The Cantilever Printer

My last 3D printer implementation, the Core3D CoreXY has been mostly done and I love it. All it needs is an automatic nozzle cleaner and I consider it done (sure will find something else to add onto it).

It’s reliable, sturdy and unfortunately big and heavy. What it is not, is something I can pick up and take along to my Parks and Rec presentation later this fall.

For that I’ve designed and implemented my 3rd 3D printer build, the Cantilever 3D. It will be lighter, simpler and I hope most importantly, something I can pick up, drop in the back seat and set up where ever there’s an outlet.

The Compact 3D will be a cantilever printer with little thrills. XYZ (X being cantileved, KFB2.0 controller board,  bowden extruder, adjustable z-enstop, non-heated bed with as little adjustment capabilities as possible.

Each of the axis are built using 3030 aluminum extrusion. each of which ends up being it’s own linear actuator (more on this later).

The entire printer was designed in Fusion 360, prior to implementation.

In this post I will walk you through the different materials used for this build. STL files and designs are available at and

Generic Axis

Each axis of this printer will be made of aluminum extrusion and will have the t2 belt “wrapper” around the extrusion and linear rail mounted to it. At one end there will be a nema 17 motor, on the other end idlers to guide the belt around/through the extrusion.

The G2 belt will be held in place by the adapter attached to the linear rail’s slider. The ribs on belt will be held in place by the grooves insider the bracket. The belt will be wrapped around the clips.


At this point there is no adjustable tensioner, other than pulling it tight when attaching. Having run for a few weeks now, it seems to work great.

End Stops

Although I’m a big fan of auto leveling, the first implementation of the Compact 3D will have end stops on each of the 3 axis. I will be using the same end stops as used on the Core3D printer. purchased on for $9.99 (set of 5)


Both X and Y will have static cases that can be attached to the extrusion of each axis.

The end stop can be slid into place and tightened by a t-nut on the extrusion.

The Z-axis will be adjustable as the first layer of each print is determined by where the Z-axis ends. It is designed to slide in the groove of the extrusion and can be adjusted by a wheel.

I have uploaded the design for this end stop to feel free to download.

Bowden Extruder

I’ve never worked with a bowden extruder before and have my doubts about it (play of filament inside bowden tube). However, since this printer will be a cantilever type, I want to limit the load that is put on the X-Axis. Direct extrusion would imply mounting the extrusion motor on the X-rail adding a lot of weight (and momentum) that might be work well for cantilever type printers.

For the bowden drive I’m using an MK8 extruder from ebay  that will be mounted to the Z-Axis.


The hot-end and nozzle are a e3d v6 knockoff from amazon.


The original thought was to go with the standard Ramps 1.4 kit but due to it’s stacked hight I ended up going with a cheap KFB2.0 controller board.


The main topics of this implementation will be the actual build, the installation of the electronics and lastly the configuration of the software.


I tried to keep the cost down to some extend but did not have to patience to go through China. Most parts were ordered off of Amazon and EBay. I am an affiliate so if you want to help me out, use the links provided.

The backbone of this printer is 3030 Aluminum extrusion. The design requires approximately 1200mm. To be safe (since you will need to cut this) I’d order more. Your best bet is to order this from

80/20 3030 seriesEbay $17.10 (plus shipping)

Linear Rails 3 x 250 mm Ebay (I was able to get mine at 16.77 per)

Stepper Motors (1.7A) Amazon $51.99 (You can get away with lighter ones)

Idlers 2 5-packs (for the linear actuators) Amazon $8.99

Belt Pulleys (16 teeth) 5-pack Amazon $10.99 (you could also get the 20 teeth)

v6 Hotend (bowden) Amazon $15.98 (You can go for the real E3d but that would blow my budget)

KFB2.0 Controller board Amazon $19.95 (Substitute for RAMP 1.4 Kit, as it doesn’t fit)

DRV8825 Stepper Motor Driver (5 pack) Amazon $11.99

LCD 12864Amazon $14.99

Bed 200×200 (220×220 actual) non-heated: ebay $12.84 (you could go with heated bed but it would require additional power).

NetGear CaseeBay 10.99 + shipping (the design is based on dimension of NetGear FSV318, could be changed though)

MK8 ExtrudereBay $8.33

Cables for Stepper motors Amazon $9.99

Power Brick 12V 8A 96W Amazon $22.50 (comes with adapter that fits netgear power input

Filament (PLA) Amazon $23.00 I did end up using a little ABS for the Hotend bracket. Everything else is PLA.

GT2 Timing belt Amazon $8.99

USB ConnectorAmazon $6.79 (optional but makes for nicer finish)

Circuit BoardAmazon $6.99 (optoinal to add jsx connectors. Cables could go directly to KFB2.0 Board)

Square Nuts M3 Amazon $6.99 (only need 7)

Hex nuts M3 Amazon $7.05

T-nut 30 series (m6) 100 pack Amazon $13.99 (Again only need 3)

T-nut 30 series (m3) 50 pack AlieXpress $8.78 (you can get them from amazon in 10 packs for way more but faster)

Pan head screws M3 30mm Amazon $8.72 (only need 20)

Hex socket screws of various sizes Amazon $13.99

JST 2.54 connectors (2/3/4/5/6) Amazon $9.99 (the KFB2.0 is all JST connectors. You may have to crimp your wires accordingly.

Cable wire Wrap (4m) Amazon $6.18

3030 Corner Bracket (come in 10 pack) Amazon $10.99 (only need 2)

As you can see things start adding up (little over $400). One has to be realistic that all the little items matter and cost money. I’ve tried to represent as close as possible all the items needed for this build.

All of this was ordered through Amazon Prime. If you haven’t tried it, check out the free trial here:

If you have time and patience many of these items can be found on for much much less. Delivery times can run up to several weeks, so again, patience is the name of that game.

Step 2: Linear Actuators

All three axis are based on the same design and are in fact standalone linear actuators that could be used for any purpose.

Components needed for each of the actuators:

Linear Rail (for this design 250mm but could be longer)

3030 Aluminum extrusion (375mm for Z-axis, 320mm for X-Axis and 320 for Y Axis). If you go with longer linear rail then go with more extrusion.

Stepper motor with belt pulley for each actuator. In this design I used 1.7A stepper but I think you can easily go with 1A steppers.

End-stop for each actuator. The end stops are Gowoops 5 PCS of Mechanical Endstop Switch with Cable. The cases in which they are attached are to be 3D printed.

GT2 timing belt

3 idlers to guide the GT2 belt

End casings for the actuator to be 3D printed

6 pan head 30mm m3 screw

Based on the Axis different linear guide slider Connectors/belt tensioners.

3D printer files for each of the axis are:


  • IdlerCapFront (Mirror).stl,
  • IdlerCapBack (Mirror).stl
  • NemaCapFront (Mirror).stl
  • NemaCapBack (Mirror).stl
  • EndStopCaseX.stl
  • HotEndAdapter.stl
  • HotEndBracket.stl
  • LinearAdapterTensionClip.stl (2x)


  • IdlerCapFront.stl,
  • IdlerCapBack.stl
  • NemaCapFront (Mirror).stl
  • NemaCapBack (Mirror).stl
  • EndStopCaseY.stl
  • LinearAdapterY.stl
  • LinearAdapterTensionClip.stl (2x)


  • IdlerCapFront (Mirror).stl,
  • IdlerCapBack (Mirror).stl
  • NemaCapFront (Mirror).stl
  • NemaCapBack (Mirror).stl
  • LinearAdapterZ.stl
  • LinearAdapterTensionClip.stl (2x)
  • AdjustableEndStopCaseZ.stl
  • AdjustableEndStopWheel.stl
  • AdjustableEndStopWheelHouseBottom.stl
  • AdjustableEndStopWheelHouseTop.stl

The Nema Endcaps are connected via a 30mm pan head screw (with idler in between) and 4 pan head screw connecting the Nema Stepper motor. In the back caps there is space to place hex nuts.

Once you’ve connected all the idlers (two in the End caps and one in the Nema caps) and attached the Nema Stepper moter to the Nema caps, you can weave the GT2 belt through (and around the pulley) and pull both ends up to the Linear rail slider.

Keep several inches past the linear slider on each end as you will be wrapping them around the tension clips and inserting these into the adapter.

I have found it easiest to do this with a lot of slack, then connect the adapter to the slider with four hex Socket screws (6mm) and only tighten one side of the belt. With pliers you can now tighten the belt on the other side (until the belt is real tight) and screw the remaining screws.

The end-stop casings are a real close fit to the actual end stops. Make sure you connect the wiring prior to sliding he end stop in the case. The case can then be attached to the extrusion with a T-nut and 20mm hex socket screw

Step 3: The Case

I used a netgear fsv318 Router as the base for the printer. It can hold the electronics and comes equipped with an on/off button as well as a power connection.

In order to prepare the case, I opened the case and cut the circuit board next to the power adapter leaving the board with the on/off swich and power adapter.

I did some rewiring to get plus and minus wires that can originate from the power adapter and can be switches on/off with the existing switch. This does require the ability to use a volt meter and to solder to figure out where and how to connect the new wiring.

I created a controller board base that uses the existing screw holes in the Netgear case and allows for the addition of a circuit board that can connect all the wiring (via jst connetors).

The Y-axis is connected via two 3D printed brackets that can be screwed into the case (by means of hex socket screws and nuts) and in turn wraps around the extrusion, to be connected via 4 t-nuts and 15mm hox socket screws.

The 3D printed items for this step are:

  • bodyClamp.stl
  • bodyClamp_2.stl
  • MotherBoardBracket.stl

Step 4: Electronics

For this implementation I ended up using a KINGPRINT KFB2.0 Controller Board (for Reprap Mendel Prusa I3 Kossel 3D Printer). I had initially order the usual RAMPS 1.4 kit but figured out quickly enough that stacked up it would exceed the height of the Router case (intended to hold the electronics).

At the time of ordering the KFB2.0 there was no documentation, whatsoever, to be found on it but it seemed to be simply everything that was on a RAMPS 1.4 shield (and then some) and for less than $20 I felt it was worth a try.

Turns out I’m pretty pleased with it. It does exactly the same as a RAMPS 1.4 shield and it takes the same software. It is basically an Arduino Mega 2560 with all the connectors needed for stepper drivers and all other 3D printer related connections.

This board can actually take 24 Volt (as opposed to only 12V for the RAMPS 1.4).

The only difference is all the connections. These are all JST 2.54 connectors and thus I did end up crimping a lot of wires. The stepper motor wires I put in the material list already use JST 2.54 so that should make it is bit easier.

In the case of my implementation I decided to leave all connections outside of the box and prepared a circuit boars with JST connetors for X, Y, Z steppers and end stops, Extruder, hotend and thermistor. I left room for possibly a second extruder.

I had hope that wiring the way I did, I could easily open the case and get to the electronics. As you can see in the images, I can do that to some extend but opening and closing the case is a pretty tight fit.

In order to pass through the wires for the LCD, I had to saw open one of the side gaps. The LCD wiring fits nicely.

I also added a secondary connector for my power brick that I can reach when the case is half open. Optional but handy.

When adding the stepper drivers, don’t forget to insert the proper jumpers (all three for each driver) to get the most accurate steps for this configuration 1/16 steps.

Make sure the drivers have their potential-meter screw pointing towards the Main Board Chip (see images). Inserting them the wrong way I believe will fry components beyond repair.

The same goes for the End stop connections. The signal is towards the outside of the board.

Most connections are printed on the bottom of this particular controller board, so check it out first prior to screwing the board down.

I’ve included an STL for a case that can be used to house the LCD. I’ve left it open in the back as I haven’t figured out if I want to connect it somehow to the case or if I want to leave it loose (I pick it up when operating it).

LCD Case: LCDCase.stl

Step 5: Bed and Assembly

At this point all components to the printer are in place. All that is left to complete the build is assembly.

The printer bed is supported by a 3D printer frame on which an aluminum bed can be added (via screws and springs).

The MK8 Extruder can be attached to the Z-axis with the provider Extruder Bracket: ExtruderBracket.stl

The STL for the 3D printed bed is: BedFrame.stl

All that is left is to attach all three axis to each other and to the case subsequently.

The X-Axis is attached to to Z-Axis via the Linear adapter on the Z-Axis by means of three 6M t-nuts and 3 M6 Hex socket screws (10mm)

The Z-Axis is attached to the Y-Axis via a “bridge” using 3030 Extrusion and 2 corner brackets.

It may take some effort and a water level to make sure the connections make perfect 90 degree angles. Not putting in that effort may make for some wonky prints.

Step 6: Software Setup

The KingPrint KFB2.0 board runs marlin software which can be downloaded at:

Once loaded locally it will need some configuration to get it to work with this printer build.

Most changes will be made to the configuration.h file (attached)


Endstops require inverting

#define X_MIN_ENDSTOP_INVERTING true // set to true to invert the logic of the endstop.
#define Y_MIN_ENDSTOP_INVERTING true // set to true to invert the logic of the endstop. 
#define Z_MIN_ENDSTOP_INVERTING true // set to true to invert the logic of the endstop.

Steps based on 1/16 and 16 teeth and MK8 extruder

#define DEFAULT_AXIS_STEPS_PER_UNIT { 100, 100, 100, 92.6 }

Since the bed is only supported by the linear slider, there will be more vibrations. The Jerk needs to be pushed down (maybe even further than the numbers shown)

#define DEFAULT_XJERK                 10.0
#define DEFAULT_YJERK                 10.0
#define DEFAULT_ZJERK                  0.4
#define DEFAULT_EJERK                  5.0

based on current build (this may differ based on stepper wiring)

#define INVERT_X_DIR false
#define INVERT_Y_DIR false
#define INVERT_Z_DIR false

based on the current build and it’s dimension I had to set the X Y and Z boundaries

// Travel limits after homing (units are in mm)
#define X_MIN_POS -17
#define Y_MIN_POS -37
#define Z_MIN_POS 0
#define X_MAX_POS 200
#define Y_MAX_POS 200
#define Z_MAX_POS 270

Since my end stop are outside the bounds of the bed I need to change the manual home settings

// Manually set the home position. Leave these undefined for automatic settings.
// For DELTA this is the top-center of the Cartesian print volume.
#define MANUAL_X_HOME_POS -17
#define MANUAL_Y_HOME_POS -37

Turn on Full graphics LCD and SD card support

//#define ULTRA_LCD   // Character based
#define DOGLCD      // Full graphics display
 * SD Card support is disabled by default. If your controller has an SD slot,
 * you must uncomment the following option or it won't work.

Enable the proper LCD

// RepRapDiscount FULL GRAPHIC Smart Controller

Because the Z-axis is belt driven (whereas most are lead screw driven) I end up with an issue when a print is stopped. If I click STOP PRINT (or even if a print is done) the Z-Axis will loose power and drop like a rock. This can damage your print or in worse case shatter your bed. For this I made some changes to the more hidden code.

Whenever a SD_FINISHED_RELEASECOMMAND is issued power is dropped to all stepper which for this printer can be bad (dropping Z-axis). I expanded the code in Configuration_adv.h to add to more command in that event.

#define SD_FINISHED_STEPPERRELEASE true  //if sd support and the file is finished: disable steppers?
  #define SD_FINISHED_RELEASECOMMAND "M84 X Y E" // You might want to keep the z enabled so your bed stays in place.
  //#define SD_FINISHED_RELEASECOMMAND "M84 X Y Z E" // You might want to keep the z enabled so your bed stays in place.

I also changed the release command to NOT drop power on the Z-Axis stepper. Now when the stop command is executed, the printer will first home to X0Y0 (which should get out of the way of any print. Subsequently the printer homes to Z0 and then drops power to X and Y (not Z).

In the stepper.ccp file the code has been changed to execute these new commands.

      if (!cleaning_buffer_counter && (SD_FINISHED_STEPPERRELEASE)) {
    _NEXT_ISR(200); // Run at max speed - 10 KHz
    _ENABLE_ISRs(); // re-enable ISRs

These are all the changes that were made to make this printer run.

Step 7: Conclusion

So this was all it took to build the Cantilever printer I set out to build. The materials list I believe is complete but mostly sourced from Amazon. The build can be lot cheaper if you dig a little deeper into AliExpress.

The printer performs fine for the budget it was built on. Having the entire bed rest on a single linear slider is a bit of a stretch but seems to work.

Step 8: STL Files and Design

All 3D printed parts that have been referenced in this build can be found in the uploaded

The entire design can be downloaded from GrabCad at

All items where printed on another custom built printer of mine. That one is a bit more complicated than this build but maybe one day I’ll create an instructable for it as well