[OT] Using a Dremel tool for drilling PCBs

[Matt]

I need some advice about PCB prototyping.

I plan to use a laser printer, an electric iron, toner-transfer paper,
and etchant to make a few PCBs. Then I will need to drill the PCBs. I
expect to have about 150 holes per board.

I have a Dremel tool with RPM adjustable from 5000 to 35000. Would it
be practical to use it to drill the holes by hand? I know Dremel makes
a drill press for the tool ... would it be a big advantage?

What kind of collet or chuck should I use?

How long should I expect the drill bits to last? What type should I get
(HSS, carbide, diamond, other)?

 

[colin]

I need some advice about PCB prototyping.

I plan to use a laser printer, an electric iron, toner-transfer paper, and
etchant to make a few PCBs. Then I will need to drill the PCBs. I expect
to have about 150 holes per board.

I have a Dremel tool with RPM adjustable from 5000 to 35000. Would it be
practical to use it to drill the holes by hand? I know Dremel makes a
drill press for the tool ... would it be a big advantage?

What kind of collet or chuck should I use?

How long should I expect the drill bits to last? What type should I get
(HSS, carbide, diamond, other)?

thats a lot of holes by hand, hope its not many boards you are doing.

IME the solid carbide drills dont last long unless you have a good chuck and
stand.
cos they break so easily, although depends what size >1mm is probably ok
the ordinary HSS last a while before they go blunt,
but probably work out cheaper for hand use.

carbide coated are somewhere inbetween.

I was interested in the direct ink jet printing of etch resistant ink.

Colin =^.^=

 

[mpm]

Depending on the circumstances, I very often find for 1-off stuff its
easier and cheaper to get boards from ExpressPCB. The money end of
that makes sense IF (Repeat "IF"), the board dimensions can be kept to
exactly 3.8" x 2.5". They call it their "Mini Board" service.

You get QTY-3 boards for $51 + $8 to ship them 2nd day. (You have
them in 3 days.)
Double-layer, plated through holes, but no solder masks or
silkscreens.

They are not paying me to say this. In fact, there are probably
"better" deals out there??

But from the sound of it, you'd be spending a lot of time using the
Dremel.
Unless you enjoy that activity of course, your time is probably more
valuable.
Just a thought. Plus, the plated-through holes should add to
reliability.

They have free layout software, as to most of their competitors.
And for $60 more, they will come off the Gerbers (for those interested
in that..)

www.expressPCB.com

Keep in mind larger, or differently dimensioned boards will cost a lot
more.
This restriction may not apply to other vendors who offer a small run
prototyping service.

-mpm

 

[kell]

(snip)
They have free layout software, as to most of their competitors.
And for $60 more, they will come off the Gerbers (for those interested
in that..)

www.expressPCB.com

(snip)
-mpm

Can the expressPCB software generate Gerber files?

 

[Matt]

You can drill 150 holes pretty quickly with good lighting and proper
RPM-- just a few minutes for the bulk of them which will probably be
around 0.8mm.

Thanks. I forgot to ask---what speed should I use?

 

[kell]

I need some advice about PCB prototyping.

I plan to use a laser printer, an electric iron, toner-transfer paper,
and etchant to make a few PCBs. Then I will need to drill the PCBs. I
expect to have about 150 holes per board.

I have a Dremel tool with RPM adjustable from 5000 to 35000. Would it
be practical to use it to drill the holes by hand? I know Dremel makes
a drill press for the tool ... would it be a big advantage?

What kind of collet or chuck should I use?

How long should I expect the drill bits to last? What type should I get
(HSS, carbide, diamond, other)?

I hear dental burs are the best for hand drilling pc boards.

 

[Robbo]

Thanks. I forgot to ask---what speed should I use?

I've got a solid pedestal drill - running at about 2000 or 3000 RPM and HSS
bits it works better than the Dremel at any speed. Carbide bits work really
well in the dremel at higher speeds but are very easily broken. Try running
the vacuum cleaner continuously to grab the dust.

 

[Matt]

mpm wrote:

Thanks for the expressPCB link. I may use them, but I will still need
to make at least some boards by hand.

Just a thought. Plus, the plated-through holes should add to
reliability.

Should I solder from both sides if the holes are not plated? Would I
need to stick a piece of wire through for hand-drilled vias, or would a
plug of solder establish the connection?

 

[[email protected]]

I need some advice about PCB prototyping.

I plan to use a laser printer, an electric iron, toner-transfer paper,
and etchant to make a few PCBs. Then I will need to drill the PCBs. I
expect to have about 150 holes per board.

I have a Dremel tool with RPM adjustable from 5000 to 35000. Would it
be practical to use it to drill the holes by hand? I know Dremel makes
a drill press for the tool ... would it be a big advantage?

What kind of collet or chuck should I use?

How long should I expect the drill bits to last? What type should I get
(HSS, carbide, diamond, other)?

Sigh.

www.olimex.com

 

[Spehro Pefhany]

I need some advice about PCB prototyping.

I plan to use a laser printer, an electric iron, toner-transfer paper,
and etchant to make a few PCBs. Then I will need to drill the PCBs. I
expect to have about 150 holes per board.

I have a Dremel tool with RPM adjustable from 5000 to 35000. Would it
be practical to use it to drill the holes by hand? I know Dremel makes
a drill press for the tool ... would it be a big advantage?

What kind of collet or chuck should I use?

How long should I expect the drill bits to last? What type should I get
(HSS, carbide, diamond, other)?

HSS will be getting dull after around one board or two. They are
cheap, you can buy an envelope of them. Cobalt should be slightly
better (but more expensive).

They generally have a shank the diameter of the hole they make.
Professional PCB drilling generally uses solid carbide drill bits with
a 1/8" shank. They are easy to break with a cheap drill press setup,
but some people have been successful using the Dremel.

As with any cutting tool, buy only good name-brand bits, cheap junk
like the TiN stuff sold to hobbyists will bring you only grief. Some
of them are amazingly soft, barely suitable for hardwood.

You can drill 150 holes pretty quickly with good lighting and proper
RPM-- just a few minutes for the bulk of them which will probably be
around 0.8mm.


Best regards,
Spehro Pefhany

 

[Ecnerwal]

Should I solder from both sides if the holes are not plated? Would I
need to stick a piece of wire through for hand-drilled vias, or would a
plug of solder establish the connection?

Use wire, bent over on both sides and soldered.

 

[Mike]

I need some advice about PCB prototyping.

I plan to use a laser printer, an electric iron, toner-transfer paper,
and etchant to make a few PCBs. Then I will need to drill the PCBs. I
expect to have about 150 holes per board.

I have a Dremel tool with RPM adjustable from 5000 to 35000. Would it
be practical to use it to drill the holes by hand? I know Dremel makes
a drill press for the tool ... would it be a big advantage?

What kind of collet or chuck should I use?

How long should I expect the drill bits to last? What type should I get
(HSS, carbide, diamond, other)?

Oh yeah, it's very practical. I use the same process for all my boards.
A drill press is an absolute necessity! Without one you WILL break your bits.
Use the standard collet, it fits the carbide bits with a 1/8" shaft.
I have never dulled a bit. I always get in a hurry and break them before they get dull.
I've never measured the speed, but just set it till it sounds right.
It is fairly slow for the Dremel tool. A few practice holes will tell you.
150 holes in a board is not problem. I can do 100-200 before I need to take a break.

Three things that really help:
1 - A #10 Optivisor. A #7 might be ok you have good enough eyes.
2 - Lots of light. I use a gooseneck lamp with a 23W screw in fluorescent bulb.
You need the light adjustable because reflection from the board changes when
I have to rotate the board and the light position makes a big difference.
3 - Make sure your layout is printed with drill guide holes etched in the center of the pads.
I set my software to print 0.025" dia guide holes.

I drill all the holes to.032 then go back and enlarge all the holes that need it.
This works much better. The larger bits don't tend to fall into the etched guide
holes nearly as well, but fall nicely into the .032 holes. They don't follow
the guide holes well if the speed is too high either.

I also setup my shop vac just behind the Dremel tool to keep the fiberglass debris down.
This makes it easier to see the guide holes and results in much less of a mess. Use a
fairly small nozzle and get it close as possible without interfering.
Don't forget to use breathing mask! It's much easier on the lungs.

Mike




When truth is absent politics will fill the gap.

 

[John Popelish]

Matt wrote:
(snip)

Should I solder from both sides if the holes are not plated? Would I
need to stick a piece of wire through for hand-drilled vias, or would a
plug of solder establish the connection?

Solder will not reliably form a thread through an unplated
hole. Definitely, use a wire. Silver plates wire wrap wire
works well. Strips and wets very easily. Good for at least
an ampere.

 

[Spehro Pefhany]

Thanks. I forgot to ask---what speed should I use?

Depends on drill diameter and drill material. Up to 0.05" or so, with
carbide, the Dremel can't go too fast. Try about 1/3 the speed for HSS
(so about 10,000 RPM at 0.05" and 20,000 at 0.025" etc.) You can
always go slower than the recommended RPM, but that reduces the
optimum feed rate (takes longer to drill each hole).

http://www.taconic-stl.com/fr4 processing_guide.pdf



Best regards,
Spehro Pefhany

 

[Mike Harrison]

You NEED a stand.

Collet is best for aligment - must be metal collets though, not plastic.

Must use carbide - PCBs eat HSS in no time. You MUST use a stand when drilling with carbide bits
otherwise they will snap very easily.
A carbide bit should last many hundred holes easily. HSS maybe a few dozen.

see www.electricstuff.co.uk/pcbs.html for plenty of info on making good homemade PCBs.

 

[DJ Delorie]

You NEED a stand.

Yup. I made my own: http://www.delorie.com/pcb/dremel-stand/

I can use 13 mil drills with it, without breaking them, and with
reasonable accuracy.

 

[mpm]

Can the expressPCB software generate Gerber files?

No, it cannot.
Here's how it works:

You place an order with them. (Using their free layout software, which
is actually pretty good*)
Then you call them back with the order confirmation number and tell
them you want the Gerber Files. They charge your credit card $60 US,
and email you the Gerbers.

A few threads back, someone was going to post an alternate solution
involving raster-to-Gerber conversion. (The ExpressPCB has 300dpi
output capability, but I don't know if this alternate solution would
provide acceptable results as I've never tried it...)

It just seemed that Matt was about to embark on a fairly involved
creation effort, and I wanted to give him the heads-up. In small
quantities, these little PCB fab houses are hard to pass up.

And honestly, I no longer have the patience or eyesight required to
thread wire for "plated-thru" holes.
I do however, has enough aspirin for same....

 

[Joel Kolstad]

You place an order with them. (Using their free layout software, which
is actually pretty good*)
A few threads back, someone was going to post an alternate solution
involving raster-to-Gerber conversion.
In small
quantities, these little PCB fab houses are hard to pass up.

Does it occur to anyone that there might be fewer of these "little PCB fab
houses" making "pretty good" software if you create software (a raster to
gerber converter) that forces them all to compete strictly on price and no
longer on what tools they provide?

Just something to think about...

 

[D from BC]

I need some advice about PCB prototyping.

I plan to use a laser printer, an electric iron, toner-transfer paper,
and etchant to make a few PCBs. Then I will need to drill the PCBs. I
expect to have about 150 holes per board.

I have a Dremel tool with RPM adjustable from 5000 to 35000. Would it
be practical to use it to drill the holes by hand? I know Dremel makes
a drill press for the tool ... would it be a big advantage?

What kind of collet or chuck should I use?

How long should I expect the drill bits to last? What type should I get
(HSS, carbide, diamond, other)?

I make my own PCB's...
I could almost write a book on the subject.

I use as much SMD as possible...I hate drilling holes.
Maybe use more SMD.
I also hate hand soldering..That's why I hot plate.
But when I do drill holes..Yes..I use a dremel on a dremel drill
press.
I buy bits at the local hobby shop. Dunno what type they are but it's
cheap and I have no idea how long they last.. I seldom drill.
As soon as I sense slow drilling or burning, I change to another bit.

By the way, I also hate toner-transfer paper
D from BC

 

[legg]

I need some advice about PCB prototyping.

I plan to use a laser printer, an electric iron, toner-transfer paper,
and etchant to make a few PCBs. Then I will need to drill the PCBs. I
expect to have about 150 holes per board.

I have a Dremel tool with RPM adjustable from 5000 to 35000. Would it
be practical to use it to drill the holes by hand? I know Dremel makes
a drill press for the tool ... would it be a big advantage?

What kind of collet or chuck should I use?

How long should I expect the drill bits to last? What type should I get
(HSS, carbide, diamond, other)?

You'll find centering to be a problem unless the art provides for
etched centers. Many gerbers do not do this, simply relying on
electronic drill file.

RL