I needed an easy pivoting arm setup so that I can test an accelerometer with the Arduino and in the process figured it would be a good time to rig something up to hold a laser for some laser scanning. I’ve been wanting to set something up for a nice slow and controlled laser movement for a couple of years now and this project presented me with a great opportunity to not only get some work done for a current project but also to take care of an old to-do.
Using some Lego Mindstorm pieces I quickly rigged something up, after several iterations of course, that I have hooked up to a geared stepper motor. I have it wired through Sparkfun’s easy driver and get the action I want. Very slow and controllable. I’ll have to calculate the gearing later to control the angle of travel but for now I have the speed and I have the control. A good start.
Seasons are changing and the rain will soon be more frequent around here. With this in mind I cut the parts for this doghouse today on the cnc machine to help keep Lola, my hairy friend, more comfortable when she is chilling outside. The fellow who built this CNC machine has also asked me to make a video for him so I’ll be checking a couple of things off of my to-do list today. I will also lay out in a simplified manner the steps involved in getting a project like this from the 3d space of the virtual world to the CNC machine and eventual use in the real world.
This PDF is a user friendly 3d model of the doghouse. Once it loads, you should be able to manipulate the model with your mouse. Rotate, Pan, and Zoom are all right there in the mouse. Click, hold, and drag. Play around with it and you’ll get the hang of it.
To start most projects like this that are made up of interlocking parts I create an exact model in a 3d parametric modeling program called Solidworks. The model is built in a way so that should parameters change, modifications can be made to one part and the other parts associated with it will update accordingly. Exchanging my Rottweiler for a Pitbull is a good example of something that brings about an unforeseen design change, in this case resulting in a smaller door.
This little doghouse is made of 15 different pieces. In Solid works, once the design is settled on and the model created, it is possible to create one large drawing that contains all of these parts, side by side in virtual space, as if they were all laid on the floor in front of me. It is this plan view that is used in the CAM program to create the tool paths that will be used by the CNC machine.
This is a screen shot from the CAM program I use. I imported a CAD drawing from Solidworks and it is with this program that commands are generated for the router. Things like which side of the line to cut on, how deep per pass, in which direction, how many inches per minute, rpm of cutter, etc. The layout of the pieces to be cut is not automatic. Something like this can be managed manually, moving parts around for the best fit.
Once the tool paths are generated they are turned into a code that basically controls the revolutions of each of the motors involved with the 3 axes of the CNC machine. Each revolution or fraction of a revolution is turned into linear motion in each axis. Simultaneous movement on 2 or 3 axes results in a 2 dimensional or 3 dimensional curve.
This wikipedia article should give you a general idea what a CNC machine(router) is :
In my experience, I find that these types of machines excel in creating very accurate pieces. Cabinets or parts for a roll bender or this origami doghouse (not really origami, I know, but it has a nice ring to it) all benefit from the accuracy that this type of operation can produce.
Here’s to taking care of man’s best friend! CHEERS!
Lately I’ve been making some curved parts in aluminum, wood, steel, and today in some Richlite. Towards the end of the day I realized that it would be a good opportunity to create a video to share this procedure. The tricky part is the curve, really. It is possible to scribe around the curve OR create points to average the curve into and then, with a flexible ruler, connect the points on the workpiece. The latter is the Mucho Mas Mejor option!
As I was laying this out next to the CNC machine it got me thinking how easy it would be to create a very accurate template and then then digitize it by using the same principle of averaging points out on a curve and getting them output into a DXF file for cutting in some more difficult material. Would use a pointed bit or laser pointer in the router and then create and log points in a grid of spacing that would meet the tolerances required by the job. CNC lasers, water-jets, plasma tables, routers, or milling machines could all take these accurately located points and cut the piece required out of a variety of materials. Stone, Steel, Aluminum, Wood, Plastics, Unobtanium, and on and on goes the list. This would be an excellent way to close the circle of the design and construction of a very organic shape that has many parts created by hand but needs to have other parts cut that fit tightly to these organic shapes and at the same time can fit into the mechanical side of the design. Would still need to template, and would do it in the same way that is shown in the video, A bridge of sorts. Anyhow…that’s for another day.
I started this island a couple of years ago as a part of a larger project . At the point of this writing I am fitting the four cooktops and their wiring and mechanical dependencies into the counter. In the perfect world I would have created journal entries as I went and documented the different and unique tasks that have been required to get this kitchen island down to the business of putting together some fabulous meals. But life is life and it is only now that I have things set up in a way that makes it practical for me to put on my scribe hat and jot down some descriptions to go along with the photos I have taken while pulling this together. I have a little catch up to do to get current.
Rather than create one long mega-post, I’ll break this endeavor up into the main parts and little by little (I hope!) the big picture will come into focus in the form of a unified postings that makes sense from one entry to the next.
Here is the basic list of tasks that I plan to break this project up into:
design
templates
glue up/roughing out
main structural design and construction
roll bender/making tool for job
cabinet boxes and counter substrate steel frame
fitting cabinet boxes
partitions/interior shelving
upper counter
install
mega-site built counter
Perhaps by the time the island is installed and cooking I will have caught up with the blog posting.
If you have arrived at this blog via my Facebook or Linked in page let me know how it works for you. If you have any suggestions or comments please drop me a line.
Have found it so useful to capture images and quick text on the go, primarily in the shop with my smart-phone, that it makes sense to create a more user friendly area here for me to document the progress of different projects, show a few images, add a little background.
Formatting will be the next step and how to get text to flow around the images is something that I figure will come more naturally as I work with this.
My website is a Joomla based site. The idea is that I can manage the content myself without having to have others get in and add a picture for me. Additions, galleries, menus, etc. are all plug-ins that you, well, plug-in? Something like that anyhow. Well, the blog plug-ins I looked at were pretty limited. The one I did try needed so much attention, fiddling, reformatting, check this box, don’t open that page, only use this font, etc. that I had to abandon it. I do not spend my day writing and when I do decide to write something down in this manner I want and need it to be easy for me to use. (Watch out…here comes another image)
I looked around the web and found a company that had a wordpress based plug-in. I was ready to go with that until I got to the point in that process where, cash in hand, I found out their plug-in required a yearly subscription fee. Crazy!
Damnation! Solution was at hand I thought. I looked some more and found a link to a site that had written instructions on how to install a wordpress blog into a Joomla based site. One look over the instructions told me that this was not something that I wanted to do. I contacted the person who put it together and asked her if she would set this up for me on my site. This is the result of her labor. She was very professional and straight forward. You can find out more about her here: http://about.me/emilyrosetheartist
