>
> The problem with feeding bare copperclad is that it has to bridge two
> of the knurled sections, so a large piece is required each time I
> think I am getting excellent back and forth feed by using two o rings
> on the top shaft, opposite the two knurled sections on the right. You
> are right, however, that the rubber does not help since it is the
> bottom roller that does all the work. Perhaps I'll put the plastic
> back on. A nice mod would be to have the whole length of the bottom
> roller textured so the copperclad could be any size.
>
> Hmmm, the top roller is spring loaded, so an easier approach might
> be to use larger diameter plastic rollers on the top roller opposite
> the textured areas, and use a thin, fixed size carrier. The
> copperclad then sits on the carrier, held by double stick or even
> registration pins, which would make double sided a snap. You could
> even put in guide rails on each side.
>
> If you are going to route the traces, I think some work has to be
> done on the Z axis. Perhaps a stronger return spring and a LOT more
> current through the solenoid. I think the dremel is fine for drilling
> holes, but I'm not too keen on it for milling traces. Perhaps this
> motor would be better
> <http://www.amazon.com/Spindle-Zen-Toolworks-Machine-Holders/dp/B0039HCK6S>,
> though it is $90 USD.
>
> I like this machine as a reasonably well constructed XY table. It
> could be used as a laser cutter, a plotter, pcb drill, light duty
> router, etc; I think it might do better by converting it to a
> standard cnc using Mach3 or some free software, but it's pretty neat
> as it is! BTW, here is a datasheet on the PM42S-096 steppers it uses
> <http://www.nmbtc.com/motors/part-numbers/Permanent-Magnet-Stepper-3.75-degree/PM42S-096/4864>.
>
> Mark
>
>
>
>
>
> At 12:43 PM 9/15/2012, you wrote:
> >Great topics!
> >
> >One thing to know is that the Z-axis is just a solenoid with a
> >spring return. A solenoid's force (-Z in this example) is
> >proportional the the electrical power applied and how clost the soft
> >iron slug (armature) is to the end of travel. This last I believe
> >varies as the square of the penetration distance so the further you
> >can get the slug to penetrate the solenoid, the higher the force. I
> >measured between 4 and 7 volts on the solenoid, depending on
> >"Thickness" selected. If you raise the inserted holder (be it for
> >the swivel blade, pen, Dremel extension handpiece, etc), the
> >downward force will increase until the solenoid bottoms out - with a
> >metallic 'click'.
> >
> >Not sure what's hanging up in your machine to cause it to skew.
> >Obviously something mechanica I'd guessl. In my hopefully educated
> >opinion, I would NOT remove the plastic rollers as
> >rubber/elastomeric ones will not exert enough pressure on the PCB.
> >Also, of the two metal rods that pinch the PCB, ONLY the bottom one
> >is driven so you will get little/no torque/force out of the top one
> >or anything you mount to it. The downward spring tension on the top
> >metal rod and rollers, pushing the PCB into the bottom metal rod's
> >knurling (grooves), is plenty to grab the material, IMHO. The
> >purpose of this assembly is to force the material against the
> >knurling on the bottom metal rod, the only thing transfering force
> >to the material. Chosing "Enhanced Cut" will roll the PCB in and out
> >(Y direction) wo hopefully wear a grooved path in the bottom of the
> >material for additional friction. I have not needed this in the
> >past. The copperclad against the grooves in the metal rollers gives
> >you the best non-slip friction possible, in my opinion. I believe
> >rubber will encourage slipping.
> >
> >I think on my web site, I recommend 0.5 oz copperclad or thinner. I
> >have had difficulty cutting through 1.0 Oz. I think Digikey sells
> >this. Try Think and Tinker as a source for high speed carbide
> >router, mill and drill bits. For the milling bits, I've had good
> >results with the 30 deg ones. If you're trying the swivel knife
> >approach, by all means go the 3rd party carbide blade route as the
> >standard steel ones will wear out quickly. I have also found a
> >source for paper backed copperclad instead of fiberglass, possibly
> >extending the life of the blade. More later.
> >
> >I have tried converting the Gerber 274x files to svg and purchased
> >the Designer Pro addition of the software but I'm not sure this is
> >required as I'm getting great results with their raster-to-vector
> >TRACE app included. I'd like to hear more if you get better results.
> >Also, I've learned from Silhouette Support that very closely spaced
> >vector objects are drawn as one, possibly compromising small traces.
> >This normally doesn't affect paper cutting other than being able to
> >cut a lot faster through highly detailed, closely spaced
> >vectors. They have offered to make a firmware change for "us". What
> >a great support team!
> >
> >Mike
> >
> > >I just received my Sillhoute Cameo and have a few first impressions.
> > >Mike, if you could chime in here I'd appreciate it because I can't
> > >seem to achieve your results.
> > >
> > >1 - I cannot get a pcb to track through the machine accurately. The
> > >cutter seems to hang the board up so that it feeds irregularly,
> > >skewing sideways back and forth as it goes in and out of the machine.
> > >This seems to be true whatever speed I select.
> > >
> > >2 - Most of the tracks I get are not completely through the copper. I
> > >am using the highest setting on the cutter.
> > >
> > >I am using Gerbv to convert gerber files to svg, then importing the
> > >svg files using the "Designer Edition" of the Sillhoute software. It
> > >seems to work well, but the feed problems make it hard to tell if
> > >everything is accurate. I ordered a pen holder for the machine, so I
> > >should be able to use it as a plotter to see exactly what is happening.
> > >
> > >The machine looks like it would be very easy to modify to feed copper
> > >clad reliably. All it should take is putting a few o rings on the
> > >shaft for friction and removing the plastic rollers. Hopefully I'll
> > >have time to take it apart over the weekend.
> > >
> > >Mark
> >
> >
> >[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
> >
> >
> >
>