1/2 Scale Star Wars E11 with Lights and Sounds

I designed and built this for my daughter's Halloween costume!

This is a ½ scale replica of a Star Wars E11 blaster, a perfect size for kids Halloween costumes.  This original design is based on the blaster Leia takes from the storm troopers during the rescue mission in Episode IV.  Therefore great if your kid wants to be Princess Leia OR a storm trooper.  The design includes sturdy front and back sling mount points so that you can add a shoulder strap if desired.

You can optionally make it have lights and sounds by including the electronics from this toy blaster, but it requires modifying the electronics with a soldering iron.  Note that I've only built one of these, so I don't know how much variation there is in the parts you get from Amazon.

Both the electronics and no-electronics versions are divided front-to-back so they'll fit on the bed of smaller printers and and left-to-right so they can print cleanly with minimal supports and maximum strength.  There left and right halves are joined by M3 screws (see the parts list in the assembly section).  There is an overlapping flange to join the front and back halves into a sturdy, solid whole.

There is a thread on the front of the blaster and a corresponding ring that should be printed in orange plastic to ensure people know it is a toy.  Do not carry the blaster around without this ring attached, or someone might think it is a real gun.

I've also included the whole model as a single STEP file to make it easy for other people to build on the design or slice it differently.

Printing

All the parts are assembled on the slicer 3mf files and configured with the print settings described below, including the painted on supports.  This is probably the easiest way to get started printing.

• Electronics model:
  • Print one slicer_with_elec_right_side_and_small_parts.3mf in black PLA
  • Print one slicer_with_elec_left_side.3mf in black PLA
  • Print one slicer_front_ring.3mf in orange PLA
  • Print one slicer_lens.3mf in transparent PETG, or cut a lens out of a plastic package or milk jug
• No electronics model:
  • Print one slicer_with_elec_right_side_and_small_parts.3mf in black PLA
  • Print one slicer_with_elec_left_side.3mf in black PLA
  • Print one slicer_front_ring.3mf in orange PLA

Below are the printed parts lists if you want to slice and print for yourself.

Parts list (no electronics)

• Front left main - use the no_elec version
• Front right main - use the no_elec version
• Rear left main - use the no_elec version
• Rear right main - use the no_elec version
• Rear sling tab - an insert captured between the left rear and right rear to make sturdy mount point for a sling.
• Front sling bar - an insert that goes around a screw in the front main to make a sturdy mount point for a sling.
• Front ring - print this in orange plastic and screw it onto the front main to identify this as a toy.

Parts list (electronics)

• Front left main - use the with_elec version
• Front right main - use the with_elec version
• Rear left main - use the with_elec version
• Rear right main - use the with_elec version
• Rear sling tab - an insert captured between the left rear and right rear to make sturdy mount point for a sling.
• Front sling bar - an insert that goes around a screw in the front main to make a sturdy mount point for a sling.
• Front ring - print this in orange plastic and screw it onto the front main to identify this as a toy.
• Internal trigger pins 2x - two (identical) pins that form the pivot for the trigger and the post the trigger spring will press against.
• Battery door screw sleeve - optional sleeve to go over the screw that forms the hinge for the battery door.

Printing instructions

• Print the blaster parts with their flat faces down in black PLA.  Use Prusa Slicer standard settings for 0.15mm layer height, except:
  • 3 perimeters
  • Supports: paint on supports for all the internal overhangs, especially on the internals of the with_electronics models
    • Enable organic supports
    • Except for the front extrusion on the scope and the insides of the front and rear sight guards, the overhang surfaces will all be internal, so they won't be visible after assembly. 
  • The battery door screw sleeve and the front sling bar may require a brim
• Print the front ring in orange PLA.  Use Prusa Slicer standard settings for 0.15mm layer height, except:
  • 3 perimeters
• For the electronics version, print a lens for the back of the scope using clear PETG
  • Adaptive layer heights (you want a top layer, one middle layer, and one bottom layer)
  • Concentric top and bottom infill

No Electronics Version

For the no-electronics version, you need a selection of different length M3 screws and one M3 nut.  I already had this kit of black M3 hardware on hand and it had all the lengths needed.

• M3x6 - 3
• M3x8 - 3
• M3x10 - 2
• M3x12 - 2
• M3x16 - 9
• M3x20 - 1 (optional) if you want to use the front sling bar
• M3 nut - 1 (optional) if you want to use the front sling bar

Assembly steps

• Rear assembly:
  • Insert the rear sling tab in the slot in the rear right main.
  • Place the rear left main on top of the rear right main so that the rear sling tab goes into the slot.
  • Connect the left and right halves with M3 screws as shown below
    • The screws cut a thread in the left main parts.  As you screw them in, they may push the right and left parts away from each other.  Hold them firmly until the M3 screws begin to thread into the left main part.
• Front assembly
  • The front halves sandwich around the flange on the rear assembly and form a single rigid unit.
  • Place the front right main over the flange on the assembled rear main
  • Place the front left main over the flange on the assembled rear main
  • Connect the front left and right halves with M3 screws as shown below.
• Front sling bar (optional)
  • Place the front sling bar between the front sight guides
  • Put an M3x20 screw through the hole in the left front main. Note: this hole has a round indent.
  • Mate the screw up with an M3 nut on the right side.

Electronics Version

The electronic version of this model is designed to use the electronics and several other parts from this toy blaster.  

Electronics Preparation

• Remove the screws that hold the two halves of the toy blaster together.
• Save the following parts:
  • The electronics, which should all be connected by wires:
    • the main board with two LEDs soldered on
    • the rear LED (flashing blue and red)
    • the firing switch
    • the speaker
    • the top battery terminals
  • The plastic trigger and the trigger spring.  Don't forget the trigger spring.
  • The battery door at the bottom of the grip
  • The lens from the front LED
  • The batteries
• Soldering
  • Take a picture of the board with a closeup of the LEDs
  • Desolder the front LED and solder in wires that extend it about 135mm. 
    • Tips for soldering and desoldering:
      • Put a piece of masking tape around the LED and mark which lead is the positive on the tape.
      • Heat the solder pads up and remove the LED
      • Use desoldering wick to remove the excess solder from the pads
      • Use a different color wire for the positive and negative leads.
      • Strip one end of the wire and wrap it around a lead.  Head the lead and the wire with a soldering iron and apply solder.
      • Cover the bare leads (or at least one bare lead) with heat shrink tubing or tape.
      • Push the other end of the wire through the hole in the circuit board.  Head the wire and the pad with the soldering iron and apply solder.  Be sure you have the positive and negative terminals correct!
  • Desolder the top LED and solder in wires that extend it about 48mm. 
  • Apply 3v to the terminals (you can use the batteries) and test that the electronics still work.  If one of the LEDs is not working, check the polarity of the LEDs.

Hardware

For the electronics version, you need a selection of different length M3 screws and one M3 nut.  I already had this kit of black M3 hardware on hand and it had all the lengths needed, except the hinge bolt for the battery door, as noted below:

• M3x6 - 3
• M3x8 - 3
• M3x10 - 2
• M3x12 - 2
• M3x16 - 8
• M3x20 - 1
• M3x25 - 1 - you will want to cut this off at 23mm or put a second nut on it to avoid the sharp end catching on things.
• M3 nut - 2 or 3

Assembly

Rear assembly

• All the electronics are designed to go in the rear right main (this is the part with the thicker offset portion of the top scopes
  • Place the battery terminal pieces in the slots above the battery wells.  Be sure the one with the spring goes in the rear position.  You may need to shim these slots to ensure a tight fit.  I used folded up pieces of masking tape.  
  • Fold the tabs where the wires are soldered so they are perpendicular to the main body of the tab This helps make sure they clear the other side of the main body.
  • Put the speaker in with the speaker side down toward the grill cut into the right side
  • Route the red/blue LED (the one with the original wires up and to the rear of the scope.  The LED should just protrude into the rear opening and should not interfere with the rear lens.
  • Route the flashing red (top LED) up and to the front of the scope.  The LED should just have room to slide into the front opening in the scope.
  • Route the yellow (front LED) out the slot in the front of the main body.  
  • Place the firing switch in the square cutout with the button facing forward and down.
  • Place the electronics board and any excess wire in the center slot.
  • When you're done, you electronics should look like this:
  • Use masking or electrical tape to ensure that all the wires stay in their slots.  Only put the tape inside cutout slots.  Do not put the tape on the flat face of the right rear main, or the rear left main will not fully mate.
• Insert the rear sling tab in the slot in the rear right main.  It will be captured and held in place by the rear left main.
• Insert the lens into the slot at the back of the scope.  It will be captured and held in place by the rear left main.
• Insert the trigger pegs into the two holes above the trigger opening.

• Before the next step, check your work.  You will need to hold the trigger in place while you install the rear left main, so make sure you have done everything needed.

• Installing the trigger spring, trigger, and left rear main:
  • Reference illustration

• Place the trigger spring over the rear trigger peg with the crossed part facing downward and one arm above the front trigger peg.  See the red line in the illustration.
• Place the trigger onto the rear trigger peg over the spring.  Make sure the back arm of the spring catches in the bracket on the back of the trigger.  See the green outline in the illustration.
• Put one hand over the rear trigger peg and use the other to depress the trigger.  See the blue line and arrow on the illustration.
  • Be sure the bracket on the back of the trigger is inside the body of the blaster, in the cutout.
• Hold the trigger under tension from below and place the rear left main part on top. 
• The rear left main part should capture all of the following and hold it in place:
  • All the electronics, including the top battery tabs.  The front LED wires will be protruding from the front of the rear assembly.
  • The trigger and the two trigger pegs
  • The rear sling tab
  • The lens on the rear of the scope.
• Tape the two halves of the rear assembly together tightly with masking tape.
• Test the assembly before putting in the screws:
  • Test the trigger to make sure it operates correctly.  You should hear a slight click when it contacts the firing button.
  • Insert the batteries and hold the battery door on the bottom to complete the circuit. When you squeeze the trigger, you should hear the sound and see all three LEDs light up.
• Connect the rear left and right halves with screws as shown below.  Leave the battery door (M3x25 screw) for last, as described in the following step.
  • The screws cut a thread in the left main parts.  As you screw them in, they may push the right and left parts away from each other.  Hold them firmly until the M3 screws begin to thread into the left main part.

• Install the battery door:
  • Install the battery door in the bottom of the grip.  It should line up with the screw hole and snap into place on the other side.  
  • Place the M3x25 screw into the hole on the left side.  This side has a round indentation.
  • Thread an M3 nut onto the screw on the right side and tighten the screw. 
  • Use a cutoff wheel or hack saw to remove the excess screw length.  You can mark the length and remove the screw first to avoid damaging the model.  If you can't or don't want to cut the screw, place a second nut on it to protect people from the sharp end.
• Install the batteries and test the electronics again.

Front assembly

• The front halves sandwich around the flange on the rear assembly and form a single rigid unit.  The wire for the front LED passes through a channel in the front parts.
• Place the front right main over the flange on the assembled rear main.  
• Ensure that the LED wires are in the channel, securing them with tape if needed. Only put the tape inside cutout slots.  Do not put the tape on the flat face of the right rear main, or the rear left main will not fully mate.
• Place the front lens from the toy blaster into the slot in the front of the blaster.   It will be captured and held in place by the front left main.

• Place the front left main over the flange on the assembled rear main.  Ensure the wires are not pinched and the LED and lens are captured in the front.
• Connect the front left and right halves with M3 screws as shown below.

Front sling bar (optional)

• Place the front sling bar between the front sight guides
• Put an M3x20 screw through the hole in the left front main. Note: this hole has a round indent.
• Mate the screw up with an M3 nut on the right side.

You did it!  Enjoy your new Halloween costume prop!