Drilling PCBs

[flanagan0718]

After using the "Dremel" drill bits I bought at Home Depot the smallest one broke. I only used it for three boards. UUUURG! Any suggestions?

[irmcdermott]

I've always used the resharpened bits from DrillBitCity. As long as I didn't use excessive force/pressure, they always last a decent amount. http://drillcity.stores.yahoo.net/restool.html

[selfdestroyer]

I use these
1 Twist Drills, Wire Number - Tungsten Carbide
        (#70) @ $1.75

1 Twist Drills, Wire Number - Tungsten Carbide
        (#64) @ $1.75

from smallbear when I just need one or two of them.

Cody

[davent]

Use the the Drill Bit City carbide as well and a drill press for the Dremel absolutely necessary as they are extremely fragile, snap if you look at them cross eyed, you can continue to use them after they've snapped.

Would be nice if someone had very short shanked carbide bits available in the tiny number sizes, we only need slightly more then 1/16", they'd be so much more robust, might even make it to dull before they broke.

Sizes i use are 71 & 65 but when these have all broken will go with 70 & 64 like Cody, 71's fine for just about everything until you need to desolder and remove the part, a little too snug then.
dave

edit. my setup- http://www.madbeanpedals.com/forum/index.php?topic=12951.msg118278#msg118278

[stevie1556]

When I used to etch boards I just used a 1mm HSS drill bit in my Dremmel and never had a problem. They cost about £2 for 10 and we're the cheapest I could find.

[Justus]

You use #70 for all the regular stuff and #64 for stuff like pots and switches?  Are these roughly 0.8mm and 1.0mm in diameter?  The bits I've been using are 0.8mm, 0.9mm and 1.0mm.  I don't know how that converts into "wire number" sizes.

[davent]

You use #70 for all the regular stuff and #64 for stuff like pots and switches?  Are these roughly 0.8mm and 1.0mm in diameter?  The bits I've been using are 0.8mm, 0.9mm and 1.0mm.  I don't know how that converts into "wire number" sizes.

I've a conversion chart; #70 = 0.7112mm,  #64=0.9144mm.

Pretty much everything i use in pedals will fit in a #71 (0.6604mm) hole. Off the top of my head the bigger hole is needed only for large diodes like  1N400x's and i use 22awg wire for off board wiring and that requires the larger hole.
dave

[lars]

Yeah, pretty much every drill bit is way too long for drilling pcbs. They're going to snap, it's unavoidable. The best part is, when it does snap you can use the shortened piece to continue drilling, and then it never snaps. I was using a tiny piece that was only like 3/8" long, and it worked great until I lost it.
It would seem like by now manufacturers would make different length bits for different projects, especially when it comes to tiny diameter bits. If they actually did that though, then we wouldn't have to keep buying their bits, so there's the reason.

[rullywowr]

The carbide bits work great for me.  I use .8mm and 1.0 mm for most stuff.  They are available on eBay for a reasonable price.  Of course, use them with a Dremel and a Dremel drill press stand at high speed for best results.

In a pinch you can use the harbor freight bits but they will break and wear out very fast.  They will tear the PCB up and not cut as clean as carbide.

[flanagan0718]

The carbide bits work great for me.  I use .8mm and 1.0 mm for most stuff.  They are available on eBay for a reasonable price.  Of course, use them with a Dremel and a Dremel drill press stand at high speed for best results.

In a pinch you can use the harbor freight bits but they will break and wear out very fast.  They will tear the PCB up and not cut as clean as carbide.

Yeah i found that out the hard way. The HF drill bits lasted about 1/3 of the way through a Cave Dweller Dub, Then SNAP!. I will absolutely check out all the suggestions, thanks guys. I have never ordered from Smallbear but it might be time to do so in the future.

[ggarms]

I've also had great luck with the SB bits. I will say I have also done ok with the bits through an amazon seller of jewelers tools. They don't last nearly as long as the ones from SB, but at 10 for approx. 3 dollars you can't go wrong.