Super Contributor
timestamp: October 19, 2015, 02:17:28 pm
content: I agree. Hoarding components is going nowhere but a house filled with crap you don't need. What works for me is to just buy what I need. For common components like resistors I buy more than I need. I always buy A brand components so I know they are within spec and useful for serious work as well. For more expensive things like DC-DC converters I buy exactly the amount I need and I'm still left with excess items.The online sales tax sounds excessive to meHow much is that?

author: tron9000
author_rank: Frequent Contributor
timestamp: October 19, 2015, 03:13:49 pm
content: WEEE bins or whatever is equivalent in the US<--- check out my blog just done a segment on stuff I find in the WEEE

author: Howardlong
author_rank: Super Contributor
timestamp: October 19, 2015, 04:43:47 pm
content: Quote from: KL27x on October 19, 2015, 02:08:19 amYou've come to the right place.

author: CrashO
author_rank: Unknown
timestamp: October 19, 2015, 08:20:52 pm
content: Quote from: nctnico on October 19, 2015, 02:17:28 pm6% on top of the normal Sales Tax of 6%. Still way cheaper then the 21% we have to pay here in most parts of the EU

author: KL27x
author_rank: Super Contributor
timestamp: October 19, 2015, 08:22:37 pm
content: If you feel the need to buy random components, I suspect you are lacking a project. Complete a project, and presto, you have parts. Unless you are very lucky or experienced, you will end up with some spare parts. And soon enough you will have so many parts, it will often be easier to order a part than to find the ones you know you have, somewhere.If you think you're going to learn electronics by randomly putting parts together, you will be wrong! You will spend so much time designing and layout out things, the time it takes for mail order parts to arrive is nothing. If you end up having to wait, at all, that's nothing but a well-deserved break.

author: Howardlong
author_rank: Super Contributor
timestamp: October 19, 2015, 08:37:16 pm
content: Quote from: AcHmed99 on October 19, 2015, 08:15:15 pmThis, although I do have a healthy selection of L, C & R kits in a number of different packaging types accumulated over the years. More recently, particularly on ebay, it's never been easier or cheaper to have a good selection of jelly bean parts, especially Rs and Cs. Really common values like 1k, 10k, 10nF and 100nF I buy by the 1000 both wire ended and in various SMD sizes, you really should never run out of some parts! I always have a reasonable stock of assorted LDOs too for prototyping, but not to anywhere near the extent of my 10k and 100nF fetish. Transistors of various shapes and sizes just seem to accumulate naturally through over-ordering. But how ever hard you try, you will never have all the parts you need, so I wouldn't bother trying too hard. Some people keep a stock of 555s for example, I know have a couple of dozen at least, last bought about 15 years ago, I can't actually remember the last time I used them. Similarly about 10 years ago I bought a bunch of glue logic LVC TTL, they hardly ever get used.

author: KL27x
author_rank: Super Contributor
timestamp: October 19, 2015, 09:13:02 pm
content: When I need a particular value SMD resistor, I order a reel. Search for the cheapest in a range of values when you can. I will usually get a 5k or 10k piece reel for $10.00 to $20.00 from Mouser. No need to use eBay. Same for decoupling caps. You are going to use them over and over.I have a little apparatus for de-reeling resistors and caps. The first time I need to use an inexpensive passive component from a reel, I will de-reel them all. I put them in a test tube rack in some semblance of order. Sprinkle out a pile of parts when needed, and sweep the leftovers into the garbage when done. 0603 resistors cost a fifth of a cent, each.The only reason to leave parts on the reel is if you have a pnp machine, plan to send out boards for assembly and provide the parts yourself, or for some directional components you will want to keep them in the same orientation and will gladly suffer the pain of dealing with cut tape.If you are a radio head, maybe you want to collect tubes, adjustable capacitors, inductors, trafos... I dunno. If I don't know how to order more of something, I will usually just as well not have just one random, unlabeled, unmarked component that is out of production. When designing a board, will want to find the best, cheapest component. Not make a footprint for some random junk I have to spend an hour to find out of a shoebox. I can find the ideal part in a few minutes and work with the datasheet until the actual part is in my hands.

author: georges80
author_rank: Frequent Contributor
timestamp: October 19, 2015, 10:36:49 pm
content: Quote from: Jesset1996.5 on October 18, 2015, 09:41:26 pm6% sales tax, right? If you order online out of state then it's 6% sales tax. Digikey/Mouser charge sales tax (certainly if I purchase from CA they charge me the same sales tax as if I purchased in-state). No big deal.Maybe it is irritating to pay the 6% sales tax on digikey/mouser but it hardly seems like it is becomes 'pricey real fast'... certainly not for jelly bean components.As stated by others, just buy the parts you need when you need them. Digikey or Mouser priority mail is around $6 - $7 on an order and you get it in 2-3 days. For anything I use a lot I'll get a reel or 1000 pieces on 'cut tape' - it's cheap enough. Weird resistors I'll order 100 pieces, costs very little and I'll likely use the part again.I will *NOT* purchase components on ebay or other asian sources - it's not particularly cheaper and you have no idea what the origin is (fake, recycled, old and oxidised etc etc). Buying components from a distributor gets you a known part, a link to the datasheet for specs and footprint info and it comes in a nice labeled bag/box etc so you don't need to guess what it is a few weeks/months later.cheers,george.

author: LaserSteve
author_rank: Super Contributor
timestamp: October 20, 2015, 02:19:45 pm
content: Digikey sells a great bundle of thru hole resistors for 20$.Best move I ever made, even if I did need to spend hours sorting them into bins.Steve

author: Howardlong
author_rank: Super Contributor
timestamp: October 20, 2015, 03:52:14 pm
content: Quote from: KL27x on October 19, 2015, 09:13:02 pmFWIW 0603 and 0805 are usually 4k reels, 0402 10k.The problem I found of decanting the parts from the reels is the risk of contamination. On a couple of occasions I've rendered some parts next to useless because of this, despite thinking I'd taken care to avoid it. Trying to sort unmarked parts manually isn't a favourite job of mine, and in both cases there were some low value inductors, so pretty hard and not economically viable to distinguish even with a decent LCR meter. The must frustrating situation was discovering that some storage boxes designed for storing SMDs allowed contamination between bins with 0201 and 0402 parts, they lids were simply not tight enough. The idea seemed sound at the time, but in practice less so, particularly when moving location, where removals folk don't take quite the care that I might do. YMMV, of course!I bought a stack of photo negative sleeves some years ago and continue to use those for storing shorter strips, but more recently you can get specifically designed empty kit books on ebay which are much better. Over the years though I've accumulated hundreds of almost complete reels, mostly from over ordering for production runs as a result of not having an up to date stock list from my assembler.But the biggest problem when you get up to a certain level is knowing what you have in stock, which is probably even more reason not to stock up too much. Unless you're really organised, and have plenty of space to allow for possible expansion, resign yourself to the fact that you'll be frequently ordering bits and pieces, and will have to occasionally re-organise, for example when the drawer for transistors becomes full and has to be separated into SMD and wire-ended, then further into Bipolar and MOSFET, further into Pch/PNP and Nch/NPN, and further still into power and signal, one drawer becomes sixteen drawers quite easily. But all that time spent organising isn't sitting there developing and designing stuff.

author: KL27x
author_rank: Super Contributor
timestamp: October 20, 2015, 05:58:09 pm
content: QuoteNever a problem for me. I use test tubes with caps. I don't pull one component out at a time, with tweezers. I decant them from the tube, and I never put small amounts of parts back into the tubes. Contamination is one of the reasons I sweep the excess decanted parts into the garbage when done.I don't know what or if there is a standard reel size. But I am positive my last resistor of 0603 came in a 10k reel (it happened to still be cheaper in sum than any smaller reel in the particular value range I needed). I de-reeled it just the other day. I believe I have purchased them in 5K, as well. Going from my own memory/experience, seems like 4k/8k is more typical for capacitors, if anything? Or maybe there really isn't a standard size for anything.

author: Howardlong
author_rank: Super Contributor
timestamp: October 20, 2015, 10:31:49 pm
content: You may well be right, but I can't remembering ordering or encountering anything other than 4ku for 0603 and 0805 on standard 7" reels, and 10ku for 0402 and 0201. These are Rs, Cs and Ls. I could see 5ku working though, the pitch density of parts on 0603/0805 is simply half that of 0201/0402.

author: ralphrmartin
author_rank: Frequent Contributor
timestamp: November 10, 2015, 12:51:48 pm
content: Take a trip to China, see the world, and buy more parts locally than you could ever need for $100.

author: KL27x
author_rank: Super Contributor
timestamp: November 10, 2015, 10:14:52 pm
content: QuoteI just searched 0603 resistors on Mouser without any other selections. Well, I sorted by price, which is hard-wired habit, lol. And then I scanned the entire first page.0603 resistors: Roughly 85% 5k, 15% 10k. Nada at 4k.0805 resistors: 5k, only0402 resistors: 10k, only0603 MLCC = 4k, all day.0805 MLCC = 90%+ at 4k, a few at 3k.0402 MLCC = mostly 10k, but also some in 8k reels.So maybe you are mixing up your resistors and caps. And yes, I should get a life.