- Parent Category: Big Blue Saw Blog
- Created: Saturday, 21 August 2010 00:41
- Written by Big Blue Saw Administrator
The data center where Big Blue Saw's main web server is hosted is soon to be no more. I'm in the process of moving everything to a new and better server at a new location. The final cutover is scheduled for this weekend, August 21.
I'm in the process of bringing up the new server:
Please let me know if you find any problems on the new machine. Please note that anything you do on the new server is likely to be wiped out when the changeover happens: comments, user accounts, uploaded files, and the like will all be deleted.
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.
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:
This will help ensure that you get the best results for waterjet and laser cutting