Introduction: JRLS 1000 DIY SLS-3D-PRINTER

About: I am a 23 years old student from Germany who love to make things. Later I want to become an Electrical Engineer :-) https://www.instagram.com/vulcaman/

In this Instructable I want to show you how to build a SLS 3D-Printer with a lot of features. I am an 18 years old guy from Germany who wants to understand how SLS-3D-Printers work in depth. I got the inspiration for this project after I saw a laser sintered object from a professionell SLS-machine. It was so detailed and so perfect. However a professionell SLS-machine is very expensive. So I designed, built and tested my own SLS-3D-Printer. It took me three month to develop the printer and I was quite surprised how well it worked. Now I will tell you some spects about the printer:

SPECTS:

  • 5x5x5cm buildvolume
  • 1.8w 445nm laser
  • 80w 12V heated-bed
  • 150w 230V powder heater with IR-Sensor
  • coater which compressed the powder
  • adjustable Feed control
  • Overflow container
  • closed buildchamber
  • total cost about +-500€

If you like my Instructable please vote for me in the Epilog and CNC-Contest.

Step 1: RESULTS

Here you can see some prints I have made with this printer. The cube is printed in grinded Instant-tea (95% Sugar). I am using Instant-Tea, because of the red color. The 450nm laser will be absorbed well by the red powder. White sugar will not work, because it will just reflect the laser. The laser is focused to 0.2mm. The power of the laser is set to 1W.

The cube has a size of 25x25x25mm and took 2 hours to print

The tube has a size of 15x20x10mm and took 45min to print

The 3D-Benchys have a size of 35x15x30mm and they each took 1 hour to print.

The black objects are printed with Stearin-Powder (wax)

Materials which can be printed on this machine:

  • Sugar --> successfully printed
  • Stearin --> successfully printed
  • Polyester --> in test
  • PA12 --> in test

Here I will show you the parameters for the materials which worked best for me (list will be extented, if I test new materials):


MaterialLayerhightTemperatur-BottomTemperatur-TopFeedrateLaserpower
Instant-Tea
0.2mm85°C70°
15mm/s perimeters
30mm/s infill
1W
Stearin-Powder (mixed with 5% carbon powder )
0.5mm45°C50°
10mm/s perimeters
20mm/s infill
1W

Video of the print process:

Step 2: CAD

The JRLS 1000 DIY-SLS-3D-PRINTER is completly designed in Fusion 360. Here is an interactive model of my printer:

If you can't see the interactive 3D model above, its probably because
you're not using a WebGL-enabled browser, or you're using the Instructables Mobile app)

All Fusion 360 files can be downloaded at this link: http://a360.co/2fkhbvN

Step 3: MECHANICS

Here are all the mechanical parts you need for this printer + the shops where you can buy them:


Extrusions and smoothrods:

QuantityDescriptionLink
4x400mm 2020 Aluminium Extrusion
dold-mechatronik
11x300mm 2020 Aluminium Extrusion
dold-mechatronik
2x260mm 2020 Aluminium Extrusion
dold-mechatronik
2x120mm 2020 Aluminium Extrusion
dold-mechatronik
2x180mm 2020 Aluminium Extrusion
dold-mechatronik
2x300mm 2040 Aluminium Extrusion
dold-mechatronik
2x90mm 1020 Aluminium Extrusion
dold-mechatronik
4x154mm 12mm smooth rod
dold-mechatronik
2x334mm 12mm smooth rod
dold-mechatronik
2x294mm 12mm smooth rod
dold-mechatronik
2x284mm 12mm smooth rod
dold-mechatronik
2x330mm 5mm smooth rod
kleinteileversand
2x110mm M5 threated rod
kleinteileversand


Nuts and Screws:

QuantityDescriptionLink
200xM4x6mm Screw DIN912
Schraubenluchs
200xM4 Square Nut DIN557
Schraubenluchs
100xM5 T-slot nuts (normal M5 Nuts grinded on two sides)
Schraubenluchs
100xM5x12mm DIN912
Schraubenluchs
100xM5x10mm DIN912
Schraubenluchs
100xM5x10mm ISO7380
Schraubenluchs
100xM3x8mmSchraubenluchs
100x
M5 Wascher
Schraubenluchs
100xM4 Wascher
Schraubenluchs


Linear Motion

QuantityDescriptionLink
4xSCS12UU Linear Bearing
Aliexpress
4xLMK12LUU Linear Bearing
Aliexpress
2xLM12UUAliexpress
1x340mm Leadscrew + Nut
Aliexpress
16xSK12 Rodholder
Aliexpress
1x130mm closed GT2 Belt
Aliexpress
1x200mm closed GT2 Belt
Aliexpress
2mGT2 Belt
Aliexpress
8x20 thooth GT2 Pulley 5mm Bore
Aliexpress
1x20 thooth GT2 Pulley 8mm BoreAliexpress
8x625zz Bearing
Aliexpress
2x608zz Bearing
Aiexpress
2x5x5mm Coupler
Aliexpress

Step 4: ELECTRONICS

Here are all the electrical parts you need for this printer + the shops where you can buy them:

QuantityDescriptionLink
1xArduino Mega 2560
Aliexpress
1xRamps 1.4
Aliexpress
5xA4988 Stepper Motor Driver
Aliexpress
1x
Laser Driver
Aliexpress
1x
1.8w 445nm LaserdiodeEbay
5xMicroswitchAliexpress
5x
Nema17 Stepper Motor
Aliexpress
1xMLX90614ESF IR-Thermometer
Aliexpress
1x
150w IR-Heater (request the seller for an black version)
Aliexpress
1x25A SSR Relay
Aliexpress
1x2004 LCD
Aliexpress
1x
LED Strip
Aliexpress
1xLED lamp 4w
Aliexpress
1x10k potentiometer
Aliexpress
a lot of
Wires

Step 5: 3D-Printed Parts

Here is the list of all required 3D-Printed Parts. All parts are printed with PLA in a 0.2mm Layer-Resolution. You can download the parts at the bottom of this step.

QuantityFile-Name
4xX-Rod-Holder.stl
1xX-Motor.stl
1xX-Idler.stl
1xX-Carriage
2xBelt-Tensioner.stl
4xY-Idler.stl
2xCoater-Idler.stl
1xCoater-Nut.stl
1xY-Motor.stl
1xCoater-Motor.stl
2xZ-Nut.stl
2xZ-Idler.stl
1xATX-Holder-Bottom.stl
1xATX-Holder-Top.stl
1xLaserdriver.stl
1xPowerpanel.stl
1xOverflow-Container.stl
1xOverflow-Wall.stl
1xFeed-Enstop.stl
1xBuild-Enstop.stl
1xY-Enstop.stl
1xCoater-Enstop.stl
1xCable-Holder.stl
4xFoot.stl (flexible material)

Attachments

Step 6: Sheets

Here are all the the required sheets files for the 3D-Printer. I'am trying to export the parts as DXF for you. However I can't export some files as DXF, so I exported them as a PDF File. Also it is high recommend to take a look at the CAD in Fusion 360.

Don't worry if you don't have professionell tools for the material preparation. I found my aluminium sheets on the scrap yard and cut them with an yig-saw. I drilled all the holes by hand. Only the Plexiglas-sheet is laser-cutted for that, I made a request at a local fablab.


5mm Aluminium sheets

QuantityFile-Name
2xY-Carriage.dxf
2xCoater.dxf
2xZ-Motor.dxf
1xFeedtable.dxf
1xBuildtable.dxf


1.5mm Aluminium sheets

QuantityFile-Name
1xLeft.dxf
1xRight.dxf
1xTop.dxf
1xBottom.dxf
1xFront-Top.dxf
1xFront-Bottom.dxf
1xChamber-Bottom.dxf
1xChamber-Top.dxf
2xChamber-Side.pdf
1x
Chamber-Backside.pdf
1x
Coater.pdf
1xHeater.pdf


3mm Plexiglass sheet

QuantityFile-Name
1xRückseite SLS-3D-Drucker


12mm Wood sheets

QuantityFile-Name
3xChamber Main Plate.pdf
2xChamber 110x60.pdf
2xChamber 60x90.pdf
2xChamber 55x60.pdf

Step 7: Let's Start to Build

What you need for this step:

QuantityFile-Name
3xChamber Main Plate.pdf
2xChamber 110x60.pdf
2xChamber 60x90.pdf
2xChamber 55x60.pdf

At first you have to build up the powder chamber. The bigger chamber is the Feed-Chamber, the smaller the Build-Chamber. Here you need to work very exact. Your chamber must be nearly 90° angeled in all three axis. To garanteer that, I used to small wood pieces wich are cutted to 55x55mm. Then I used some screw clamps to fix the wood sheets. After that you can pre drill the sheets and screw the sheets together. You have to use four wood dowels in the middle, because there is no other possibilty to connect the sheets. For the exact dimensions please open the CAD-File in Fusion 360 or an other CAD-Programm.

After you finished the chamber you can attach the four Corner Brackets printed parts to the chamber.

Step 8: First Stage

What you need for this step:


QuantityFile-Name
5x300mm Alumnium Extrusions
1xSpacer.stl
1xassembled powder chamber

Now you have to build the first aluminium stage. You need to use 5x 300mm 2020 extrusions to build the first stage. Insert some M5 Nuts to the extrusions. Then install the Spacer.stl . You do that by using two M5x10 DIN 912 screws. After that you can install the powder chamber from the previous step. Use the corner brackets and the spacer to screw the stage and the chamber together.

Step 9: Z-Idler

What you need for this step:

QuantityDescription
4xSK12 rodholder
2xZ-Idler.stl
2x625zz Bearing
12x
M5x10mm DIN912 srews
12xM5 t-slot nut

As you can see, you have to connect the SK12s and the Z-Idler.stl to the alumnium extrusion. In addition you have to push the 625zz bearing to the Z-Idler.stl

Step 10: Feed- and Build-table Part A

As you can see on the pictures, the aluminium parts are made by hand. It is recommend to print the DXF Files of the 5mm aluminium parts on paper. Then it is easy to transfer the right dimensions to the raw aluminium. You have to grind, drill and sand the aluminium parts. Try to work as exact as possible.

Step 11: Feed- and Build-table Part B

What you need for this step:

QuantityDescription
4xLMK12LUU Linear Bearing
16xM4x6mm DIN912 screws
1xFeedtable.dxf
1xBuildtable.dxf

Now you can connect the LMK12LUU Linear Bearings to the 5mm aluminium plates. You have to use M4x6mm DIN912 screws to connect the Bearings to the plates

Step 12: Install the Feed- and Build-table

What you need for this step:

QuantityDescription
1xassembled Feed-table
1xassembled Build-table
4x154mm 12mm smooth rods

Here you have to install the Feed- and Build-table. At first you have to slide the 12mm smooth rods into the SK12s. Then you can attach the Feed- and Build-table to the smooth rods.

Step 13: Z-Motor

What you need for this step:

QuantityDescription
2xNema 17 Motor
4xSK12-Rodholder
2xZ-Motor.dxf
8xM3x8mm DIN912 screws
12x
M5x10mm DIN912 screws
12x
M5 t-slot nut
1x
300mm 2020 Aluminium Extrusion

At first you have to connect the Nema 17 motors to the Z-Motor.dxf by using the M3x8mm screws. Then you attach the motors and the SK12s to the alumnium extrusion.

Step 14: Install the Z-Motors

What you need for this step:

QuantityDescription
1xassembled Z-Motors
1x300mm 2040 alumnium extrusions

Now it's time to install the Z-motors to the frame. Just push the Z-Motors on the smooth rods. Tighten the SK12s.

In addition you have to connect the 2040 alumnium extrusions to corner-brackets.stl at the front.

Step 15: Process Chamber Frame

What you need for this step:

QuantityDescription
2x400mm 2020 Alumnium Extrusion
1x300mm 2020 Alumnium Extrusion
2x180mm 2020 Alumnium Extrusion
2x260mm 2020 Alumnium Exrusion
2x
120mm 2020 Alumnium Extrusion

Here you have to install the aluminium extrusions for the process chamber. I made some notes on the photos for you, where you can see how the extrusions will be connected.

Step 16: Coater-Axis

What you need for this step:

QuantityDescription
4xSK12 Rodsholder
8xM5x12mm DIN912 Screws
4xM5x10mm DIN912 Screws
2x608zz Bearing
2x
Coater-Idler.stl

Here you have to install the SK12 rodholder and the Coater-Idler.stl. For the SK12s you need the M5x12mm for the Idler the M5x10mm DIN 912 screws. After you fixed the parts, you can insert the 608zz Bearing to the Coater-Idler.stl.

Step 17: Coater

What you need for this step:

QuantityDescription
2xSCS12UU Linear Bearing
2xCoater.dxf
2x90mm 1020 Aluminium Extrusion
8xM5x10mm DIN912 Screw
8xM4x12mm DIN912 Screws
1xCoater-Nut.stl
2xM5 T-slot nut
1xLeadscrew Nut
4xM3 Hex-Nut
4xM3x16mm Screw

At first you have to connect the alumnium extrusions to the Coater.dxf alumnium sheets by using M4x12mm screws. Then you can attach the SCS12UU bearings and the Z-Nut.stl printed part.

Step 18: Install the Coater to the Frame

What you need for this step:

QuantityDescription
1xassembled Coater
2x334x12mm smooth rods
1x340mm leadscrew
1x8mm Bore GT2 Pulley
1x200mm closed GT2 Belt

Here you have to install the Coater to the frame. Install the smoothrods first, then the leadscrew. After that you have to push the leadscrew through the Bearings and the Leadscrew-Nut. Don't forget to install the GT2-pulley and the GT2 belt to the leadscrew.

Step 19: Y-Motor / Coater Motor

You Need:

QuantityDescription
2xNema 17 Motor
2x5mm GT2 Pulley
7xM3x8mm DIN912 screws
1xY-Motor.stl
1xCoater-Motor

Here you simply have to screw the motors to the printed parts. After that you attach the GT2-pulley to the motor shaft

Step 20: Y-idler

What you need for this step:

QuantityFile-Name
4xY-Idler.stl
4x625zz Bearing

Here you just need to push the 625zz Bearings to the Y-idler.stl printed part. Repeat this step four times.

Step 21: Connect the Motors / Idlers

What you need for this step:

QuantityFile-Name
1xassembled Y-Motor
1xassembled Coater-Motor
4xassembled Y-Idler

Now you can screw the Y-Motor, Coater-Motor and the Y-Idlers on the frame. Don't forget to install the belt to the Coater-Motor.

Step 22: X-Axis

For the X-Axis you need:

QuantityDescription
2xY-Carriage.dxf 5mm Aluminium sheets
4xX-Rod-Holder.stl
1xX-Motor.stl
1xX-Idler.stl
1xX-Carriage.stl
16xM4x12mm DIN912 Screws
1xNema 17 Motor
16xM5x12mm Screws
2xLM12UU
2xGT2 Pulley
4xM3x8mm
2x284x12mm smooth rod
2xSCS12UU Linear Bearing
2x625zz Bearing

At First you have to insert the LM12UU inside the X-Carriage.stl printed part. Then you can attach to both Y-Carriage.dxf 5mm alumnium sheets the SCS12UU and the X-Rod-Holder.stl. You connect the X-Rodholder.stl by using M4x12 DIN912 screws, the SCS12UU with M5x12mm screws. After that you can connect the motor and the Idler to the SCS12UUs. Finally press the 284x12mm smoothrods inside the X-Rods-Holder.stl printed parts.

Step 23: Install the Pulleys

What you need for this step:

QuantityFile-Name
2x330mm 5mm smoothrod
5x5mm Bore GT2 Pulley
1x130mm closed GT2 Belt
Here you have to install the 5mm smooth rod to the Y-Idlers. You hold the smooth rod in place, screw the pulleys down. Also you have to attach the 130mm closed GT2-belt to the Y-Motor.

Step 24: Attach the Y-Axis Holders

What you need for this step:

QuantityFile-Name
4xSK12 rod holder
8xM5x12mm DIN912 screws
8xM5 t-slot nut

Here you just have to screw the SK12s to the frame.

Step 25: Install the X-Axis

What you need for this step:

QuantityFile-Name
1xassembled X-Axis
2x294mm 12mm smooth rods

Now you can attach the X-Axis to the frame. You do that by pushing the 12mm smoothrods into the SK12s. As you allready see, the machine is build to be very compact. There is less than 10mm space between the X-Axis and the frame.

Step 26: The Build-Piston

The heated build piston is one of the most important parts of this printer. The Build piston is used for hold the temperature of the powder. However some powders need a high temperature so the pistion needs to withstand a lot of temperature. So I searched for an material which isolates good and can withstand a lot of heat. I found foamed glass which has optimal characteristics. It isolates prefect, can withstand a lot of heat (Over 1000°C) und is strong enough to build on it.

The heat unit is build from an 10mm aluminium block. I drilled two holes for 40W heat cartridges and one hole for the 100k Thermistor. So I have 3.2W per square centimeter of power, which is more than enough to heat the block to over 150°C.

Over the block I installed two 1.5mm thick aluminium sheets, between these plates I installed an heat-resitant silicone to seal the piston. Because professionell silicones are very expensive, I was searching for a cheaper alternative. I found in an one dollar shop a silicone backing plate which can withstand 250°C. This is enough for my application. However the silicone isolates al lot of heat, so I am using an aluminium sheet as thick as the silicone and placed it in the middle of the silicone (see pictures). With this modification enough heat is transferred to the upper alumnium sheet

The feed pistion is build as the Build-Piston just without the heat unit.

Step 27: The Process-Chamber Backside

The Process-Chamber backside needs be sealed to prevent that powder will fall into the electronics. To realise that I am using the backing silicone plate and two alumnium sheets. The sheets have two slots for the coater. You have to cut the slicone plate in the middle of the sheets.

Step 28: Install the Pistons / Process-Chamber Backside

Here you can see how I installed the Pistons and the Process-Chamber backside.

Step 29: The Process Chamber Lamp

To light the process chamber up, I am using a normal LED-Lamp for 12V. I cut the led by half to fit it to the side panel of the process chamber. Also you have to extend the wires from the LED-Lamp. Use some heat shrink tube to isolate the driver from the aluminium sheets. Fix the lamp with two little screws in the heat sink.

Step 30: Z-Nut

What you need for this step:

QuantityFile-Name
2x5x5 coupler
2xZ-Nut.stl
2x110mm M5 threaded rod

Here you have to intall the M5 threaded rod to the Z-Motors. In addition you have to screw the Z-Nut.stl printed part to the Z-Table. You have to repeat this step two times (Feed & Build).

Step 31: The Process Chamber

This is the process chamber, the chamber where parts will be printed. As you can see inside the process chamber are no plastic parts. It is build to withstand around 150°C.

As you can see the Coater is angeled, this necessary to compress the powder for the Laser Radiation. If the powder is not compressed enough, then the sintered object will not be rigid enough, but to much compression will also damage the print. You have to find the perfect compression for your powder. Also you should raise the feed so much that at every coating process a little bit of powder falls into the Overflow.

The 230V Heater is also angled to the Build-Piston. I am simply using an small 1.5mm aluminium sheet to mount the heater to the process chamber. The MLX90614 IR-Thermometer is also angled to the Build-Piston. The dimensions for the alumnium sheets can be seen in the CAD-File.

Step 32: Plexiglas Backside

What you need for this step:

QuantityFile-Name
1xRückseite SLS-3D-Drucker.dxf 3mm Plexiglas
2x60mm Fans

As you can see, the backside of the printer is out of plexiglass. I uses Plexiglas, because I want to see inside the printer. I designed some holes for the fans, to prevent an overheating of the printer.

Step 33: The Laser

The Laser is the most important part of the printer. It melts the powder layer by layer to create an 3D-object. Because the Laser gets warm while printing you have to ensure that your laser gets cooled. For that I am using an alumnium heatsink with an 12mm bore. On top of the heatsink I've added an 30mm fan. The X-Carriage is designed for this heatsink with an additional 30mm fan.

The Laserdriver I am using is a cheap one from Aliexpress. It can controll up to 3A of current, the voltage and the current can be adjusted via potentiometer. Also it has an TTL input to controll the intensity of the Laser. Where the laser needs to be connected, is printed on the Laser-driver.

Step 34: Assembled X/Y-Axis

Here I want to show you how the X/Y-Axis of the printer looks like. As you can see I added some led strips inside the extrusions to light the printer up.

Step 35: How to Connect the Electronic

Here I made an schematic for you where you have to connect all the sensors, endstops and motors to the Ramps 1.4 . Take also a look at my photo. Also take a look at the Fusion 360 File, where you can see where the Endstops are located.


Endstops:

You have to switch the endstops between Ground and the Signal pin.

EndstopRamps1.4-PIN
XX- Endstop
CoaterX+ Endstop
YY- Endstop
BuildZ- Endstop
FeedZ+ Endstop


MLX90614:

MLX90614-PINRamps1.4-PIN
SDA20
SCL21
GNDGND
VCC5V


Thermistor-Bed:

Thermistor-PINRamps1.4-PIN
Thermistor-PinT1


SSR:

SSR-PINRamps1.4-PIN
+D10 +
-D10 -


BED:

BED-PINRamps1.4-PIN
+D8+
-D8-


LASER-TTL:

LASER-TTLRamps1.4-PIN
+D11
-GND


Motors:

MotorRamps1.4-PIN
X-MOTORX
Y-MOTORY
Build-MOTORZ
Coater-MOTORE0
Feed-MOTORE1

Step 36: The SSR

This is the SSR to controll the 230V Heater in the process chamber. The SSR is directly connected to the bottom plate for a good heat transfer. Because 230V is very dangerous, you have to make sure that you ground your complete printer. Also you have to make a central ground point.

Step 37: The ATX

I am using an ATX-Powersupply for my printer because it is cheap and compact. I connected the ATX to the frame by using the ATX-Holder-Bottom.stl and the ATX-Holder-Top.stl printed part. You have to drill two holes in the case to fix the Top-Holder. Be carefull with the ATX and make sure that you don't damage any electronics inside the case while drilling.

Step 38: Wire Magentment

I am trying to put all the wires in a spiral tube. On the one hand it looks more professionell and on the other it is more compact. I used these tubes to managed my wires: Aliexpress

Step 39: Overflow-Container + Data-Panel

To collect the unused powder, I designed an Overflow-Container which can fit inside the printer. The hoper garanteers that the powder falls into the container. The hole where the Overflow-Container is located, is completely capseld from the electronics that no powder can reach the electronics. Right to the Overflow Container, the Data-Panel is located. The Data-Panel has an AC-Connector and an USB-B Connector.

Step 40: The Firmware

For this printer I modified the Repetier Firmware, which can now controll the 4./5. Axis and the MLX90614 IR-Sensor. Also the 4./5. can be homed to a specific point.The Laser will be enable on every G1 move and disable on every G0 move. All heaters are PID-Controlled. The Firmware can be downloaded at the bottom of this step. You have to open your Arduino IDE and upload the .ino File to the Arduino. Modifications like Feedrate, PID and Accelerations can be set later in Repetier Host.

Step 41: Repetier-Host

This is the Host software for the SLS-3D-Printer. You can download it from Repetier.com. After you start the programm you have to create an profile for your printer. Go to Printer Settings --> Printer Shape there you adjust the parameters like an the screenshot above. After that you connect the Arduino to your computer, connect it with Repetier-Host. Then open in Repetier-Host Config-->Firmware Eeprom Configuration. And upload the Eeprom File from the bottom of this step. In the "Firmware Eeprom Configuration" you can set the most parameters like feedrate, PID... .

If you go to manual conrtroll you can move all the axes and heat the bed and the 230V Heater. To move the Feed and the Coater, you have to type some commands in the G-Code commandline:

P0 = Coater-Motor

P1= Feed-Motor

G-Codes

G-CodeDescription
G201 P0 X100
Go to position X100 with motor P0
G202 P0 X10
Set the position of motor P0 to X10
G203
Report current motor position
G204 P0 S0
S0 = disable motor / S1 = enable motor
G205 P0
Homes axis, sets position to 0 when endstop hits

Step 42: Slic3r

To create an Gcode File, out of an STL File, which the 3D-Printer can understand, you need an Slicer. I am using Slic3r for that, because there i can easily add G-Code between every Layer-Change. This is important, because I want to drive the coater after every layer change. Also I want to raise the feed-piston every Layer.

In Slic3r you can also adjust the speed for the Laser. You can set every speed parameter to the same value. If you see that your Laser is to strong, raise the speed. If this not help, you adjust the Laser intensity with M3 S<0-255>

If you trying to test an new Material, you can create an new Material profile in Slicer. Go to Filament Settings where you can adjust the Bed-Temperature and the 230V Heater Temperature (called Extruder in Slic3r). Start here with low Tempetures. If you see that your print warps, raise the tempeture. In SLS-3D-Printing the most important Heater is the Partbed-Heater, this is the 230V Heater in this Printer. This heater has the most effects on the warping.

You can download all the Slic3r Settings from here:

Attachments

Step 43: Safety First

While working with Lasers you should always wear Laser glasses. Don't buy cheap ones from Aliexpress or Ebay, buy a certified glass for your Wavelenght.I use a LG10 from Thorlabs.

CNC Contest 2016

Runner Up in the
CNC Contest 2016

Design Now: 3D Design Contest 2016

Second Prize in the
Design Now: 3D Design Contest 2016

Epilog Contest 8

First Prize in the
Epilog Contest 8