Swapper3D Instructions

Set servo start positions

These are the most important instructions in the Swapper3D guides. You must follow them exactly or damage to the Swapper3D could result. If you have any uncertainty then please create a post in the community forum. We will reply there.

   The reason for these steps; Short answer: You will be setting the start position of the servos, which is the start position of all motion during a “Swap”.


   Long answer: During the manufacturing process the output shaft is pressed into the servo but the manufacturers of servos don’t align the splines on the output shaft to a specific starting angle. For this reason each servo is different.
   Longer answer: The output shaft of the standard servos, either 180 or 360 degree, have 25 “teeth”, aka “notches”, aka “splines”. You can confirm that by looking on the servo horn and it will show “25T” which refers to having twenty-five(25) teeth. That means if you are pressing the horn onto the output shaft there are 25 positions that you could press the horn onto. Since the number of degrees in a circle is 360, and there are 25 teeth, then each tooth is 14.4 degrees rotated from the last. This means that there could be a maximum angular variation between the starting position of any two(2) different servos of 14.4 degrees.
   In the Remote Controlled world (re:R/C) whether planes or cars, setting the neutral, or starting position, of each servo is called “setting the trim” or “trimming”.  That is what you are going to do here, you are going to adjust your specific unique servo so that it points to the starting position needed during a swap. There are 7 servos (or 8 if you have a palette), and each one will be different than any other so you need to repeat this process for each servo. Because of these steps, every servo, in every Swapper3D kit we send out, can have the same starting position despite any manufacturing difference.
   Because your servos are unique from any other in existence, the example offsets that are shown here (in pictures or video) will be different than the offset you will have for your servos. Just make sure that your horn arrows point to the correct alignment mark on the alignment guide, and the offset value, if different than in the example pictures or videos, doesn’t matter. Remember, the most important thing is that each servo is set to its starting position mark on the alignment guide.

Power on the printer

  1. Plug in the power cord to the printer (Green arrow)
  2. plug the power into the wall outlet (Red Arrow)
  3. turn the printers power switch ON (Yellow arrow)

Use the alignment guide to set the servo start position

Pro Tip: Watch the video below! You only need 1 of the alignment guides for the standard size servos and one for the micro servo. You will screw the guide to the servo while adjusting it and remove it to use on the next one.


  1. Add the alignment guide to the servo using two(2) M3x10mm socket cap screws
  2. Add the servo horn to the closest output shaft spline position that is one(1) or two(2), output shaft notches, counter-clockwise to its respective mark on the alignment guide.
  3. Secure the horn to the output shaft as per the servo primer
  4. Add the arrow and a screw to the end of the horn
  5. Use the <> arrows on the lcd to select the servo whose start position you want to set
  6. use the +- buttons on the lcd to adjust the servo horn and the arrow to point exactly at the line for the respective servo, for example TH servo points to the TH line on the Alignment guide. The minus(-) button will lower the number, and the plus(+) button will increase the number on the LCD. If you go past the line then press the opposite button to go back in the other direction. Holding the either button will make the horn arrow rotate continuously, and a single press will adjust the number by one(1) either more or less depending on whether you are pressing the + or – button.
  7. Once the adjustment is made press the “S” button to save the position to the Arduino controller permanent eeprom memory.
  8. The servo will sweep from it’s start to end position and back again. Make sure it still points to the correct line marker.
  9. remove the adjustment guide and horn arrow BUT leave the black metal horn in place.
  10. Repeat for each of the servos; The steps that follow show the positions for each servo after adjustment as per this step. The order that you adjust them does not matter, but the steps below go in the order of the Arduino LCD menu from left to right. If you adjusted the TH Tool Holder servo during this step then you do not need to do it again.

Important note: If you make mistake with alignment of the start position for a particular servo then you should start again.
That means:

  • Leave the power ON!
  • Remove the screw holding the horn on.
  • Wiggle the horn free and take it off completely.
  • Set the start position of the current servo back to zero(0) on the LCD
  • Read the instructions again starting with step #1
  • watch the video again
  • follow each step precisely

Tool Rotate (TR) 360d

Tool Height (TH) 180d

QuickSwap- Hotend Lock (QL) 180d

Tool Holder Rotate (HR) 360d

Cutter Rotate (CR) 180d

Cutter Action (CA) 180d

Tool Lock (mini) 280° (TL)


  1. Fit the adjustment template onto the servo. Remember that the output shaft must be aligned with the zero line (cyan arrows).  Don’t bother securing it with any screws. The micro servo adjustment template can be found in a small baggy full of the small plastic parts including the horn arrow used previously.
  2. Using the two(2) small M2x8mm round head N0.1 Phillips drive screws (pink arrow),
  3. see image with top and bottom labelled
  4. attach the horn extension (red arrow) to the TOP-SIDE of the micro servo horn (yellow arrow).  DO NOT OVER-TIGHTEN!!!! The horn plastic is very soft so just screw into it until the extension is flat but no more. It should not wobble when you shake it.
  5. Screw in an M3x10mm socket cap screw(green arrow) into the end of the extension
  6. Position the white end of the horn one(1) spline counter-clockwise to the TL mark,
  7. then press the horn onto the micro servo.
  8. Secure the horn with one(1) M2x3mm button cap screw into the center hole (orange arrow)
  9. Set the start position for the TL micro servo by follow the same instructions as those for the standard size servos
  10. Afterwards the exposed white horn will point to TL.
  11. Remove the alignment guide
  12. Repeat these steps for WA micro servo if you have a palette kit.

Waste Cup Action (mini) 280° (WA) (For Palette users only!)


  1.  Secure the horn with one(1) M2x3mm button cap screw into the center hole (orange arrow)

One last Save


Make sure you press the ‘S’ button one last time to ensure that all the settings have been saved!

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