Questions on PCB making

Hi guys, today i just did my own PCB's for the first time, one friend of me had all the stuff in his workshop brand new and unused for a couple of years so i had to use it  ;D, and it turned out to be a success ;D ;D ;D, the only hard part is the drilling bits, all broken  :'(, damn these are expensive, they were 0.8mm and 1mm.
Something like this but a little longer on the bit:

I use a Dremel at full speed, but the axis feels kind of wiggly (talking about all the system with the dremel on...), but i believe it's the built quality made of plastic etc... but i think Livingnote is using that exact same system + a vaccum so.....
I drilled fast with a steady mouvement, worked fine for the 1mm for about 5 holes, after that it's just broke.
The 0.8mm was like after the 2nd one.
What are the bits you guys using for drillings, and possible to tell me more on what to do and should not do regarding this???

Thanks a lot for your inputs.

Not bad for a first shot  , i went easy for the first time tough... 2 and a half mn in UV and about 6 to 7mn for the bath, kind of a lot from what i read, but maybe not enough temp??? Anyway the traces are clean so i believe it's ok and better go with visual check than timing....

Are you using a drill stand with a level to operate the drill ?  It makes a big difference with that type of drill bit because they are quite brittle compared to normal drill bits.  Also don't move the pcb while the drill is anywhere near the board.

Rob Flinn said:

Are you using a drill stand with a level to operate the drill ?  It makes a big difference with that type of drill bit because they are quite brittle compared to normal drill bits.  Also don't move the pcb while the drill is anywhere near the board.

Click to expand...

Yes i'm using this,


but isn't there any bits that are shorter, something like 0.5mm/0.7mm long and that's it???, i mean that could also do a difference, mines were about 12mm long, that's why i'm asking what people are using exactlly with success.
I was steady when drilling holes, but who knows even a tiny movement will brake these for sure so i believe that's what happened even if i don't remember moving, but the frame that keepd the drill in place is kind of wiggly, i had the press for some time now, thinking of this day, and it seems people are using this one with succes, but maybe it's just mine????
Or maybe it's better to use HSS ones for first times???

Those Dremels are hobby tools and will last in prime condition for several years maximum. No matter what you do it will slowly become wiggly. Especially if you do "rougher work" with it as well, like cutting metal with sideways movement. The plastic+metal design is a real limitation and stuff comes loose even if it doesn't seem like it. Some people get lucky and their particular dremel doesn't become wiggly quite as soon, others (like you and me) not so lucky. Warranty has no effect on this.

For those tiny drills, dremel is just not a great choice. Unfortunately the next best options are in industrial grade area, and prices more than quadruple. Size too.

I have used HSS  & the type in your picture.   The HSS type are possibly more forgiving.  The machine type definitely require a bit of care, any lateral movement & goodbye drill bit.

I don't break them that often, but I am using a relatively cheap chinese drill press, which is actually pretty good, & is actually pretty solid.  It cost about £40 UK, & was one of those things that when you start using it you wonder why you never bought it before.

You should not have a hard time with that setup...when you are drilling, use high rpm and light pressure, do not force the bit through the pcb.

I use discarded (yes, the pcb house threw them out) used pcb drill bits, there's a ton on ebay resharpened. My are NOT resharpened and I don't break them on both my cnc and cheap drill press. I'm more than willing to bet it's your technique and nothing more. Also, bits with a shorter flute will be more forgiving because they will be more rigid.

Cheers

You need a press... those bits are too brittle for anything with any instability at all... those dremel press things just can't substitute

Here's the one I'm using for pcb's

http://compare.ebay.com/like/170569541076?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&rvr_id=204301622495&crlp=1_263602_309572&UA=%3F*I8&GUID=bf95d28f12d0a026531715b7ff23dba1&itemid=170569541076&ff4=263602_309572

I've got the same ryobi as dustbro... it runs from 570 to 3050 rpm... which I've been running it at 1390 with no problems at all. 
I think that generally faster is better when it comes to PCB drilling, but with the carbide bits it's a piece of cake

dustbro said:

Here's the one I'm using for pcb's

http://compare.ebay.com/like/170569541076?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&rvr_id=204301622495&crlp=1_263602_309572&UA=%3F*I8&GUID=bf95d28f12d0a026531715b7ff23dba1&itemid=170569541076&ff4=263602_309572

Click to expand...

wow! I had no idea decent drill presses can be that cheap. I mean it's cheaper than dremel in many places! 

My concern was the speed because all these presses don't go over 8000rpm, but if you say it works than it's good to go, thanks  

Hi Tony 

Your setup should work well, as it does for others.
First thing you need is to get rid of vibrations. This stand is light, therefore it will vibrate much less once screwed on the bench...
Now, you said that you can clearly see the bit not turning centered. That's BAD! Are you sure that the chuck is clean? Sometimes a scrap of metal gets in, and prevent the bit from being centered...
Now if the chuck itself is off-center, or if the gap is in the bearings, you just need to throw away the drill...
At any rate, seeing your bit turning centered is a preliminary requirement. Even a top carbide bit on a 5000$ CNC will break almost instantly if not centered properly.

I have a press like the Ryobi, but I don't use it for PCB work. Because of the lower speed, you need to apply more pressure on the bit. Hence it heats, wear faster, and break often. Plus you need another chuck cause the stock one cannot hold bits smaller than 1.5mm...

FWIW, when I broke my Dremel, I bought a cheap chinese thingie for 15€ in some bargain shop (see picture). I use the flexible, without stand. The flexible in one hand, the PCB in the other. I find I can drill faster this way than having to center the PCB on the stand. And hands are perfect to absorb vibrations... Anyways, I have drilled as much a 600 holes in a row (0.6mm) with a cheap chinese HSS bit, without breaking. The bit was totally worn out, and the last hundred holes were more burned than drilled, but it didn't broke... Maybe I am just lucky...

Axel

mad.ax said:

FWIW, when I broke my Dremel, I bought a cheap chinese thingie for 15€ in some bargain shop (see picture). I use the flexible, without stand. The flexible in one hand, the PCB in the other. I find I can drill faster this way than having to center the PCB on the stand. And hands are perfect to absorb vibrations... Anyways, I have drilled as much a 600 holes in a row (0.6mm) with a cheap chinese HSS bit, without breaking. The bit was totally worn out, and the last hundred holes were more burned than drilled, but it didn't broke... Maybe I am just lucky...

Click to expand...

Yes, you are very lucky indeed. I have a lot of experience on this subject of dremels and cheap chinese knock offs wiggling. The first cheap chinese knock off I ever bought had severe (+1mm) wiggle brand new off the wrappers. Must have cost like €15 as well but back to the store it went. Then I borrowed a real dremel, but noticed it had developed a wiggle. At this point I was none the wiser and just went out and bought my own dremel with the extension included. No wiggle anywhere, hooray! Except now that I've had it for some years both the extension *and* the dremel itself have developed a wiggle. I suspect it is because of a lot of sideways metal cutting panel work that I've done.

The point being, there is a serious design error in the main *idea* of dremel and the likes somewhere. The wiggle doesn't matter for low precision cutting, sanding etc. rough work. In fact dremel is great for that. But for precious drilling like PCB work it makes dremel useless.

I had no idea drill presses were that cheap so those are likely the best option here, but if you absolutely must use something like a dremel for PCB work, look into what dentists and jewelry artisans are using. These industrial grade machines are unfortunately very expensive. Last I looked, they start from something like €400, and you have a choice of separate engine+extension, or models with high speed micromotors in the handle.

wow! I had no idea decent drill presses can be that cheap. I mean it's cheaper than dremel in many places! 
[/quote]

Yeah, I paid more for my dremel than for my press... it's not the best press in the world, but pretty good bang for the buck

mad.ax said:

Hi Tony 

I have a press like the Ryobi, but I don't use it for PCB work. Because of the lower speed, you need to apply more pressure on the bit. Hence it heats, wear faster, and break often. Plus you need another chuck cause the stock one cannot hold bits smaller than 1.5mm...

Click to expand...

I haven't had any problems with the lower speeds... (after reading this thread, I went out and upped the speed of my press )  I break more bits through dropping them than in PCB work... good luck
with other methods!!

I know that I have been lucky!
And I totally agree with the 'design error' that you point out Kingston. At 15000 RPM, anything made of plastic will wiggle, it's just a matter of time. And sometimes it wiggles out of the box!
I have been lucky to find a cheap one that runs straight, and Zayance may has been unlucky to buy a Dremel that wiggles...
Using those kind of tools for 'hard work' such as grinding just accelerate the process. Better to have different tools for different purposes...

I still insist that a drill press is not the right tool for PCB work. Needs another chuck. Speed is too low. And for a <100€ press, a precision of 1/10 mm is deemed very good.
When you drill a 6mm hole (the primary purpose of such press), 1/10 is nothing to worry about (in most cases). But when you drill a 1mm hole, 1/10 is 10%! More than it takes to break the bit...

I agree that dentist tools or high speed spindles like the ones used in routers would be the best option. Just a bit on the expensive side...

Axel

Small drill presses can be had around $50 on sale. If you look closely, the majority of the inexpensive (but perfectly functional) come from the exact same chinese manufacturer.

> My concern was the speed because all these presses don't go over 8000rpm

The "ideal" speed for a 1mm bit is much higher, but lower RPM works, just slower.

And you are removing so little material, slower is not that slow, and you won't have heat build-up as you would in a deep hole.

A saw should move about 5,000 feet per minute. 3000+RPM for a 7" blade, 500RPM for a 4-foot sawmill blade. A hand-saw moves 150 or 300 feet per minute, FAR below "optimum". But until about 200 years ago, nearly ALL sawing was done with hand-saws (although a few sawmills existed back to Roman times).

Kingston said:

wow! I had no idea decent drill presses can be that cheap. I mean it's cheaper than dremel in many places! 

Click to expand...

There's a direct chinese importer called "Harbor Freight" here in the U.S. that sells good cast iron tools criminally cheap. I walked into their store and bought this one new:
http://www.harborfreight.com/5-speed-drill-press-38119.html

Twice a year it goes on sale for $59. Yes, less than a dremmel.

But I have to admit, I'm conflicted by the knowledge that such purchases probably contribute to global suffering and oppression. I love getting a good deal, but this just didn't feel right.

Zayance, you'll notice that the dremmel press doesn't plunge perfectly perpendicular to your pcb plane. The farther it travels, the more variance, so I found it helps to position the drill bit tip as close to the PCB as possible; just enough room to slide the pcb under the bit.

Once I switched to these tungsten carbide bits from DrillBit City, my instances of breakage went way down.

kato said:

But I have to admit, I'm conflicted by the knowledge that such purchases probably contribute to global suffering and oppression. I love getting a good deal, but this just didn't feel right.

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*** veer warning****
It is generally considered that increasing trade with a nation increases our influence with them. When Ho was just in Washington meeting with Obama, and US business leaders, he was questioned about human rights (twice) and made a conciliatory statement. While words are words and actions are actions, this appears to be some movement, in their position, in the right direction.

If you want to feel bad, feel bad for american workers who are no longer making the entry level drill presses, but they should be learning how to do higher value work anyhow. This is a natural pattern and at one time we were the cheap labor stealing jobs from Europe.

JR