Bill of Materials / parts lists

[simonallaway]

I've been wondering for a while how everyone compiles their parts lists for any given project. I see plenty of 'best practices' for schematics and layouts, but I haven't come across that for parts.

While getting things together for my projects I've been adding things to a spreadsheet, and the one below is based on the Hoffman website 5E3 parts list:

https://spreadsheets.google.com/ccc?key=0At6xt5ia12JZdEpUcHUzMmctd2lrWTlCOWV3SldBNHc&hl=en&authkey=CMiO9YQL

Am I missing anything else that I'd find useful later on, but wish I'd done earlier?

[stingray_65]

Are you trying to make a 100% complete and accurate BOM?

do you want to add things like screws, nuts and washers to mount tube sockets and transformers?

maybe a brass 8-32 screw and a couple copper washers for your ground point?

Stuff like that? or more in the line of components.

OH! do get more than ONE fuse. Seriously. Even if they just rattle around in a junk drawer for years to come.

Ring terminals too, order a few more than you need, they have a way of  pulling out when you test your crimp.

Same note turrets bend when installed some times. 6 more is less than a buck.

It's those sort of things that really aggravate me when I'm in the middle of a build and I have to run to the hardware store, and it's only 450 paces from by front door.

[Fresh_Start]

Lockwashers for nuts/bolts, pots & switches
Speaker terminals
Grommets (for holes in chassis)
Heatshrink
Shielded cable
Cab (corners, feet, handle, etc.?)
Speaker?

I like to use "keps kepts nuts" with an integral lockwasher for most bolts.  Those nuts with a plastic insert to keep them tight are good for transformers.

I keep track of shipping in my bill of materials spreadsheet.  Learned the hard way that going to more than 2 or at most 3 suppliers to get the lowest price on every component costs MORE due to shipping.  Hoffman is my supplier of choice, but I do go elsewhere for tubes and selected components he doesn't carry.  

Did you know that Hoffman carries a high quality 5E3 chassis?

For quantities, I have columns for:
Design / Extras / Total / On Hand / Net Order

No matter what, you might as well order extra plate resistors, coupling caps, and cathode bypass caps in different values.  Sooner or later you'll want to experiment and paying $7.50 shipping for $3 of parts drives me crazy.  Also, don't forget that your workshop gremlins WILL hide 1 or more metal film resistors or other small components

Chip

[eleventeen]

OH! do get more than ONE fuse. Seriously. Even if they just rattle around in a junk drawer for years to come.

KEP nuts = proper name. Yes, those are wonderful.

How many fuseholders have YOU snapped in half overtightening them? Me? Less than half a dozen, I'm sure, LOL.

There's no question that missing one part that prevents further progress, especially when you have those weird "finished amp" thoughts running around in your head AND have managed to scrape together the free time to proceed....can make one unhinged. I think this was a big source of my "tube amps are so tedious to build" rant...as I am restarting tubistics, I have literally not one spare 6-32 screw lying around. But I'm getting over it!

[PRR]

> how everyone compiles their parts lists for any given project

Here's my current project.



Guess who got home yesterday withOUT 2-inch pipe?

Guess who got home today withOUT the 3/8" rod?

I scored some 3/8 from the neighbor but obviously I need to replace it double. Tomorrow's list (I don't dare scan it for you or I will leave it in the scanner) has 3/8 in big print.... betcha I get home without it.

What I need is a pocket toy, I squat in the cellar and enter my needs. They get wirelessed to Home Despot. When I walk in, a laser-light leads me to each aisle and part; the exit door won't let me out until every part is _IN_ my cart or confirmed missing (out of stock, changed my mind).

[eleventeen]

PRR, is the 2" pipe single ended?

[LooseChange]

Man, always makin' lists. Always forgetting something.  I tell myself, I need the exercise as I go out again.

[John]

What I need is a pocket toy, I squat in the cellar and enter my needs. They get wirelessed to Home Despot. When I walk in, a laser-light leads me to each aisle and part; the exit door won't let me out until every part is _IN_ my cart or confirmed missing (out of stock, changed my mind).

That is a tremendous idea.

[simonallaway]

I have same problem PRR. I get text messages from my wife, on the way home from work, that say "beer ciggies milk catfood". Chances are I will forget one of those 4 items.

But, I've been trying to use a program called "Things" on my phone that lets me (and my wife) create lists/tasks/honey-do that I can keep in my pocket. It's only a matter of time before I get it working with the GPS Lasers!

And thanks for everyone's insights and additions to my spreadsheet attempt. I will update it accordingly :)

[tubesornothing]

My BOMs are a little more complicated, because I build models of amplifiers and due to tax laws & inventory I must be able to keep track of how much each amp cost to build (total PIA).  I was using a database, but it turned out to be a pain.  So I went back to using multiple spreadsheets.

One spreadsheet per model per version.  It lists the quantity, a part identifier, description, and use.  I also have the circuit that it belongs in (preamp, PI, etc.) and the type of component (resistor, cap, etc.)

The part identifier is the key.  Its not dependant upon its use within a schematic, but the component and its value.  E.g. a 100k 1/2 Carbon Comp resistor might be "res 100k 1/2W CC"

On another spreadsheet (the inventory) I have the same part identifier, a description, the pick bin, manufacturer, supplier, supplier part number, price per quantity, date of price and number on hand.

When I go to order parts, I first double check amount on hand, then using a little excel formulas I create an order sheet based on the two spreadsheets.

This is way too complicated for building one off amps.  But if you are doing a model series plus the govt wants you to know how much each cost, you will need something complex like this.

[shortfuse]

This has been my biggest roadblock to getting started.  I have made a spread sheet in excel very similar to yours but I have picked a project that does not have a parts list so I have been going through the schematic's quantifying parts and pieces and looking at pic's closely for the illustrious hidden hardware.  Hopefully with not many honeydo's this weekend I get mine completed and get the 1st order in.  I say 1st order because this will be my first build so I fully expect to be placing a 2nd and possibly a 3rd so guess I will just bite the bullet and get what I have listed and keep a hidden items list at the bottom of the spread sheet for the next build.  Growing pains I guess.

[Fresh_Start]

Shortfuse - it's a PITA, but triple checking the BOM with your schematic and layout using a highlighter helps avoid that awful "Oh @#$) I didn't order a 470pf cap!" feeling.

[Heinz]

Just in case nobody noticed...the latest version of JSchem can make a BOM (text or Excel format) from your schematic.

EDIT: it's actually CSV format which can be imported into Excel or OpenOffice

[shortfuse]

Hummmm I played with JSchem a bit but didnt realize it did all that also.  I think I only downloaded the original program to see what it was about.  Is that an add on do I just need to upload the latest version.  I believe I saw several custom type tools while at the down load site or area.

[Heinz]

That feature is built into the latest release. Just go to the website and download the version for your operating system, if you don't have it already.

There are just a few things to keep in mind when drawing your schematic:

• make sure all components are grouped as components in JSchem
• use the same initial character for each type of component (R for resistors, C for caps, etc) in the property "Part ID
• set the property "Part Name" to the value (or name e.g. for semiconductors) of the component
• use "Info" properties to display additional information in the schematic

Once you're finished with your schematics invoke "File->Export Sheet..." (for the current single sheet) or "File->Export Schematics..." (for a multi-sheet schematic including all sheets) and select file type "Bill of Materials (txt)" or "Bill of Materials (csv)". The text file is a simple readable file that can be edited or printed with a text editor or e.g. MS Word. The CSV file can be imported into Excel for further processing. Opening it in Excel via double click does not work as expected, unfortunately. I'll have to improve that in the next version.

I have added a .jsch file and the BOM that JSchem creates from this file to demonstrate what it can do and how it works.

[tubeswell]

I've given up on parts lists. I have have a gazzillion parts in my amp cupboard, which I fight my way into on amp building days. When I'm at the electronic shop (or on-line), I order 10 of this MOSFET or that diode, bulk bags of nuts, bolts, grommets, sockets, chicken-head knobs, bulb and fuse holders, pots, cap resistors, wire, wire and more types of wire etc. Besides that I am always buying stuff (transformers, tubes and speakers) for a rainy day. I got so much stuff in my inventory I could probably build 1/2 a dozen amps right now without needing to make another trip to the shop. But I do wonder at times about whether I may've become obsessive about making sure I have enough of everything I need.  Hmmm...

[GuitarPilot65]

Weber has all of their kit BOMs neatly organized in one Excel spreadsheet:
https://taweber.powweb.com/store/bom.xls

You can select the different circuits via the worksheet tabs at the bottom of the workbook.

[ckilgore]

PCB Express will generate a parts list for you from the schematic.