Homebrew PCBs

Well, I can't say as I am thrilled or dissappointed.  I tried running 
a small PCB with fairly large traces.  There are a number of problems 
that I will need to resolve before expecting a good PCB from the 
machine.

1) I have to fix the problem with the Z axis saddle - this is 
something one of the newer list members has been helping me with 
(Ron), but I screwed up my end of the fix so I was running the test on 
the old hardware.  This is a mechanical problem that creates some 
inaccuracy in positioning in the Z axis.  With a samll 'V' cutter, you 
don't have much room for variations before your trace gets milled away.

2) A glitch somewhere caused the machine to lose position in X axis by 
about .200". This didn't happen on the first attempt, but did on the 
second attempt.  Not sure at all what the cause was or could be so 
this one will be a long term bug hunt I think.

As one would expect from cutting copper with a V shaped tool, the cuts 
are not the greatest.  Copper itself is not the best machining metal.  
Couple that with the reality that the cutting SFM is so low because of 
the small cutter diameter.  The most RPM I can currently get out of 
the machine is only 7500 RPM, ideally it should be running at 100K or 
even faster but that can't happen till I can figure out a new spindle 
and afford some new hardware to do it.

The traces that were not mucked up, were a tad smaller than they 
should have been.  They should have been .020" width but as best as I 
can measure it, they appear to be .012" wide.  I am using a small 
adapter chuck that is normally used as a quick change chuck for Dremel 
type tools. Having a few thousandths run-out on that is expected so I 
am not too concerned yet.

The cutter I have is a V cutter, 60 degrees "D" shaped or in other 
words a 1/2 round tool bit (or another way of putting it is a single 
flute cutter).  It is solid carbide and seems to have held up good 
during these cuts so far.

Had the X axis not lost position on the second attempt, I would 
probably have a good PCB to continue onto the second side machining.  

Also not overly thrilled with the Gerber tranlation software I have.  
It's a trial version so I can't really complain till I learn a bit 
more about it.  The isolation milling seems to work well, but I can't 
figure out what it needs/wants for the drilling operations. Luckily, 
that is pretty easy to program manually so if I can't get that to 
work, it still may be okay.

I can see I will have to get going on the closed loop concept of the 
software and hardware.  Even though I am running stepper motors, I do 
plan to have a "near closed loop" operation at some point along the 
way.

As for the speed of the process, I can see where it will be slow.  
However, I cannot yet determine how much longer it will take to do a 
PCB using isolation milling versus etching.  A higher speed spindle 
would certainly reduce the machining time so that is a primary 
drawback with my machine at present.  

But, looking at what is involved, it may not be much slower overall if 
you have a good spindle.  By comparison, the layout software I use can 
be used to print the layout for toner transfer then etching, or it can 
output the gerber files.  The translation software I am playing with 
takes about 1~2 minutes to translate the gerber into G-Code.  Once I 
have that, I load the G-code into the machine, set the origin on the 
workpiece and can (once I fix a few problems) hit start and let it 
run.  Once the first side is done, flip it over, re-set the origin, 
and let it run the second side.  Using stops on the table will reduce 
the amount of time there.  The machine has a 38 tool, automatic tool 
changer so once it get's going, there isn't much to do except watch it 
do the work.  It will do the isolation milling, drill the holes, and 
then mill the second side (although that requires manual intervention 
to flip the part).

Compared to etching, I would eliminate the toner transfer which is 
mostly "Hit" for me rather than "Miss" so that doesn't take too long.  
Still have to print the layout, cut away the excess, align the two 
sides, transfer it, soak off the paper, scrub off the residue, touch 
up any spots that are not good.  Then it's into the etchant for about 
20 ~ 30 minutes (it's cold in the shop so it etches pretty slow this 
time of year).  Once done there, it's manual drilling.  That goes 
pretty fast for me, but it is SOOOOOOOOOOO boring to me that the CNC 
machine is a welcome sight just for that alone.

So, that's my first attempts at isolation milling.  I have to fix some 
software and hardware bugs before I can really do much else with the 
machine.

Chris

It's nice to hear someone air the dirty laundry. People usually don't talk
much about what didn't work. I've been pretty leary about the isolation
milling route (pun intended) so I tried the toner transfer method yesterday.
I was not impressed with that either. Granted, I used regular laser paper
but the results were so bad I didn't have much confidence in better paper
either. The toner appeared to cover well but came off way too easy. If I
have to iron for 15 minutes and maybe make multiple attempts it's just not
worth the trouble. I'm not that broke. So I bought a bottle of spray-on
negative resist and a can of developer, about $15 together. I've used it
before and it's a piece of cake, works perfect every time. If I use the mill
for drilling only I can avoid most of those Z axis problems as well, and
maybe keep the time consumed down to a level where it is worth the trouble.
There is some point at which it is actually more cost-effective to pay for
prototypes.
--
Phil Mattison
http://www.ohmikron.com/
Motors::Drivers::Controllers::Software

----- Original Message -----
From: lcdpublishing <lcdpublishing@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Sunday, December 31, 2006 1:51 PM
Subject: [Homebrew_PCBs] First efforts with isolation milling and the new
machine....


> Well, I can't say as I am thrilled or dissappointed.  I tried running
> a small PCB with fairly large traces.  There are a number of problems
> that I will need to resolve before expecting a good PCB from the
> machine.
>
> 1) I have to fix the problem with the Z axis saddle - this is
> something one of the newer list members has been helping me with
> (Ron), but I screwed up my end of the fix so I was running the test on
> the old hardware.  This is a mechanical problem that creates some
> inaccuracy in positioning in the Z axis.  With a samll 'V' cutter, you
> don't have much room for variations before your trace gets milled away.
>
> 2) A glitch somewhere caused the machine to lose position in X axis by
> about .200". This didn't happen on the first attempt, but did on the
> second attempt.  Not sure at all what the cause was or could be so
> this one will be a long term bug hunt I think.
>
> As one would expect from cutting copper with a V shaped tool, the cuts
> are not the greatest.  Copper itself is not the best machining metal.
> Couple that with the reality that the cutting SFM is so low because of
> the small cutter diameter.  The most RPM I can currently get out of
> the machine is only 7500 RPM, ideally it should be running at 100K or
> even faster but that can't happen till I can figure out a new spindle
> and afford some new hardware to do it.
>
> The traces that were not mucked up, were a tad smaller than they
> should have been.  They should have been .020" width but as best as I
> can measure it, they appear to be .012" wide.  I am using a small
> adapter chuck that is normally used as a quick change chuck for Dremel
> type tools. Having a few thousandths run-out on that is expected so I
> am not too concerned yet.
>
> The cutter I have is a V cutter, 60 degrees "D" shaped or in other
> words a 1/2 round tool bit (or another way of putting it is a single
> flute cutter).  It is solid carbide and seems to have held up good
> during these cuts so far.
>
> Had the X axis not lost position on the second attempt, I would
> probably have a good PCB to continue onto the second side machining.
>
> Also not overly thrilled with the Gerber tranlation software I have.
> It's a trial version so I can't really complain till I learn a bit
> more about it.  The isolation milling seems to work well, but I can't
> figure out what it needs/wants for the drilling operations. Luckily,
> that is pretty easy to program manually so if I can't get that to
> work, it still may be okay.
>
> I can see I will have to get going on the closed loop concept of the
> software and hardware.  Even though I am running stepper motors, I do
> plan to have a "near closed loop" operation at some point along the
> way.
>
> As for the speed of the process, I can see where it will be slow.
> However, I cannot yet determine how much longer it will take to do a
> PCB using isolation milling versus etching.  A higher speed spindle
> would certainly reduce the machining time so that is a primary
> drawback with my machine at present.
>
> But, looking at what is involved, it may not be much slower overall if
> you have a good spindle.  By comparison, the layout software I use can
> be used to print the layout for toner transfer then etching, or it can
> output the gerber files.  The translation software I am playing with
> takes about 1~2 minutes to translate the gerber into G-Code.  Once I
> have that, I load the G-code into the machine, set the origin on the
> workpiece and can (once I fix a few problems) hit start and let it
> run.  Once the first side is done, flip it over, re-set the origin,
> and let it run the second side.  Using stops on the table will reduce
> the amount of time there.  The machine has a 38 tool, automatic tool
> changer so once it get's going, there isn't much to do except watch it
> do the work.  It will do the isolation milling, drill the holes, and
> then mill the second side (although that requires manual intervention
> to flip the part).
>
> Compared to etching, I would eliminate the toner transfer which is
> mostly "Hit" for me rather than "Miss" so that doesn't take too long.
> Still have to print the layout, cut away the excess, align the two
> sides, transfer it, soak off the paper, scrub off the residue, touch
> up any spots that are not good.  Then it's into the etchant for about
> 20 ~ 30 minutes (it's cold in the shop so it etches pretty slow this
> time of year).  Once done there, it's manual drilling.  That goes
> pretty fast for me, but it is SOOOOOOOOOOO boring to me that the CNC
> machine is a welcome sight just for that alone.
>
> So, that's my first attempts at isolation milling.  I have to fix some
> software and hardware bugs before I can really do much else with the
> machine.
>
> Chris
>
>
>
>
>
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and
Photos:

> http://groups.yahoo.com/group/Homebrew_PCBs
>
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/
> Yahoo! Groups Links
>
>
>

On Sun, 31 Dec 2006 23:22:45 +0100, Phil Mattison <mattison20@...>  
wrote:

> I've been pretty leary about the isolation
> milling route (pun intended) so I tried the toner transfer method  
> yesterday.
> I was not impressed with that either. Granted, I used regular laser paper
> but the results were so bad I didn't have much confidence in better paper
> either. The toner appeared to cover well but came off way too easy. If I
> have to iron for 15 minutes and maybe make multiple attempts it's just  
> not
> worth the trouble. I'm not that broke.


You are just not persistent enough. If you think you need to iron for 15  
minutes, and if you think you can expect it to work for you with regular  
laser paper when it does not for anyone else, then please do go and buy  
the photo resist. Nobody wants to persuade people that just don't want to  
try seriously. I'd rather spend my time making boards using suitable paper  
and a single pass through a fuser which takes maybe 15 seconds.

I can force photo process not to work just as much as you forced toner  
transfer not to work, if i'd want to.

I mean, come on, a single try and you didn't even follow the most basic  
instructions, what did you expect!

ST

Phil,

If it's one thing I am, it is telling it like it is.  As for my 
first attempts at isolation milling, more effort needs to be put 
into it.  There is only so much one can learn from running the 
first "real part" on a process that is being done for the first 
time, on a machine that is running it's first part, using embedded 
software in about 10 different micros for the first time, using CNC 
control running a part for the first time, on electronics designed 
by me :-)

Virtually every aspect and element of this machine is new.  Chances 
are if it is anything bigger than the most basic of components, I 
had to design and make it and program it.  So I expect lots of 
problems in the debugging process.  Heck, if I expected it to work 
on the first part, I should also be able to walk on water at will!

As for your first attempt at toner transfer, well, you didn't make 
an attempt at all.  It certainly isn't perfect, but it can and will 
give you very good results up to the limits of the technology.  If 
you are serious about trying it, you may want to put a little more 
effort into it, otherwise stick with the board houses. No doubt they 
will produce a better PCB that you can at home.

Chris




--- In Homebrew_PCBs@yahoogroups.com, "Phil Mattison" 
<mattison20@...> wrote:
>
> It's nice to hear someone air the dirty laundry. People usually 
don't talk
> much about what didn't work. I've been pretty leary about the 
isolation
> milling route (pun intended) so I tried the toner transfer method 
yesterday.
> I was not impressed with that either. Granted, I used regular 
laser paper
> but the results were so bad I didn't have much confidence in 
better paper
> either. The toner appeared to cover well but came off way too 
easy. If I
> have to iron for 15 minutes and maybe make multiple attempts it's 
just not
> worth the trouble. I'm not that broke. So I bought a bottle of 
spray-on
> negative resist and a can of developer, about $15 together. I've 
used it
> before and it's a piece of cake, works perfect every time. If I 
use the mill
> for drilling only I can avoid most of those Z axis problems as 
well, and
> maybe keep the time consumed down to a level where it is worth the 
trouble.
> There is some point at which it is actually more cost-effective to 
pay for

> prototypes.
> --
> Phil Mattison
> http://www.ohmikron.com/
> Motors::Drivers::Controllers::Software

And of course everyone has a "fuser." There were lots of factors that went
into my decision to skip it. I looked at lots of articles and photos. Lots
of people have to try over and over and still end up with fairly crappy
results. Some people have reported good results with ordinary paper. I have
no interest in proving or disproving that toner transfer is good. I just
want boards with the minimum cost and hassle. I was only sharing my
experience. If you don't like it you can easily ignore it.
--
Phil Mattison
http://www.ohmikron.com/
Motors::Drivers::Controllers::Software

> You are just not persistent enough. If you think you need to iron for 15
> minutes, and if you think you can expect it to work for you with regular
> laser paper when it does not for anyone else, then please do go and buy
> the photo resist. Nobody wants to persuade people that just don't want to
> try seriously. I'd rather spend my time making boards using suitable paper
> and a single pass through a fuser which takes maybe 15 seconds.
>
> I can force photo process not to work just as much as you forced toner
> transfer not to work, if i'd want to.
>
> I mean, come on, a single try and you didn't even follow the most basic
> instructions, what did you expect!
>
> ST
>

Hi Chris,

You are correct that Z depth is very important.  As is spindle run-out.

Some tips to try in the early stages.

#1) do only single sided as you are getting used to making boards.

#2) never try to run a trace between pads if at all possible.

#3) make all the traces as wide as possible. shoot for 50 mil.

There is a feature called rub-out. that will remove all the copper
around things.  it will take forever to do the whole board, but in
places like a set of dbl row header pins, it is nice to have only
pads, and not the little diamonds.

As you found out, depth of cut is vital.  I run the cutter along the
edge of a board and feed it down until it just touches the copper.  in
some cases, that will actually penetrate the copper.

A spring set cutter and a foot type stand-off will allow you to
eleminate the Z axis from the work, however, it probably will not work
with your tool changer.

http://www.2linc.com/engraving_depth_controlling_system.htm

expensive, but it might be possible to make your own.

as you get better making boards, running traces between pads can be
done. the feel for the depth stop is the key.  if you are getting good
depth control, your traces will be of uniform width and your between
pad, traces will be reliable.

The single sided is really just to eleminate the frustration of
getting the back of the board wrong and having to start all over again.

I really am envious of your tool changer.  great idea.

Dave

--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing"
<lcdpublishing@...> wrote:
>
> Well, I can't say as I am thrilled or dissappointed.  I tried running 
> a small PCB with fairly large traces.  There are a number of problems 
> that I will need to resolve before expecting a good PCB from the 
> machine.
> 

I forgot to mention to run the board at a short penetration, then
before you remove it, inspect it for any non-cuts. if the board is not
flat, there may be some rises, and some dips.  you can re-cut the dips
pretty easily.  Just erease everything else in your software and leave
the lines you want to re-cut.

A vac hold down will almost eleminate the board from flexing.

Dave

--- Phil Mattison <mattison20@...> wrote:

> And of course everyone has a "fuser." There were lots of factors that went
> into my decision to skip it. ...

you are absolutely right! mine is in the cupboard in the backroom, my wife uses
to call it an iron...   go figure...

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com

I have watched this PCB milling discussion with interest.  I have neither the time nor the inclination to attempt to make a PCB mill.  I could use one however for very small quantity commercial work I do here.  Realistically, what are the low-end options that are actually viable (not mere toys)?  I would consider anything up to maybe $5,000.00 to not be outside the realm of reason, but I understand some of the commercial machines can be $12,000.00 or more, definitely outside of my budget for this project.  

Any guidance on realistic options would be much appreciated.

Syd

  ----- Original Message ----- 
  From: Dave Mucha 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Monday, January 01, 2007 7:53 PM
  Subject: [Homebrew_PCBs] Re: First efforts with isolation milling and the new machine....


  Hi Chris,

  You are correct that Z depth is very important. As is spindle run-out.

  Some tips to try in the early stages.

  #1) do only single sided as you are getting used to making boards.

  #2) never try to run a trace between pads if at all possible.

  #3) make all the traces as wide as possible. shoot for 50 mil.

  There is a feature called rub-out. that will remove all the copper
  around things. it will take forever to do the whole board, but in
  places like a set of dbl row header pins, it is nice to have only
  pads, and not the little diamonds.

  As you found out, depth of cut is vital. I run the cutter along the
  edge of a board and feed it down until it just touches the copper. in
  some cases, that will actually penetrate the copper.

  A spring set cutter and a foot type stand-off will allow you to
  eleminate the Z axis from the work, however, it probably will not work
  with your tool changer.

  http://www.2linc.com/engraving_depth_controlling_system.htm

  expensive, but it might be possible to make your own.

  as you get better making boards, running traces between pads can be
  done. the feel for the depth stop is the key. if you are getting good
  depth control, your traces will be of uniform width and your between
  pad, traces will be reliable.

  The single sided is really just to eleminate the frustration of
  getting the back of the board wrong and having to start all over again.

  I really am envious of your tool changer. great idea.

  Dave



   

[Non-text portions of this message have been removed]

Stephen Lane wrote:
    I've just been sent an email alerting me to this months (Jan) 
Elektor having a kit CNC Mill for sale they want 1099 UK or 1599Euros 
for it not sure about international freight. the Article is a free pdf 
download & the pics look like it'll be a good machine.

Regards
Stephen

----- Original Message ----- 

From: Stephen Lane
To: Homebrew_PCBs@yahoogroups.com
Sent: Tuesday, January 02, 2007 2:11 PM
Subject: [Homebrew_PCBs] Re: First efforts with isolation milling and the 
new machine....


Stephen Lane wrote:
I've just been sent an email alerting me to this months (Jan)
Elektor having a kit CNC Mill for sale they want 1099 UK or 1599Euros
for it not sure about international freight. the Article is a free pdf
download & the pics look like it'll be a good machine.

--------------------------

I just saw the mag in my local WHS branch. It's very expensive, a Taig CNC 
milling machine only costs about $2,000.

Leon
--
Leon Heller, G1HSM
Suzuki SV1000S motorcycle
leon355@...
http://www.geocities.com/leon_heller

>I could use one however
>for very small quantity commercial work I do here. 

Anything to do with PCBs? IMO, you'll be better off using traditional 
methods to create the board then using the mill to drill. PCB milling 
is usually popular with the following types;

1. Those unsatisfied with the toner transfer board creation process 
and cannot manage the photo process for whatever reasons.

2. Those with an underutilized mill/router.

3. Those in the business of selling mills/routers or selling plans 
for such.

4. Environment conservation freaks who see the chemicals used in 
traditional board creation processes as one more doomsday ingredient. 

--- In Homebrew_PCBs@yahoogroups.com, "AnaLog Services, Inc." 
<wireline@...> wrote:
>

Holding any Dremel type tool in just the mid section says BOGUS.
The motor tool needs to be held in two places for best results. 




--- In Homebrew_PCBs@yahoogroups.com, Stephen Lane <sjlane@...> wrote:

>
> Stephen Lane wrote:
>     I've just been sent an email alerting me to this months (Jan) 
> Elektor having a kit CNC Mill for sale they want 1099 UK or 1599Euros 
> for it not sure about international freight. the Article is a free pdf 
> download & the pics look like it'll be a good machine.
> 
> Regards
> Stephen
>

Hi John

I had an old Dremel that lasted for 10 years of hard
use. As soon as they started screwing around with the
design of it, they lasted a year at best. Is there a
such thing as a good Dremel model now?

Thank you,
John

--- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@...> wrote:
>
>     Holding any Dremel type tool in just the mid section says BOGUS.
> The motor tool needs to be held in two places for best results. 
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, Stephen Lane <sjlane@> wrote:
> >
> > Stephen Lane wrote:
> >     I've just been sent an email alerting me to this months (Jan) 
> > Elektor having a kit CNC Mill for sale they want 1099 UK or 1599Euros 
> > for it not sure about international freight. the Article is a free
pdf 

> > download & the pics look like it'll be a good machine.
> > 
> > Regards
> > Stephen
> >
>

Interesting observations.  Does anybody have pics of milled vs. toner transfer PCBs on their website?  How decent is possible with the toner transfer process really?  If one is willing to buy the commercial product rather than trying to use conventional paper, can better results be had?

  ----- Original Message ----- 
  From: derekhawkins 
  To: Homebrew_PCBs@yahoogroups.com 
  Sent: Tuesday, January 02, 2007 9:52 AM
  Subject: [Homebrew_PCBs] Re: First efforts with isolation milling and the new machine....


  >I could use one however
  >for very small quantity commercial work I do here. 

  Anything to do with PCBs? IMO, you'll be better off using traditional 
  methods to create the board then using the mill to drill. PCB milling 
  is usually popular with the following types;

  1. Those unsatisfied with the toner transfer board creation process 
  and cannot manage the photo process for whatever reasons.

  2. Those with an underutilized mill/router.

  3. Those in the business of selling mills/routers or selling plans 
  for such.

  4. Environment conservation freaks who see the chemicals used in 
  traditional board creation processes as one more doomsday ingredient. 

  --- In Homebrew_PCBs@yahoogroups.com, "AnaLog Services, Inc." 
  <wireline@...> wrote:
  >



   

[Non-text portions of this message have been removed]

I bought two MultiPro models (field coil) with speed control.
One has a rubberized body. I bought both of them at Home Depot($59).
Both have seen several sets of carbon brushes. The Dremel will run for
hours straight at 3-1/2 (12,000RPMs) Make sure you have good airflow!!
 There are many clones out there that suck. The newer Dremel again
uses magnets instead of a field coil. This give better torq. Older
Dremels had magnets. My old Dremel (1984)is mounted in a Dremel Drill
Press. It is very old. The table lifts up on the drill press.

     To mount a Dremel you unscrew the finger grip to reveal mounting
threads. Grip the unit at the threads and the body. When done
correctly you can flex the bit without the Dremel moving. When
designing a CNC machine it is done from the cutting bit out. Holding
the Dremel in the midsection with a 1/2" wide clamp shows you have not
done your homework. A longer "V" block mount with clamp would be
acceptable. Drilling is not Milling.




--- In Homebrew_PCBs@yahoogroups.com, "John Hansford" <kz1927@...> wrote:
>
> Hi John
> 
> I had an old Dremel that lasted for 10 years of hard
> use. As soon as they started screwing around with the
> design of it, they lasted a year at best. Is there a
> such thing as a good Dremel model now?
> 
> Thank you,
> John
> 
> --- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@> wrote:
> >
> >     Holding any Dremel type tool in just the mid section says BOGUS.
> > The motor tool needs to be held in two places for best results. 
> > 
> > 
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, Stephen Lane <sjlane@> wrote:
> > >
> > > Stephen Lane wrote:
> > >     I've just been sent an email alerting me to this months (Jan) 
> > > Elektor having a kit CNC Mill for sale they want 1099 UK or
1599Euros 

> > > for it not sure about international freight. the Article is a free
> pdf 
> > > download & the pics look like it'll be a good machine.
> > > 
> > > Regards
> > > Stephen
> > >
> >
>

Is it possible to make or buy a nut that the front end of the Dremel
will screw into? I've been looking, but so far haven't been able to
source one. I've been trying to think of a way to make a casting of
the thread, but it seems tricky.

Thanks John,

I wasn't sure which one you'd said to get. I looked back
in the posts and see the Multipro is the one you suggest.
I'll also do the shimming.

I appreciate the quick reply. I'll be off to get one tonight.

Thanks again!
John


--- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@...> wrote:

>
>       I bought two MultiPro models (field coil) with speed control.
> One has a rubberized body. I bought both of them at Home Depot($59).
> Both have seen several sets of carbon brushes. The Dremel will run for
> hours straight at 3-1/2 (12,000RPMs) Make sure you have good airflow!!
>  There are many clones out there that suck. The newer Dremel again
> uses magnets instead of a field coil. This give better torq. Older
> Dremels had magnets. My old Dremel (1984)is mounted in a Dremel Drill
> Press. It is very old. The table lifts up on the drill press.
> 
>      To mount a Dremel you unscrew the finger grip to reveal mounting
> threads. Grip the unit at the threads and the body. When done
> correctly you can flex the bit without the Dremel moving. When
> designing a CNC machine it is done from the cutting bit out. Holding
> the Dremel in the midsection with a 1/2" wide clamp shows you have not
> done your homework. A longer "V" block mount with clamp would be
> acceptable. Drilling is not Milling.
> 
> 
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "John Hansford" <kz1927@> wrote:
> >
> > Hi John
> > 
> > I had an old Dremel that lasted for 10 years of hard
> > use. As soon as they started screwing around with the
> > design of it, they lasted a year at best. Is there a
> > such thing as a good Dremel model now?
> > 
> > Thank you,
> > John
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@> wrote:
> > >
> > >     Holding any Dremel type tool in just the mid section says BOGUS.
> > > The motor tool needs to be held in two places for best results. 
> > > 
> > > 
> > > 
> > > 
> > > --- In Homebrew_PCBs@yahoogroups.com, Stephen Lane <sjlane@> wrote:
> > > >
> > > > Stephen Lane wrote:
> > > >     I've just been sent an email alerting me to this months (Jan) 
> > > > Elektor having a kit CNC Mill for sale they want 1099 UK or
> 1599Euros 
> > > > for it not sure about international freight. the Article is a free
> > pdf 
> > > > download & the pics look like it'll be a good machine.
> > > > 
> > > > Regards
> > > > Stephen
> > > >
> > >
> >
>

The "Acid Test" of a DIY machine is to mount the 1/8" bit in the
Dremel and flex it with your fingers. You will quickly figure out if
your machine or Dremel mount has design flaws. You won't need a dial
indicator the first go around. There are machines out there that flex
like a tree in the wind. Some flex in only one direction. While others
flex in all directions. The goal is to make the machine stiff enough
to equal the power of the Dremel. A stiff machine is worthless if the
Dremel stalls first. Most people mistake machine flex for backlash.   


--- In Homebrew_PCBs@yahoogroups.com, "John Hansford" <kz1927@...> wrote:
>
> Thanks John,
> 
> I wasn't sure which one you'd said to get. I looked back
> in the posts and see the Multipro is the one you suggest.
> I'll also do the shimming.
> 
> I appreciate the quick reply. I'll be off to get one tonight.
> 
> Thanks again!
> John
> 
> 
> --- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@> wrote:
> >
> >       I bought two MultiPro models (field coil) with speed control.
> > One has a rubberized body. I bought both of them at Home Depot($59).
> > Both have seen several sets of carbon brushes. The Dremel will run for
> > hours straight at 3-1/2 (12,000RPMs) Make sure you have good airflow!!
> >  There are many clones out there that suck. The newer Dremel again
> > uses magnets instead of a field coil. This give better torq. Older
> > Dremels had magnets. My old Dremel (1984)is mounted in a Dremel Drill
> > Press. It is very old. The table lifts up on the drill press.
> > 
> >      To mount a Dremel you unscrew the finger grip to reveal mounting
> > threads. Grip the unit at the threads and the body. When done
> > correctly you can flex the bit without the Dremel moving. When
> > designing a CNC machine it is done from the cutting bit out. Holding
> > the Dremel in the midsection with a 1/2" wide clamp shows you have not
> > done your homework. A longer "V" block mount with clamp would be
> > acceptable. Drilling is not Milling.
> > 
> > 
> > 
> > 
> > --- In Homebrew_PCBs@yahoogroups.com, "John Hansford" <kz1927@> wrote:
> > >
> > > Hi John
> > > 
> > > I had an old Dremel that lasted for 10 years of hard
> > > use. As soon as they started screwing around with the
> > > design of it, they lasted a year at best. Is there a
> > > such thing as a good Dremel model now?
> > > 
> > > Thank you,
> > > John
> > > 
> > > --- In Homebrew_PCBs@yahoogroups.com, "crankorgan" <john@> wrote:
> > > >
> > > >     Holding any Dremel type tool in just the mid section says
BOGUS.
> > > > The motor tool needs to be held in two places for best results. 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > --- In Homebrew_PCBs@yahoogroups.com, Stephen Lane <sjlane@>
wrote:
> > > > >
> > > > > Stephen Lane wrote:
> > > > >     I've just been sent an email alerting me to this months
(Jan) 
> > > > > Elektor having a kit CNC Mill for sale they want 1099 UK or
> > 1599Euros 
> > > > > for it not sure about international freight. the Article is
a free

> > > pdf 
> > > > > download & the pics look like it'll be a good machine.
> > > > > 
> > > > > Regards
> > > > > Stephen
> > > > >
> > > >
> > >
> >
>

Hi Neil,

If you use the old Johnsons paste wax as a mold release
with 2hr. set epoxy, you shouldn't have any trouble.

2 hr. epoxy shouldn't be mixed more than 1/2 oz in a small cup
or it'll boil and foam.

Use the existing nut to make a thread model, I wouldn't
chance it on the dremel itself.


John


--- In Homebrew_PCBs@yahoogroups.com, "Neil Baylis" <neil.baylis@...>
wrote:

>
> Is it possible to make or buy a nut that the front end of the Dremel
> will screw into? I've been looking, but so far haven't been able to
> source one. I've been trying to think of a way to make a casting of
> the thread, but it seems tricky.
>

----- Original Message ----- 

From: John Hansford
To: Homebrew_PCBs@yahoogroups.com
Sent: Tuesday, January 02, 2007 4:28 PM
Subject: [Homebrew_PCBs] Re: First efforts with isolation milling and the 
new machine....


Hi John

I had an old Dremel that lasted for 10 years of hard
use. As soon as they started screwing around with the
design of it, they lasted a year at best. Is there a
such thing as a good Dremel model now?


I've been using a Minicraft drill and stand for PCB drilling for some years, 
they are similar to Dremel.

Proxxon drills have a good reputation, but are more expensive. The 
Professional Drill Grinder IB/E looks pretty good:

http://www.chronos.ltd.uk/acatalog/index.html?http%3A//www.chronos.ltd.uk/acatalog/Proxxon_Tools.html&CatalogBody

I might get myself one.

Leon

The front threads are 3/4-12 on the MultiPro and 3/4-10 on the
really old ones from the 80s. The Tap made in the US went for over $30
and the China made one was about $26 when I bought my tap and drill
bit set. You can clamp the Dremel at two points (Threaded section and
Body) without using a tapped nut. This allows you to put the Dremel in
and out quicker than having threads. 

--- In Homebrew_PCBs@yahoogroups.com, "Neil Baylis" <neil.baylis@...>
wrote:

>
> Is it possible to make or buy a nut that the front end of the Dremel
> will screw into? I've been looking, but so far haven't been able to
> source one. I've been trying to think of a way to make a casting of
> the thread, but it seems tricky.
>

Hi Leon,

I'd like to get a Proxxon for my personal machine. I'm trying
to decide on a *generic* toolholder for our other machine. The
Dremel seems to be most widely availabe 24/7. They've
come up with so many variations on it that I honestly don't
know what's the good one. John cleared that up for me.
I have 4, but they're not as good as my old one was.

I see good things on the Proxxon and before long, I'll have one.

Thanks!
John



--- In Homebrew_PCBs@yahoogroups.com, "Leon" <leon355@...> wrote:
>
> ----- Original Message ----- 
> From: John Hansford
> To: Homebrew_PCBs@yahoogroups.com
> Sent: Tuesday, January 02, 2007 4:28 PM
> Subject: [Homebrew_PCBs] Re: First efforts with isolation milling
and the 
> new machine....
> 
> 
> Hi John
> 
> I had an old Dremel that lasted for 10 years of hard
> use. As soon as they started screwing around with the
> design of it, they lasted a year at best. Is there a
> such thing as a good Dremel model now?
> 
> 
> I've been using a Minicraft drill and stand for PCB drilling for
some years, 
> they are similar to Dremel.
> 
> Proxxon drills have a good reputation, but are more expensive. The 
> Professional Drill Grinder IB/E looks pretty good:
> 
>
http://www.chronos.ltd.uk/acatalog/index.html?http%3A//www.chronos.ltd.uk/acatalog/Proxxon_Tools.html&CatalogBody

> 
> I might get myself one.
> 
> Leon
>

On Tue, 02 Jan 2007 17:47:42 +0100, AnaLog Services, Inc.  
<wireline@...> wrote:

> Interesting observations.  Does anybody have pics of milled vs. toner  
> transfer PCBs on their website?

> How decent is possible with the toner transfer process really?

Plenty decent to do any SMD stuff which you can possibly use without THP.  
8/8 rules work just fine. There is no significant difference to  
photoprocess in my experience, if both done at home. Of course you can get  
a bit better with photoplotters and stuff, but that's not generally  
homebrew any more. Also, you soon run into underetching problems with both  
processes anyway.

> If one is willing to buy the commercial product rather than trying to  
> use conventional paper, can better results be had?

No. It makes no difference at all, some even had worse results.

The quality of TT can easily be what one would call "flawless", but the  
board will still look homebrew. Because of THP and soldermask. Milling is  
worse though, in terms of looks.

ST

On Tue, 02 Jan 2007 20:01:01 +0100, John Hansford <kz1927@...> wrote:

> Hi Leon,
> I'd like to get a Proxxon for my personal machine. I'm trying
> to decide on a *generic* toolholder for our other machine. The
> Dremel seems to be most widely availabe 24/7. They've
> come up with so many variations on it that I honestly don't
> know what's the good one. John cleared that up for me.
> I have 4, but they're not as good as my old one was.
> I see good things on the Proxxon and before long, I'll have one.
> Thanks!
> John


It must be said that the bearings on the proxxon IB/E are too close  
together. This isn't ideal for side-loads. I expect the new "long throat"  
version would be much better, if they have put the bearings at either end  
(which i hope). A cheap tool construction with a long shaft going from the  
collets all through the motor may actually be better in that regard, but  
the dremel has too many other drawbacks to consider it over a proxxon, IMO.

But the IB/E is well worth the money, i liked it so much i got a smaller  
12V proxxon for the PCB drill so i could use the IB/E for other jobs  
without having to pull it from the mount.

ST

----- Original Message ----- 

From: "Stefan Trethan" <stefan_trethan@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Tuesday, January 02, 2007 8:02 PM
Subject: Re: [Homebrew_PCBs] Re: First efforts with isolation milling and 
the new machine....


> On Tue, 02 Jan 2007 20:01:01 +0100, John Hansford <kz1927@...> 
> wrote:
>
>> Hi Leon,
>> I'd like to get a Proxxon for my personal machine. I'm trying
>> to decide on a *generic* toolholder for our other machine. The
>> Dremel seems to be most widely availabe 24/7. They've
>> come up with so many variations on it that I honestly don't
>> know what's the good one. John cleared that up for me.
>> I have 4, but they're not as good as my old one was.
>> I see good things on the Proxxon and before long, I'll have one.
>> Thanks!
>> John
>
>
> It must be said that the bearings on the proxxon IB/E are too close
> together. This isn't ideal for side-loads. I expect the new "long throat"
> version would be much better, if they have put the bearings at either end
> (which i hope). A cheap tool construction with a long shaft going from the
> collets all through the motor may actually be better in that regard, but
> the dremel has too many other drawbacks to consider it over a proxxon, 
> IMO.
>
> But the IB/E is well worth the money, i liked it so much i got a smaller
> 12V proxxon for the PCB drill so i could use the IB/E for other jobs
> without having to pull it from the mount.

A die-grinder would be the best thing to use, but they are very expensive. 
They are designed for large side-loadings and very fast.

Leon
--
Leon Heller
Amateur radio call-sign  G1HSM
Suzuki SV1000S motorcycle
leon355@...
http://www.geocities.com/leon_heller

"Stefan Trethan" <stefan_trethan@...> writes:
> > If one is willing to buy the commercial product rather than trying to  
> > use conventional paper, can better results be had?
> 
> No. It makes no difference at all, some even had worse results.

I use TT paper, and can do 7/7 fairly reliably.  However, the limit is
my printer, not the paper - I've checked the prints under a microscope
and the toner edge just isn't "perfect" enough to go better,
regardless of the paper.  OTOH it's an old drum, so it's not like I'm
trying that hard ;-)

This is on normal paper, but it gives you an idea of what I'm talking
about: http://www.delorie.com/pcb/smd-challenge/fp-pix/

You can see how the etching comes out here:
http://www.delorie.com/pcb/first.html

My GAWD.. how did you take those photos???

On 02 Jan 2007 18:39:29 -0500
DJ Delorie <dj@...> wrote:

> 
> "Stefan Trethan" <stefan_trethan@...> writes:
> > > If one is willing to buy the commercial product rather than trying to  
> > > use conventional paper, can better results be had?
> > 
> > No. It makes no difference at all, some even had worse results.
> 
> I use TT paper, and can do 7/7 fairly reliably.  However, the limit is
> my printer, not the paper - I've checked the prints under a microscope
> and the toner edge just isn't "perfect" enough to go better,
> regardless of the paper.  OTOH it's an old drum, so it's not like I'm
> trying that hard ;-)
> 
> This is on normal paper, but it gives you an idea of what I'm talking
> about: http://www.delorie.com/pcb/smd-challenge/fp-pix/
> 
> You can see how the etching comes out here:
> http://www.delorie.com/pcb/first.html
> 
> 
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> 
> If Files or Photos are running short of space, post them here:
> http://groups.yahoo.com/group/Homebrew_PCBs_Archives/ 
> Yahoo! Groups Links
> 
> 
> 
>

I don't know how he took them, but you can get some special lenses 
(not expensive at all) that you can attach to a digital camera for 
micro photography.

Get em on ebay at:

http://cgi.ebay.com/10x-Macro-HD-Lens-for-Kodak-Z7590-DX7590-DX6490-buySAFE_W0QQitemZ140068731988QQihZ004QQcategoryZ79000QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/Hi-Def-Close-Up-Lens-Kit-for-Kodak-Z7590-DX7590-DX6490_W0QQitemZ280065757990QQihZ018QQcategoryZ67345QQrdZ1QQcmdZViewItem

http://cgi.ebay.com/10x-HD-Pro-Macro-Lens-for-Kodak-Z7590-DX7590-DX6490_W0QQitemZ280065510912QQihZ018QQcategoryZ67345QQrdZ1QQcmdZViewItem

The above are for a Kodak Z7590 digital camera.  Do check these out!

I am not selling these, but am looking to buy one of these lenses for 
close up work.

Brian G.

James Washer <washer@...> writes:
> My GAWD.. how did you take those photos???
> 
> DJ Delorie <dj@...> wrote:
> > I've checked the prints under a microscope

My microscope is an IntelPlay digital USB microscope.  So, I just hit
the image capture button.

On Wed, 03 Jan 2007 00:39:29 +0100, DJ Delorie <dj@...> wrote:

> I use TT paper, and can do 7/7 fairly reliably.  However, the limit is
> my printer, not the paper - I've checked the prints under a microscope
> and the toner edge just isn't "perfect" enough to go better,
> regardless of the paper.  OTOH it's an old drum, so it's not like I'm
> trying that hard ;-)
> This is on normal paper, but it gives you an idea of what I'm talking
> about: http://www.delorie.com/pcb/smd-challenge/fp-pix/
> You can see how the etching comes out here:
> http://www.delorie.com/pcb/first.html


I have found that the edge definition seems somewhat better with glossy  
paper rather than matte paper.

ST

I purchased a Taig CNC milling machine six years ago and have been
very happy with it.  The people at Taig stand firmly behind their
products and Nick Carter from cartertools (taig dealer) has been a
pleasure to work with.

http://www.cartertools.com/

Ed

> I just saw the mag in my local WHS branch. It's very expensive, a
Taig CNC 
> milling machine only costs about $2,000.

--- In Homebrew_PCBs@yahoogroups.com, "AnaLog Services, Inc."
<wireline@...> wrote:
>
> Interesting observations.  Does anybody have pics of milled vs.
toner transfer PCBs on their website?  How decent is possible with the
toner transfer process really?  If one is willing to buy the
commercial product rather than trying to use conventional paper, can
better results be had?
> 
> 

> 
>   Anything to do with PCBs? IMO, you'll be better off using traditional 
>   methods to create the board then using the mill to drill. PCB milling 
>   is usually popular with the following types;
> 
>   1. Those unsatisfied with the toner transfer board creation process 
>   and cannot manage the photo process for whatever reasons.
> 
>   2. Those with an underutilized mill/router.
> 
>   3. Those in the business of selling mills/routers or selling plans 
>   for such.
> 
>   4. Environment conservation freaks who see the chemicals used in 
>   traditional board creation processes as one more doomsday ingredient. 
> 


I would add a little refinement to the above.

if you want the best boards, the finest lines, the most professional
you can do at home.  use pre-sensitized boards, use a photo resist set-up.

If you want the cheapest from start to stop, use TT.

The PCB milling has it's advantages.

#1) drilling the holes in precise locations.
#2) cutting the boards to precise sizes.
#3) environmentally friendly

notice, I did not list anything to do with making traces ?

A small CNC machine to drill the holes is just great.  smaller holes
can be used for many things as they are so well aligned.
 
slots can be routed that would otherwise be a mess to do by hand.

Now, assuming you have the CNC machine, what else can you do ?

you can also mechanically etch boards. A side benefit.  I would not
recommend to anyone that they dispense with any of the other tools in
their box and only use one.

I think that in Stefan's #3 above, what happens is that we lose focus
on my #1 and #2 and get all excited about the abilities of a CNC machine.

The CNC is a great addition to a shop, especially if one does any
repetitious work or any enclosure holes that could be done on a CNC
machine.

Dave

Dave, Any closer to a release date yet for your machine?

Chris

>I think that in Stefan's #3 above, what happens is that we lose focus
>on my #1 and #2 and get all excited about the abilities of a CNC 
>machine.

Somehow, "Stefan's #1" just doesn't seem typically Stefan. Are you sure 
you got the poster right?

--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@...> 
wrote:
>

--- In Homebrew_PCBs@yahoogroups.com, "derekhawkins" <eldata@...> wrote:
>
> >I think that in Stefan's #3 above, what happens is that we lose focus
> >on my #1 and #2 and get all excited about the abilities of a CNC 
> >machine.
> 
> Somehow, "Stefan's #1" just doesn't seem typically Stefan. Are you sure 
> you got the poster right?
> 


I am not positive.  Syd had posted in a response and that was part of
what he quoted.

I searched thru the messages and did not find the origional poster.  

If I mis-quoted, please correct it.

I do agree that a lot of people get that tunnel vision and not look at
the overall picture.  hence my post.

Dave

--- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing"
<lcdpublishing@...> wrote:
>
> Dave, Any closer to a release date yet for your machine?
> 
> Chris
>

Of course... every day that passes means it is getting closer.

I cannot take credit for the machine, it is really John Hansford that
is making the machine. I'm doing the electronics on some of them. 
many will be sold bare-bones.

I'll going to to be doing the full electronics package on it for those
who want a turn-key unit.

Dave

Since we are all eagerly anticipating the machine photos, how about a 
little info on the electronics to whet out appetites.

Myc

--- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha" <dave_mucha@...> 
wrote:
>
> --- In Homebrew_PCBs@yahoogroups.com, "lcdpublishing"
> <lcdpublishing@> wrote:
> >
> > Dave, Any closer to a release date yet for your machine?
> > 
> > Chris
> >
> 
> Of course... every day that passes means it is getting closer.
> 
> I cannot take credit for the machine, it is really John Hansford 
that
> is making the machine. I'm doing the electronics on some of them. 
> many will be sold bare-bones.
> 
> I'll going to to be doing the full electronics package on it for 
those

> who want a turn-key unit.
> 
> Dave
>

--- In Homebrew_PCBs@yahoogroups.com, "mycroft2152" <mycroft2152y@...>
wrote:
>
> Since we are all eagerly anticipating the machine photos, how about a 
> little info on the electronics to whet out appetites.
> 
> Myc

That's easy.

using wires and connectors, the bits and bobs are connected to each
other using Ben Franklins discovery of St. Elmo's Fire or maybe
slightly more correctly the harnessing of it.

With copper and tin, solder and flux, electricity is directed thru
paths and across depletion regions and even thru carbon !

I know many of you would like the details, so here it is....

Starting with some gallium and arsenic a voltage is passed, that runs
into the black box and from there magic happens.

That magic extends to end switches on each end of each axis, (6) along
with HOME switches on each axis (1 per), all controlled by one master
Emergency stop switch that also substitutes as a master-ON switch.

In another set of conductors, other magic happens.  pulses are
transfered from digital bits to electroncal bits and then into motion.
these pulses create a pattern that control the movements of 3 separate
motors.  each motor is controlled independently and with a precise
driver so that each pulse represents one specific movement in the axis
of which it controls. 

The 1/4-20 leadscrews are connected directly to a stepper motor that
has an natural or full step movement of 200 steps per revolution. 
mathematically, this results in 4,000 steps per inch in a full step
mode.  One can calculate how a half step mode would yield 8,000 steps
per inch, or a 1/4 step mode would yield 16,000 steps per inch and so on.

For those who have a passing interest in the distance a 'step' might
be, at 4,000 steps per inch, each step would be 0.00025 inches or 1/4
of a mil. For those who prefer the metric system, that would be
0.00635 mm.

Power comes from a generating plant many miles from your location and
travels, uninterrupted, in a sinusoidal pattern called an AC wave
form.  Our black box takes that AC wave and converts it into a 24
volt, 10 amp output.  From there it takes a simple bridge to the DC
side and with the aid of some Aluminum Electrolytic material, is
turned into a much refined direct current.  Interestingly, this also
simultaneously decreases and increases the voltage.  First a slight
decrease of about 1 volt to get up and over the bridge, and then a
whopping 1.4x increase to yield a robust 33 volts to be used to power
the motors.  Sadly, our endevours have not revealed the free lunch, so
that 10 amps on the primary side is reduced to about 7 amps on the DC
side.

Motor control is by means of a microstepping driver that can be set by
the user for full step, 1/2 step, 1/4 step, 1/8 step and even 1/16
step.  All by some very simple jumper settings.  nice !

We include the requisite red, ON light to indicate that power is
present along with a slightly audible hiss from the motors that
indicates the motors are being powered.

Motor power is still a little bit of a consideration.  A PCB could be
etched with a 50 oz-in motor, although that is on the light side for
the capability of the machine, especially if one wanted to cut hard
woods and some dense plastics.

On the flip side, 200 oz-in is so robust that small carbide cutters
are in danger of breaking.

This is an area we do hope to get a lot of feed-back.  just what
materials are being cut and how well the motors perform.

I hope I've answered some of your questions.

But, I think that any further discussion is best done on the FireBall
group, as this is really off-topic for this group, and although the
members have been very patient and courteous about this topic, I hate
to take advantage.

http://groups.yahoo.com/group/Fireball-CNC/


Dave