Hello,
The way to use a sherline to make PCB's is to add a 2 x6 x 1/4 wall
rectangular tubing extrusion to the mill table. then set the mill up
in "horizontal mode" (using their conversion plate makes it easy; but
that is only a plate of alumiunum with some well placed 1/4-20 tapped
holes. Anyone with a drill press could make their own , and someone
with a hand drill could do a work-able job of it.
Anyways, what you NOW have is a VERTICAL travel of 6+ inches,
your "normal" x travel of 8-9 or so, and the "former" Y axis is what
feeds your bits...
The problem with a sherline for PCB work is twofold. First, even with
the hi-speed spindle option, you still only have 10K rpm's... Which
means you're going to have TERRIBLE cutter life, pcb epoxy smear in
the holes, burrs, etc.
And second, the mass of the machine parts, and the fine thread of the
leadscrews means that you'll be cutting slowly, again a recipe for
less-than-stellar results... Been there, done that, still have the
2x6 rect tube<G>
(In fact, I might have some I could sell, if someone is interested in
trying the sherline setup I mentioned. It DOES work for Pcb's to some
degree--better than a std. sherline setup anyways-- and for other
things besides pcb's and is a great way to turn a 5000 mill from an
8x3 to a 6x8... A 5400 or 2000 will not see as greast an increase;
but the ntuaral choip clearing from the vertical cutting is still an
improvment) Maybe I'll put together a kit for this too?
Hope this helps,
Ballendo
--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> wrote:
> Jan, Dave, thanks for commenting.
>
> Dave, I re-read your post five times and to me it was a very
dramatic
> story.
>
> I know from your posts that you are exceptionally qualified on the
> subject. Since you have done so much work, have you considered
> writing down plans and selling them. That is exactly what John
> Kleinbauer.com does. Take a look here:
> http://www.littlemachineshop.com/products/product_view.php?
> ProductID=2353 He sells plans for retrofitting a minimill, you
could
> have your own plans and you already have a yahoo group with great
> following.
>
> I used to have a T-tech that I should have kept for drilling. Now I
> have a Sherline 5000 that has a very long (7") X but very short Y
> (3"). That is way to short for boards I have in mind. I am looking
> into moving a Z-column behind the base. I posted that message on
CNC
> SHerline butit did not post it- I don't know why. Does it make
sense
> to place that Sherline on a thick and larger base and relocate the
> base of Z behind the original base? That would gain another 3 " and
> overall would work for me. Maybe you heard of that kind of
> modification. Sherline is an unusually rigid machine and I can feel
> it would be great for PCBs. Mike
>
>
>
>
> --- In Homebrew_PCBs@yahoogroups.com, "Dave Mucha"
<dave_mucha@y...>
> wrote:
> > --- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...>
> wrote:
> > > Dave, thank you for commenting. Have a look at this:
> > > www.easgmbh.de/images/Bgs60.jpg I think it was about 1200 euro.
> > >
> > > How hard would it be to make something like that? Parts seem to
> be
> > > mostly from a catalog. I don't see the Y-axis motor, maybe it's
> > > hidden behind the Z... ALso, how to contact Ballendo off list
so
> I
> > > don't irritate Stefan for the n-th time? (is dollar sunken so
> LOW?)
> > >
> > > Mike
> > >
> >
> > Hi Mike,
> >
> > I know and use G-code so an X/Y would be much faster for me to
get
> up
> > to speed with.
> >
> > I just ran thru a design for a 12 x 12 x 2" work envelope
machine.
> > it would use $150.00 worth of mechanical parts in the form of
> > aluminum and ground shaft and such. I figure another $100 for
the
> > electronics, so before I look at steppers and lead screws, I'm up
> to
> > $250.00.
> >
> > Using all-thread and surplus steppers would up the cost to around
> > $300.00 for a unit that is pretty good. Using ACME screws would
> not
> > all too much to the cost, but the big factor would be the machine
> > time to drill and tap all the holes to make the unit stable in
all
> > directions.
> >
> > Since I don't have a milling machine, it would cost me a couple
> > hundred $$ to have all the holes drilled and tapped to get that
> good
> > alignment that would be needed to eliminate poor fits.
> >
> > Then assembly of the unit would be a few more hours.
> >
> > IF (really big IF) all the motions went perfectly and I got a
great
> > deal on the machining and all the parts fit flawlessly I still
> would
> > be over $500.00 for the machine.
> >
> > The head on the Z axis is still a question. There are more than
a
> > few ways to actuate that, but since I'm mostly concerned with
> > drilling, it is of little importance.
> >
> > I did a design recently for a proposal and used ballscrews and
> linear
> > rails and the cost was close to $2,000.00 for a 12 x 18 x 4 work
> > envelope.
> >
> > If I had access to a milling machine, I would be done already,
but
> my
> > access retired last year and moved on to those things old
> machinests
> > do when they retire.
> >
> > I had thought of trying to barter with someone who has a mill for
a
> > machine, but that is hard to do. Most people who have a mill
don't
> > need PCB's and already to the machining.
> >
> > My Neighbor has a Bridgeport but it is in stoarage as he has no
> place
> > to put it. When that gets mounted, then I will make my machine
as
> I
> > can trade machining time for use. He's an auto mechanic and I
> spent
> > 5 years working in a machine shop.
> >
> > Dave