Details

Written by Simon Arthur

Parent Category: Big Blue Saw Blog

Created: 11 March 2016

When we last took a look at the lighting situation here at the Big Blue Saw secret underground base, I had created some translucent P95 acrylic lighting diffusers to cover up our bare CFL bulbs. They were nice, but I had a burning desire to make something even better. As I noted before, I really liked the way the light caught the edges of the lighting diffuser. So of course, I wanted more edges. The original design was a bit difficult to install because it was hard to keep the hooks straight with only one hole per hook in the diffuser, so there was room for improvement there as well.

Adding more edges meant expanding into the 3rd dimension. I had in my head Big Blue Saw themed diffusers like before, but stacked and wrapping completely around the bulb to keep it hidden from more angles. I realized that by using a  slot technique, I could assemble the flat laser cut diffusers into a multi layered shade.

The next step was to fire up Inkscape and get started. I experimented with several designs until I came up with one I liked. Below are the risers. They each contain 6 evenly spaced slots to hold the saw-shaped diffusers. Each has two holes on the top to hold the mounting hardware which will keep the whole fixture in place. The risers are about 9.6 inches in total length, with approximately 6.3 inches between the top and bottom saw pieces.

The next step was to design the 6 Big Blue Saw themed lighting diffusers. I used the same outer shape as on the previous diffuser project, but with a center hole in each one 6.7 inches in diameter to make room for the light bulb. These diffusers ranged from about 9.8 inches in diameter up to about 15.8 inches in diameter. The plan was to put the smallest on the bottom and the largest on the top, that way every piece would be visible since you're typically looking at this from underneath (thanks to Julie Simancek for pointing that out).

 

The bottom piece was different from the rest, though. It needed to be solid on the bottom to completely hide the bulb. It also needed to keep the risers in alignment. I created a set of slots on the bottom piece running in a circle to keep the risers in alignment while still obscuring the bulb. The slots are also decorative and show more of the edge effect from the lighting.

The whole design was then laser cut from 3 mm thick P95 acrylic.

Assembling the shade was a lot more work than I thought it would be. I actually cracked one of the risers on my first attempt. I eventually figured out that the saw diffuser pieces had to be supported while the vertical risers were slid into place, otherwise too much stress would be placed on the risers. So I slowly built up the shade from the bottom, supporting the diffusers with some miscellaneous parts from around the shop, and clipping the first riser in place to each diffuser.

Having run out of small waterjet cut parts, I switched to Keva planks for my scaffolding. Below is the finished scaffolding with the riser clipped into all 6 diffusers.

If I did this again, I would add slots to the saw pieces to help keep them in alignment while the structure was assembled. I'd also consider laser cutting some stands which could support the whole structure while I assembled the shade.

With the scaffolding and the first riser in place, I slid the risers in and squared up the whole assembly. The finished weight was just over 2.5 pounds

Now the piece was ready to install. I made a few clips from copper wire and ran them through the holes at the tops of the risers. This allowed me to attach the whole shade to the lighting fixture.

Do you have any ideas for improving this design? Let me know in the comments section.

Details

Written by Simon Arthur

Parent Category: Big Blue Saw Blog

Created: 08 March 2016

We're not sign specialists, but we do make a good number of signs for various clients, including business owners, interior designers, architects, and builders. See our gallery of signs and stencils for just a taste of the many signs we've helped create over the years. When you're developing your own custom sign, it's important to think about how the sign will be mounted onto the wall, or wherever you need it to be.

You've got a lot of options for mounting a sign. This includes hanging with wire and edge-grip methods. A range of specialty hardware exists to help you out. Rowmark makes an entire line of hardware just for hanging various types of signs in various locations. You can also search the McMaster-Carr website for "panel standoffs".

The most straightforward way to mount a sign is to fasten it to a wall through mounting holes using screws or bolts. It's crucial to make sure that the hardware you're using can hold the weight of the sign.  You wouldn't want the sign falling on some unlucky person who happens to be standing by. For example, when using drywall anchors, check their load rating. If you're unsure about how to mount it securely, it's best to get a contractor or someone who knows what they're doing.

In general, we recommend including mounting holes when designing a sign. This is the easiest and most flexible way to allow a sign to be mounted to a wall. In the photos below, we've mounted an Inkscape logo sign to the wall through its mounting holes.

 

 

This holds the sign pretty well. The mounting holes and potentially the hardware used to mount the sign are still exposed, however.

A better approach might be to use decorative hardware to cover up the mounting holes. The thumb screws in the photo below have a fancy knurled edge, black coating, and a smooth machined face. They also have big enough heads to cover up the mounting holes. They are available from McMaster-Carr in various materials including black oxide coated steel, stainless steel and brass. The ones in this photo are part number 90200A547.

 

The photo also shows several aluminum spacers (McMaster-Carr 92510A767). These are used to offset the sign from the wall and give it a little more depth. This works well with a sign that has internal cutouts, as the shadows the holes cast make the design "pop". When using thinner material, this is an easy way to add some depth to the sign without adding weight or increasing the material costs or cutting time. Even with the 1/4 inch thick aluminum used here, the extra depth helps the appearance.

Photos of the sign mounted with decorative screws and standoffs are below.

 

Do you have a great sign you've created with Big Blue Saw? Let us know!

Details

Written by Julie Simancek

Parent Category: Big Blue Saw Blog

Created: 26 February 2016

With greater availability of digital technology, we have seen an increased demand for waterjet cutting jewelry components. This is the first part of a two part article on how to use Big Blue Saw’s waterjet and laser cutting services to get the best components and parts for that new jewelry line you are thinking of creating.

It all starts with a drawing

Firstly, we will need a drawing of your new part. Personally, I like start out in my sketchbook, and fiddle around with construction paper until I have a few shapes that really catch my fancy.

 

Now it’s time to get these digitized. I could scan in my sketchbook, and then try using a tracing program to trace these shapes, but that would give me shapes that are imprecise and a little wonky. Wonky doesn’t work for stone settings or creating parts that fit together well. So drawing it out in design software is the way to go.

 

 

There are a whole slew of free and paid CAD programs out there in which you can design your pieces. Some are easier to learn than others. The more the program is focused on engineering clients, the harder it will be to pick up and learn- however once you have something designed in say, Solidworks, all of the pain pays off. The settings I design in Solidworks can actually exist in real life and they keep their dimensional constraints. Which is a fancy way of saying that I can dictate exactly what size I want all of the elements in a part to be. No designing it and then realizing it won’t fit my stone in real life.

If you have and are familiar with Adobe Illustrator, you are already a step ahead of the game. Illustrator can be used to create vector images and DXF files. The difference between a vector image and your familiar jpeg, is that you can scale up or down a vector image without losing detail or having your curves devolve into choppy pixel soup. From Illustrator, you can save your drawing as a EPS file or get a DXF export plugin from PluginsWorld.com, and export a DXF file.

Don’t have Illustrator? There are also a lot of free CAD programs out there that you can download and use for your drawing. Click here for a list of our recommended CAD software.

Get it all down in black and white

Essentially, all the cutter needs to know is what is the part and what is waste. This is similar to when we were kids and cut snowflakes out of construction paper. You want your part to be easily defined as a black and white outline or silhouette. Like this:

Or this:

 

Plan around the limitations of the cutting tool

In the drawing above, two of the rings have 1 hole and the third has two.

The waterjet can’t make holes that are perfectly round that are less than 0.1”, and in the 0.04” to 0.09” range, any holes that it does make are oblong and not perfectly round.

The laser cutter can cut holes that are smaller than that, but the plastic can get really melty and ooze into the hole it just cut.

So for the sake of making sure that every hole I cut will be accurate, I only have the machines cut the holes that are 0.1” and larger. All the smaller holes you see in my examples are drilled out with a drill bit in my Foredom rotary cutting tool.

Interior corners can also be tough to get accurate as well. If the angle of the hole in a part is smaller than the kerf of the waterjet or laser cutter, it will cut that corner a bit short.

 

So in this drawing, we have a interior corner that is sharper than what the waterjet can do. Instead of trying to cut that tiny bit and messing up the corner, it will round the hole off where the blue line is.

When I’m designing for these kinds of cuts, I usually use the Fillet tool to smooth down these interior corners, thicken up connections between areas, and create smooth transitions from one side to the other. Software like Solidworks will allow you to create exacting designs where tiny tips of stars touch other thin webwork designs exactly in the center with extreme precision, but that doesn’t mean that when your part is cut from the material that it will be as perfect as you designed it. Super thin areas of webwork design get blasted into oblivion in the waterjet, and the laser cutter will cut things so finely that even gentle handling after cutting makes it crumble. Be sure to keep all of the parts of your designs thick enough to withstand general wear and tear.

So how thin of a strip can you cut with the waterjet? Well, that depends a lot on how thick your metal is and how supported it is. Cutting a lace pattern out of sheet metal would be cool, but you’ll want to scale the design up till the individual lines in the pattern are 0.09” or larger. Otherwise the water stream is going to blast the material away and end up doing waterjet air guitar in the pattern you’ve designed. Waterjet air guitar doesn’t give us pretty pieces to work with.

You might be able to cut a few thinner lines if they are surrounded by solid parts. You could cut something like this and have it work out:

Those two thinner strips in the middle are connected on both ends and supported by the thicker edge on the pendant. What wouldn’t cut well would be something like this:

Trying to cut that could work out one of two ways. One, the strip down the middle is too thin and gets blasted into oblivion under the water stream. Two, because it is unsupported, it can start to vibrate like a tuning fork under the pressure of the water stream. That wiggle will make the cutting path wiggly- and I’ll end up with a mess instead of the pendant I wanted.

If that was my design, and I needed to cut a bunch of these for a line of jewelry, I would make my CAD drawing look like this:

Then after cutting on the waterjet, I’d cut the bottom of the strip off with my jeweler’s saw.
 

Checking your corners and hole sizes.

A quick easy way to check your part to make sure that it will cut well is to create a hole and corner tool. So for checking hole sizes, draw a circle that is 0.1” in diameter and change the outline to something easy to see like orange. Now use the selection tool to drag the orange circle over the holes in your piece. If they fit inside the circle, they may cut oblong or get messed up.  Same goes for interior corners, draw a circle that is 0.04”, and drag it over all of the interior corners. If the corner is smaller than the circle, then the waterjet is going to stop short of going all the way in. Which means that you’ll need to decide if you want to get in there with a file or jeweler's saw post cutting.

What about shapes?

If you’ve ever looked at the costs involved in getting a custom stamping die, you know why most jewelers only own a circle cutter. Fact is, you can use the waterjet and laser cutter to blank out a ton of shapes in metal and plastic, but there are some limits to this. Metal shapes that are smaller than a dime run the risk of getting blasted away the same way tiny strips of metal do. They also will have to be tabbed to a sheet so that they don’t fall into the water tank on the waterjet. Here is a link showing what small waterjet cut features look like. The little “V”s at the top of the parts are the tabs. If your parts are tiny or have a bunch of rough edges, there may not be a good place to put or they may obstruct the perimeter of the part enough to make usability questionable.

That said, if you need 100 triangles, 40 kitty pendants, 20 new bangle bracelet bands, 60 ring bases, and 12 earring dangles; the waterjet can cut them all out of the same sheet of copper or brass in a single sitting. With no fees for custom machining separate stamping dies for each shape.

Can you cut precious metals and sheet I send you?

Usually we can. There are some brittle elements like gallium that shatter in the waterjet, so we can’t guarantee materials that we haven’t cut before. We’ve tried cutting glass, and it has always shattered, so we won’t take that in. There are some metals like gold and platinum group metals where the drops and lost sweeps negate the benefits of waterjet cutting, so plan your profit margins accordingly.

If you can cut it with your jeweler’s saw, it should work in the waterjet. Our laser cutter doesn’t have the muscle to cut metal.

We also can’t do same line cutting. We do have some kicking nesting software that will get you the most mileage out of your sheet though. If you are looking to have me cut your sheet, email me at info@bigbluesaw.com and we’ll talk about the particulars.

The ideal parts, cut just the way you want them.

So what works the best in the waterjet? Bigger components that would take a ton of time and skill to saw out with a jeweler’s saw. Chunky ring bases, statement necklace bibs, cuff bracelet blanks, bangle bracelets, shapes for pendants and earrings all work really well when they are designed with the waterjet’s abilities in mind. The accuracy of the machine means that cutting geometric shapes is a lot less of a hassle than when doing it by hand, and the edge clean up for a waterjet part is less than for a hand sawn piece. So get designing, and stay tuned for round two where I show off some examples and talk about finishing techniques!

Details

Written by Simon Arthur

Parent Category: Big Blue Saw Blog

Created: 19 February 2016

Elsewhere on the website, I've shown how waterjet cutting and laser cutting make it easy to create simple signs. Most of the signs we do are in a single layer, with the figure being either positive space (solid material) or negative space (holes). Read more about the variations on this kind of sign.

Occasionally, a customer will need something a little more sophisticated. Their logo, symbol, or seal will have many distinct elements. I'm going to walk you through how you can create one of these types of signs using the reverse of the Great Seal of the United States as an example. You probably recognize this design from the back of the $1 bill. The design was created in the 1780's and is used on official US government documents. The Wikipedia article on the Great Seal has more information about the symbolism and meanings of the mottoes "Novus ordo seclorum" and "Annuit cœptis".

Thanks to Wikipedia we have a nice vector version of this design. Here's what it looks like when you open it in Inkscape.

 

Note that in Inkscape's outline view, we can see something a little different. Many of the pieces that appear to be one thing in the design are in fact made of several elements. The eye is created by using clipping and in the outline view doesn't look much like the regular view at all. I scaled the design to 11.5 inches in diameter so that it could be cut from a 12 inch wide sheet of brass.

 

So this needed some cleaning up before it was ready to be waterjet cut. Changes include:

• Deleting the plants in the foreground
• Removing several entities that were only there to provide gradient colors.
• Redrawing the outer circle to be made as false bevels [link] and still look like the original design.
• Eliminating the shadow layer from the letters at the top. These will be 1/8" thick metal and will really cast shadows.
• Redrawing the burst around the eye so that it's practical to waterjet cut.
• Changing the eye in the triangle so that it can be cut as one piece. The fill tool was essential for this.
• Fattening up the lines in the pyramid bricks, and making bridges so that it could be cut as one piece. The bridges were placed at the bottom of each layer so that it looks like they should be there.
• Adding an extra layer behind the eye so that its details wouldn't be lost in front of the sunburst.
• Modifying the banner so that it is one continuous outline. Again, the fill tool was essential for this.

 

Here's the outline view:

 

 

Next, the parts were split up by material: most parts  were to be made from aluminum, or from stainless steel. These two methods are a slightly different color and provide contrast for pieces that are directly adjacent. The border and sunburst were done in brass for maximum impact. The backing piece for the eye in the triangle was black acrylic. All parts are 1/8 inch thick.

 

 

After waterjet cutting, it turns out that some of the details were a little too fine on the banner and lettering that appears at the top. You can see that many of the solid areas between letters on the banner were simply wiped out. The narrow areas from the letters at the top on the "A" and "P" also proved to be too thin.

 

I bumped up the size of these about 10%. I also carefully widened the bridges and other narrow areas to make absolutely sure that these pieces could be cut on the waterjet.

 

After waterjet cutting, all the pieces needed to be sanded to clean up any handling marks, mill marks, or overspray from the waterjet. Some pieces were tabbed together. The parts needed to be removed from their tabs, and the residual tab filed off.

 

 

The pieces as cut needed to be cleaned up to remove any waterjet overspray, mill marks, and other handling marks. Here's a closeup of the parts before finishing:

 

 

The smaller pieces like the letters, had tabs attached. The pieces could be broken off of their tabs by hand, but needed some additional filing afterward to completely remove the tabs.

Here's what the letters loked like after being sanded, but before the tabs were filed off:

 

After filing off the tabs:

 

Finally the whole thing was assembled and the layers carefully glued together using a 2 part epoxy.  If I make a sign like this again, I would use a clear epoxy or E6000 adhesive, rather than the opaque grey epoxy I did use. A clear adhesive is harder to see when it squishes out from the edges or accidentally goes where it's not supposed to. Here is the final assembled version:

 

 

What do you think of the results? Let us know in the comments.