JRLS 1000 DIY SLS-3D-PRINTER

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.

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):

Video of the print process:

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

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

Extrusions and smoothrods:

Nuts and Screws:

Linear Motion

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

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.

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

1.5mm Aluminium sheets

3mm Plexiglass sheet

12mm Wood sheets

What you need for this step:

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.

What you need for this step:

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.

What you need for this step:

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

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.

What you need for this step:

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

What you need for this step:

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.

What you need for this step:

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.

What you need for this step:

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.

What you need for this step:

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.

What you need for this step:

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.

What you need for this step:

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.

What you need for this step:

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.

You Need:

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

What you need for this step:

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

What you need for this step:

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.

For the X-Axis you need:

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.

What you need for this step:

What you need for this step:

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

What you need for this step:

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.

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.

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.

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

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.

What you need for this step:

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).

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.

What you need for this step:

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.

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.

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.

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.

MLX90614:

Thermistor-Bed:

SSR:

BED:

LASER-TTL:

Motors:

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.

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.

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

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.

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.

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

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:

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.