I was invited to this really cool event called ORD Camp. ORD Camp is unique, yearly event put on by Inventables and Google in Chicago. It brings together 200 people with a far range of interests. The common thread is a exceptional passion for what you do.
You are encouraged to bring a “creation /invention” you are working on. I did not want to bring the 2.x laser because it is hard to move around, it takes up a lot of space, and is not real conducive to just operating in the middle of a room. I will probably bring the camera slider, but I really felt like using the opportunity to create something new and cool with the MakerSlide material.
I was recently inspired by this Kickstarter Printrbot 3D printer. It seemed like a real ‘outside the box’ look at 3D printers. Brook of printrbot contacted me recently about collaborating with some of the people he is working with on some projects which got me more inspired. I decided to try a similar concept using Makerslide.
MakerSlide has these main features. It is a linear bearing. It is a structural element. It is accurate and it is cheap. The concept is, if you keep some of this laying around and have access to a few tools, you can quickly brainstorm an idea and fabricate it right away. This project was hashed out in about 3 hours, fabricated in about 2 hours and assmebled in about 2 hours. That includes cutting all the custom parts.
The result is the ORD Bot 3D printer platform. The structure and linear bearings are 100% MakerSlide. The motion is smooth, ridged and accurate . The parts are cheap. This uses less than $60 dollars worth of MakerSlide rail, wheels and idler pulleys. The rest are off the shelf items or fabricated by CNC router, laser cutter, 3D printer or other means.
A huge feature of this design is the scalability. It can scale in X,Y, Z or any combination by simply using different lengths of MakerSlide. All brackets stay the same. You might need to change belt lengths, but all the belts are open ended belts, so you don’t need the exact length, just some belt stock. The lead screws also need to change if the Z changes, but that is standard cut threaded rod. The version I built is probably as small as you would ever want to go, so I called it the Quantum ORD Bot. The build area is slightly larger than a standard MakerBot.
The frame is extremely ridged. Cut squareness does not matter very much. Every parts has multiple adjustable points and does not rely on the quality of any cuts. Parts can be aligned with a square and bolted down.
Feet.
I initially had some screw on leveler feet in the design, but after some design tweaks, extra bracket were going to be needed to mount them. I made these feet out of HDPE. They are soft and will not scratch any surface. I added the holes at the bottom to get a little spring to them, but I also think it brought in a nice design element. The rounded end and three point contact make them self leveling. The rear feet also act as a secondary brace for the Z axis.
Handle.
The handel is not required, but adds a lot of strength, can be used to mount electronics and also serves as a gauge for alighning the uprights. If you use a handle and scale the X axis you would need a hew handle. An alternative is to use a standard 20×20 t-slot piece across the top.
Scaling
Here is the build area increased by 100mm in each direction. I put a 20×20 extrusion across the top instead of the handle. I just did it as an example to show a more easily scaled version. This cost would be $4 higher for the MakerSlide about $3-$4 more from Misumi, about $2 more for longer lead screws and about $5 more for the longer belts. You would also need a bigger build platform (not shown). The total increase is easily less than $20. The increase in Z weight is about 4 ounces (0.1kg). At very large widths you might want to add a second Y axis extrusion, but that would just be a repeat of the existing one.
Prototyping
The pictures above are mostly renderings. Here are some real pictures of the prototype. I cut all the parts on my CNC router. I could have used my laser cutter, but I wanted to make a few counter bores for some screw. I don’t think that is needed, but it looks cool. I also used some optional non laser cuttable materials like carbon fiber and HDPE.
I came up with this idea about 6 days before the ORD Camp date, so I was a little rushed. The biggest problem was lack of motors. I also was so busy that I really could only allocate about 6 hours to the project. I let the delivery time of the motors set the schedule so only worked an hour or so a day over the week.
This design is very strong. I could stand on it or hang from it without damaging it. It is quite light at about 6.25 lbs. I am very happy with it and hope to get some good feedback at ORD Camp.
Where Are The Wires?
The element I really liked when I did some initial renderings was the clean look. I knew it would quickly turn into a RepRap hair ball as I wired it, so I decided to take advantage of the built in passage ways in the MakerSlide. I drilled some holes into the faces in some areas to pass the wires from extrusion to extrusion. The wires to the gantry had to be exposed because they move with the gantry. I put the wires into an extrension spring. This is a 1/4 O.D. 0.018 wire springs. If you stretch a spring the diameter reduces. I used this feature to mount the spring. I drilled holes slightly less than 1/4″ and stretched the spring through the holes. When I released the spring the diameter expanded to fit snugly in the holes. I tried to find a tap that matched a spring pitch so I could just thread the spring in, but couldn’t find a match. This mod falls into the “its not worth doing, unless you overdue it” category. I also wanted to reinforce the extreme rigidity look, by using carbon fiber parts, but the budget limited me to just the small thin parts. Again, this was overkill and just for fun.
What is Next?
If there is any interest, I might add this as a kit to the Makerslide store. I would like to quote all the carriages and brackets in aluminum, so I don’t have to fabricate much. I would probably need a 50 piece buy to justify the work and cost.
I have been using a ShuttlePro as a pendant for years on my router. A pendant is basically a hand held remote control for your CNC. It allows you to control a set of functions right at the machine. I typically use it to zero the machine on the part, tweak the feedrate, start/pause/restart the job and do an e-stop.
The router’s pendant is starting to die. It has been through hell. I have dropped it about 10 times on the concrete floor. It has also seen a lot of oil and fine dust. A couple buttons are getting intermittent. I have the functions to working buttons, but I was getting worried it would stop working completely. I could not live without it, so wanted to get a replacement on order. I found a good deal on eBay ($54) and since they had several, I decided to get one for the laser as well.
The ShuttlePro was designed for video editing. One thing you do a lot in video editing is jogging the video forward and backward. Typically you want to race forward until you get close then slow down and even go frame by frame until you get to the desired spot. Sounds like CNC doesn’t it? It has three dedicated functions for this. Full speed forward and back via buttons, variable speed via a spring loaded jog dial and a frame by frame little detented rotator wheel. It also has a lot of redefinable buttons. These buttons have clear snap on caps, so you can add labels to them. I have a Corel and PDF template at the end of the post. Someone at the Mach3 forum dicovered this product and within days there was a plugin for it.
Setting it up is easy.
Download the ShuttlePro plugin from the Mach3 downloads page. Place the ShuttlePro.m3p file you download in a convenient place like your desktop. Double click on it. That will launch a program that registers it with Mach3. Plug in the ShuttlePro into your computer. It uses the built in Human Interface Driverss (HID) so you do not need to install a driver. It comes with some software to test it, but you must uninstall it before using Mach3. Start Mach3.
Use the config Plugins menu pick to open the
Make sure the plugin is enabled with a green check. Now click on the word config to the right of the plugin name.
That will bring up the screen above. Each button can be associated with any of many functions. My config is shown above. You probably want some keys across the top to select the current axis. I like to have the two buttons to the outside of the central wheels be rapid movement buttons. It is also handy to be able to lock the pendant so accidental button pushes do not screw up a run. I used the second button from the lower right. The rest are up to you and how you use your laser.
I saw couple of thing on various blogs regarding PVC lately. I think every general purpose maker has made something out of PVC at some point. It has a lot of desirable qualities. It is cheap, easy to find, and very easy to work with. It is relatively strong and can hold a lot of pressure. I have made a plastic bottle launcher, a paper rocket launcher and even a crude trebuchet for a scouting contest.
The first new PVC item I saw was these FORMUFIT PVC fittings. They are aimed squarely at the maker side of PVC usage. All of the parts are smooth, glossy, tapered, high quality parts without any of the annoying printing. labels or bumps. Some of the nice features are interior detents so you have a consistent stop point so your project will come out square. There are also slip tees. The tee section on these are not a tight fit to the pipe so it creates hinge. (This would have been real handy on the trebuchet). The other part that fit in this category are the table cap (attaches legs to table), caster base and internal pipe coupling.
They also have pre-made Google Sketchup and MS Visio parts ready to design with.
I saw this over at Hackaday. Magx1 has created a homebuilt CO2 laser using air exhaled into a balloon as the gas source. There is a great Flickr set and a video.
He explains a little bit about how it works in the video. To fill in some blanks…a flowing gas electrical discharge plasma laser works like this: Gas is pulled into a tube using a vacuum pump. The gas has be to pulled down to a very low pressure before the air will start. There is a bit of a balance done using a needle value to keep the pressure right on the sweet spot.
Most people buy premixed gas for flowing gas CO2 lasers. It is a mix of gases that “cooperate” to produce the best beam. I never suspected you could get a decent beam with such a rough gas mixture.
There is a saying amongst DIY CNC router builders that goes something like this… “You only need to build your first router good enough to build you second one“. In my case that turned out to be true.
I built a wood, conduit and skate bearing Solsylva router. I painstakingly layed out the various pieces using calipers, t-squares and compasses. I cut them out using hand held tools like jigsaws and drills. It worked remarkably well, but every time I routed out a perfect CAD drawn piece, I always thought “Gee, I wish I had this thing when I built the router“.
It wasn’t too long before I built my bigger, better, more accurate router. I was able to use tougher materials, hold tighter tolerances and cut more exotic shapes. It works much better. A few months ago I finally pulled off all the good bits and Sawzall’ed the old one apart to get more room in the shop…a bitter sweet day.
Most of today’s designs develop inside a computer. Resolution and accuracy are infinite in this realm. We expect our fabrication machines to output similar accuracies, but how does one construct a machine with this accuracy with common (analog) tools.
Today’s open source machine are addressing this head on. There is a big push towards self replication. Struggle past the first one and the rest will be easy. It is not just an accidental bonus it is initial design requirement. It is a lot more work, but I think it builds the strong communities behind these projects that help insure their success.
Here are three examples of self replicating machines…
Update. Peter is still working on his SLS project. He is experimenting with a new fully laser-cuttable x/y stage. He is catching some flack for the ideas in some blog comment sections like hackaday. Obviously there is some refinement needed for accuracy, backlash, etc, but I applaud his efforts. I am sure some of his ideas will find their way into the final design and we will all benefit from it for this and other projects.
If he was just building a device for his own use, it would probably be easier and cheaper to use conventional materials, slides and gears, but he is clearing spending a lot of time to design something the budget conscious maker can afford.
Many people put similar questions to me on the design of the open source “self replicating” laser cutter. I have redesigned and rebuilt constantly to lower the costs, tools and skills required to build it. I swapped out very robust milled aluminum parts with laser cut Acrylic ones to prove they would work.
His most recent changes area aimed at removing the “shearing/binding issues” from the previous iteration. He is using Kapton tape (Polyimide-film) to reduce friction and using a four gear contact point.
“In this lithography experiment light creates free radicals from phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide which induce polymerization of 1,6-hexanediol diacrylate. Light is supplied by a computer projector which shines the pattern for one layer at a time. After each layer, the elevator is slightly lowered and the process is repeated. A dye (Sudan I) is included to prevent light from penentrating much below the surface of the solution.”
The process in serious needs of some steppers motors, but they manage to get some pretty detailed parts. Normally Stereolithography uses UV lasers to cure the material by rapidly scanning the image onto the surface. This images an entire layer at a time. Go to the web site to see some videos (warning Quicktime required)
This is an interesting modular CNC system Industrial Designer Nicanor Santillan is working on. It is a portable, transformable and multi-functional. It can be setup to to horizontal or vertical milling. It can be reconfigured in a matter of minutes with a minimum number of tools. At first I did not think it looked very robust, but he is using some pretty good linear components and thick materials. The system can be broken down and transformer into a cart for moving it around.
There is a great Selective Laser Sintering (SLS) project being blogged at ReRap Builders by Peter Jansen. Sintering is basically fusing powder by heating it just under the melting point. SLS is 3D printing using a laser to selectivly heat the material. It is done like most 3d printing, a thin layer at a time. The nice thing about this method is that the surrounding powder supports the part as is is being built.
The current design is completely laser cut out of hardboard, even the gears. The target price for a complete assembly is around $200. The project is open source and design files are available on Thingaverse.
I recently had these nozzles made using SLS at Shapeways. The detail is amazing and while the part is only about 0.04 inch thick in most places, it is quite strong.
There is an Interesting Instructable on integrating a 1W fiber coupled laser into a pen. The whole project is a rather low tech approach, so it shows how easy it is to do. I found a few of the fiber optic coupled laser diodes on eBay, all for less than $100. In the video, it does not appear to burn real fast, but it still looks usable.
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