Hi Tom,
And I take it you stack boards up on top of the template, and the
template limits the cutting. Neat idea! Although I'm not to sure about
running my import drill press at 25,000 rpm! Sounds like something that
could be done on the Sherline mill also.
Routing the edges is not a problem... yet, I'm just trying to cut down
the swarf from the isolation cuts. Only one or two boards at a time.
The work last weekend was on PCB's less then 1" dia (parts for a
digitizer probe)!
Thanks for the description, I hadn't heard of it before.
And I just won my bid on a 20" x 30" (or so) light table. This table
has 3/4" round guides for X & Y, and a carriage for Z with a platform.
It has a 1/8" chain drive (both sides on Y), or maybe the chains drive
encoders ?? I won't get it until tomorrow. All this sets on top of a
small steel table that can be elevated. Probably something for
inspection.
LOOKS like it could make a nice PCB router! Maybe the chains would need
to be replaced with a lead screw, maybe not! But getting the XYZ
carriage all built up couldn't hurt. And I have various steppers and
early versions of the Gecko drive (also surplus) to drive it.
Wait'll my wife sees this! Now where to put it...
Alan KM6VV
twb8899 wrote:
>
> --- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> > Hi Tom,
> >
> > I wish I had a 25K spindle! I'm looking at various laminate
> routers. I
> > was using a .093" endmill. The Phenolic I was cutting made nice
> tame
> > swarf, heavy enough not to blow around, and not the "itchy glass"
> dust.
>
> Alan,
>
> Here is something you could try. Take a regular drill press and put
> a large pulley on the motor and the smallest possible pulley on the
> spindle. You should be able to find the right ratio to get up to
> 25,000 RPM.
>
> You can then attach a piece of plywood to the drill table and drill a
> hole into this wood with a .125" drill bit. Remove the bit, close the
> chuck all the way and use the chuck to press a .125" dowell pin into
> this hole. Now chuck a .125" router bit and lower the spindle until
> it is almost touching the pin. Lock the drill spindle to this depth
> and you have a pin router.
>
> You may have to make a new pulley shield since the motor pulley could
> end up being larger than the original shield after the correct ratio
> is established. Make a template the finished size of your board with
> at least two tooling pins and you can route the boards to size. As
> many as three and sometimes four boards deep can be routed this way
> depending on your spindle power. The only negative with this method
> is the Morse taper on most drill spindles can't take too much side
> load but I have seen this method work and you don't have as much
> noise as the Dremel tool and die grinders make. This is similar to
> how the big pin routers work.
>
> I use a commercial pin router and have always been able to out
> perform all but the largest CNC machines. If you are making larger
> quantities this is a good way to get the job done with a small
> investment. I also use pin routers to make my control panels and
> other plastic parts.
>
> Tom