We agree with [Mário Saleiro] that the motors from a car’s power windows make for a fantastic high-torque solution to your next project. If you have a you-pick junkyard in your town they’ll be dirt cheap after you put in a bit of time to find and removing the parts from the yard. But you’ll probably want to add a few extra steps to get them ready, and he’s done a great job of documenting how he augmented them with wheels and rotary encoders.
One aspect of the project which really struck home with us was his machine-shop-101 style tricks to mate the axle of the motor with the wheel. He has a process which ensures you will find the exact center of a cylinder as you work. This starts by lining up a bench vice on his drill press. He then inserts a drill bit upside down in the drill chuck, lowers it and clamps the vice on the bit. After loosening the chuck he ends up with the bit pointing up at the exact center of the chuck. Next he chucks up a piece of threaded rod, drilling a perfectly centered hole by lowering it into the drill bit while the drill press is rotating. The image above shows him using this machined part as a guide to continue the hole into the motor’s axle. Click through the link above to learn the rest of the tricks he uses.
Most 3D printers use stepper motors to control the movement of the extruder head. If you could actually print those motors it would be one more big step toward self-replicating hardware. Now obviously [Chris Hawkins’] working 3d printed stepper motor wasn’t built 100% through 3D printing, but the majority of the parts were. All that he had to add was the electronic driver pieces, magnets, wire, and a few nails.
The coils are made up of nails wrapped in magnet wire. The rotor is a 3D printed framework which accepts neodymium rare earth magnets. The axle is pointed which reduces the friction where it meets the cone-shaped support on either side of the frame. The IC on the upper right is a transistor array that facilitates switching the 20V driving the coils. The board on the lower right is a Digispark, which is an ATtiny85 breakout board that includes a USB edge connector for programming and a linear regulator which is how he gets away with feeding 20V as the source.
Don’t miss the demo video after the break where you can see the motor stepping 7.5 degrees at a time.
Continue reading “Working 3D printed stepper motor”
Roasting the perfect coffee bean is an art form. But even the most talented of roasters can use a little feedback on what’s going on with their equipment. [Ludzinc] recently helped out a friend of his by building this set of 7-segment displays to show what’s happening with this coffee roaster.
The yellow modules hiding underneath the display panel are responsible for setting the speed of the hot air blower and the rate at which the drum turns. They’re adjustable using some trimpots, but it sounds like the stock machine doesn’t give any type of speed feedback other than direct observation.
The solution was to patch into those speed controllers using the ADC of a PIC chip. They each output 0-10V, which [Ludzinc] measures via a voltage divider. After the speed is quantified the microcontroller outputs to one of the displays. Since there’s a different chip for each readout, the firmware can be custom tuned to suit the operator’s needs.
Keep this in mind if you’re still planning to build that coffee roaster out of a washing machine.
At first we thought that [Pete Prodoehl] was using the wrong term when calling his project a Laser Kaleidoscope. We usually think of a kaleidoscope as a long tube with three mirrors and some beads or glass shards in one end. But we looked it up and there’s a second definition that means a constantly changing pattern. This fits the bill. Just like the laser Spirograph from last week, it makes fancy patterns using spinning mirrors. But [Pete] went with several 3D printed parts rather than repurposing PC fans.
In the foreground you can see the potentiometers which adjust the motor speeds. The knobs for these were all 3D printed. He also printed the mounting brackets for the three motors and the laser diode. A third set of printed parts makes mounting the round mirrors on the motor shaft quite easy. All of this came together with very tight tolerances as shown by the advanced shapes he manages to produce in the video after the break. Continue reading “Laser Kaleidoscope uses more 3D printing and less scavenging”
[Chipsy] found himself with an interesting problem. The room that serves his home theater has a wall mirror which reflects part of the screen during viewing. In an otherwise dark room this was very distracting. His solution was to add a blind that covers the mirror during viewing, but who wants to constantly pull that down and back up again? Since the motorized projection screen he is using has a remote control he figured out a way to motorize the blind and synchronize it with the screen’s remote.
The screen uses mechanical relays to switch the motor. He patched into these with an Arduino to detect whether the screen was going up or down. It was easy enough to use his own relay and motor with the blind, but he needed a way to stop the blind once it was in position. For covering up the mirror he simply sets an 18 second timer, but for retracting the blind he wanted precise alignment so he added a magnet and sense its position with a reed switch. See the synchronized screen and blind in the clip after the break.
Continue reading “Add motorized blinds to your home theater”
There are a number of things that can go wrong with an automatic ice maker. But one of the more common problems is that the motor which scoops the ice out of the integrated trays can burn out after years of use. [Dave] recently repaired a common ice maker motor and shows us how cheap and easy it can be. See how he did it in the video after the break.
Pictured above is the motor and gear box from the ice maker. Before disassembly he verified that the problem is with the motor by placing a piece of paper in the path of the fingers that move the newly formed ice. After removing the sensor arm and three screws he was able to pull this front portion from the unit. The two wires are clipped as near to the motor as possible and the motor itself comes out with just a twist. After verifying that the gears are not broken he sourced a $2.50 motor replacement by Googling the part number (M004 3W in this case). Once the new unit arrived the motor wires are connect in much the same way that a punch down Ethernet jack makes a connecting with insulated wires.
This is something worth looking into if your ice maker is not working. The manufacturer may suggest replacing the entire unit which can be well north of a hundred bucks… this is a worthwhile gambit to save some cash. Well, we guess you could always build your own non-electrical ice maker.
Continue reading “Repair your ice maker motor without buying a whole new assembly”
[Lou] is on a hot streak when it comes to interesting builds. This time around he made his own motor using wood, PVC, some fasteners, and a bunch of enameled wire.
His method of building a commutator is intriguing. He first builds a rotor by cutting two opposing sides off of a PVC four-way connector and pushing a short galvanized pipe through what’s left. After adding two PVC nubs with caps and nails as pivot points he wraps the PVC and metal pipe with a continuous length of enameled wire. The enamel is then sanded off the windings around the PVC, and half is covered with electrical tape. The spinning rotor will cause the brushes to contact the bare wire during half of the rotation, and be insulated by the tape during the other half. The video after the break shows the motor in action, then walks you through each step of the build.
If you liked this video you should check out [Lou’s] water bottle rocket launcher, or his automated Ping Pong table topper which stores the game in the ceiling.
Continue reading “Scratch-built motor uses a clever design”