Author Topic: What to look for in a PCB drill?  (Read 4935 times)

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Offline ShiftPlusOne

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What to look for in a PCB drill?
« on: March 30, 2011, 10:16:35 am »
Hello, I've tried making my own boards using a printed iron on type thing, HCl and H2O2 and they come out pretty good. The only thing I need now is a drill.

Can anyone recommend any low budget drill which would be good for the job? Does it have to be a drill press? If I was to walk into a hardware store, what would I look for exactly?
 

Offline Psi

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Re: What to look for in a PCB drill?
« Reply #1 on: March 30, 2011, 10:36:48 am »
i use a dremel and this dremel brand drillpress attachment

It's not the most accurate thing ever, because its made of plastic, but it still works fine for drilling pcbs when i need.

The trick is to pre-dent the pads in the center, the drill bit then naturally finds the dent.
Denting the pads in the center is probably the hardest part of making your own pcb i reckon. They're so tiny and there isnt much room for error.



« Last Edit: March 30, 2011, 10:40:21 am by Psi »
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Offline johnwa

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Re: What to look for in a PCB drill?
« Reply #2 on: March 30, 2011, 10:55:40 am »
Hi,

I would suggest that you look at acquiring a drill press. While the ideal tool will be high speed, precision, rigid, well balanced, and designed especially for PCBs, I have found you can get quite good results with the drill presses you can get for around AUD120 in hardware shops. These will usually go up to about 3600RPM, which is a bit slow, but OK if you are not in a hurry. Make sure that the chuck runs true and will hold the drills you are intending to use. You can get mini 'adapter' chucks, but in my experience the drill bit ends up all over the place with these. A better solution is to use a bit with an expanded (~3mm) shank.

You will also want to get some carbide drills - normal HSS ones will start to go blunt after about 10 holes, and blunt drills make a real mess of the PCB. You need to take a bit of care with the carbide bits as they are quite brittle, and somewhat expensive (~AUD5 each), but you will get much better results.

Set up the press so the drill is only about 1mm above the board, and you will be able to drill holes with a light touch on the handle. Good lighting is required - eg a 50W halogen lamp right up close. It is also more convenient if you have an air blower to remove the swarf. I use a 12V air mattress inflator for this.

Try to resist the urge to automate the whole process by building a CNC drilling robot. I played around with this for years, the accuracy I achieved was only just acceptable, and I don't think I really saved any time with it. But it was a fun project! :)

 

Offline DaveW

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Re: What to look for in a PCB drill?
« Reply #3 on: March 30, 2011, 11:32:20 am »
Maybe not so low budget, but absolutely ideal for the job is
http://www.axminster.co.uk/proxxon-proxxon-tbm-220-bench-drill-prod725383/

Look for as high a spindle speed as you can and use a carbide drill bit, preferably add some lighting close to the board as well
 

Offline ShiftPlusOne

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Re: What to look for in a PCB drill?
« Reply #4 on: March 30, 2011, 11:51:16 am »
Thanks everyone.

I am having trouble finding anything for under $150 (or $200 for that matter) that goes up to at least 3600RPM. Looks like I need to double my budget here.
 

Offline Zero999

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Re: What to look for in a PCB drill?
« Reply #5 on: March 30, 2011, 06:16:18 pm »
I just use a normal hand drill in a drill stand. It's probably not as good as the real thing but it's find for what I do.
 

Offline PetrosA

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Re: What to look for in a PCB drill?
« Reply #6 on: March 31, 2011, 03:59:45 am »
Proxxon makes some really nice tools, but when I needed them they were way out of my price range. I would look into getting something like a cheap dremel (I have two 12V cheapies that I actually like better than my dremel) and stock up on various dental bits. I would even go so far and recommend you visit your dentist and ask them to save any bits they would otherwise be throwing away. I used to have more time for making models and I was able to drill most materials that way very accurately. If you want to use really small bits (under 1 mm) I think you'll have to look at brands other than dremel. They don't have a chuck insert that can hold such small bits that I know of...
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Offline Lance

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Re: What to look for in a PCB drill?
« Reply #7 on: March 31, 2011, 04:36:34 am »
Go for a dremel and some sort of stand. It's effective, and dremels are very useful for lots of other things.
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Offline joelby

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Re: What to look for in a PCB drill?
« Reply #8 on: March 31, 2011, 05:16:01 am »
If you want to use really small bits (under 1 mm) I think you'll have to look at brands other than dremel. They don't have a chuck insert that can hold such small bits that I know of...

The carbide PCB drill bits I've seen all have a wider bit at the top (and a fat bit in the middle) and fit into a standard Dremel chuck.
 

Offline ShiftPlusOne

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Re: What to look for in a PCB drill?
« Reply #9 on: March 31, 2011, 05:51:01 am »
Thanks again, everyone.
 

Offline Psi

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Re: What to look for in a PCB drill?
« Reply #10 on: March 31, 2011, 06:18:37 am »
i find the drills that expand up to a ~3mm shaft tend to break easier than the drills that are the same diameter the entire length.
Probably because the 3mm shaft doesn't flex, so any flexing is put entirely on the short and thin drill section.

However it's definitely harder to use the non-shafted drills as they're so tiny that you lose them easy and have to get the right size collet for each size bit.

« Last Edit: March 31, 2011, 06:25:44 am by Psi »
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