How to upgrade your 3d printer into laser cutter or engraver

Adding laser cutting or engraving to your 3d printer will make it into much more powerful tool and let's face it: everything is infinitely cooler with some lasers on it.

Here are two solutions if you want to transform your 3d printer into tabletop miniature Death Star and decide to laser cut / engrave some shapes or engravings into balsa, acrylic, Mylar or other suitable material ...

Universal Laser Attachment for 3D Printers Stand Alone System

Is freely available rough project with code and schematics published on Thingiverse. You will need more hands-on previous experience with Arduino programming, electronics, soldering, laser diodes and putting it all together.

http://www.thingiverse.com/thing:140663
by James Sesler (http://www.youtube.com/user/MrInventWorld?feature=watch).
It is work in progress and further upgrades and refinements are possible.

Laser-Bot Personal Manufacturing System by J Tech Photonics

This is more advanced finished commercial laser kit with laser diode and amp driver board that is compatible with several printers like some RepRaps, Makerbot Replicator 2 and 2X, Felix Printers and Makerbot Thing-O-Matic.
They provide their own G-code "LaserEngraver" plugin to convert Inkscape drawings.

Laser Bot hardware setup 

Laser Bot workflow

Here is their laser kit cutting balsa wood:





Here is a video of it in action cutting thin Mylar transparency film sheet into soldering stencil.

Laser diode head

Kit is priced slightly over 220 USD.

Technical specifications from product page:

This kit is a combination of the popular 1.7W 445nm Laser Diode Component and the 2.0 Amp matching laser driver kit with a 12V adapter. This includes everything you need to get your laser up and running in your product or project. We now even cable the laser with a Mini Fit Jr. connector at 2.5 feet to make it even easier to hook everything up! The kit includes:
1.7W 445nm Laser Diode Component (now with 2.5′ Mini Fit Jr. Connector Cable included)
2.0 Amp Adjustable Laser Diode Driver Kit, 8V Compliance
Power Adapter 12V 2A, US Style Plug
Laser Specifications:
This multi transverse mode laser diode component is pressed fit mounted in an aluminum housing and has an aluminum mountable heat-sink. The front of the component contains a glass collimating lens for the laser output.
Absolute Maximum Ratings:
Item Absolute Maximum Ratings Unit
Forward Current (Tc = 25°C) 1.7 A
Allowable Reverse Current (Tc = 25°C) 85 mA
Operating Case Temperature 50 °C

Electrical / Optical Characteristics
Item Min Typ. Max Unit
Optical Output Power 1.6 W
Dominant Wavelength 435 455 nm
Threshold Current 80 220 mA
Operating Voltage 3.7 5.5 V
Beam Divergence Full Anlge (1/e^2) // 5 14 25 deg.
Beam Divergence Full Anlge (1/e^2) – Perp 30 44 50 deg.
Driver Overview:
2 Amp Version, 12V adapter Kit
This version of the popular High Current Laser Driver offers up a lot of current in a small package for an excellent price. The design team perfected several versions of this driver to give a quality current source with a large compliance voltages with both adapter choices to be able to work with most every laser diode. They packed it with multiple features and made it capable of interfacing with even the oldest of your equipment in your lab or the newest wiz bang in your product or system. This version includes a 12V power adapter that will provide 8 volts at maximum load of 2 amps. This can be used to power higher voltage laser diodes in the 4-7 volt range like the 445nm laser diode component. It can also power IR laser diodes in the 2-4 volt range, but it might need additional cooling fan if left on for extended amounts of time.
This driver will provide 1 amp of constant regulated and protected current to the diode. Configurable current limits with jumpers for 0.5 and 1.0 amp settings and adjustable output with an analog trim pot. It also can be remotely controlled with an opto isolated input with a super huge range of acceptable voltages for turning your driver on and off. Does your equipment in your project or system that you want to interface with have backwards logic? No problem! There is a jumper for choosing inverted or non inverted logic as well! Perfect for integrating into any final product or project.

Features:

High power current source for driving Laser Diodes and Light Emitting Diodes.
Current Range of 2 Amps.
Current Ranges are adjustable in 500ma increments.
No need for extra cooling at maximum load. (depends on power adapter and compliance voltage.)
Soft start for diode protection.
Reverse diode and ESD protection.
Thermal Protection and Over Current Protection.
Compact Size.
CW Mode and Input Control Mode.
Digitally isolated control input.
Control from CW to 5KHz.
Configurable Input signal: Inverting /Non-Inverting.
Multiple connector options for both Laser/LED output and control input.
LED status lights for input laser enabled and laser on.
Optional fan for extra thermal stability.
Specifications:
Specification HCDBSA 2 AMP
Current Source Range: 0 – 2 Amps
Current Limit Jumper Settings: 0.5, 1.0, 1.5, 2.0 Amps
Compliance Voltage w/7.5V adapter: 3.5 Volts
Compliance Voltage w/12V adapter: 8 volts
Current Resolution: 0.1%
Current Adjustment: Analog Trim Pot
Current Range Accuracy Always greater than limit, no more than 15%
Laser Diode Protection: Soft Start, Reverse Voltage, Current Limit, Thermal Shutdown
AC Adapter Input Voltage: 100 – 240 VAC
Control Signal Digital Isolation Voltage: 4500 Vrms
Minimum Control Signal ”Turn On” Voltage: 2.8 Volts
Control Signal Maximum Voltage: 36 Volts
Control Signal Maximum Current: 50 ma
Control Signal Maximum Frequency: 5KHz
Connectors: Screw Terminal and Molex Mini-Fit Jr™ Connectors
Operating Temperature: 0 to 40 °C
Storage Temperature: -40 to 70 °C
Dimensions: 2.85″ x 2.1″

http://jtechphotonics.com/?page_id=333


Here are some previous post on DIY 3d printers turned into desktop laser cutters / engravers, some are more advanced then others:

http://diy3dprinting.blogspot.com/2013/09/more-diy-reprap-laser-cutters-and.html

http://diy3dprinting.blogspot.com/2013/07/laser-cutting-with-prusa-mendel-i2.html


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