Better Lasing With Pulses

laser

The folks at the Lansing, Michigan hackerspace built themselves a 40 Watt laser cutter. It’s an awesome machine capable of cutting plywood and acrylic, and is even powered by a RAMPS board, something normally found in 3D printers. They wanted a little more power out of their 40 Watt tube, though, and found pulsing the laser was the best way to do that.

Unlike the fancy Epilog and Full Spectrum Laser machines, the Buildlog.net 2.x laser cutter found in the Lansing Hackerspace didn’t use Pulse-Per-Inch (PPI) control until very recently. When a laser tube is turned on, the output power of the laser is much higher – nearly double the set value – for a few milliseconds. By pulsing the laser in 2-3 ms bursts, it’s possible to have a higher effective output from a laser, and has the nice added benefit of keeping the laser cooler. The only problem, then, is figuring out how to pulse the laser as a function of the distance traveled.

To do this, the laser cutter must accurately know the position of the laser head at all times. This could be done with encoders, which would require a new solution for each controller board. Since laser cutters are usually driven by stepper motors controlled with step and direction signals, a much better solution would be to count these signals coming from the CNC computer before it goes to the RAMPS driver, and turn the laser on and off as it moves around the bed.

A few tests were done using various PPI settings, each one inch long, shown in the pic above. At 200 PPI, the laser creates a continuous line, and at higher PPI settings, the lines are smoother, but get progressively wider. The difference between PPI settings and having the laser constantly on is subtle, but it’s there; it’s not quite the difference between an axe and a scalpel, but it is a bit like the difference between a scalpel and a steak knife.

It’s an impressive build for sure, and something that brings what is essentially a homebrew laser cutter a lot closer to the quality of cutters costing thousands of dollars. Awesome work.

 

BeagleBone Black + RAMPS

CRAMPS

The BeagleBone Black, with an impressive amount of computing power and a whole bunch of I/O, would make an impressive CNC controller, save for two shortcomings: The BBB isn’t in stock anywhere, and CNC capes are a little on the pricey side. [Marc Peltier] can’t do anything about finding a distributor that doesn’t have the BeagleBone on backorder for you, but he did come up with an adapter for the very popular RAMPS-FD 3D printer controller board (Forum, French, Here’s the Google translation matrix).

The RAMPS-FD is an extension of the RAMPS board and a shield for the Arduino Due. Both the Due and BBB work on 3.3 V, meaning controlling the RAMPS-FD is simply a matter of finding the correct wiring diagram and pin assignments on the BeagleBone. [Marc] solved this problem by using the settings from the BeBoPr cape and using the existing BeBoPr LinuxCNC configuration.

The end result of [Marc]‘s tinkering is something a lot like [Charles Steinkueler]‘s CNC capes for the BeagleBone Black we saw at the Midwest RepRap Fest. [Charles] isn’t selling his capes, but no one else seems to be selling BeagleBone Blacks, either.

[Read more...]

BeagleBone Black does CNC with RAMPS

bbb-cnc-adapt

[Bart] Wanted to try controlling a CNC with his BeagleBone black, but didn’t want to invest in a CNC Cape. No problem – he created his own translator board for RAMPSLinuxCNC for the BeagleBone Black has been available for a few months now, and [Bart] wanted to give it a try. He started experimenting with a single stepper motor and driver.  By the time he hooked up step, direction, and motor phases, [Bart] knew he needed a better solution.

Several CNC capes are available for the BeagleBone boards, but [Bart] had a RAMPS board just sitting around, waiting for a new project.  Most RepRap fans have heard of the RAMPS – or Reprap Arduino Mega Pololu Shield.  In fact, we covered them here just a few days ago as part of our 3D Printering series.   RAMPS handle all the I/O needed for 3D printing, which carries over quite nicely to other CNC applications as well.   The downside is that they’re specifically designed for the Arduino Mega series. [Read more...]

3D Printering: Electronics Boards

If you’re gearing up to build a 3D printer, one of the first things you’ll need to look at is your options for electronics boards. Whether you decide to optimize for cost or capability, the choices you make during the planning stages of your build will drastically affect what the final project will look like and how it will behave.

There are a ton of electronics boards out there, so for this installation of 3D Printering, we’re going to take a look at what’s available. Hit the link below to give Hackaday more pageviews read the rest.

[Read more...]

Eventorbot 3D Printer

Tired of 3D printers that use t-slot construction? The Eventorbot is yet another open source 3D printer,  but it’s built out of steel and 3D printable parts. The design also aims to minimize the effect of vibrations by using a single solid frame. All of the wiring runs through the steel frame, which gives the printer a professional look.

The Eventorbot page on the RepRap wiki provides details on how to build your own, along with STL files for all the printable parts. If you want to see renders of the parts, they’re all available on Thingiverse. The material cost is $300-$500, and the assembled cost is quoted at $799.

Like many of the open source printers we’ve seen, this one uses the RepRap Mega Pololu Shield (RAMPS) to control the actuators. This is attached to a Sanguinololu motherboard, which runs the RepRap firmware.

The Eventorbot Youtube channel has a collection of videos detailing the assembly of the robot. Check out a video of a test print after the break.

Via Make

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Toorcamp: Type A Machines

Type A Machines designs and builds 3D printers in San Francisco. [Miloh], one of the founders, brought two of their flagship Series 1 printers to Toorcamp. He printed out a variety of models including water tight cups and quadcopter arms.

The RepRap Arduino MEGA Pololu Shield (RAMPS) is used to drive the stepper motors for each axis, as well as the extruder. This is attached to an Arduino MEGA running the Marlin RepRap firmware. Type A Machines ships the printer with Polylactic Acid (PLA) filament, which is biodegradable.

On software side, you start with a 3D model in STL format. This can be exported from 3D software such as Google SketchUp or Autodesk 123D. You then need a slicer to generate G-code and machine control software to command the printer. [Miloh] used Slic3r and Repetier for his workflow, but he also pointed out a good summary of 3D printer workflows.

The Series 1 was launched at the Bay Area Maker Faire this past May. It has a print volume of 1200 mL, which is the largest print volume of any desktop printer around. The Series 1 brings another option into the low-cost 3D printer market.

Solar-powered RepRap prints even when the power is out

solar_powered_3d_printer_reprap

[Mark] wrote in to share a little creation that he is calling the first solar-powered 3D printer in existence. While we can’t say that we totally agree with him on that title, we will give him the benefit of the doubt that this is the first solar-powered RepRap we have seen thus far.

You might remember [Mark] from his previous exploits, but rest assured that there’s little possibility of anyone losing an eye with this one. He has taken his RepRap outdoors, and with the help of a solar panel plus a few batteries from Harbor Freight, he has the world’s first solar-powered RepRap*.

The trick behind keeping the RepRap running for such a long time with the sun as its only power source lies in the RAMPS board [Mark] uses. He has the 1.3 revision of the shield, which enables him to print objects loaded from an SD card rather than requiring a computer to be connected at all times.

So, if you happen to need the ability to print 3D objects where an extension cord cannot possibly reach, check out [Mark’s] setup and get to building!

* Maybe. Perhaps.

[Read more...]

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