Skip to main content

Topics

This section allows you to view all Topics made by this member. Note that you can only see Topics made in areas you currently have access to.

Topics - teletypeguy

1
Tools of the trade / Making Chassis Overlays with a Cameo
After finally getting stencils working with my Cameo cutter, I wanted to try making chassis overlays.  Over the years I have spent good money getting polycarbonate overlays (7 to 10-mil) with rear silkscreen for connector identification and such, a flood-fill color, backed with 3M 467 adhesive, and die-cut with all the openings and outer shape.  It's a great way to allow multiple overlays to work for different products using a single chassis with a flexible common hole pattern, but pricey.

So I have this Cameo that can cut up to 24x12, and an inkjet that can print up to 11x17, and I have found inkjet-printable adhesive-backed plastic sheets in up to 11x17 -- can I make my own overlays?

The Cameo's included Silhouette-Studio program let me get the job done.  First off, Silhouette-Studio has lots of oddities, but it also provides some important "drawing" tools (for drawing your cut lines, that is) -- not just the basics like line, polygon, rectangle/square, and ellipse/circle, but the ability to copy-and-paste-in-front (exactly in front, not offset a bit), and then move the object precisely.  I use this a lot for arrays of connector holes.  But besides just letting you define a cut pattern, they have a feature called "Print-n-Cut."  Now this was designed so crafters could print a pretty picture of a unicorn or something, print it from sil-studio to a printer (maybe on a thin cardstock paper), ADDING REGISTRATION MARKS, then define a cut layer (which for many projects is just an outside edge), then load the printed item on the mat, and load it into the Cameo.  But you are not limited to just an outside edge.  In fact, I found a lot of railroad model makers printing and cutting intricate window frames and stuff.

Here's the important part:  the Cameo has an optical sensor near the knife, and it can find the registration marks on the thing you just printed/loaded, and get precisely-oriented for its cut pass.  You then tell it to cut, and bada-boom-bada-bing, it makes nice.

The Print-n-Cut adds a step to the process of creating your cut file -- first, you open a jpeg (or other bitmap) file.  Then you add cutlines as needed.  You add registration marks, print it out, and so on as previously described.  So for my bitmap file, I wanted the text for my connector definitions, and thin lines where my cuts were to go.  My artwork came from Adobe Illustrator, but I could not export a jpg with decent resolution.  I could, however, open the .ai file in Photoshop, and save-as a jpg.  I used 600 dpi (lower-res was not as clean, and higher res made sil-studio hang).  I had all of my text plus hairlines identifying where to cut.  This worked great for an 8.5x11 sheet but I also wanted to do 11x17 -- this also made sil-studio hang on file open (probably a bug, since their workspace is 24x12), but I could fake it out by dividing the image in two in photoshop, opening them both in sil-studio, copy one, paste into the other, align visually, group, and then I had my 11x17 image ready to go.  Clumsy, but whatever gets the job done.

I opened my image, added reg marks (you need to avoid printing in keep-out areas), and started adding the cut lines for the hole pattern and the perimeter of the overlay.  I put as many overlays on a single sheet as I could fit.  After the hole pattern for one is done, select the whole group, copy, paste-in-front, move, repeat -- it was pretty easy.  There were a few annoying things along the way but I am happy with the results.

The inkjet material I used I found at texascraft.com -- WVF1117KH white waterproof adhesive-backed vinyl 11x17 sheets, $1.44 ea in 100s (but they also sell 10 packs or single sheets).  It is also available in 8.5x11.  They also have laser vinyl, but my laser does not do 11x17, nor does it do color, and I want to try color overlays next.  This stuff is about 4-mils thick including adhesive, which is a bit flimsy, so after printing a sheet, I stuck it onto a second sheet for added thickness, before cutting. Enough talking:

In Sil-Studio, the black is the jpg text, and the red is the cutlines I added.
[attachment=3]

Some settings.
[attachment=2]

Printing it on Big-Brother.
[attachment=1]

Loading it the Cameo (on the optional 24x12 cutting mat)
[attachment=0]

to be continued...
2
Tools of the trade / Cutting mylar stencils with a silohuette cameo
Hey folks:

I saw this note from Laszlo buried in a pnp thread and wanted to start it as a new topic:

Quote
László Monda says:
February 21, 2013 at 11:36 pm
Instead of messing around with the solder paste dispenser I highly recommend you picking up a Silhouette Cameo.
So far I’ve had wonderful results with it. Created a short video and some pictures of the action at https://plus.google.com/photos/10643536 ... 0625134033
Also take a look at
http://www.idleloop.com/robotics/stencil/index.php https://github.com/pmonta/gerber2graphtec
http://hackaday.com/2012/12/27/diy-smd- ... ft-cutter/

Yes Laszlo, I too was impressed with the fine-pitch (even 0.5mm looked workable) stencils that Cathy was cutting with her cameo:
http://www.idleloop.com/robotics/cutter ... hp#stencil
http://www.idleloop.com/robotics/stencil/

I peeked at your pics/vid as well, but could not see close up -- how fine a pitch did you cut?  What were your cut settings?

I just got a cameo for making stencils as well, and fired it up today with a sheet of mylar overhead transparency film.  I used the eagle ULP file linked from Cathy's site, which very nicely extracted a dxf file for the cameo to open.  Sadly, I was quite disappointed in the resulting stencil, and think perhaps I got a bum machine.  I used the same settings Cathy used (blade depth 1, speed 1 = slowest, thickness 33 = max-force).  Tweaking these didn't change my two fundamental problems:  1)  a square shape is actually a right-leaning parollelogram, and 2)  the straight sides are actually bowed out.

Here is a pic of simple 100-mil and 50-mil squares:
[attachment=3]

A 50-mil pitch SOIC and SOT23:
[attachment=2]

A 0.65mm (26-mil) pitch TSSOP:
[attachment=1]

And a 0.5mm (20-mil) pitch HDMI connector with SOT23 for reference:
[attachment=0]

Am I doing anything different than you?  Any thoughts appreciated.
thx,  gil smith