Re: Basic questions

in doing circuit boards, my machine is set up with two pins.
these reside at the very center of the table. and are the zero point.

the stock is drilled with these two hole and then placed on the pins. everything to one side is + the other side is-.
when I flip it over, the software reverses the numbers and can cut the rest of the traces.

although the 1/8" thick fiberglass is not exactly the same as balsa, the principal would work and I have no problem cutting out shapes.

I use 1/4" Masonite as the sacrificial layer. I tend to replace it when it has tracks that have eaten about 80% of the face, so for me, it lasts a long time.

as for vacuum, really thin cling wrap is very hard to work with. you could use wax paper as it will conform to the surface in a similar fashion, but does not tend to move with the wind or static electricity from your clothes.

Dave

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Roland Jollivet <Roland.Jollivet@...> wrote:
>
> An idea I've seen, for porous materials, is to drag a sheet of 'cling wrap'
> over the workpiece to make it airtight. How much gets cut away before
> vacuum is lost is another matter. I suppose a new sheet could be pulled
> over between cutting passes.
>
> Regards
> Roland
>
>
> On 2 January 2012 23:13, John Jackson <jackson@...> wrote:
>
> > **
> >
> >
> > Gordon,
> >
> > My suggestion for work holding would be to get some sacrificial 1/8 or 1/4
> > hardboard the same size or a bit larger than the material you want to cut.
> > Use double faced tape to hold the balsa to the hardboard and then clamp the
> > hardboard to your router table. This way you can cut through balsa into
> > hardboard but not into the good table.
> >
> > Test your tape/balsa/hardboard combo first on scrap because some tapes are
> > too good, they would rather rip your balsa apart than give up the part! The
> > stuff I use comes from a woodworking store and is used to hold hardboard
> > templates to wood for routing.
> >
> > A vacuum table is not a bad idea if you are doing a lot of cutting, as in
> > mass producing kits for sale. Small parts will move on many vacuum tables,
> > especially with balsa since it is porous.
> >
> > For software I would recommend Vectic's Cut2D (
> > http://www.vectric.com/WebSite/Vectric/cut2D/c2d_index.htm). Demo version
> > on their website with tutorials. It is easy to use, does a good job at
> > making scanned bitmaps of ribs and formers into vectors that can be cut. It
> > also allows for 'tabs' which you can put on a part to hold it to the
> > material; when routing is done just cut through tabs with an xacto and
> > touch up with sandpaper. With good use of tabs you can keep the double
> > faced tape out from directly under the parts
> >
> > Good luck,
> >
> > John
> >
> >
> > --- In CAD_CAM_EDM_DRO@yahoogroups.com, Gordon Anderson <GAA@> wrote:
> > >
> > > Hello, I have been lurking on this list for sometime and I have a couple
> > of dumb questions that I hope someone can answer for me or point me in the
> > right direction. I am very close to buying a DIY CNC router kit like the
> > blueChick. I have read a lot about the machines and control software but my
> > questions are pretty basic and most likely dumb, here goes:
> > > 1.) How do I hold material on the table? I will be cutting thin wood,
> > liteply and balsa wood. I will be cutting through the wood to cut out
> > parts. My question is how do people hold the material in place and what do
> > you put under the part you are cutting to make sure you do not cut into the
> > bed of the machine.
> > > 2.) I have old drawings with patterns for formers (mostly from model
> > airplanes) that I would like to convert to gcode files to enable cutting
> > the parts. Is this possible? If so where can I learn more about the
> > process. I hope I can scan them in and then convert them to gcodes.
> > >
> > > I hope these questions are appropriate for this list and appreciate any
> > input.
> > >
> > > Thanks!
> > >
> > > --Gordon
> > >
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
>
>
> [Non-text portions of this message have been removed]
>