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Hey Apple, here's a solution. If your ME is custom-spec'ing screws - they're not a very good ME. There is precious little reason to use a custom screw, it would be VERY few and far-between uses, and definitely not one I could ever see for a desktop computer. Custom-designed screws are a lazy way out...

McMaster-Carr isn't exactly at the top of the list when people are asked to name 'technology' companies, but they sell pretty much any parts or tools you could want for a build project, they deliver overnight, and their website should be required reading for any e-commerce developer -- frankly, Amazon included: http://mcmaster.com/

Cloudflare gets a lot of props for protecting websites against DDoS attacks and for affirmatively disclaiming from themselves the power of censorship. (They did drop the Daily Stormer over their content, but I'll give them one mulligan.)

Nope. See this "1 NPT Pipe Size" pipe is ~1.3" OD and ~0.6" ID:

https://www.mcmaster.com/#6880...

Crazy, but it ain't OD or ID. But that's an effed up pipe. Schedule 40 is much closer to 1" ID:

https://www.mcmaster.com/#4461...

It's the way it is because it's matching THREADS.

Hose - IMO - tends to be bought via ID but you can likely find exceptions:

https://www.mcmaster.com/#mult...

Nope. See this "1 NPT Pipe Size" pipe is ~1.3" OD and ~0.6" ID:

https://www.mcmaster.com/#6880...

Crazy, but it ain't OD or ID. But that's an effed up pipe. Schedule 40 is much closer to 1" ID:

https://www.mcmaster.com/#4461...

It's the way it is because it's matching THREADS.

Hose - IMO - tends to be bought via ID but you can likely find exceptions:

https://www.mcmaster.com/#mult...

Nope. See this "1 NPT Pipe Size" pipe is ~1.3" OD and ~0.6" ID:

https://www.mcmaster.com/#6880...

Crazy, but it ain't OD or ID. But that's an effed up pipe. Schedule 40 is much closer to 1" ID:

https://www.mcmaster.com/#4461...

It's the way it is because it's matching THREADS.

Hose - IMO - tends to be bought via ID but you can likely find exceptions:

https://www.mcmaster.com/#mult...

It turns out that the vast majority of consumers prioritize cost over quality. This is not irrational and those that have a need can usually do otherwise.

For example, Harbor Freight tools are generally crap. But they are cheap. Professionals who use them ten hours a day, six days a week are not going to buy them unless they work in an environment where the tools "disappear" after a couple months (both because they fail more often and because they, generally, are not as easy to do quality work with quickly) -- these professionals buy professional tools. The rest of us are well served by buying a $19.99 "sawzall". If it ends up that we wear it out in five years or less than ten hours of "run-time", we will buy another OR a better brand -- but, in reality, most of these tools end up working for the rest of your life (at least as a backup to the better one you bought because you decided you wanted the cool features or smooth operation of the better one). Sometimes, the best tool from 40 years ago is inferior to the Harbor Freight tool (due to technology advances) and it is better to just buy new tools incorporating recent technology every ten years than using "great" tools that are thirty years old but can't hold a candle to the cheap tools available now.

If you build a new server/desktop, do you buy the "highest quality" bits? If you're wealthy, doing so makes sense for bragging rights. However, for most engineers who are going to toss it in three to four years, it really doesn't matter if the case is plastic or thick steel or flimsy steel -- the resale value of the case is essentially zero and all three types of cases work fine if you don't have a full grown pet gorilla in your household who likes to play "toss the computer against the wall" (in which case, the quality of the case is likely the least of your worries as the gorilla grows up).

Most of the durable goods bought at Walmart (tools, kitchen utensils, small kitchen appliances etc) probably end up being used a few times over the owner's lifetime. If they are going to bake all day, every day, they will buy a professional mixer instead of the deprecated KitchenAid crap that Target or Kohls or Walmart sells. Generally, why pay for "quality" -- do you really care if the kitchen gadget still works when your great grandchild inherits it and it's completely technologically obsolete anyway? Engineers should understand "cost:benefit" tradeoffs very well.

I've got a very cool looking meat grinder that got passed down from my grandparents that still works as it did when my grandmother used it. Guess what, I look at it but don't use it. It's not dishwasher proof (my grandmother probably never saw a dishwasher), it's a pain to clean (my grandmother was used to things being a pain to clean), it spews blood around while grinding (my grandmother probably never thought about that - "it is what it is" - as all her friends' grinders did the same), I have to find a place to clamp it and there's no rational place to do so my kitchen (but probably was in my grandmother's kitchen).

If you care about "quality" (or false pretenses of same), you're not shopping at Walmart, Home Depot, Target, or McDonalds. However, every one of those vendors has multiple competitors who DO offer quality products and better selection (of course at a higher price). For a tiny example, if you want selection and access to quality products, check out McMaster-Carr or similar -- but make sure you've got a high limit on your credit card.

aluminum, stainless and 18K gold?

6061 Aluminim Billet 1" Diameter Rod 1' long Unpolished $9.10

316 Stainless Steel Billet 1" Diameter Rod 1' long Unpolished $23.68

That's a cost increase in just the raw material alone. Now have you ever tried to machine Stainless Steel? It's a very hard allow. By contrast aluminum cuts likes a hot knife through butter. So when are machining Stainless you are more likely to break your tooling. You need to factor that cost into the final price as well. You can try this your self. Get a chunk of aluminum, stainless steel and a hack saw and see how long it takes you cut one compared to the other.

aluminum, stainless and 18K gold?

6061 Aluminim Billet 1" Diameter Rod 1' long Unpolished $9.10

316 Stainless Steel Billet 1" Diameter Rod 1' long Unpolished $23.68

That's a cost increase in just the raw material alone. Now have you ever tried to machine Stainless Steel? It's a very hard allow. By contrast aluminum cuts likes a hot knife through butter. So when are machining Stainless you are more likely to break your tooling. You need to factor that cost into the final price as well. You can try this your self. Get a chunk of aluminum, stainless steel and a hack saw and see how long it takes you cut one compared to the other.

"mil-spec" is the abbreviation for "military specifications", and has nothing to do with the unit of measure called the 'mil'.

"military specifications" has nothing to do with metric.

I went drugstore.com to look for a new razor. I typed in razor and it is a couple pages of that scooter thing and razor scooter accessories. At *DRUGSTORE*.com. Once narrowing in on the actual razors one might want at drugstore.com, I saw the same overpriced goods that my local Wal*Mart sold. In fact, I'd have been content overpaying for cartridges but for them putting their razors on lockdown so I need "assistance" to spend too much money.

Googled my problem and quickly found:

http://www.dorcousa.com/

Razors! It seems to be all they sell. $26 later I got about 26 cartridges, the 4-blade razor (not ready for fuck-it 5), and it delivered in a couple days.

Often I know what I want, but what brand....? Anyway, the best site with best drill down and best service (IMO - of course we live near a distibution center which helps) is

http://www.mcmaster.com/

Of course, if you're looking for something they don't sell, you won't see it. But that's kind of the point, ain't it?

I might use amazon after identifying what I wanted elsewhere although there are many exceptions. I bought a food scale and bathroom scale there and did rely on the reviews, am satisfied with both and had free shipping on each item. I'm not a hater, I just see lots of ways to compete with them.

I call BS on your BS! Here, took all of 5 seconds to find: http://www.mcmaster.com/#pentalobe-screwdriver-bits/=je2gwq Troll...

PCB's? as in http://en.wikipedia.org/wiki/Polychlorinated_biphenyl

I dont think you can draw on those...

Now if you are talking BLANK phenolic boards with holes in them? Those are not "Printed Circuit Boards" therefore you can never buy a PCB without the P.

you are looking for this stuff....

http://en.wikipedia.org/wiki/Perfboard

although that's for old skool stuff. I prefer sheets of thin fiberglass board to do surface mount on...

http://www.mcmaster.com/#plastics/=cyzx5h is what I keep on hand....

I keep thinking of Buckminster Fuller(inventor of Bucky Balls - fullerene molecules) and McMaster-Carr one of the most awesome sites on the internet, where you can find nearly anything.

Here here

Try here and here. I build custom automation for for a living. Find a waterjet company in your area and have them make your custom stuff. If you want to get really artistic or detailed you might have to buy your own machine shop equipment. However with the tanking economy, they can be had cheap.

That site does look useful. However, it looks a bit pricey. Am I right in understanding that spur gears start at $8.61 EACH and go up from there? That seems a bit pricey for tinkering.

I'm also puzzling over the plain bore. It might well be machinable but I don't want that. I want gears that are easily mounted using a setscrew or which attach to a hexagonal or square shaft. I want to avoid using taper pins, welding, etc.

For big stuff: McMaster-Carr

For little stuff: Small Parts, Inc.

For custom stuff, use a local machine shop or emachineshop.

good luck.

Perhaps the greatest company in the world. McMaster has a huge inventory, reasonable prices, quick delivery and an easy to use website. If you want gears, machinable material, welding supplies, or anything else a kinetic sculptor would need, you should find it there.

218 ends in 80, its digikey's fax.
404 is for McMaster-Carr parts(?): http://www.mcmaster.com/#contact

I don't think the fire retardant foam that he mentioned is Areogel...

http://www.mcmaster.com/ctlg/DisplCtlgPage.aspx?se snextrep=272735319180963&ReqTyp=Catalog&CtlgEditio n=113&CtlgPgNbr=3426&ScreenWidth=1920&McMMainWidth =857

The part number he gave is for the "Fire-Retardant Extreme-Temperature Silicone Foam Rubber", 24" x 24", #85925K423, $80.73

I know you didn't mean that seriously, but I think you might be surprised how thin the foil has to be for light to pass through it. The quantity of interest is "skin depth". You can calculate it with the formula here, which uses several constants that are pretty easy to find:

frequency of visible light: 600 THz (source)
conductivity of aluminum: 3.8 x 10^7 siemens per meter (source)
permeability of free space: 1.3 x 10^(-7) weber per ampere meter (source)

I calculated that the skin depth of aluminum is 8 nanometers. This means that the thickness of aluminum needed to stop 99.9% of the light is one 400,000th of an inch. For comparison, this is 10,000 times thinner than the thinnest aluminum foil available from McMaster-Carr (it's a company that sells materials for scientific research, among other things). Since the atomic radius of aluminum is 125 pm, this foil would be only 250 atoms thick, and would still block 99.9% of the light.

By the way, if you've never used it, you should check out Google's calculator. It handles units for you, so it makes calculations like this really fast.

Page 809 - 817 of http://www.mcmaster.com/

(Just do a search on that site for 'Push-button switches')

Damn, it would be easier if you could just copy + paste the url...

I agree with you, except on what to use. Dynamat is basically a cheap sheet of asphalt, that somehow goes up 10X in price when they silkscreen "Dynamat" on it. If you know where to get it, you can save a lot of money for the same thing.

Check out McMaster-Carr. Use the search box on the left to look for (page) 3302, and that will take you to the sound damping materials. The "white box Dynamat" is the Polymeric Mastic, stock # 9709T19, at $14.62 for 12sq feet. Shipping might cost a bit due to weight, but it should still come out cheaper than Dynamat brand sheets (at ~$12/sq foot).

There is a lot of value in knowing the dude down the street with the corner electronics shop when a drive or a valve in the demo fails 2 hours before said demo.

For the mechanically inclined, there's McMaster-Carr.

If you're in the same city like I was, you could order and one thousand reverse-threaded titanium compact swivel joints (real product!) would appear on your doorstep in two hours. Providing that's what you ordered, of course.

Not quite the same, but the small robotics company I use to work for used McMaster-Carr for a lot of the mechanical parts, as well as some of the electronics. As they say on the website, 98% of the items ordered are shipped from stock, and the majority of them are delivered (just outside of Philadelphia) within 1 day. If the orders are placed early, they may be delivered on the same day. I am fairly sure this is with basic ground shipping only. Too bad more companies aren't that efficient.

I hope I don't get modded OT for this one...

It's not a computer supply company and my personal experiences with them have been non-commercial and always to the same address, but McMaster Carr is by far my favorite online store.

I first visited it on a recommendation of a friend; we needed very specific fittings for a potato cannon that we were building, and the parts were nowhere to be found in any of the hardware stores we drove to. I ordered the parts on a Tuesday around noon, and the parts were waiting in the mailbox the next day when I got home around 6. I think they came UPS or FedEx but it was a few years ago so I don't recall exactly. I had similar experiences with the rest of my orders from them (2 or 3 more orders). Also, most of their inventory is geared towards commercial purposes, so even though my order was non-commercial, I believe that they deal with companies regularly.

Want keyed Torx wrenches? Want a fire hose nozzle? Want an 18" long 0.25" diameter drill bit? No problem.

For those interested, vortex tubes that run on compressed air are commercially available. Search McMaster-Carr for 31035K11.

I have this tool, bought it from McMaster-Carr, item #5102A2. It has vice-grip style locking pliers - they're great to have available. Also a one-hand-openable knife blade, philips + flat screwdriver, file, saw, bottle opener. Nice solid stainless steel. It's big and heavy, though.

customers can just put in a query and have it spit out "Aisle 12, Rack 10

My local Lowes home improvement store had a rack as people walked in that had a stack of sheets that showed where things were in the store. Low tech, but at least an effort to help the customer. Now, that rack has sale fliers, and they've completely rearranged the store... again. Every time I walk in and see where the store maps were, I consider the electronic solution you proposed. I think about it when I'm trying to find stuff in other stores, too.

And you're completely correct about Home Depot. There are two of them in my town, and there is no similarity in layout. They both have an orange color scheme, but that's about the extent of the similarity. When I stop at my "away" HD store, I wander, and wander, and wander....

McMaster-Carr is only one day away by ground UPS. Their prices are reasonable compared to Lowes or Home Depot, and are even in the ball park of Wal-Mart on some things. The quality is excellent and McMaster-Carr has an unbelievable variety. And their online catalog is very convenient. I do a lot of my shopping on the internet now, even though Wal-Mart, Home Depot and Lowes are each about a mile from my house. For recent purchases such as a water heater, 5 gallons of paint or ceramic floor tile, I'll go to Home Depot or Lowes. For silicone sealant, hardware, plastic, hinges, etc., I'll shop the internet and save a lot of time and aggravation.

For example, Mcmaster-Carr is quoting $215.13 for a 4'x 4' sheet of .019 1100 aluminum. A 4x4 sheet of .019 Galvanized carbon steel goes for $31.17. That's about 1/7th the cost of aluminum.

<a href="http://www.mcmaster.com">McMaster-Carr Web-site</a>

If anyone is planning to do this, you can get the foam here (main site, search for unifoam).

It's known as computer foam, special in that it's nonconductive and doesn't create electrostatic discharge, which is probably why they chose it for this purpose. You'll find hard drives often encased in it.

If anyone is planning to do this, you can get the foam here (main site, search for unifoam).

It's known as computer foam, special in that it's nonconductive and doesn't create electrostatic discharge, which is probably why they chose it for this purpose. You'll find hard drives often encased in it.

The one complaint I always had about Dynamat was expense. I finally found a solution though:

Go to an industrial materials supplier (McMaster-Carr was the one I used). Search for "mastic." Specifically, polymeric mastic was what I used. It is very similar to Dynamat -- dense, vibration absorbing, self-adhesive, and temp-resistant. Best of all, you can get big sheets (32"x54") for 15 or 20 dollars.This price is way cheaper than dynamat.

I bought some to reduce the noise inside my car, but ended up with some leftover. I used it on the inside of my PC case with pretty good results. YMMV, of course.

Think: how else to you code data on a string?

Ever heard of macrame? There are all kinds of ways to encode data on a string, and no need to limit yourself to binary.

For example, who can tell me the best mix for bronze? Not many now.

Not many then, either. The Hittites managed to keep that a secret for quite some time (at least decades), and later they did the same with iron. Of course, not everyone had access to tin, so how to make bronze wasn't even necessarily relevant or useful information. That they kept iron a secret for so long is impressive, since iron is so common. Even when that was "common" knowledge, though, it wasn't all that common. It might have been common knowledge among smiths, depending on the specific time period we're talking about, but the average man-on-the-street wouldn't have a clue any more than the average-man-on-the-street today would if asked "emacs or vi?"

To answer your question directly though, here is how they made it back in the day, and you can find here[1] information that will help you find the best bronze for your specific purpose (since, as with all things, it depends on what you want to do with it). Of course, I could also go to the library and check out a book or two on the subject, or if I were really serious I could call up my best friend, who's a materials engineer, or another guy I know who made his own bronze dagger recently.

My point is, that information is readily available if I care to look for it. That wasn't the case back then, when such things as how to make a particular alloy were closely guarded secrets. That's the fundamental difference that makes our society so much more advanced than theirs. For that reason, I think I'll stay comfortably on my high horse, although I'll agree that we've always been ingenious.

As for the 7-bit thing, ASCII is 7-bit, and the Intel 4004 was 4-bit. Why? Sometimes there are reasons for doing things other than the number of digits on your hand. Sometimes it just makes sense to use a different base. Hell, why use binary at all? There are such things as analog computers. It probably just made sense to use 7-bit encoding for the data they were trying to record. 5 probably wasn't enough, and 10 would have left the upper 3 places empty, why waste them? If we figure out what it was they were actually recording, it would likely be quite clear why they used 7.

[1] Sorry I can't provide a direct link, scroll down to Raw Materials and Springs, click on Metals, and choose Bronze from the list. If you then click on Catalog Pages you'll get actual recipes.

McMaster-Carr

At first glance many will disagree, and likely every one of them will have no experience with McMaster-Carr. The thing you have to realize is that their printed catalog is about 3500 pages, and they stock over 400,000 items, and this site incorporates all that and more. I have to say this is hands down the most usable e-commerce site I've ever had to deal with, putting many sites with far fewer items to shame.

You might consider the aluminum structural framing used in a lot of custom industrial equipment. This is basically bolt-together aluminum channel. It is fairly easy to put together, makes a very nice rigid frame, is easy to attach brackets to, can be cut with simple hand tools, and some brands look pretty good. A lot of small to mid-sized custom industrial equipment is in boxes built with these frames - often with rectangular tubing forming the edges of a box and glass or PVC sheets forming the face of the box. Using stained glass in place of the window glass or PVC seems a natural fit.

The problem would be that this stuff is priced for industrial users. To get an idea of what is available and what it costs look up structural framing at McMaster Carr. McMaster Carr is a full-priced industrial supply company, so nothing there is cheap, but this type of stuff is hard to get cheap. If you can find somebody who is buying this stuff in bulk they might be willing to sell you some of their scrap pieces. The type of company that might have this stuff would be automation houses or custom machine builders.

A few of the many suppliers out there are:

• 80/20 The Industrial Erector Set
• Bosch Structural Framing System
• Unistrut
• Parker IPS
• Compact-Technik Automat

Fred

Let's get our semantics right. All plastics are polymers. Not all polymers are what we would call "plastics" (e.g. DNA), but from an engineering perspective, virtually all polymers are interrelated.

Your example shows you don't know what your are talking about. Acrylic is a plastic. You can buy chunks of it from McMaster-Carr. It is dissolved in a solvent and sprayed on for paint, but what do you think happens when the solvent dissolves? The acrylic re-deposits to form a film, but it is still fundamentally the same material that is used to make those clear tumblers you can buy at Crate & Barrel.

Can you heat it up and cause the film to flow? Yes, but that just makes it a thermoplastic (as opposed to a thermoset). You could do the same thing with a polyethylene film. The difference with polyethylene is that the flow temperature is about 120C (250F), whereas Acrylic will flow at temperatures closer to 60C (150F).

All paint contains a lot of highly engineered polymers with adhesive properties. Thus, paint amounts to brush on (or spray on) plastic coatings.

I couldn't find non-alloy W, but maybe Tungsten Carbide is good enough? These guys also have plenty of other metals in various forms, like diamond plate or titanium sheets, for when you hunger for other materials.

McMaster-Carr

First, I was speaking from personal experience and presented several observations to support my inflamatory statement, which I'm guessing you didn't bother to read.

Second, not everyone who reads /. is a web monkey. I mostly do mechanical design, and take care of IT stuff and maintain the website as needed.

Third, I've worked under some excellent managers, and it hasn't escaped my notice that not one of them had an MBA! I even went so far as to describe one of them. It also hasn't escaped my notice that the MBAs that I've worked under have universally been morons with no managerial skills, and the only apparent benefit they brought to their respective companies was the ability to manipulate the quarterly statements in order to raise the stock price.

Fourth, the whole problem with MBAs is that they generally go into it because it's a bright career path. Conversely, most engineers go into engineering because they like it. Anyone who chooses a career path based solely on how much money they can make is going to be bad at it.

Fifth, yes most companies websites are mostly formalities, and that's probably because most companies websites suck. For an example of an extremely useful and well-designed website I encourage you to visit McMaster-Carr. The first thing you will probably notice is the lack of gratuitous graphics. What's less obvious is that they took a 3000+ page catalog with over 370,000 products and made it so usable online that the person at my company who still uses the print version is a part-time machinist who's a total technophobe. If more companies made their sites that useful and usable, they'd be a much bigger part of the business world.

Forget the eMachines.

I've just finished building a (really small) 4-node cluster for some research I'm doing.

Each node is a Duron 750 w/256MB RAM and a 100Base net card, power supply and floppy drive. They're vertically stacked on some 2' threaded rod from McMaster Carr.

But get this: I built the whole thing for $170 per node . That's everything, shipped to my door.

They load the kernel off the floppy and grab the NFS root from a fileserver I've got set up, so no need for hard drives. Granted, there's a bit more network and memory overhead (both /var and /tmp sit in memory), but I can buy more nodes from the money that I've saved on hard drives.

The *most expensive* hammer I could find at McMaster Carr is an 18lb nonsparking sledge made of ampco metal at $334.25 a pop. page 2500.
...Just in case anyone has a yen to spend a fortune on a hammer without doing the paperwork.