Drill bits for homemade PCBs?

[Supercap2F]

Hey Everyone!

I wonder if you guys could tell me what you use to drill your homemade PCBs with (like what drill press you use/where you get your drill bits).

I started drilling a PCB I made but after a only few holes, the drill bits snapped. I think that it may be because the drill press I'm using isn't very precise and has quite a bit of play in the shaft. It may also be because I was using some $4 bits I bought off of ebay.

I was thinking about buying a special drill press for PCBs, but before I did I though I would ask you guys what you use.

Thanks a ton for your time!!!
Dan

 

[Martaine2005]

Hi Dan,
It wont be the bits or the press.
It will be how fast you try and drill the hole. These tiny 1mm to 4mm bits really need to be drilled slowly, no pressure and let the bit do the work.
Have a practice while drilling some off-cuts.
This applies to drilling anything with tiny drill bits.
Metal 'HSS' bits are best at these tiny sizes.

Martin

 

[Martaine2005]

because the drill press I'm using isn't very precise and has quite a bit of play in the shaft

Oops, depends a little on that too. But taken slowly, even a bent drill bit will still drill a bigger hole!!

Martin

 

[BobK]

I use a Dremel tool and an Dremel drill press. I have never broken a bit while drilling. Unlike Martaine, I go really fast, a fraction of a of a second to drill a hole. I use double sided tape to fasten the PCB to a backing block of wood. I set the drill height so that it just barely clears the PCB, which allows me to accurately position it. When I am not paying attention, I remove the PCB board and backing board too quickly and catch the bit as I pull it out, which breaks the bit (twice I think, I have now learned my lesson.)

I use bits with an 1/8 in shank to fit the Dremel, made by Kyocera or Hertel (both seem of equal quality). I get the at MSC Industrial supply:

http://www.mscdirect.com/

Bob

 

[hevans1944]

... the drill press I'm using isn't very precise and has quite a bit of play in the shaft.

Any wobble or "play" in the spindle will quickly kill a silicon carbide drill bit, which are virtually required for drilling holes in circuit boards. HSS bits will dull after only a few holes are drilled.

I am currently attempting to use a Dremel tool mounted in a Dremel "drill press" accessory, having recently purchased some el-cheapo carbide drills from a vendor in China. The Dremel tool spins at about 10,000 RPM (more or less) and has very little run-out, so it should not be a problem. Not so sure about the drill press accessory: it doesn't actually move the tool up and down, it moves the circuit board up to meet the drill. We'll see how that goes.

Desktop drill presses for drilling circuit boards are very nice things to have. I used one at an employer sometime in the last century, but they tend to be a bit pricey for home hobbyist use.

Edit: Ooops! @BobK beat me to it. Glad to hear that the Dremel + drill press accessory works for him because that means it will probably work for me, too!

 

[Old Steve]

And everyone beat me.

I'm with Bob. Except I don't use my Dremel - it's a bit heavy and bulky. I bought a mini version, 12V 1A. Much easier to manoeuvre.( I drill by hand, too, not with a drill press.):-




And I find that HSS drill bits, especially the cheap ones, wear out way too fast, so I always buy titanium-nitride coated bits now. For the most common size, 0.8mm, I buy slightly better quality with a 3.2mm shank:-



Edit: And I use small blobs of 'Blu-Tak' to hold the board on a kitchen cutting board while drilling.

 

[Old Steve]

hevans, I bought some eBay "carbide" bits some time ago, too. No chance of breaking these babies - they're so soft they bend.



The only use I found for them was cleaning the holes after drilling if they were blocked by swarf.
I hope your's are better.

 

[BobK]

Not so sure about the drill press accessory: it doesn't actually move the tool up and down, it moves the circuit board up to meet the drill. We'll see how that goes.

Mine (Dremel model 220) moves the drill, so you must not have the same model.

Here is a link to the one I have:

http://www.amazon.com/Dremel-220-01...552&sr=8-1&keywords=dremel+220-01+rotary+tool

Bob

 

[Old Steve]

Mine (Dremel model 220) moves the drill, so you must not have the same model.

Here is a link to the one I have:

http://www.amazon.com/Dremel-220-01...552&sr=8-1&keywords=dremel+220-01+rotary+tool

Bob

I have one the same as your's Bob, but I found that using a drill press was more of a pain than it was worth, and much slower than drilling by hand with a small, lightweight drill, especially when there are hundreds of holes to drill in a variety of sizes.
I keep my Dremel strictly for my woodworking these days.

 

[Martaine2005]

HSS bits will dull after only a few holes are drilled.

I beg to differ with you.
My set of HSS bits have been around the houses for many years. If you use them for plastics or pcb, fibreglass etc, they will blunt if the speed is too high.(RPM)
I was giving Dan a place to start. And to start slowly, let the drill bit do the work.
Drilling a hole in micro secends as Bob said is totally wrong for any engineer or anybody drilling any kind of hole.
No tool should be forced to cut.
Let the tool cut. It will last 1000 times longer.

This is not a dig at any body, just how it should be done.

Martin

 

[Arouse1973]

Hey Dan
I use these at work to go with the milling machine. They are a bit more expensive but last a long time. You could contact a local PCB manufacture and ask them if they have any used bits you could have or purchase. They replace them often and they will certainly have enough life left in them for your use.

http://cirqoid.com/collections/consumables/products/pcb-drill

Adam

 

[Old Steve]

I beg to differ with you.
My set of HSS bits have been around the houses for many years. If you use them for plastics or pcb, fibreglass etc, they will blunt if the speed is too high.(RPM)
I was giving Dan a place to start. And to start slowly, let the drill bit do the work.
Drilling a hole in micro secends as Bob said is totally wrong for any engineer or anybody drilling any kind of hole.
No tool should be forced to cut.
Let the tool cut. It will last 1000 times longer.

This is not a dig at any body, just how it should be done.

Martin

That's true. Martin, but when drilling 1.6mm fibreglass PCB material with an 0.8mm sharp drill bit, even when you let the drill do the work, it goes through very fast.

And the reason HSS bits dull so quickly when drilling PCBs is because of the glass. My drill is not too fast, well below 10000rpm, and I never force bits into the material, but they still don't last for 'years' as you say. Not when drilling many hundreds of holes.
Try making a bunch of PCBs first, before 'teaching' us.

 

[Martaine2005]

Ouch, that was a little un-called for.
I am not teaching any body. Never force a bit faster than it can cut. Standard practice.

Martin

 

[Martaine2005]

That's true. Martin, but when drilling 1.6mm fibreglass PCB material with an 0.8mm sharp drill bit, even when you let the drill do the work, it goes through very fast.

And the reason HSS bits dull so quickly when drilling PCBs is because of the glass. My drill is not too fast, well below 10000rpm, and I never force bits into the material, but they still don't last for 'years' as you say. Not when drilling many hundreds of holes.
Try making a bunch of PCBs first, before 'teaching' us.

You of all people should understand Steve.
Whack a blunt chisel into wood turning. It will burn.
Whack a sharp chisel in and it will destroy your master piece if you are not careful.

Martin

 

[Old Steve]

Ouch, that was a little un-called for.
I am not teaching any body. Never force a bit faster than it can cut. Standard practice.

Martin

Martin, I was only correcting you in the same way you corrected hevans. Don't take it too hard.
I didn't mean to get personal, but I guess it sounded like it.
It was because when hevans said,
"HSS bits will dull after only a few holes are drilled.",
you said " I beg to differ with you."

You were wrong in this case.

And I definitely agree regarding not forcing the bits though, as I said in my last post.

 

[davenn]

I'm with Bob. Except I don't use my Dremel - it's a bit heavy and bulky. I bought a mini version, 12V 1A. Much easier to manoeuvre.( I drill by hand, too, not with a drill press.):-

I have one of those units shown by Steve .... had it for some 30+ yrs still going strong

 

[Old Steve]

I have one of those units shown by Steve .... had it for some 30+ yrs still going strong

Yeah Dave, they're not bad. ex-Jaycar or Altronics. Mine would be 20 years old now. Something's rattling inside it, but it still works great.

 

[Supercap2F]

Awesome, Thanks for the replies guys!

The drill bits I bought were like these: http://www.ebay.com/itm/361393793317. I didn't drill really quickly or force them, so it must have been the play that killed them.

I'll have to buy some more and try them with a Dremal. I think I will hold off on buying the Dremal stand thing for now though, I know I can make one for cheaper than $50.
Dan

 

[davenn]

I didn't drill really quickly or force them, so it must have been the play that killed them.

that bit is the bad part .... sometime I can be happily drilling away 30 - 40 holes and lack of concentration and I accidentally flex the drill and snap another bit down. other times several 100 holes before snapping a bit

 

[Martaine2005]

Just hold a small drill steady and don't rock it. Any drill will do. So wil the bit.,
All this nonsense about drill bits and what ever.
Just get on with it and post your results.

Martin