General Updates

I recently conducted an interview with Ray Russell, founder of RoPro Design, a robotics engineering firm. Ray talked about his robotics and prototyping work with RoPro, as well as the tools and techniques he uses to turn his customers' ideas into reality.

In this interview, Ray talks about how his production schedule doesn't match with a traditional machine shop's ordering process. This eventually led him to order from Big Blue Saw.

The typical waterjet companies around here have the traditional quoting system. where you send them a paper drawing, you wait 3 weeks, the guy contacts you with a formal quote and it's just way too slow. In 3 weeks we usually have robots designed and built.

He mentions some of the advantages to making parts using waterjet cutting.

With waterjetting, you can get arcs and things that you can't get in a billet piece.

Ray is a big fan of rapid manufacturing techniques and believes that it will help US manufacturing competitiveness.

The only we're going to compete with foreign manufacturing is through this high tech arena. There's no way we're going to be able to do it on the old style of intensive labor.

Download the whole interview in MP3 format.

Here's the interview with some images of RoPro Design's and Ray's work.

Skip ahead to 8:15 in the video to see video of the hexapod robot he built in conjunction with Carnegie Mellon University.

As many of you know, our online quoting system accepts both vector (DXF format or Big Blue Saw Designer JPX format) and bitmap (AKA raster) format files (like PNG or GIF) for automatic online quoting. When customers ask, I tell them that DXF is really the better format, and a raster file is really only appropriate where close tolerances are not required, such as for decorative applications. Let's take a look at why that is so.

Here's a typical part designed in Inkscape. It is a simple 5x4 inch plate with some 1/8 inch diameter holes in it.


When you export this file as a DXF, the holes turn out pretty close to being circular. The image below shows how the laser cutter will make those 1/8 inch holes from a DXF file exported from Inkscape.


Inkscape can also export a bitmap file as well. When you export the same file as a PNG and zoom in on one of the holes, here's what you'll see. Notice, first of all, that the image contains anti-aliasing (grey pixels), which, as mentioned in the FAQ on raster files doesn't work so well with our online quoting system.


The edges aren't well defined, so when we go to make the part on the laser, the system has to "guess" as to where to cut the part. Here's a diagram showing how the hole will be cut.


Finally, the following photo shows a closeup of one of the holes laser cut into black acrylic. As you can see, the hole has an irregular shape to it.


For many applications, the irregularities caused by using a bitmap file aren't a significant problem, such as decorative pieces or parts where a close fit is not required. But for maximum precision, it's best to use a DXF or JPX file.

If you are file with the limitations of using a PNG or GIF file, please read our FAQ on raster files first and make sure that your file is formatted correctly. In particular please ensure that:

  1. The file is formatted so that the solid parts are in black, with the holes or negative space in white.
  2. The edges are not antialiased in the file.

This will help ensure that you get the best results for waterjet and laser cutting

There's something really easy you can do to save money when you're ordering online from Big Blue Saw. I've mentioned it to many customers over the years. Here it is in one sentence:

If you have two or more parts that are made from the same material, combine all of your parts into a single file before uploading.

Let's take a look at how this might work. Suppose you have designed the two parts shown below, and want to purchase one of each. They're both going to be made from 0.25 inch thick 6061 alloy aluminum.



If each of the two parts is stored in a separate DXF file, you'll have to upload them separately. When you do this, your total cost will be $86.10 for the first part, and $81.10 for the second part, for a total of $167.20.

But take a look what happens when you combine both parts into a single DXF file, using your favorite CAD or design software as shown here.


The price comes down to $89.60 for both parts. That's a savings of $77.60, or over 46%!

Get an immediate quote and order now by uploading your CAD files!

Save Even More by Getting the Latest Discounts, Sales, and Design Tips on Big Blue Saw's Mailing List

Email Address:


Big Blue Saw now has a new RSS feed, courtesy of Google Feedburner. Everyone using the old RSS feed is encouraged to switch to the new feed URL:

The new location will automatically function as a podcast feed, so you can easily download audio and video from Big Blue Saw.

Our old feed URLs are eventually going away, so it's probably best to just switch now.


I've told this story many times to customers, friends, and business associates, but I've never posted the full story here on the Big Blue Saw website itself.

The story really begins in the mid 1990's. Marc Thorpe was a a guest at the Dragon*Con science fiction convention. He was showing videos of an event he had produced in San Francisco called Robot Wars. It featured robotic gladiators with names like The Master and Thor fighting to the death in a hazard filled arena. Robot Wars was a game of destruction and brawn, true, but it also featured elegance and beauty as well, and required brains to win. As a bonus, Dragon*Con had been running a fighting robot of its own for several years: Robot Battles. In summary, my mind was blown and I was hooked on making fighting robots.

Being a computer programmer, the closest I had ever come to building my own robot was making a mutant R2D2 with the Star Wars Droid Factory when I was a kid. Eventually I became interested not only in the robots themselves, but in the tools and techniques I needed to make them.

I eventually learned that many of the things I wanted to create were well beyond the capabilities of my simple home workshop. Often, I found myself reaching out to fabrication and machine shops to create the designs I had envisioned. Dealing with these types of business was incredibly unsatisfactory. Their sales teams, such as they were, usually consisted of one surly fellow who seemed like he desperately wanted to be anywhere but his rusty office chair. I would find myself calling repeatedly to check on the status of an order or even just to get a quote. E-mail communication was non-existent. Most commonly, I found that they simply did not want to deal with a hobbyist ordering just a handful of parts.

One incident in particular sticks out in my mind. I contacted one of the largest machine shops in Georgia to weld a robot frame for me from my pre-cut parts. The finished piece 3 weeks late and the welding work was shoddy. To add insult to injury, I later learned that I was charged 4 times the going rate. When I picked up the part, the man who wrote up my receipt had to ask for my help spelling the name of the city where the shop is located.

I knew there had to be a better way to get custom machined parts, but I couldn't find it.

In 2005, I was facing a life-changing prospect: becoming a father for the first time. I had been making a living as a freelance computer consultant for the past 5 years, taking on clients as it suited me and making enough to earn a good living. I loved the variety of the work and the ability to take long chunks of the year off if I chose to. But I knew, in order to create a stable future for my family, I had to do something that was independent of both the labor market for freelance software engineers and my ability to work billable hours. I'm not really cut out for corporate jobs; I get bored just thinking about it. I know, I thought, there's nothing more secure and stable than starting a new business; that'll bring in the steady cash! (No, it didn't work out that way, but more on that in a moment.)

Graphic from an early version of the Big Blue Saw website

Based upon my experience building robots and my background developing software for the web, I decided I could make a website that made it easy for people to order high-quality parts online, custom made to their specifications. There would be as little friction as possible in the ordering process, making it as easy to order 1 simple part as it is to order 1000 complex ones. My eventual goal was, and still is, to allow engineers, artists, hobbyists, crafters, designers, and makers of all kinds to turn a concept or idea into a real thing.

There were (and still are) a few websites out there that attempt to make the whole process of ordering custom machined parts easier. For example, the first one I looked at in 2005 required you to download and install a Microsoft Windows-only client program just to get a quote. The prices they gave for waterjet cutting when I started Big Blue Saw were 2-3 times higher than what I charged (and still are, the last time I checked).

After having created the great way to order waterjet and laser cut parts online, I was thoroughly shocked that I didn't get an immediate flood of grateful customers. Instead, it's been a slow and deliberate process of regularly improving the website, making buying from Big Blue Saw more pleasant, and building relationships with customers. I still take on consulting work from time to time to make ends meet. But sales keep going up, and this year is on track to be the most profitable ever. My wife has been very understanding, even when I need to work long hours or when the sales have been slow. We now have two little rugrats.

Big Blue Saw continues to grow because of you, our customers. Without your visions for what we can do with raw material, Big Blue Saw wouldn't exist. Thank you.