In the course of building a new delta printer, [thehans] decided he needed his own endstop design that used minimal hardware. Endstops are just switches that get hit when the printer moves at the extreme of an axis, but [thehans] wanted something with a bit of refinement for his BigDelta 3D Printer build.
The result is a small unit that cradles a microswitch and needs only a single zip tie that mounts flush, resulting in a super tidy looking piece. In addition, it mounts on the delta’s v-slot rails such that the mount does not take up any of the machine’s range of motion, because the carriage can travel past it. It is a parametric design made in OpenSCAD, so feel free to modify it to accommodate other types of switches.
Continue reading “Endstops That Stay Out of the Way”
[Jochen Alt] is on a roll. We just covered his ball-balancing robot, Paul, only to find his phenomenal six-DOF robot arm in full retro style. Its name is “Walter” and it’s done up in DDR style (the former East Germany), in painted, 3D-printed plastic. The full design and build documents are an absolutely amazing resource if you’re into robot arm or legs.
In particular, the sections on trajectory planning and kinematics are fantastic. If you’re interested in robot motion planning by Bezier curves, you know where to go. (We’ve always wanted a Bezier-curve 3D printer slicer, but that’s another story.) The construction is also top-notch here, and the attention to detail that went into this arm is phenomenal. It’s all done with stepper motors and geared belts, which allow each of Walter’s joints to be driven by a motor that’s one joint further upstream than would be the case if it were designed with servos. [Jochen] even went so far as to expose the belt in some places to show off the gearing. Walter is worth checking out.
Even if you’ll never build such a fancy robot arm, you should read through the docs just to appreciate all of the thought and work that went into this very refined and simple-from-the-outside design. If you’d like to start out on the simple side of the spectrum, check out these robot arms made of office supplies or a desk lamp. Once you’re ready for your second arm project this short list, some of which [Jochen] mention in his writeup, should get you up and grasping. And do check out his balancing bot, Paul.
If you had a choice between going to your boss and asking for funds for a new piece of gear, would you rather ask for $3000 to buy off-the-shelf, or $200 for the parts to build the same thing yourself? Any self-respecting hacker knows the answer, and when presented with an opportunity to equip his lab with a new DIY syringe pump for $200, [Dr. D-Flo] rose to the challenge.
The first stop for [Dr. D-Flo] was, naturally, Hackaday.io, which is where he found [Naroom]’s syringe pump project. It was a good match for his budget and his specs, but he needed to modify some of the 3D printed parts a little to fit the larger syringes he intended to use. The base is aluminum extrusion, the drive train is a stepper motor spinning threaded rod and a captive nut in the plunger holders, and an Arduino and motor shield control everything. The drive train will obviously suffer from a fair amount of backlash, but this pump isn’t meant for precise dispensing so it shouldn’t matter. We’d worry a little more about the robustness of the printed parts over time and their compatibility with common lab solvents, but overall this was a great build that [Dr. D-Flo] intends to use in a 3D food printer. We look forward to seeing that one.
It’s getting so that that you can build almost anything for the lab these days, from peristaltic pumps to centrifuges. It has to be hard to concentrate on your science when there’s so much gear to make.
Continue reading “DIY Syringe Pump Saves Big Bucks for Hacker’s Lab”
Exploiting the flexibility of plastic, a group of researchers has created a 3D printable microscope with sub-micron accuracy. By bending the supports of the microscope stage, they can manipulate a sample with surprising precision. Coupled with commonly available M3 bolts and stepper motors with gear reduction, they have reported a precision of up to 50nm in translational movement. We’ve seen functionality derived from flexibility before but not at this scale. And while it’s not a scanning electron microscope, 50nm is the size of a small virus (no, not that kind of virus).
OpenFlexure has a viewing area of 8x8x4mm, which is impressive when the supports only flex 6°. But, if 256 mm3 isn’t enough for you, fret not: the designs are all Open Source and are modeled in OpenSCAD just begging for modification. With only one file for printing, no support material, a wonderful assembly guide and a focus on PLA and ABS, OpenFlexure is clearly designed for ease of manufacturing. Optics are equally interesting. Using a Raspberry Pi Camera Module with the lens reversed, they achieve a resolution where one pixel corresponds to 120nm.
The group hopes that their microscopes will reach low-resource parts of the world, and it seem that the design has already started to spread. If you’d like to make one for yourself, you can find all the necessary files up on GitHub.
Continue reading “This 3D Printed Microscope Bends for 50nm Precision”
Here at Hackaday, we love clever 3D prints. This amazing lion statue remixed by [ _primoz_], makes us feel no different. It is no secret that FDM 3D printers have come a long way, propelled by the enthusiastic support from the open source community.
However, FDM 3D printers have some inherent limitations; some of which arise from a finite print nozzle diameter, tracing out the 3D object layer by layer. Simply put, some print geometries and dimensions are just unattainable. We discussed the solution to traditional FDM techniques being confined to Planer layers only in a previous article.
The case in point here is a 3D printed lion whose original version did not fully capture its majestic mane. [_primoz_] solution was to construct a support cylinder around the head and form the actual hair as a series of planar bristles, which were one extrusion wide.
This was followed by some simple post processing, where a heat gun was used to form the bristles into a dapper mane.
The result is rather glorious and we can’t wait for someone to fire up a dual extruder and bring out the flexible filament for this print!
Reaching the end of a spool of filament when 3D printing is inevitable. The result ranges from minor annoyance to ruined print. Recently, I needed to print a number of large jobs that used just over half a spool of plastic each. Unwilling to start every print with a fresh spool (and shelve a 60% used one afterward), I had a problem to solve. What my 3D printer needed was filament monitor, or at least that’s what I thought.
After reviewing some projects and aftermarket options, I ended up making my own. Like most prototypes, it wasn’t an instant success, but that’s fine. One of the goals of prototyping is not only to validate that the problems you’re solving are the same ones you think exist, but also to force other problems and issues you may not have considered to the surface. Failure is only a waste if nothing is learned, and the faster and cheaper that learning happens, the better.
Sensible design steps also help minimize waste, so I started by looking at what kind of solutions already existed.
Continue reading “Let’s Prototype! This Filament End Needs 80 Decibels”
[Tinker_on_Steroids] made some awesome looking spinners that not only light up when spun but are a really professional looking build on their own. Before we’d watched his assembly video we were sure he’d just added on to something he’d bought, but it turned out it’s all custom designed and made.
In case you’ve never played the old arcade games, a spinner is an input device for games such as Tempest or Breakout where you rotate a knob in either direction to tell the game which way and how fast to move something. In Tempest you rotate something around the middle of the screen whereas in Breakout you move a paddle back and forth across the bottom of the playing field.
He even detects rotation with a home-made quadrature encoder. For each spinner, he uses two ITR9608 (PDF) optical switches, or opto-interrupters. Each one is U-shaped with an LED in one leg of the U facing a phototransistor in the other leg. When something passes between the two legs, the light is temporarily blocked and the phototransistor detects it i.e. the switch turns off. When the thing moves away, the light is unblocked and it turns on again. The direction of movement is done by having the thing pass between two ITR9608’s, one after the other. The “things” that pass between are the teeth of a 3D printed encoder wheel. Continue reading “Awesome Illuminated Arcade Spinner”