drill bit connection for pcbs?

[bifbangpow]

So i read in a thread here that i should be using micro drill bits when I make my own pcbs.  Most of you reccommended ".03" size drill bit.  This has caused me some confusion because i bought a micro drill bit kit and they run .2 through .6  so there's a .3mm but not a .03.  Which am I supposed to use? Honestly everything in the micro drill kit looks a tiny bit too small to me.  I'm trying to build a typical pcb for a guitar pedal so i need to drill the standard holes for resistors.  Also, I don't think the micro bits will fit in my drill press.  Do I need a converter?

[Brisance]

1mm or 0.8mm works just fine for THTs if you ask me..

EDIT: but really, forget the numbers, see your component leads, put your drill bit next to them and you'll see instantly.

[Ice-9]

Ok I see where you are going wrong here, I believe you are thinking 0.03mm when in fact for pcb sizes a brill bit of 0.03 inches is about the right size which is app 0.7mm

[thelonious]

Ok I see where you are going wrong here, I believe you are thinking 0.03mm when in fact for pcb sizes a brill bit of 0.03 inches is about the right size which is app 0.7mm

+1. I use 1mm for most holes. I find that the smaller ones tend to break too much (or maybe I am too impatient when drilling).

[duck_arse]

a drill press will have a minimum size it will chuck properly, 1/16" ? I dunno, I don't work in inches. for drilling tiny, most would use a mini-drill type thing, like a dremel. there are mini chucks available, usually with a hex end, would fit yr press. you can also get a pin vise to hand drill, but that gets old quickly.

[davent]

I use numbered bits, a #71 covers most holes, bigger stuff a #65. Both too small for a regular drill press in themselves but if carbide they have 1/8"/3mm bases which you can chuck in a regular chuck. Problem is a drill press turns  too slow for best results with the tiny bits, you want 10's of thousands of rpm not just a few thou. You also want no runout or you snap the carbides like toothpicks, you can keep using them after they break, they're then at a much more useful length, the length they should have been manufactured at in the first place.

#71/0.026"/26mil/0.6604mm
#65/0.035"/35mil/0.8890mm

When i reorder i'm going to #70 & #64 for easier desoldering/component removal.
dave

[bifbangpow]

Wow everyone is so helpful. Thank you.  Could one of you send me a link to the drilling product i should buy? like the dremel or whatever you recommend.  (and any other parts or components i need to get for said drill).

that would be great.

[R.G.]

1. Use carbide bits. A steel bit will be unusably dull after 100 holes in 1/16 inch, 1.6mm glass-epoxy PCB.
2. Carbide bits have a fairly standard 1/8" / 3.175mm diameter shank.
3. Carbide bits break if you wobble them, so use a drill press.
4. If you can, use a jeweler's drill press. They don't wobble, but cost about $140 new. But that may save you the cost of the press in drill bits.
5. Drill small holes at very high speed. 10,000 RPM isn't too much. 3,000 is about minimum. Rotating small bits slowly is asking to break them.
6. Metric bits in 0.7, 0.8, 0.9 and 1.0 mm diameters are the most used sizes.

[Ice-9]

It still really annoys me that here in England we have gone over to metric while imperial measurements are so much more.. well.. accurate.

[davent]

After 40 years... we're still in transition.

[Buzz]

It still really annoys me that here in England we have gone over to metric while imperial measurements are so much more.. well.. accurate.

I love the metric system. So much easier on the maths. Both hit a point of inaccuracy somewhere. Take Pi for example. I guess the preference comes down to what system you learned when your brain was young and easily programmable.

[Ice-9]

When it come to engineering specs the imperial system is more accurate. If you measure in metric with a ruler then it sounds mathematically easier to imagine the size.

[Buzz]

I have a dremel and I love it. You don't have to buy the dremel brand though, they are quite expensive.

Many of the cheapies work just as well. It's hardly a flux capacitor, just a small handheld high speed drill. The Dremel brand comes with a small attachment that allows it to act like a press drill. I have found it useless and just drill by hand under magnification.

[Buzz]

When it come to engineering specs the imperial system is more accurate. If you measure in metric with a ruler then it sounds mathematically easier to imagine the size.

Ok. Well above my needs though.

My level of education is more along the lines of "get a bigger hammer"

[davent]

I have a dremel and I love it. You don't have to buy the dremel brand though, they are quite expensive.

Many of the cheapies work just as well. It's hardly a flux capacitor, just a small handheld high speed drill. The Dremel brand comes with a small attachment that allows it to act like a press drill. I have found it useless and just drill by hand under magnification.

Can't imagine hand drilling with carbide bits in either size i use, not going to happen, can do it with HSS bits however. I use a Dremel too but with their old style, slightly modded drillpress stand, works great.
dave

[Ice-9]

When it come to engineering specs the imperial system is more accurate. If you measure in metric with a ruler then it sounds mathematically easier to imagine the size.

Ok. Well above my needs though.

My level of education is more along the lines of "get a bigger hammer"

Yes, there is nothing like using a bigger hammer. I do that too. 

[Buzz]

Can't imagine hand drilling with carbide bits in either size i use, not going to happen, can do it with HSS bits however. I use a Dremel too but with their old style, slightly modded drillpress stand, works great.
dave

Yeah I only use the HSS bits. The attachment I have for my newer Dremel is a plastic collar with a spring in it, not a drillpress stand. Goes on the business end of the tool and you push the dremel down with your hand. There is a picture of one on this page:

http://www.rcgroups.com/forums/showthread.php?t=2002624

Described as a thingy, lol. Useless for PCBs. For the small amount of boards I make the HSS bits work out to be the most economical choice.

[R.G.]

After 40 years... we're still in transition.

Down with metric !
Don't give an inch !!

[Brisance]

When it come to engineering specs the imperial system is more accurate.

How can one precisely defined measurement system be more accurate than another? (within reason of course, a meter is probably more accurate though, since it is defined by an universal constant. Just checked while meter is still defined by C, an inch is defined as "exactly 25.4 millimetres"  )  

also to the OP, I use this works just fine an is as accurate as my hand is. I think you could theoretically put heat shink over the drill bits end and fix it to the chuck that way too.

[PRR]

> When it come to engineering specs the imperial system is more accurate.

?? They are the SAME. Different numbers on the SAME ruler.

Well over 100 years ago, England the US and Canada compared their copies of "The Imperial Yard". They did not agree. Measurement technology had improved a LOT since the three "identical" sticks were made. The French actually had a better stick (they had invested a lot in it). Between the three Imperial sticks the difference was enough that you could claim 1"=25.4mm and split the spread of the three sticks.

And then let the French have the headaches of maintaining a platinum bar in a cellar, and issuing precision copies. (Eventually they moved to more fundamental properties of matter and then light/time.)

One Inch IS 25.40000.... mm exactly, by King/Congress/Parlament decree.

(There was about one US company which could resolve the difference between the US Old Inch and the new French 25.4mm inch. For a while they offered micrometers in both standards. Almost nobody else could tell the difference, and the Old Inch faded away.)

So any Imperial length converts to a Metric length with a simple 3-digit factor EXACTLY.

1 Furlong is *exactly* equal to 201.168 Meters.

_I_ find Imperial more convenient. An Inch is the distance between two knuckles of my forefinger. My sneaker is about a foot long. My stride is so near 5 feet that I don't bother with a tape-measure.

And /8 /16 /32 fractions. I lived with them all my life, but I still can't instantly decide the next wrench down from 7/16. So 7/16 is 14/32, then next-down is, uh, 13/32? When my 10mm wrench is too loose, I instantly know to grab the 9mm.