Homebrew PCBs

I've been watching some videos on YouTube that are very interesting:

    http://ciciora.com/picknplace.html
<http://ciciora.com/picknplace.html>

and in the menu there is one called

    CNC Taig mill solder paste dispenser

I'm very interested in doing something like this with my mill but I
don't know very much about the pneumatics involved.  They seem to be
using ordinary syringes as the tool head for picking up and placing the
parts.  They are also using a syringe filled with solder paste for
dispensing.  They must be using an air pump that can be both a vacuum
pump and compressor.

Can anyone direct me to a site where I can learn something about the
pneumatics involved?  When I google "pneumatics" I get a gazillion hits.
I don't know where to start.  I also would like to know what kind of air
pump to look for.

Thanks,

Mark



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

There aren't any pneumatics being used in the video.
You just need a vacumm.
--- "mark.mickelsen" <mark.mickelsen@...>
wrote:

> 
> I've been watching some videos on YouTube that are
> very interesting:
> 
>     http://ciciora.com/picknplace.html
> <http://ciciora.com/picknplace.html>
> 
> and in the menu there is one called
> 
>     CNC Taig mill solder paste dispenser
> 
> I'm very interested in doing something like this
> with my mill but I
> don't know very much about the pneumatics involved. 
> They seem to be
> using ordinary syringes as the tool head for picking
> up and placing the
> parts.  They are also using a syringe filled with
> solder paste for
> dispensing.  They must be using an air pump that can
> be both a vacuum
> pump and compressor.
> 
> Can anyone direct me to a site where I can learn
> something about the
> pneumatics involved?  When I google "pneumatics" I
> get a gazillion hits.
> I don't know where to start.  I also would like to
> know what kind of air
> pump to look for.
> 
> Thanks,
> 
> Mark
> 
> 
> 
> [Non-text portions of this message have been
> removed]
> 
> 



      ____________________________________________________________________________________
Never miss a thing.  Make Yahoo your home page. 
http://www.yahoo.com/r/hs

It seems to me like you could just use an ordinary syringe in the Z-axis.
Then increment a stepper motor to depress the syringe however many steps it
takes to place an appropriate sized drop of solder on the board.  You
shouldn't need to mess with pressurized air or vacuums.

 

 

Paul Symansky

 

Biology

A&S 2009

954.478.7285

http://www.symtechlabs.com

 



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

Oops, I retract my statement: the above would work for just the solder
dispenser.  You're right, you'll probably need some sort of vacuum pump for
the pick-and-place machine.  It can't be that difficult, though: the vacuum
needed to pick up one of those parts must be incredibly small.  You could
probably even have the Z-axis stepper pull the plunger on a syringe to
create the vacuum to lift the part.  

 

Paul Symansky

 

Biology

A&S 2009

954.478.7285

http://www.symtechlabs.com

 



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

If you start to make a P&P that work ,,think you will have enough 
work for much time ahead... wish you luck with the project..
I can give some of my experiences with a small PP system that I have 
used and teached students in the use of it.. 
The component place part.:
there was a syringe to lift components and place them on the board.. 
the movement to the position was moving the arm with the hand..!
There was problems with taking up components.. only resistors and 
transistors was easy to pick up..the surface roughness ,think,was a 
problem.. When placing them and lowering the syringe to the board,the 
final step was to remove the vacuum.. sometimes the component turned 
a bit..If we had put paste on too many pads ,the paste had allready 
gone stiff and the component did not atttach to the paste. so a 
conclusion was ,not to put paste on more than ten or twenty pads 
before placing the components.
The dispensing of solder paste:
there was a preasure unit that pumped the paste out..
This was the real problem.. it had ,think , 20 steps , some for 
solder some for glue and each time we took out the syringe with paste 
from the fridge ,it acted different. sometimes nothing came out 
somtimes a whole lot came out. We never managed to get a equal 
process.
throug the time, I realized ,that if the paste was not within the 
date ,there was on it for "best before"..then it only made 
trouble .If we had a new one, and we did not replace the tip before 
next use, it would again not work good.. tried to clean the tips , 
but that did not make it work. so we had to spend a tip, to say one 
pound ,each time. If I went for a coffe break , which I did very 
often, it would allready have been too thick in the tip and a new tip 
had to be put on..
This is the main problems with this kind of work .. I hope.. but 
think it would be good for you to know what kind of problems ,you 
will have to work with.
Alex

Probably the cheapest powered vacuum pump on the market right now is 
the Reynolds Handi-Vac that's used with vacuum sandwich bags.  You 
can pick them up for around $10.  It wouldn't be hard to set up an 
I/O pin to turn on/off the vacuum source.


--- In Homebrew_PCBs@yahoogroups.com, "Paul Symansky" <symansky@...> 
wrote:
>
> Oops, I retract my statement: the above would work for just the 
solder
> dispenser.  You're right, you'll probably need some sort of vacuum 
pump for
> the pick-and-place machine.  It can't be that difficult, though: 
the vacuum
> needed to pick up one of those parts must be incredibly small.  You 
could
> probably even have the Z-axis stepper pull the plunger on a syringe 
to

> create the vacuum to lift the part.  
> 
>  
> 
> Paul Symansky
> 
>  
> 
> Biology
> 
> A&S 2009
> 
> 954.478.7285
> 
> http://www.symtechlabs.com
> 
>  
> 
> 
> 
> [Non-text portions of this message have been removed]
>

There are _VAST_ differences in solder paste. I only do manual
dispensing, but you can tell from that. Some pastes already come hard
in the syringe. Some have extremely uneven mixing (lumps of just
flux). Some pastes dry very quickly.
I have tried a few different makes, and now found one that works good.
It is very expensive because there is very little in the syringe
compared to other brands, but since i order it at work i don't mind.
Fiddling around with a bad paste would cost the company more anyway.
I believe this one is EDSYN CR44, but i am not 100% sure better have
me check it if you want to buy the same.
I found that a used dispensing needle left overnight on the bench
(removed from the syringe, which i put in the fridge just to be sure)
would still work just fine the next day. This wasn't possible with any
other paste i tried, but i have not looked that long either.


If you pay 1 pound per needle, you are also doing something wrong.
Even at farnell you can buy 50 pcs for 10 or 20 eur. With clever
shopping i expect you can get them for much less, they are a cheap
mass produced part after all.


I think pneumatics are the way to go for CNC dispensing. You need the
Z-axis to move the needle up and down, it is not free to press a
plunger. Also, it is very easy to rig a pneumatic valve with timer.
Syringe/hose adapters are readily available. Some dispensing systems
have a "suck back" function to eliminate dripping. I don't think it is
required for the solder paste with such a high viscosity. All you need
is compressed air, a pressure regulator, and a 2-way solenoid valve.

For pick and place, very little vacuum is needed. A small handheld
pen-sized suction tweezer can also do the job after all. A diaphragm
pump will offer plenty of suction (for example the kind they sell to
pump air bubbles into fish tanks, very cheap). I have used an old
fridge compressor (get it from recycling yard or as a replacement
part), which is overkill for lifting parts with vacuum. You would be
amazed what you can do with it, for example if you want to discard
some foam rubber put it in a plastic bag, apply the vaccum hose, watch
and be amazed ;-).
But that is another story, the fridge compressor can also easily
create the pressure needed for dispensing. All you need is a safety
valve and a pressure switch. If you want more air for other stuff you
can add an air receiver tank (used fire extinguisher or helium party
ballon tank or...). You need to make sure this tank is pressure tested
well above your safety valve pressure. Fire extinguishers seem ideal
since they already have a safety valve in the lid, but many gas tanks
have that too.

Anyway, if you have a CNC machine you need not be afraid of the
pneumatics of dispensing and pick/place, they are very simple. The
mechaincs seem vastly more complex to me.


ST

On Dec 25, 2007 4:37 PM, b52chris <christiansen_alex@...> wrote:
> If you start to make a P&P that work ,,think you will have enough
> work for much time ahead... wish you luck with the project..
> I can give some of my experiences with a small PP system that I have
> used and teached students in the use of it..
> The component place part.:
> there was a syringe to lift components and place them on the board..
> the movement to the position was moving the arm with the hand..!
> There was problems with taking up components.. only resistors and
> transistors was easy to pick up..the surface roughness ,think,was a
> problem.. When placing them and lowering the syringe to the board,the
> final step was to remove the vacuum.. sometimes the component turned
> a bit..If we had put paste on too many pads ,the paste had allready
> gone stiff and the component did not atttach to the paste. so a
> conclusion was ,not to put paste on more than ten or twenty pads
> before placing the components.
> The dispensing of solder paste:
> there was a preasure unit that pumped the paste out..
> This was the real problem.. it had ,think , 20 steps , some for
> solder some for glue and each time we took out the syringe with paste
> from the fridge ,it acted different. sometimes nothing came out
> somtimes a whole lot came out. We never managed to get a equal
> process.
> throug the time, I realized ,that if the paste was not within the
> date ,there was on it for "best before"..then it only made
> trouble .If we had a new one, and we did not replace the tip before
> next use, it would again not work good.. tried to clean the tips ,
> but that did not make it work. so we had to spend a tip, to say one
> pound ,each time. If I went for a coffe break , which I did very
> often, it would allready have been too thick in the tip and a new tip
> had to be put on..
> This is the main problems with this kind of work .. I hope.. but
> think it would be good for you to know what kind of problems ,you
> will have to work with.
> Alex
>
>
>
>
> Be sure to visit the group home and check for new Links, Files, and Photos:
> http://groups.yahoo.com/group/Homebrew_PCBs
> Yahoo! Groups Links
>
>
>
>
>

Hi Stephan,

 

I am interested in getting a hobby pick-and-place capability going with my
hobby CNC mill.  I don't know anything about the pneumatics of dispensing
and pick/place, so any references would be appreciated.  I would be VERY
interested in a brand of solder paste the "works good".  If you would
confirm the brand, I would definitely appreciate that.  I'm in the US so I
hope it is available here, and I hope it is a type that is water soluble.
It may seem expensive but if you end up throwing away whole syringes of
paste that can't be used then the "expensive" one is worth it if you can use
the whole thing.

 

Thanks for your help.

Mark Mickelsen

 

  _____  

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Stefan Trethan
Sent: Sunday, January 06, 2008 5:01 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: Pick-and-place using a CNC mill

 

There are _VAST_ differences in solder paste. I only do manual
dispensing, but you can tell from that. Some pastes already come hard
in the syringe. Some have extremely uneven mixing (lumps of just
flux). Some pastes dry very quickly.
I have tried a few different makes, and now found one that works good.
It is very expensive because there is very little in the syringe
compared to other brands, but since i order it at work i don't mind.
Fiddling around with a bad paste would cost the company more anyway.
I believe this one is EDSYN CR44, but i am not 100% sure better have
me check it if you want to buy the same.
I found that a used dispensing needle left overnight on the bench
(removed from the syringe, which i put in the fridge just to be sure)
would still work just fine the next day. This wasn't possible with any
other paste i tried, but i have not looked that long either.

If you pay 1 pound per needle, you are also doing something wrong.
Even at farnell you can buy 50 pcs for 10 or 20 eur. With clever
shopping i expect you can get them for much less, they are a cheap
mass produced part after all.

I think pneumatics are the way to go for CNC dispensing. You need the
Z-axis to move the needle up and down, it is not free to press a
plunger. Also, it is very easy to rig a pneumatic valve with timer.
Syringe/hose adapters are readily available. Some dispensing systems
have a "suck back" function to eliminate dripping. I don't think it is
required for the solder paste with such a high viscosity. All you need
is compressed air, a pressure regulator, and a 2-way solenoid valve.

For pick and place, very little vacuum is needed. A small handheld
pen-sized suction tweezer can also do the job after all. A diaphragm
pump will offer plenty of suction (for example the kind they sell to
pump air bubbles into fish tanks, very cheap). I have used an old
fridge compressor (get it from recycling yard or as a replacement
part), which is overkill for lifting parts with vacuum. You would be
amazed what you can do with it, for example if you want to discard
some foam rubber put it in a plastic bag, apply the vaccum hose, watch
and be amazed ;-).
But that is another story, the fridge compressor can also easily
create the pressure needed for dispensing. All you need is a safety
valve and a pressure switch. If you want more air for other stuff you
can add an air receiver tank (used fire extinguisher or helium party
ballon tank or...). You need to make sure this tank is pressure tested
well above your safety valve pressure. Fire extinguishers seem ideal
since they already have a safety valve in the lid, but many gas tanks
have that too.

Anyway, if you have a CNC machine you need not be afraid of the
pneumatics of dispensing and pick/place, they are very simple. The
mechaincs seem vastly more complex to me.

ST

 



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

Hi,

just checked, it is Edsyn CR44 ordered from Farnell.

I agree, it will be much better to throw this one away empty for a change.

ST

On Jan 7, 2008 8:05 AM, Mark Mickelsen <mark.mickelsen@...> wrote:
> Hi Stephan,
>
>
>
> I am interested in getting a hobby pick-and-place capability going with my
> hobby CNC mill.  I don't know anything about the pneumatics of dispensing
> and pick/place, so any references would be appreciated.  I would be VERY
> interested in a brand of solder paste the "works good".  If you would
> confirm the brand, I would definitely appreciate that.  I'm in the US so I
> hope it is available here, and I hope it is a type that is water soluble.
> It may seem expensive but if you end up throwing away whole syringes of
> paste that can't be used then the "expensive" one is worth it if you can use
> the whole thing.
>
>
>
> Thanks for your help.
>
> Mark Mickelsen
>
>

On Mon, 7 Jan 2008, Stefan Trethan wrote:

> just checked, it is Edsyn CR44 ordered from Farnell.

I've not yet used solder paste, but in my next project I'd like to try:
being a complete newbie to this, what needles do you need for that
syringe? I've heard you need to get the applicator needles separate to the
syringe.

Thanks for checking, Stefan.  Unfortunately, I can't order from Farnell.
Something about import licenses, or export regulations, or some such.  I
wonder if Kester has an equivalent product that "works good".

 

Mark

 

  _____  

From: Homebrew_PCBs@yahoogroups.com [mailto:Homebrew_PCBs@yahoogroups.com]
On Behalf Of Stefan Trethan
Sent: Monday, January 07, 2008 1:50 AM
To: Homebrew_PCBs@yahoogroups.com
Subject: Re: [Homebrew_PCBs] Re: Pick-and-place using a CNC mill

 

Hi,

just checked, it is Edsyn CR44 ordered from Farnell.

I agree, it will be much better to throw this one away empty for a change.

ST

On Jan 7, 2008 8:05 AM, Mark Mickelsen <mark.mickelsen@
<mailto:mark.mickelsen%40comcast.net> comcast.net> wrote:
> Hi Stephan,
>
>
>
> I am interested in getting a hobby pick-and-place capability going with my
> hobby CNC mill. I don't know anything about the pneumatics of dispensing
> and pick/place, so any references would be appreciated. I would be VERY
> interested in a brand of solder paste the "works good". If you would
> confirm the brand, I would definitely appreciate that. I'm in the US so I
> hope it is available here, and I hope it is a type that is water soluble.
> It may seem expensive but if you end up throwing away whole syringes of
> paste that can't be used then the "expensive" one is worth it if you can
use
> the whole thing.
>
>
>
> Thanks for your help.
>
> Mark Mickelsen
>
>

 



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

Too bad, but i'm sure there are other brands that work just as well.

Dylan, yes you need a dispensing needle. It is just like those doctors
use for injections, only with a blunt tip and usually shorter and of
larger diameter. I tend to cut mine down even further to reduce the
length of the narrow section even more.

ST

On Jan 7, 2008 1:30 PM, Mark Mickelsen <mark.mickelsen@...> wrote:
> Thanks for checking, Stefan.  Unfortunately, I can't order from Farnell.
> Something about import licenses, or export regulations, or some such.  I
> wonder if Kester has an equivalent product that "works good".
>
>
>
> Mark
>
>
>

On Mon, 7 Jan 2008, Mark Mickelsen wrote:

> Thanks for checking, Stefan.  Unfortunately, I can't order from Farnell.

I think Farnell are called Newark-in-One in the USA, you might be able to
order it via them.

On Mon, 7 Jan 2008, Stefan Trethan wrote:
>
> Dylan, yes you need a dispensing needle.

I presume they are pretty standard, and this kind of thing (order code
7951663 in the Farnell catalogue, 921050-TE OKI/METCAL needle) is what I'm
after?

Thanks.

Yes, although i remember them a bit cheaper, like usual the OKI/metcal
label seems to demand extra payment with no apparent benefit.
What about Farnell 3975605 "KDS2012P" 10eur. Those are almost a bit on
the small side, diameter-wise, for manual dispensing without pneumatic
dispenser. Should be about right if you have air assistance.

ST

On Jan 7, 2008 3:06 PM, Dylan Smith <dyls@...> wrote:
> On Mon, 7 Jan 2008, Stefan Trethan wrote:
> >
> > Dylan, yes you need a dispensing needle.
>
> I presume they are pretty standard, and this kind of thing (order code
> 7951663 in the Farnell catalogue, 921050-TE OKI/METCAL needle) is what I'm
> after?
>
> Thanks.
>