Homebrew PCBs

Hello,

   I spent about half a day experimenting with this today.  I had just
obtained a box of HP gloss laser paper #Q2419A, which was well 
reviewed in the database.  Had my new GBC 9 1/2 inch laminator, ready 
to go to town.  It's not quite happening yet.

    At first, I tried folding the paper over the copperclad and taping
it on the back.  This resulted in massive bad transfer at the edges.

    OK, I tried cutting the paper to the exact size of the copperclad 
and bending the tape around the edges.  A bit better, but still some 
edge problems.  

   Also, the paper does not release cleanly from the toner - I have to
scrub it off piecemeal by rolling it off with my fingers.  Or does 
one scrub it with a toothbrush?  Maybe I should have done a cold 
water bath before putting it in the hot soapy water - will try that 
tomorrow.  Just like peeling a hardboiled egg.

   Do you pass it through the laminator same direction every time?  
Or do you rotate the board, put it through this way then that way?

   Do you make the board its final size, or is it better to make it 
somewhat bigger, then etch it, then cut it down to size?  That way, 
the crappy edges would all be unused.

   I had better luck with some Epson photo paper I had laying around,
and my wife's clothes iron. That released really clean, and gave me a 
usable board.  Unfortunately, I don't know what paper that was - it 
was part of a multi-tryit pack that came with a printer.

   I find that failed experiments clean off easily with paper towels 
and lacquer thinner.  Is that good enough - "clean enough" to try 
again, or do I need to clean it some more?

  Thanks in advance,

                             - Jerry Kaidor

yes to all your questions.

Edge problems are common. There can be many reasons, like
contamination or bad surface preparation, which is tricky along the
edges. Also, the pull from the paper shrinkage under heat is greatest
on the edges.
I simply leave a solid copper border around the PCB (or around the
outside of several if i make more than one on a panel), and cut it
away later. It is the only sure way i have found. Apparently
pre-shrinking the paper by running it through the laminator before
printing has also brought relief to some.

Most papers release only with some effort involved. That is OK and you
can use a foam rubber sponge instead of your fingers. A paper that
sticks some even on the non-printed areas has advantages too, there is
less pull from the shrinkage on the toner.

I only pass it once through my homemade lamniator so i do not know if
the direction makes a difference.

Laquer thinner could be a bit hit-and-miss. Probably it is just fine
but i'm unsure of the exact composition and also i don't like the
required ventilation. I use acetone and the board is good to go after
a cleaning with that (since it is just the same as i would use for the
final cleaning on a fresh board). There is no need for renewed
abrasive cleaning, after all if you have many transfer failures you
would wear the copper through eventually.

Keep trying, eventually you'll find a good combination.

ST

On Sat, Dec 20, 2008 at 7:47 AM, jerrytr2.com <jerry@...> wrote:
> Hello,
>
>   I spent about half a day experimenting with this today.  I had just
> obtained a box of HP gloss laser paper #Q2419A, which was well
> reviewed in the database.  Had my new GBC 9 1/2 inch laminator, ready
> to go to town.  It's not quite happening yet.
>
>    At first, I tried folding the paper over the copperclad and taping
> it on the back.  This resulted in massive bad transfer at the edges.
>
>    OK, I tried cutting the paper to the exact size of the copperclad
> and bending the tape around the edges.  A bit better, but still some
> edge problems.
>
>   Also, the paper does not release cleanly from the toner - I have to
> scrub it off piecemeal by rolling it off with my fingers.  Or does
> one scrub it with a toothbrush?  Maybe I should have done a cold
> water bath before putting it in the hot soapy water - will try that
> tomorrow.  Just like peeling a hardboiled egg.
>
>   Do you pass it through the laminator same direction every time?
> Or do you rotate the board, put it through this way then that way?
>
>   Do you make the board its final size, or is it better to make it
> somewhat bigger, then etch it, then cut it down to size?  That way,
> the crappy edges would all be unused.
>
>   I had better luck with some Epson photo paper I had laying around,
> and my wife's clothes iron. That released really clean, and gave me a
> usable board.  Unfortunately, I don't know what paper that was - it
> was part of a multi-tryit pack that came with a printer.
>
>   I find that failed experiments clean off easily with paper towels
> and lacquer thinner.  Is that good enough - "clean enough" to try
> again, or do I need to clean it some more?
>
>  Thanks in advance,
>
>                             - Jerry Kaidor
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>

--- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan" 
<stefan_trethan@...> wrote:
>
> yes to all your questions.
> 
> Edge problems are common. There can be many reasons, like
> contamination or bad surface preparation, which is tricky along the
> edges. Also, the pull from the paper shrinkage under heat is 
greatest
> on the edges.
> I simply leave a solid copper border around the PCB (or around the
> outside of several if i make more than one on a panel), and cut it
> away later. It is the only sure way i have found. Apparently
> pre-shrinking the paper by running it through the laminator before
> printing has also brought relief to some.

*** I tried this.  Sure can get some serious shrinkage with a full 
sheet.  In fact, the paper ( HP Q2419A ) just wrinkled up.  Obviously 
wouldn't have worked at all.  

    I tried again this morning.  Used a board about two inches
too big in each dimension - so there was an inch of dead space on 
each side.  I printed onto the HP glossy paper with the following
settings on my Brother MFC8600DN:  
  * resolution 1200HQ
  * "transparency" ( figured those are smooth, and the printer might
    put down more toner )

   I cleaned the board with laquer thinner, and then with denatured 
alcohol.  Trimmed the printout a bit smaller than the board, and 
taped it on with Scotch Magic tape.

   Gave it 5 passes through the laminator (GBC 95P ) doused it in 
cold water, and then  let it in hot soapy water for about 15 minutes.
It mostly worked, although the corners were still crumbly, and I had 
to spend about a half hour rolling the soft paper off.

   Bits of toner were coming off in the ferric chloride bath.  I 
fished the board out and touched up with a fine-tip marker pen.

   The circuit side etched faster than the back side, so when it was 
done ( and the back side still had a ways to go ), I taped off the 
whole circuit side with masking tape and finished etching off the 
other side.  It's not pretty, but it'll work.

   Things I want to try next time:

   * Sand the board.  I think that a bit of a tooth will help the 
toner stick.  Say 400 or 600 grit.
   * Try different temps.  I think maybe the "foil" setting is a bit 
hotter than needed.  I noticed some pots on the circuit board in the 
laminator.  A lower temp should help with the shrinkage.  Would like
it hot enough to melt the toner, but no hotter.

                           - Jerry

Yes, the wrinkling is a problem. I even got a crease when i tried, so
i didn't try again.
Possibly the sheets can be dried between two plates in an oven or some
such complicated method.

You don't need an inch, i usually draw a 5mm line around my boards and
that's enough.
Sometimes i also forget, and apart from the board outline rarely lose
any traces that way.

Clearly your surface preparation is not sufficient. I didn't know you
didn't sand it, try that first and then we can look further.

You probably won't avoid shrinkage with any heat setting, you need
well over 100°C to melt toner and i think the shrinkage is mostly from
expelled water.
If it is a huge problem you need another paper.

The toner is strong enough to resist the etchant almost permanently,
if done right. So it's no problem to wait as long as it took to etch
one side again to finish the other, as long as your traces are wide
enough so that undercutting is no problem. The other side always takes
much longer to etch for mee too (more copper i suppose).

ST

On Sun, Dec 21, 2008 at 2:39 AM, jerrytr2.com <jerry@...> wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "Stefan Trethan"
> <stefan_trethan@...> wrote:
>>Apparently
>> pre-shrinking the paper by running it through the laminator before
>> printing has also brought relief to some.
>
> *** I tried this.  Sure can get some serious shrinkage with a full
> sheet.  In fact, the paper ( HP Q2419A ) just wrinkled up.  Obviously
> wouldn't have worked at all.
>
>    I tried again this morning.  Used a board about two inches
> too big in each dimension - so there was an inch of dead space on
> each side.  I printed onto the HP glossy paper with the following
> settings on my Brother MFC8600DN:
>  * resolution 1200HQ
>  * "transparency" ( figured those are smooth, and the printer might
>    put down more toner )
>
>   I cleaned the board with laquer thinner, and then with denatured
> alcohol.  Trimmed the printout a bit smaller than the board, and
> taped it on with Scotch Magic tape.
>
>   Gave it 5 passes through the laminator (GBC 95P ) doused it in
> cold water, and then  let it in hot soapy water for about 15 minutes.
> It mostly worked, although the corners were still crumbly, and I had
> to spend about a half hour rolling the soft paper off.
>
>   Bits of toner were coming off in the ferric chloride bath.  I
> fished the board out and touched up with a fine-tip marker pen.
>
>   The circuit side etched faster than the back side, so when it was
> done ( and the back side still had a ways to go ), I taped off the
> whole circuit side with masking tape and finished etching off the
> other side.  It's not pretty, but it'll work.
>
>   Things I want to try next time:
>
>   * Sand the board.  I think that a bit of a tooth will help the
> toner stick.  Say 400 or 600 grit.
>   * Try different temps.  I think maybe the "foil" setting is a bit
> hotter than needed.  I noticed some pots on the circuit board in the
> laminator.  A lower temp should help with the shrinkage.  Would like
> it hot enough to melt the toner, but no hotter.
>
>                           - Jerry
>
>
>
>
>
>
>
>
>
>
>
> ------------------------------------
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>
>

I've never tried the paper you are using, but I was under the
impression that the *Inkjet* glossy is preferable to the laser glossy,
because the laser paper is obviously made to hold onto the laser
toner.

I get good results and none of the problems that you mention using
paper from a magazine, an iron, and a rolling pin. I would describe
the paper as 'cheap', thin, and fairly glossy but not super glossy. It
lifts right off under running water with very little encouragement.

The only problem I have is with toner density on my samsung ml-2010,
which can result in some pitting. I like your idea of setting it to
'transparency' paper, I'll try that and see if it helps...

I also remember reading something about a brother printer that was
unsuitable because the melting point of the toner was too high...

--- In Homebrew_PCBs@yahoogroups.com, "James Bishop" <bishopaj@...> 
wrote:
>
> I've never tried the paper you are using, but I was under the
> impression that the *Inkjet* glossy is preferable to the laser 
glossy,
> because the laser paper is obviously made to hold onto the laser
> toner.

*** Sort of makes sense.

> 
> I get good results and none of the problems that you mention using
> paper from a magazine,

*** I tried the glossy front page of a Ram Welding catalog.  The 
toner transferred well, but so did Ram Welding's print.  Apparently 
they'd printed their catalog on a laser printer :).

> 
> I also remember reading something about a brother printer that was
> unsuitable because the melting point of the toner was too high...

*** Now THAT's interesting.  I remember looking for magnetic toner 
for printing checks, and the check toner store telling me that 
Brother printers would not do at all.  Same problem?  I do have a 
Laserjet 1020 ( that I use to print checks ).  And I also have the 
original unused toner cartridge.  Might try that out.

   I have a board soaking right now.  This time, I sanded it with 600 
grit, cleaned it off with lacquer thinner and paper towels, then with 
denatured alcohol and cotton balls. We'll see how it turns out.

   I am absolutely fascinated by the process of board design.  It's 
just amazing to me that one can now download software to actually do 
this for FREE of the Internet.  My wife is annoyed by how much time 
I'm spending in front of the computer drawing pretty pictures.

    If I get the single sided process down pat, I am eager to proceed 
to double-sided.  I just designed a PIC24F CPU card, and was unable 
to do any sort of reasonable routing single-sided.

                              - Jerry Kaidor

--- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...> wrote:
>    I have a board soaking right now.  This time, I sanded it with 600 
> grit, cleaned it off with lacquer thinner and paper towels, then with 
> denatured alcohol and cotton balls. We'll see how it turns out.

*** Just got back from the kitchen sink.  The board is GORGEOUS.  I
flushed it with cold water, then gave it a 15 minute soak in  warm 
soapy water.  The paper mostly peeled off in one piece, except for a 
thin layer, that I carefully rubbed off with my fingers.  The traces 
came out flawless, the edges perfect.  The only damage to the toner was 
a bit of one of my initials rubbed off - but that's a seriousoy thin
"trace" :).

   This is a simple analog/power regulator board with fat traces, wide 
spacing and lots of ground plane.  The only thing at all challenging 
was a single 16-pin DIP.  And I didn't even have to shoot traces 
between any of the pins.  Keeping it Simple to start....

                        - Jerry Kaidor

See, i told you so ;-)

You can probably tune down the preparation a little. What i do is rub
the surface with 1000 grit sandpaper or one of those plastic abrasive
pads sold for plumbing work. Just enough so that the surface is
scratched. Then i put a paper towel on it (actually, something else
that comes on rolls...), apply a few drops of acetone, and wipe.
Alcohol should work too but i need the acetone anyway to remove the
toner remains that didn't come off with scraping.

Of course it's good to go over the top if something doesn't work, to
eliminate problems, but once it works you shouldn't need more than a
few seconds to prepare a small board.

ST

On Mon, Dec 22, 2008 at 7:30 AM, jerrytr2.com <jerry@...> wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...> wrote:
>>    I have a board soaking right now.  This time, I sanded it with 600
>> grit, cleaned it off with lacquer thinner and paper towels, then with
>> denatured alcohol and cotton balls. We'll see how it turns out.
>
> *** Just got back from the kitchen sink.  The board is GORGEOUS.  I
> flushed it with cold water, then gave it a 15 minute soak in  warm
> soapy water.  The paper mostly peeled off in one piece, except for a
> thin layer, that I carefully rubbed off with my fingers.  The traces
> came out flawless, the edges perfect.  The only damage to the toner was
> a bit of one of my initials rubbed off - but that's a seriousoy thin
> "trace" :).
>
>   This is a simple analog/power regulator board with fat traces, wide
> spacing and lots of ground plane.  The only thing at all challenging
> was a single 16-pin DIP.  And I didn't even have to shoot traces
> between any of the pins.  Keeping it Simple to start....
>
>                        - Jerry Kaidor
>
>
>

Congratulations!  Now that you are hooked, you can try some variations in the preparation process.  Some light sanding with a 3M abrasive pad to lend some tooth, followed by a Simple Green (buty cellusolve, mostly) scrub, then an acetone wipe.  Lint-free paper wipes (Kimwipes or similar) are very good as they won't leave cruft behind.

Keep notes.  Do what works and know what doesn't.

HTH,
Donald.

 -------------- Original message ----------------------

From: "jerrytr2.com" <jerry@...>
> --- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...> wrote:
> >    I have a board soaking right now.  This time, I sanded it with 600 
> > grit, cleaned it off with lacquer thinner and paper towels, then with 
> > denatured alcohol and cotton balls. We'll see how it turns out.
> 
> *** Just got back from the kitchen sink.  The board is GORGEOUS.  I
> flushed it with cold water, then gave it a 15 minute soak in  warm 
> soapy water.  The paper mostly peeled off in one piece, except for a 
> thin layer, that I carefully rubbed off with my fingers.  The traces 
> came out flawless, the edges perfect.  The only damage to the toner was 
> a bit of one of my initials rubbed off - but that's a seriousoy thin
> "trace" :).
> 
>    This is a simple analog/power regulator board with fat traces, wide 
> spacing and lots of ground plane.  The only thing at all challenging 
> was a single 16-pin DIP.  And I didn't even have to shoot traces 
> between any of the pins.  Keeping it Simple to start....
> 
>                         - Jerry Kaidor
>

--- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...> wrote:
>
>  It's not quite happening yet.

Here's the basic process I use and get great results with.

Board prep. I scrub the board both sides with dawn dish soap and a 3M
scotch brite sponge (use the scrubby side). I make sure I go in both
directions well (scrub a couple of minutes total) and then I dry it
with a clean white paper towel. If I get any marks on it after that, I
wipe it with 99% alcohol from the drug store.

I still use an iron myself and I get excellent results with it. It's
also easy to place the image on the board and to align images for
double sided boards. I place 3 alignment marks on the layouts (near
the corners, component drill holes can be used as well). I poke a hole
through the holes in each image and then mark and drill these holes in
the board. I then use pins to alight the image to the board, place the
pin through 2 opposite holes and then align the pins to the holes in
the pcb. 3 holes give a third check point or an alternate alignment
point if one seems off. With the image aligned on the board, I press
it firmly with my fingers to hold it there and then tack it down with
the iron. Once tacked down, I place the extra sheet of typing paper
over it and proceed to iron it thoroughly to the board. I use highest
setting, light pressure, and iron for about 3 minutes per side to make
sure it's transferred well. I just place a single sheet of typing
paper between the iron and the transfer sheet, it seems to help the
iron slide without moving the image on the board. I make sure the
edges of the iron pass over the board and around the boards edges but
I never tip the iron, always keep it flat to the board. I never have
any trace adhesion problems doing this. A laminator seems like it
would be nice but my results are good so I haven't bothered with one yet.
For double sided, I let the board cool, flip it over (image & transfer
paper still attached), align the second image using pins and the
pre-driiled alignment holes. Then repeat the ironing process.

The best paper for me has been the cheap office gloss type, A lighter,
semi-glossy paper that has the feel of a good brochure stock. It picks
up the toner well and then breaks down easily in water. The light
weight and semi-gloss let it saturate well and break down quickly. I
had some Epson paper that literally just floated right off but it was
an old pack and I'll be darned if I can find anything like it again.
This office gloss stuff is the next best thing for me. After ironing,
I let the board cool a little and then soak it in warm water. After it
soaks a couple of minutes, I rub it to start it peeling and then
rolling it back, peel most of the paper off under water (it kind of
just mushes a way leaving a thin paper residue). This I let soak for a
time. 10 to 20 minutes probably (I just go do something else and come
back after a while). The remaining residue rubs off easily with just a
little finger pressure. I've never used anything like a toothbrush
(although the foam rubber or a magic sponge is nice some times for
thin gaps, just a light rubbing with it). For paper I'm using the
Hammermill OfficeOne Glossy Paper #229030 (upc 0 10199 16302 8) which
seems to be discontinued. I think it's actually been re-branded as
Hammermill Color Laser Gloss Paper, 300ct #292253 (Sam's number). It's
the same weight, package size, and brightness as the other stuff but I
haven't tried it myself yet. Both Sam's Club and Office Max carry it
(same sources I had for the other stuff too).
My printer is an HP1200 with good rebuilt cartridges. The results are
excellent with this printer. At work we have HP 8000 series. These
also work very well but not quite as good as my 1200 (might just be
the heavy use they see). 

With this procedure I etch in Ferric Chloride and have no problems
with Traces lifting or edge erosion & undercutting. Even when I forget
the board in the etchant for extended periods (usually happens ... get
going on something else and 'Oh, crap ... my board!'). I like to
'float' the board top side down for faster etching and then submerge
it to etch the bottom side (takes little etching as I use planes and
copper pours).

Other tips:  
The wide boarder around the whole board is a good idea, that really
helped me a lot (thanks Stephan!).
I take a small file and file the ridge off the edge of the board.
Sometimes there's one left from the shear process and it can keep the
image from being pressed well.
I use copper pours on both sides (connect to ground). This leaves less
etching (etchant lasts a long time) and gives lots of toner. It may
help with the trace adhesion (like the boarder does).
I apply the toner to a larger board and then cut it to size before
etching (you can do this easily if you cut with a Dremel tool as I do,
I use the emery cut off discs and if you have a steady hand, they work
great ... if not, then you better buy a lot of the discs ;-) ).
I still like the ferric chloride best. It's not as fast as the others
but it's way more forgiving. I had undercutting problems with the
mixed up acids (muratic acid + hydrogen peroxide).

Phil KA0HBG
>

--- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...> wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "James Bishop" <bishopaj@> 
> wrote:


>    I have a board soaking right now.  This time, I sanded it with 600 
> grit, cleaned it off with lacquer thinner and paper towels, then with 
> denatured alcohol and cotton balls. We'll see how it turns out.

Again, I like the scotch pads, they clean the board well and leave
just enough texture (that soft brushed look) and the nature of the pad
makes sure the whole board gets cleaned well. And Dawn dish soap
because it is rated as a number one grease cutter. This seems more
than sufficient for good adhesion. If it isn't doing it, I'd look at
transfer temperature or maybe the type of toner (ie printer brand).
When I tried this process years ago, I had mediocre results (always
some traces lifting). Now it's flawless for me and I'm pretty sure
it's mostly due to a better printer.

>  My wife is annoyed by how much time 
> I'm spending in front of the computer drawing pretty pictures.

I turn out a board and it looks so perfect, I think they are so cool
with all those little copper traces. I proudly show my wife my
finished boards ... she's clearly not impressed *sigh*.


Good luck Jerry,
Phil

--- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...> 
wrote:
> *** Just got back from the kitchen sink.  The board is GORGEOUS. 

*** And yesterday I ran to the store and bought the dremel drill 
press attachment to drill the holes.  Worked great!  Stuffed the 
board last
night, and it just worked.  Well, except that my TO3 transistor got 
too hot.  Gonna have to heatsink that thing, which is going to pork 
things up considerably.  Or I might mount it remotely on a heatsink 
or on the back of the chassis....

   This morning, I spent a bit of quality time with various 
components and a dial caliper.   Thinking about drill bits here.  My 
quarter watt resistors have .018" dia leads, augat machine sockets 
have .019" pins, etc etc.

   Yesterday while drilling I noticed that my drill bits were mostly 
way too small or way too big.  I had purchased an assortment from 
Jameco.  Most small parts have lead diameters between .018 and .040.
And Jameco only lists two drill sizes in that range - #75 at .021 and
#59 at .040.  Jameco's prices are reasonable at less than $2 a bit.
  
Digikey OTOH has the same limited stock, and their prices are through 
the roof.  $8/bit and up.  They have priced themselves out of the 
Jerry drill bit market.

Harbor Freight has an assortment of 50 bits for $10.  Has anybody 
bought this one?  Are the sizes useful?


                              - Jerry Kaidor

I bought my drills from ebay. There were a couple of sellers with new
and used PCB drills. I could get pretty much the dimensions i needed.
Can't comment on your sizes because i'm not prepared to convert inches
to mm or even less look up what these weird # sizes equate to but i
can tell you i mostly use 0.8 mm drills for just about all small parts
and 1mm or 1.2mm for sockets and larger transistors. I also have one
3.5mm drill for mounting holes.

BTW. a useful tool to make is a setting tool for the little plastic
rings on PCB drills. This makes it considerably quicker to chuck them
to the right height.

ST

On Tue, Dec 23, 2008 at 6:15 PM, jerrytr2.com <jerry@...> wrote:
> --- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...>
> wrote:
>> *** Just got back from the kitchen sink.  The board is GORGEOUS.
>
> *** And yesterday I ran to the store and bought the dremel drill
> press attachment to drill the holes.  Worked great!  Stuffed the
> board last
> night, and it just worked.  Well, except that my TO3 transistor got
> too hot.  Gonna have to heatsink that thing, which is going to pork
> things up considerably.  Or I might mount it remotely on a heatsink
> or on the back of the chassis....
>
>   This morning, I spent a bit of quality time with various
> components and a dial caliper.   Thinking about drill bits here.  My
> quarter watt resistors have .018" dia leads, augat machine sockets
> have .019" pins, etc etc.
>
>   Yesterday while drilling I noticed that my drill bits were mostly
> way too small or way too big.  I had purchased an assortment from
> Jameco.  Most small parts have lead diameters between .018 and .040.
> And Jameco only lists two drill sizes in that range - #75 at .021 and
> #59 at .040.  Jameco's prices are reasonable at less than $2 a bit.
>
> Digikey OTOH has the same limited stock, and their prices are through
> the roof.  $8/bit and up.  They have priced themselves out of the
> Jerry drill bit market.
>
> Harbor Freight has an assortment of 50 bits for $10.  Has anybody
> bought this one?  Are the sizes useful?
>
>
>                              - Jerry Kaidor
>
>
>

> 
> Harbor Freight has an assortment of 50 bits for $10.  Has anybody 
> bought this one?  Are the sizes useful?
> 
> 

I've bought these in the past. They're handy for around the garage and
ok for general machining but I wouldn't recommend them for PCB's.
They're only HSS and not necessarily really small. I get by on the 2
sizes from Jameco myself (every thing is either #75 or #59, if the
components don't like it, tough bounce ;-) ). Actually I try to avoid
drilling as much as possible as it's the most time consuming and
tedious. I use as much SMD as possible and no fancy equipment either.
I tin the whole board after etching (flux it and flow solder over it
with an iron or heat gun) and then hand solder each part. It's not
that bad really (and beats drilling in my opinion). I'm left with just
a few holes for connectors and some feed-thru's here and there. I did
check out the drill bit city link and they look good but I like having
fewer sizes and lots of each on hand so I still prefer Jameco's.

Phil

"pgdion1" <pgdion1@...> writes:
> every thing is either #75 or #59,

I find I use the #80 (13 mil) the most, because most of the holes I
need are vias!  I cut up some 22 gauge stranded speaker wire and
de-strand it; the individual conductors are fine enough to fit through
a 13 mil hole just fine, and it's probably the cheapest wire I can
get.

Second most is the 26 mil bit, for the friction-fit pins I use to make
adapter boards.  After that is whatever I need for whatever parts I'm
using.

--- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@...> wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "jerrytr2.com" <jerry@> 
> wrote:
> > *** Just got back from the kitchen sink.  The board is GORGEOUS. 
> 
> *** And yesterday I ran to the store and bought the dremel drill 
> press attachment to drill the holes.  Worked great!  Stuffed the 
> board last
> night, and it just worked.  Well, except that my TO3 transistor got 
> too hot.  Gonna have to heatsink that thing, which is going to pork 
> things up considerably.  Or I might mount it remotely on a heatsink 
> or on the back of the chassis....
> 
>    This morning, I spent a bit of quality time with various 
> components and a dial caliper.   Thinking about drill bits here.  My 
> quarter watt resistors have .018" dia leads, augat machine sockets 
> have .019" pins, etc etc.
> 
>    Yesterday while drilling I noticed that my drill bits were mostly 
> way too small or way too big.  I had purchased an assortment from 
> Jameco.  Most small parts have lead diameters between .018 and .040.
> And Jameco only lists two drill sizes in that range - #75 at .021 and
> #59 at .040.  Jameco's prices are reasonable at less than $2 a bit.
>   
> Digikey OTOH has the same limited stock, and their prices are through 
> the roof.  $8/bit and up.  They have priced themselves out of the 
> Jerry drill bit market.
> 
> Harbor Freight has an assortment of 50 bits for $10.  Has anybody 
> bought this one?  Are the sizes useful?
> 
> 
>                               - Jerry Kaidor
>

Jumping in here: The best bits to use (from my experience) are the
carbide bits. They are super-sharp, cut beautifully, and stay sharp
MUCH longer than HSS bits. I get mine from Drill Bit City
(http://www.drillbitcity.com/). They sell resharpened bits, which are
much better priced than new. They often have specials on various sets
of bits and, if you don't see a set that will suit your needs, they'll
make up whatever you need.

Carbide bits are VERY brittle, so you need to be careful. If your bit
is off-axis at all it will break. If you have one of the newer Dremel
chucks you'll have to make sure the bit doesn't wobble, but the
carbide bits are worth the effort.

flight