High-RPM Tool for Drilling Circuit Board Holes?

[The New Steve H]

I have totally reorganized my garage, and now I have a really nice space for amp-building.

Having returned from the dead, I have a question.

A hotshot machinist gave me the lowdown on drilling holes in circuit boards. He said to use carbide at high RPMs. Sadly, my drill press probably tops out at 5000, even if I cheat by doubling the motor RPMs. If you drill too slowly with carbide, the holes aren't as pretty. I got some nice carbide bits, but I would like to make prettier holes.

Has anyone found a good solution? I can always get a drill press gadget for my rotary tool, but I thought I'd ask.

[Aurora]

The only reasonably priced alternative I can think of is is a Dremel with stand. The standard Dremel collet is also 1/8", which is also standard for carbide PCB drills. We still use a Dremel at work for backup and odd jobs.
I'm more than willing to bet that the first lab PCB drill we had at work was built around a Dremel motor, with added lift and sighting device ( it drilled the PCBs from the underside )

[martin manning]

I am getting by quite well with a 3k RPM, 8-1/4" drill press with a 1/2" chuck (and a light touch!), even for #70 holes. If you are drilling a 1/8" hole, and you are going to put an eyelet or turret in it, it doesn't have to be perfect anyway. 5K should be more than enough.

[jestaudio]

Flaming Norah, I must be in the dark ages then, I use a decent battery drill , hss drill bits and a lot of patience when I make boards up

[playonit]

What are we drilling through.. G10? I use my drill press with no ill effects and the holes are fine..

[Aurora]

The main pupose with high speed is to use carbide drills, which really needs 10000 RPM++, since they are very brittle.
Ordinary HSS drill bits wears off rather quickly in G10 and the likes.

[martin manning]

In my experience, HSS holds up quite well for the low-production rates seen in a hobby shop, carbon steel does not.

[Bob S]

Good info on the Dremmel & carbide.
I'm also in the dark ages making boards.
Welcome back Steve - haven't seen you in a while.

[DonMoose]

In my experience, HSS holds up quite well for the low-production rates seen in a hobby shop, carbon steel does not.

Besides which, HSS 'jobber' bits are cheap enough to be effectively disposable.

[jestaudio]

In my experience, HSS holds up quite well for the low-production rates seen in a hobby shop, carbon steel does not.

Besides which, HSS 'jobber' bits are cheap enough to be effectively disposable.

Plus I can "lose" them in normal business costs, I think the accountant might get a wee bit suspicious if I changed the ordering habit of a lifetime lol

[davent]

From ideas presented by R.G.Keen i've been working this up. Posted this at diystompboxes earlier this month.

Still haven't given it a run through yet but no reason it shouldn't work.

[IMG:600:800]http://i216.photobucket.com/albums/cc30 ... e58bc8.jpg[/img][IMG:800:600]http://i216.photobucket.com/albums/cc30 ... a347ac.jpg[/img]
Laptop view from USB endoscope.
[IMG:640:480]http://i216.photobucket.com/albums/cc30 ... 2babe6.jpg[/img]

Flipped the Dremel carriage, secured Dremel drillpress stand to bench top beside my regular tabletop press. Drillpress table swung out over the Dremel stand so now have a table. To advance the drill carriage it's just a short thumb storke.

Cheap USB Endoscope held by a Magnetic Base Flashlight holder from LeeValley looking down at the drill.

Downloaded free Web camera software from Oasis Scientific as the supplied software wasn't doing it. Found another free utility that by Hotkey turns the cursor to fullscreen crosshairs. Attach a scrap piece of PCB to the drillpress table, drill a test hole, line up the crosshairs with the test hole, hit another hotkey the crosshairs are pinned and the cursor returns to normal. You now just line up your pcb pads with the crosshairs and drill away.

As far as the carriage swing of the Dremel, on the old one i have there's a yoke that travels up and down the depth gauge and it's this yoke that limits the swing of the carriage but it's not tight to the depth marker. I heatshrinked each arm of the yoke and that totally eliminated any play that was there before when advancing the drill carriage. You can see the heatshrinked yoke in the first photo.

Small Bear now have individual carbide bits for sale at a very reasonable price, less then what i have to pay aroung here for good quality HSS.

http://www.smallbearelec.com/servlet/Detail?no=1442

dave

[Cantplay]

The enemy of the drill bit is heat.

Cobalt M2 steel should be fine for this if you can resist the temptation to push too hard.

A bit of water soluble coolant brushed or spritzed on would also go a long way for bit life.

John

[Structo]

All I know is that G10 is hard on drill bits.

Expensive or cheap, only good for so many holes until they dull.

But as mentioned, if this is just a eyelet or turret board, then the holes don't have to be perfect.
Not sure of the RPM on my drill press but I don't go crazy with real high speed.

If I am drilling a printed circuit, then yes, I want a new sharp bit.

[The New Steve H]

Just drilled some holes. I modified my drill press a few weeks back. I put a new motor and VFD on it, and the top speed is higher than it used to be. It turns out that 4400 RPM is fast enough to give perfect holes with a carbide bit.

[dynaman]

Wow, y'all are hard on bits! I must be lucky cuz I've been using the same old 3/32" bit for many boards (mostly G10) and never had a problem drilling properly sized clean holes with my $20 POS Chinese benchtop drill. I often use the same bit for drilling pilot holes in aluminum as well. Go figure.