cutting PCB's

its not the fiberglass that dulls your blades , .. its the copper..

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I Don't Think So.

I cut some Round Discs out of circuit board, Copper Removed and with a hole in the Center. Using them "as you would with a Steel or Tile, Cutting Disc", they will Nicely Cut Tool Steel. VERY ABRASIVE.

I'm from Missouri, WilliB, and have a bit of trouble agreeing with that statement. The hacksaw blade in the scroll saw should loaf right through that thin, soft copper layer. Once you imbed glass fibers in that "epoxy", it makes for a danged abrasive material. Rubbing an edge of G-10 across rusty steel will make an impression on it! I bought an odd retractable "scouring pen" made of a tassle of fiberglass fibers and it was darned abrasive. I hated the thing, though, because it left all kinds of little glass splinters everywhere that would manage to get under-skin easily. I tossed that puppy.

Dean

copper in itself is very abrasive also..and does a good job of dulling a tool bit..thats why i thought it was the copper ..if yall think it is the glass epoxy combo , i will go with that , i havnt tried to cut any in a while..

Hey, I could always make hacksaw blades out of the abrasive bandsaw blade material I have. But it would need to be drilled- difficult with tempered steel.

Copper is not abrasive at all. In fact, in stronger alloys such as bronze it makes a bearing sleeve for low wear, direct metal-to-metal contact. Copper is not very strong and cutters go through it easily. However, like other soft metals (such as aluminum), there is a chance you can jam up the cutting teeth or a grinding stone particularly when high speeds are used. It is generally not a problem with cutting disks.

BTW, the Dremel was good in its day, and it's still useful in itself, but it's now totally obsolete and overpriced. Black and Decker RTX, the one with the continuously variable speed, is WAY better. AND cheaper. It's got a regulated speed, better form, maybe 50%-100% more power at full speed, and at the low speed settings, around 5x the power.

Having the speed regulation and high torque at low power is extremely important to the versatility of the tool. Most of the pitfalls with rotary tools come from using them at too high a speed for the job. Using brushes that fly apart if used at too high a speed, avoiding melting plastics, avoiding burning fiberglass, avoid shattering the cutting disks- gotta have a regulated speed and the torque to back it up.

If you dont have a dremmel a bench grinder is your next best friend here. Sure the bench grinder wont cut it, but it certainly will makew the edges smoother and straighter.

Ive seen a guillotine used for this kind of application. Don't know where you would get one though.

EDIT:The dust that is given is terririble, I had serious breathing issues for the next 15 minutes Use a dust mask if you have asthma.

**broken link removed**

that's what I use for cutting PCB's. they are less than $40 on ebay, and come with a carbide-toothed blade. I've cut quite a few boards and the carbide teeth don't show signs of wear. (after all, carbide is one of the toughest materials typically used for cutting edges, short of diamond)

might not be obvious from the picture, but it's also very small. the blade is 4" diameter, and the whole unit is only about 8-9" long by 6-7" wide

they also come with a lapidary diamond blade for cutting ceramic tile, but the diamond grit gets worn off within a few cuts, so it's useless.

cutting PCBs

I've had good luck using the method described in the first response by WilliB. A dremel or the cheaper Craftsman equivalent along with a dremel drill press (~ $40 US) will give you very precise cuts. What I do is set the dremel cutting wheel height, then slowly slide the PCB along the drill press surface through the cutting wheel (PCB perpendicular to the drill press surface and the cutting wheel). This works best with etched FR4 boards (no copper on the cutting surfaces). My dremel bit drops down about 1/16" when turned on, so make sure you make adjustments with the dremel tool running. Wear eye protection. The abrasive cutting wheels are inexpensive and last a long time if you go slow and let the tool do the work.

As a sidenote, dremel drill presses are a little more now. As of about december of 2004, they discontinued the drill press. People have been snatching up leftover ones on ebay for inflated prices, $55 or more... And now they are JUST releasing the replacement, the dremel work station, model number 220, which is a combination drill press, tool holder, and flex-shaft stand. I just received mine today. As of now the only place to order them is tower hobbies, or by calling dremel directly and placing a phone order, but they should start selling normally soon. I paid about $50 for mine, so they are about $10 more than the original.

evandude, that's a cool mini table saw. I like it.

You can probably get an abrasive cutting disk that fits it. In fact, a piece of sandpaper cut into a circle with an appropriate hub can do some remarkable things in itself, with an extremely small curf width. You'd think that single-sided sandpaper wouldn't work, but I've used the sandpaper disks on my hand rotary tool (RTX) for a lot of stuff and it often does cutting jobs better than the disks. Thinner and doesn't break.

Oznog:
Hey, I could always make hacksaw blades out of the abrasive bandsaw blade material I have. But it would need to be drilled- difficult with tempered steel.

Oznog, usually you can simply take a torch (propane, not flashlight) to the ends of the blade to take the temper out and let you drill or cut it. The ends that fit the pins on the hacksaw frame don't have to be tempered.


pike:
I've seen a guillotine used for this kind of application. Don't know where you would get one though.

Kepro makes the PCB shear ("guillotine") and it has been carried by Kelvin Electronics here in the U.S., but as I mentioned, it's pricey.

Kelvin Electronics
280 Adams Blvd.
Farmingdale NY 11735 USA
631-756-1750 (voice)
631-756-1763 (fax)
https://www.kelvin.com


Dean