Homebrew_PCBs

--- In Homebrew_PCBs@yahoogroups.com, JanRwl@... wrote:
>
> In a message dated 2/13/2011 1:11:52 P.M. Central Standard Time,
> cs6061@... writes:
>
> Anyone got and good ideas?<<
> For home-brew, use MASKING TAPE around the edges, onto the machine's
> table-surface.
> Jan Rowland
>
>
>
> [Non-text portions of this message have been removed]
>

On 13.Feb.11 20:11, designer_craig wrote:
> I am about to build a vacuum table to hole down the blank stock when I cnc drill my boards. I am looking some low cost sacrificial material to use between the board and the vacuum table.
>
> The material needs to be thick enough so as not to drill into the vacuum table and be some what porous to allow air diffusion for a good vacuum grip.
>
> The ideal material would be something like 1/16" thick MDF. I have heard MDF is fairly porous. I have only seen MDF in 1/2 and 3/4" thickness. Possilble some sort of construciton paper or cardboard. Guess I need to do some experiments.
>
> Anyone got and good ideas?
>
> Craig
>

You should be able to find 1/4" MDF, just mask the unused MDF.

- --
Best Regards,
Zoran A. Šćepanović
zastos@...
http://zastos.com
+381 63 609-993

=====


Never let anyone drive you crazy when you know it's within walking distance.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (MingW32)

iEYEARECAAYFAk1ZFcoACgkQeEZQoPqyQm2AIACgu6sm90D5SxWzUOmm5zLb3n8B
4/8AoOK2P43frPlrxxiqlJQ9y+6dl5z/
=OPvG
-----END PGP SIGNATURE-----


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

--- In Homebrew_PCBs@yahoogroups.com, "Zoran A. Scepanovic" <zastos@...> wrote:
>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> On 13.Feb.11 20:11, designer_craig wrote:
> > I am about to build a vacuum table to hole down the blank stock when I cnc drill my boards. I am looking some low cost sacrificial material to use between the board and the vacuum table.
> >
> > The material needs to be thick enough so as not to drill into the vacuum table and be some what porous to allow air diffusion for a good vacuum grip.
> >
> > The ideal material would be something like 1/16" thick MDF. I have heard MDF is fairly porous. I have only seen MDF in 1/2 and 3/4" thickness. Possilble some sort of construciton paper or cardboard. Guess I need to do some experiments.
> >
> > Anyone got and good ideas?
> >
> > Craig
> >
>
> You should be able to find 1/4" MDF, just mask the unused MDF.
>
> - --
> Best Regards,
> Zoran A. Šćepanović
> zastos@...
> http://zastos.com
> +381 63 609-993
>
> =====
>
>
> Never let anyone drive you crazy when you know it's within walking distance.
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.9 (MingW32)
>
> iEYEARECAAYFAk1ZFcoACgkQeEZQoPqyQm2AIACgu6sm90D5SxWzUOmm5zLb3n8B
> 4/8AoOK2P43frPlrxxiqlJQ9y+6dl5z/
> =OPvG
> -----END PGP SIGNATURE-----
>
>
> [Non-text portions of this message have been removed]
>

> On 13.Feb.11 20:11, designer_craig wrote:
> > I am about to build a vacuum table to hole down the blank stock when I cnc drill my boards. I am looking some low cost sacrificial material to use between the board and the vacuum table.
> >
> > The material needs to be thick enough so as not to drill into the vacuum table and be some what porous to allow air diffusion for a good vacuum grip.
> >
> > The ideal material would be something like 1/16" thick MDF. I have heard MDF is fairly porous. I have only seen MDF in 1/2 and 3/4" thickness. Possilble some sort of construciton paper or cardboard. Guess I need to do some experiments.
> >


> You should be able to find 1/4" MDF, just mask the unused MDF.
>

>
>
> > You should be able to find 1/4" MDF, just mask the unused MDF.
> >
>
> If I understand him correctly he was wanting a backer board to protect the
> table top but also wanted it to have air flow for the vacuum to hold down
> the board. I don't think that your going to get much air flow thru what I
> call MDF of any thickness. Maybe the Masonite Hardboard Peg Board material
> would do what he wants.
>
> Ben
>
> Yeah, I wondered about that when I first read this thread too. What I know

>
>

On Mon, 14 Feb 2011 19:10:38 -0700, you wrote:

There're several densities of fiberboard. MDF is rather dense and
more expensive. The stuff typically sold in home stores may not be
MDF (or HDF, if it exists), It does exist in a lower (and perhaps more
porous) version.

That's what I've heard.

Harvey

>>
>>
>> > You should be able to find 1/4" MDF, just mask the unused MDF.
>> >
>>
>> If I understand him correctly he was wanting a backer board to protect the
>> table top but also wanted it to have air flow for the vacuum to hold down
>> the board. I don't think that your going to get much air flow thru what I
>> call MDF of any thickness. Maybe the Masonite Hardboard Peg Board material
>> would do what he wants.
>>
>> Ben
>>
>> Yeah, I wondered about that when I first read this thread too. What I know
>as MDF definitely will not let air through. It's pretty dense stuff. The
>only thing that would probably go through MDF is water, and once that
>happens, you wouldn't have MDF anymore - just some kind of soupy puddle.
>
>Andrew
>
>>
>>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>------------------------------------
>
>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, "Ben L" <bhleavi@...> wrote:
>
>
>
> > On 13.Feb.11 20:11, designer_craig wrote:
> > > I am about to build a vacuum table to hole down the blank stock when I cnc drill my boards. I am looking some low cost sacrificial material to use between the board and the vacuum table.
> > >
> > > The material needs to be thick enough so as not to drill into the vacuum table and be some what porous to allow air diffusion for a good vacuum grip.
> > >
> > > The ideal material would be something like 1/16" thick MDF. I have heard MDF is fairly porous. I have only seen MDF in 1/2 and 3/4" thickness. Possilble some sort of construciton paper or cardboard. Guess I need to do some experiments.
> > >
>
>
> > You should be able to find 1/4" MDF, just mask the unused MDF.
> >
>
> If I understand him correctly he was wanting a backer board to protect the table top but also wanted it to have air flow for the vacuum to hold down the board. I don't think that your going to get much air flow thru what I call MDF of any thickness. Maybe the Masonite Hardboard Peg Board material would do what he wants.
>
> Ben
>

On Mon, 14 Feb 2011 19:10:38 -0700, you wrote:

There're several densities of fiberboard. MDF is rather dense and
more expensive. The stuff typically sold in home stores may not be
MDF (or HDF, if it exists), It does exist in a lower (and perhaps more
porous) version.

That's what I've heard.

Harvey

>>
>>
>> > You should be able to find 1/4" MDF, just mask the unused MDF.
>> >
>>
>> If I understand him correctly he was wanting a backer board to protect
the
>> table top but also wanted it to have air flow for the vacuum to hold down
>> the board. I don't think that your going to get much air flow thru what I
>> call MDF of any thickness. Maybe the Masonite Hardboard Peg Board
material
>> would do what he wants.
>>
>> Ben
>>
>> Yeah, I wondered about that when I first read this thread too. What I
know
>as MDF definitely will not let air through. It's pretty dense stuff. The
>only thing that would probably go through MDF is water, and once that
>happens, you wouldn't have MDF anymore - just some kind of soupy puddle.
>
>Andrew
>
>>
>>
>
>
>[Non-text portions of this message have been removed]
>
>
>
>------------------------------------
>
>Be sure to visit the group home and check for new Links, Files, and Photos:
>http://groups.yahoo.com/group/Homebrew_PCBsYahoo! Groups Links
>
>
>






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

----- Original Message -----
From: designer_craig
To: Homebrew_PCBs@yahoogroups.com
Sent: Tuesday, February 15, 2011 6:24 PM
Subject: [Homebrew_PCBs] Re: PCB drilling vacuum table ??



I wondered about the air flow thorugh MDF but the idea came from a post I saw a couple years back that I now can't find. The guy was using 1/2" material to build the vacuum chamber and had to paint the non table areas to hold his vacuum. Now he may have been using particle board and calling it MDF, particle board is much less dense.

I don't want to use 1/2" or 3/4" that I can get at the home center, just too thick and heavy. My brother sent me a link showing the stuff is available from 1/8" to 1-1/8" thick. As for the air flow, it only needs to transport a very small volume of air over a relative long time since the PCB stock material is sealing the top surface of the MDF.
I have some 3/4" MDF, guess I should go slab off a 1/4" thick piece on the band saw and see if it works.

Criag

--- In Homebrew_PCBs@yahoogroups.com, "Ben L" <bhleavi@...> wrote:
>
>
>
> > On 13.Feb.11 20:11, designer_craig wrote:
> > > I am about to build a vacuum table to hole down the blank stock when I cnc drill my boards. I am looking some low cost sacrificial material to use between the board and the vacuum table.
> > >
> > > The material needs to be thick enough so as not to drill into the vacuum table and be some what porous to allow air diffusion for a good vacuum grip.
> > >
> > > The ideal material would be something like 1/16" thick MDF. I have heard MDF is fairly porous. I have only seen MDF in 1/2 and 3/4" thickness. Possilble some sort of construciton paper or cardboard. Guess I need to do some experiments.
> > >
>
>
> > You should be able to find 1/4" MDF, just mask the unused MDF.
> >
>
> If I understand him correctly he was wanting a backer board to protect the table top but also wanted it to have air flow for the vacuum to hold down the board. I don't think that your going to get much air flow thru what I call MDF of any thickness. Maybe the Masonite Hardboard Peg Board material would do what he wants.
>
> Ben
>





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

> Note, commercial PCB drilling is not done with vacuum tables. Often
> multiple layers of boards are stacked and pinned to the table. The drill
> head basically has a spring-loaded ring that presses down on the PCBs while
> drilling.
>
> Bertho
>

> I wondered about the air flow thorugh MDF but the idea came from a post I saw a couple years back that I now can't find. The guy was using 1/2" material to build the vacuum chamber and had to paint the non table areas to hold his vacuum. Now he may have been using particle board and calling it MDF, particle board is much less dense.
>
> I don't want to use 1/2" or 3/4" that I can get at the home center, just too thick and heavy. My brother sent me a link showing the stuff is available from 1/8" to 1-1/8" thick. As for the air flow, it only needs to transport a very small volume of air over a relative long time since the PCB stock material is sealing the top surface of the MDF.
> I have some 3/4" MDF, guess I should go slab off a 1/4" thick piece on the band saw and see if it works.
>

> > I wondered about the air flow thorugh MDF but the idea came from a post I saw a couple years back that I now can't find. The guy was using 1/2" material to build the vacuum chamber and had to paint the non table areas to hold his vacuum. Now he may have been using particle board and calling it MDF, particle board is much less dense.
> >

--- In Homebrew_PCBs@yahoogroups.com, "designer_craig" <cs6061@...> wrote:
>
> I am about to build a vacuum table to hole down the blank stock when I cnc drill my boards. I am looking some low cost sacrificial material to use between the board and the vacuum table.
>
> The material needs to be thick enough so as not to drill into the vacuum table and be some what porous to allow air diffusion for a good vacuum grip.
>
> The ideal material would be something like 1/16" thick MDF. I have heard MDF is fairly porous. I have only seen MDF in 1/2 and 3/4" thickness. Possilble some sort of construciton paper or cardboard. Guess I need to do some experiments.
>
> Anyone got and good ideas?
>
> Craig
>

> I am about to build a vacuum table to hole down the blank stock when I cnc drill my boards.  I am looking some low cost sacrificial material to use between the board and the vacuum table.

--- In Homebrew_PCBs@yahoogroups.com, Jan Kok <jan.kok.5y@...> wrote:
>
> On Sun, Feb 13, 2011 at 12:11 PM, designer_craig <cs6061@...> wrote:
> > I am about to build a vacuum table to hole down the blank stock when I cnc drill my boards.  I am looking some low cost sacrificial material to use between the board and the vacuum table.
>
> Why use a vacuum table? Why not use hold down clamps, something like
> what is commonly used on milling machine tables?
>

On Feb 19, 2011 3:22 PM, "designer_craig" <cs6061@...> wrote:



Clamps get in the way of island milling and they will not hold down the PCB
material as flat as I would like for fine milled traces as would a vacuum
table. For drilling it may be ok especially if I add a drilling foot to the
quill to depress the material to the table.

Craig

--- In Homebrew_PCBs@yahoogroups.com, Jan Kok <jan.kok.5y@...> wrote:


>
> On Sun, Feb 13, 2011 at 12:11 PM, designer_craig <cs6061@...> wrote:
> > I am about to build a ...



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