HF Question

These look like micro bits used to drill PCB holes.

cheers T.Alan

"Breaking a few" is seldom a good plan. If you're cutting G10, get an 1/8 diamond endmill from Mcmaster and use it carefully. It will last a long time and make a beautifully clean cut. It will be about $30 well spent.

Breaking a few is conservatively saying I don't know what I am doing with this machine yet. I don't have a manual and Roland no longer supports this thing.

I fully expect that it will "overdrive" it's cutting capability at least once. I don't want to be breaking $30 bits as a regular circumstance.

I agree it's not a good plan, but during R&D I think it is to be expected. After some familiarity with the machine I may invest in some good bits, but not until I am reasonably confident.

JW

Jim Stewart wrote:

I got several boxes of these from Grizzly a few years go. The ones I got are a mix of drill bits and burrs, not end-mills. They are designed to turn 20,000-30,000 rpm with a vacuum to clear out the dust. We have a DOALL drill press that runs this fast and does a good job of drilling with the tiny bits.

I have used lots of them to drill out broken taps, etc. Sure they break, but the price was really cheap a few years ago.

Sometimes handy to have around!

Paul

Most likely these are "burrs" or rotary files. If you keep the feeds down you can make your own engraving style cutters out of drill or carbide rod. Goodle for 1/2 round 1/4 round and facated engraving tools. Won't be as good as the "store bought" ones but will work. You might want to get a few "store bought" ones for models.

Looking at the picture, it looks like these might be pretty good to modify to 1/41/2 round style cutters by grinding back past the "file"

Uncle George

I've used these in my CNC mill setup. The tiny ones are fragile as hell, as would be expected. Plus it's mix-n-match - you can't guarantee what sizes you're going to get, so if you program for one - break it - then oops! The .050" units and above I've had pretty good luck with.

Still, I find them useful (finally). HF isn't the only supplier, these are available from a variety of places. The price in your link is pretty agressive from what I've seen in the past. If the freight is low, not much of a loss.

jw said the following on 1/17/2006 12:12 PM:

Those are carbide drills for drilling printed circuit boards. They drill holes just fine but they will not tolerate side thrust at all; they snap if you even look at them crosseyed.

I would suggest getting some small cobalt HSS endmills from Enco. They'll dull much faster than carbide when cutting PCB's, but they're also a lot cheaper and not as easy to snap. Then go to carbide endmills when you have things all sorted out so you are less likely to break things.

They are mostly tiny PCB drills, with perhaps one or two tiny endmills. It is a grab bag of sizes, typically not well assorted. They have been resharped and perhaps out of size or length spec, so that's why so cheap.

But they are otherwise good quality, and have worked great drilling miniature holes for me on a few rare occasions when I needed to. They're worth buying a few packs just to have on hand if you ever might have a need for something that small.

As others have said, carbide is brittle and in that small size you need a very sensitive, low-runout, high-speed machine to use them without a problem. I used them on a Bridgeport, but the quill is a bit heavy handed.

If you are in the Bay area - or a PCB area - go to a grinding shop. You will find boxes of un-claimed drills and mills and other shaped cutters.

LPKF trained - ran the software on computer and later on the machine. Interesting blazing along with a 7 mill endmill or drilling holes... Important to have a vac cleaner on it - to keep the glass fiber down.

Do you have any documentation - ? Hope so - it helps.

Martin

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

jw wrote:

I've used those before.

They are simply Carbide - number and metric drills - with a plastic collar on it that is set at a precise distance. When the Drill gets ground the plastic is re-set.

The ring is for automated machines - it is a seating plane.

I used to get those by the shoe box full for free every time we went to the grind shop (all automated machines) as the counters were filling up with them.

After a grind or two - the cost of grinding and the age of drill - they dump them and buy new. Smaller companies forget or can't pay...

I wonder what happened to my box that I brought home. We could only use a small percentage of the ones as they are to small for most parts. They are used for parts, feed troughs, RF parts...... Hybrid and IC stack ups.

Martin

Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

jw wrote:

Unfortunately no. I live out in the sticks(relatively speaking). There may be some companies around here that do this type of thing though. I will have to do some calling and see what I can find out.

Sounds like these may be useful, but neccesarily everything I need. Drilling PCBs is part of the goal, but still need a cutter for traces and other modelling.

Yes and no. I can't find a manual for my exact machine, but I have found stuff for newer machines that is "close enough" to at least get me somewhere. W/O that I probably would still be swearing at it.

FWIW - It is a CAMM3 PNC-3000 made by Roland. Mfg in the mid-80s.

Thanks

JW

G10 was unsafe - it caught on fire - so years ago we switched to FR4. I used G-Tek on my last boards. They really were nice. 12GHz when 6 was needed. The parts were toggling at 3GHz. Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

Jim Stewart wrote:

I went to LPKF school - it was instructive - a little obtuse due to the software being a little that way.

We used mostly 7 and 10 mil 2 flute endmill and some stronger drill like tools that were used to cut out slots and holes.

The pcb was mounted atop a special type of Masonite like board - flat on both sides and dust free - more or less. Use a vac of some type - the fine fiber can be harmful.

The board under the one we were drilling is there to protect drilling through into the metal bed.

Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder

jw wrote: