Inventables is now taking pre-orders for Hadron ORD Bots. I will not be shipping anymore kits and Inventables is now the official, authorized distributor of the kits. Go here to get on the list for one of the units. The Inventables kits will also have the following improvements.
Bright Dipped Finish
The previous version looked great, but the matt finish quickly gets dirty and scuffs often looked like sceatches. Bright dipping is a chemical polishing that is done before the anodizing process. The goal is to get the finish quality of a Mag Light.
Open Ended Wiring Holes.
A well wired ORD Bot is a thing of beauty, but once wired some of the parts are trapped by the wiring.
By adding open ended wiring holes, the wires can escape out the sides. This will allow you to completely side off thing like the gantry without removing any connectors.
Wider Extruder Platform.
Deep extruders like some of the Wade’s family of extruders previously had to overhang the front a bit. This adds more depth and an extra hole pattern to give you more options.
Loop Belts
With loop belts you will not have to measure and cut from open ended stock. They will be a lot easier to install and will have twice the grab in the belt clamps.
Build Platform Changes.
Added holes for the ORD Bot heated build platform.
Increased spacing between the wheels. This improves rigidity, reduces the sensitivity and cleans up the busy center area where the clamp and switches. fit.
Electronics Plate Changes
The Electronics plate will now have hole patterns for the RAMPS, ORDuino and Azteez controllers.
There has been a lot of interest in an ORD Bot with a bigger build area. This is the Quantum’s larger brother. This uses the MK1/MK2 heated built platform which is about 214mm x 214mm. You can go larger, but you are on your own.
The name is not yet determined. I wanted something similar to Quantum that conveyed a larger volume. A search of units of volume reminded of one of my favorite units “The Firkin”. Not only does Firkin sound cool, it is part of the FFF (Furlong/Firkin/Fortnight) unit system and it is a measure of beer. The other suggestions was Hadron, which is very similar to Quantum but larger and means thick or stout in greek. Firkin is cool, but Hadron is more family friendly.
They share all parts except the MakerSlide length, the handle and the build platform.
The ORD Bot made its debut at the Chicago HackerSpace, Pumping Station One. They host a monthly DIY CNC night that is open to the general public. I have been going for about 6 months and it is always a lot of fun and you meet some great people. Last night’s event was very well attended with about 30-40 people. Many of the people were there for the first time and found out about it via the Hackaday blog post. They usually have a 15-20 minute presentation and then everyone starts breaks away to work on projects or discuss ideas.
I was drafted into the presentation role to present the ORD Bot. It was received very well. Everyone liked the simplicity and clean look to it. Just about everyone picked it up to hold it in their hands. You don’t see people just spontaneously pick up someone else’s 3D printer very often. I guess when it is small, cute and has a handle, it is just asking to be picked up.
Up until then, the ORD Bot had never actually tried to do a full print. I had a lot of trouble getting the PLA filament. I had some get lost in shipping and two orders canceled due to lack of stock. I had some scraps of ABS that I used to test the extruder and I had run all the axis motors. I had done all my testing on a desktop PC at home and brought my laptop to the HackerSpace without all the software. I hooked into the PS1 Wifi and got the nessesary software.
This is the software “stack” I ran. Sprinter was already loaded on the Arduino. I used Slic3r to create the G-Code. I used Printrun (Pronterface) to interface with the printrer. Jeremy from tinymachineshop had a similar setup on his Makerbot and had Slic3r setup in about 3 minutes with the settings I needed. He also donated a length of black PLA
I decide to run the 20mm calibration cube STL that comes with RelicatorG. Slic3r generated the code in about 1 second. We spend about 5 minutes running PLA through to clear out the old ABS. The first attempt immediatly had a problem with the Y axis. I releazed that the set screw was never tighten on the pulley and it was just running on shaft friction. I tightened the set screw and the print ran great. I probably could play with the retract a little.
We were amazed how quiet the machine ran. You can compare it to the background voices in the video. There is even a Makerbot in the background about 10 feet away you can hear. I am not sure why it is so quiet. I think it might be because there is really nothing to resonate. All the flat parts are pretty small and pretty well bolted down.
The completed part measure about 20.015mm square. The layering looked quite even. There were several 3D printer owners in the room and they all commented that it took many hours of trial and error to get the quality I got on the first try. I am sure the tools have evolved a lot since they started and they helped by giving me the good Slic3r settings.
I took a bunch of pictures, but I left my camera at home. I will post more soon. Here is a picture of the part I took later. If anyone else has some pictures, please send me a link.
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.
Here is the ORD Bot running at 160mm/sec, but the current print speeds are exceeding 400mm/sec with 1000mm/sec rapids. The limiting factor right now is the extruder, but we have preliminary prints close to 500mm/sec.
I have developed an inexpensive control system (less than $70) that can be used to both get more cutting power out of a DC discharge laser and significantly improve cutting accuracy for home built laser systems. The control system implements a control technique known as Pulse-Per-Inch (PPI) control. PPI control involves pulsing the laser every time the head travels a certain distance. PPI control allows a CNC laser to produce consistent cuts at the same power level setting over over a wide range of speeds. In effect, pulsing the laser as a function of distance along a cut decouples the power input to cut from the speed that the head travels. Therefore, the speed and acceleration of the CNC system have minimal bearing on the cut characteristics. Furthermore, the unique transient rise response of a DC discharge laser allow PPI to deliver more power to a cut in comparison to the same laser system with just on/off control.
Background and Motivation
A while back, I was active on a forum in which we were discussing the time it takes to turn a laser on and off and how that relates to engraving control. One of the forum members from Full Spectrum Engineering posted a high-speed intensity spectra for the cheap DC discharge lasers that we use for DIY laser cutters. I was quite surprised by the spectra. I expected to see a nice exponential rise to set power level, but what we saw was a rapid rise to a very high power level (nearly double the set value) followed by an exponential decay to a set value. The Spectrum in question is shown below (credit for the spectrum rests with Full Spectrum Engineering). The yellow square wave is a 5ms pulse sent to the laser power supply. The green spectra is the intensity spectra of the laser. For whatever reason, the magnitude of the spectra is upside down (I think the ground and signal leads were reversed), so on for the digital signal and higher intensity for the laser power spectra are down rather than up. Anyhow, the spike in intensity is caused by the necessity voltage to start a plasma in a DC Laser. The laser power supply generates a very high voltage to start the plasma which is stored in a capacitor. When the signal comes to turn on the power, the power supply dumps this charge into the system and then supplies a nominal (still very high) voltage to sustain the plasma once it is on.
There has been a ton of interest in camera slider applications for MakerSlide. A while ago I decided to make a very simple reference design for a motorized slider. This design only required fabrication of one part. The rest of the parts are existing components. The part can be made on a laser cutter, router or even by hand. There are no tight tolerances and you can use the MakerSlide carriage as a template for drilling some of the holes. I can sell a complete slider system including motor for less than $120 for a 1 meter setup. It would only be $10 for each addition meter. The longest I can ship is 2.5 meters, but I stock the material in 4.5 meter lengths if you can figure out how t0 get it.
I don’t know much at all about this type of camera work so I did not see all this interest coming. Several people approached me about buying my prototypes and I have sold several of them. Most of them asked me how to control the motor. I come from a CNC background so most of my demonstrations were done using CNC software like Mach3, EMC2 or even GRBL. This has few issues. The first is many photographers have no knowledge of CNC or G-Code. The second is the solution is way overkill in cost and complexity for a single axis machine. The third issue is portability. This will probably be used in the field where a PC is impractical and power may be unavailable.
I decided to make an Arduino based controller. Arduinos are good because they are cheap, small and easy to program. They also use very little power. I wrote a similar controller for the PIC processor a long time ago and borrowed the basic algorithm from that. The method used could work for multi-axis machines if you want to steal the code. The Arduino is. using my Stepper Shield. I have just one driver installed and in another “slot” I have a bread boarded switch. The stepper shield is nice because it can act as a mother board for many future features.
MakerSlide: Camera Slider Control Program 2011 CC-A-SA
0 = Set Current Location as 0
S = Stop now!
D = Disable Motor
E = Enable Motor
H = Home (Move to 0)
M = Move to ..(M Dest Speed Accel)
J = Jog until stopped ('J 1' for forward, 'J -1' for reverse, 'J' to stop )
I = Info (show current parameters)
G = Go (start program)
P = Show Program
C = Clear Program
L = Edit Line. Format: L Line# Dest Speed Accel) Ex: L 0 2000 3000 1500
Use 0 for destination and speed to indicate end of program
Use 0 for speed to indicate a pause. Dest is pause in milliseconds
R = Set Max Speed
A = Set Max Accel
V = SaVe to EEPROM
? = Redisplay this menu
The controller uses a menu driven interface via the USB connection. The easiest way to talk to it is though the Arduino IDE serial monitor. That allows a free, common interface between PC, Apple and Linux, but most serial terminals would work. The commands currently work in the unit of stepper motors steps. It could be easily converted to a real world unit, but at this time it is just easier to use the same unit that the motors use. My system has 4000 steps per inch. That makes for a very smooth system. Extremely slow rates are possible. It can go 1 step per second at 4000 steps per inch, so it could take well over and hour to go an inch. You could hack the code to easily drop this by many orders of magnitude. Each move can have its own speed and acceleration to fine turn the affect you want.
It has several commands to interactively move the carriage around. This would probably be done to setup the system before the actual “shot”. These include Move, Home (go to zero), Jog and Zero (define current location as zero). You can also create a move program. This allows you to define a couple dozen moves that run sequentially. These can either be moves or dwells (pauses). Once the program is entered it can be saved. This allows you to pre-program the device before you take it in the field.
At power up the motor disables. This allows you to slide the carriage by hand. This is handy if you don’t have a PC to do it in the field. As soon as you make any move or run a program the motors enable.
How it works (programmers only)
The controller uses a timer to run an interrupt function at a regular interval. The default is 40,000 times per second, but that be be tweaked by changing one program line. The interrupt function determines if a step should be taken. If you want to move at 20 steps per second, you allow the interrupt to run (40000/20) or 2000 times before the step is taken. A counter in the interrupt counts up until it is time to step. By varying the count on the fly you can create smooth acceleration. All the math required to smoothly accelerate could limit the interrupt rate, so the calculation are done once, before the move occurs. Inside the interrupt is all simple integer counting and a few tests.
Stepper motors draw a lot of power. I was running my NEMA 17 at 11V and 0.1 amps. You need a decent battery of 2000-3000 mAH to do a multi-hour run. Steppers are also notoriously loud. The camera will pick up the noise if the mic is close the the motor like on the camera itself. The motors I have are way over kill and running at less than 10% of their rated current. I have some NEMA 14 motors on order. Servo (not hobby servo) motors would be a lot quieter but and lower power, but are more complicated and might require gearing down.
A guy I met at WorkShop 88 is putting together a Maker Faire like event through the local ASME group. It is called the “AMSE Open Source Microcontroller Workshop“. He wants to get a bunch of local open source people to show off their machines and electronics. If you are interested in a meet up, stop by. I can probably get a few free tickets.
I agreed to go, but I don’t like hauling my laser around because I might break something. I have a second laser build going to test the MakerSlide changes. This will be fully functional except for the tube and tube power supply. It will also be run via Mach3 rather than an expensive controller.
The only problem with Mach3 is that you need to haul around a complete computer, with keyboard mouse and monitor. I am already bringing my laptop, so I was trying to figure out a passable way of using that. I know there are options like SmoothStepper and PCMCIA (rarely works) parallel ports, but I did not want to spend any money just for this event.
I have a very small desktop computer with a parallel port. I decided to try putting a VNC server on that computer to see if the laptop could be the display, keyboard and mouse for Mach3. I have used several flavors of VNC, but have found UltraVNC to be my favorite. VNC stands for Virtual Network Computing, but a better description is remote control software. You basically get to control the desktop of a remote computer.
I installed it as a service so that it would be available as soon as possible. I already had the computer setup to boot right into XP without a login. The server computer did not complain at all about not having a keyboard attached. I gave that computer and my laptop different static address on the same subnet. I connected the two computers with an Ethernet crossover cable. Once the VNC server (the Mach3 computer) booted, I connected with the viewer software from the laptop.
It connected fine and I was able to start Mach3 and run the laser. It worked quite well and the display update rate was acceptable, even on the DROs. The only issue I found was arrow key control of the axes was rough. It took me a little time too figure out the problem. The axis would start up fine then start to stutter a bit. I think it worked fine until the key went into auto repeat mode. If you hit the tab key to bring up the pendant looking thing, you can use the mouse to move the axes quite well.
I also hook up my Shuttle Pro and that works so much better than arrow keys any way.
Running G-Code worked perfectly. It is not a permanent solution, but it met my goal of not spending any money. It could also work as a simple remote monitor on a running job.
I just got my production boards for my Pololu compatible relay driver. This is a little plug in module that can be used to drive off board relays. It uses the signals that are normally used for step and direction to control two relays with the voltage that is normally used to power motors.
Pololu stepper drivers are great little items. They are inexpensive and very easy to use. You only need a step and direction signal to control them. If you use them in sockets, as I show here, they are portable between projects and experiments. If you accidentally smoke one, you only need to replace the single driver.
There are a lot of carrier boards for these. There are Arduino shields and many other applications. Often, it would be nice to be able to drive a larger external load like a spindle or blower. You can then use the existing step and direction signals to drive the relays. It uses the voltage normally used to drive the motors for the coil voltage. The only wiring required is two wires to the relay.
I chose to put the relays off board because the real estate was pretty limited and I wanted to provide the voltage isolation for AC powered devices. I am also a big fan of DIN rail mounted relays. They are very reliable and inexpensive. They are easy to swap around and have some nice features. The relays shown have a LED indicator and also a manually test button that moves the contacts. The relays shown are about $10 each, including the DIN rail sockets.
I got the boards from Gold Phoenix in 2 sheets of 50. They were not cut out, only V scored. Fortunately I have access to a depanelizer at work and was able to easily separate them. I probably could have snapped them apart too. The depanelizer looks similar to this one. Two slowly spinning sharp disks chop them apart.
The boards have all the components required to drive the relay including a supression diode. I am using a pretty hefty transistor here, but you could substitute a smaller one.
One of the worst jobs with the 2.x Open Source laser is the hardware kit. I hate counting out all the parts. Some of the part counts are like 150+. The MakerSlide reward kits have a lot of parts too for the wheels and spacers, etc.
I finally decided to get a part counting scale. Essentially what this scale does is weight things in part weight units. The scale has a resolution of 0.0001 lb. It can only weight up to 3.3lbs, but that is fine for what I do. You can get higher rated scales, but the resolution goes down. When weighing light things like nylon spacers, you need the resolution.
First you zero the scale with the container you want to use, then you go through a calibration routine. The scale tells you how many parts to load. It has a few options for this, but I generally use the 10 piece count. You then load the 10 pieces in and tell it when you are done. It then tells you if the scale has enough resolution to do the job with a “PASS” message.
You can then dump parts in and it tells you how many are in the container. You actually get quite good at estimating hand fulls, so you get quite close with the initial toss. You then know how many more you need.
