Stepstruder Mk6 Plus Assembly 3mm
These instructions are for buildling the MakerBot Stepstruder MK6+ kit, rather than the MK6 kit. If you are upgrading a MakerBot Plastruder MK5 to a MakerBot Stepstruder MK6 using the MakerBot Stepstruder MK6 Upgrade Kit, proceed to Stepstruder MK6 3MM Upgrade Instructions.

Tools You'll Need

Cannot fetch Flickr photo (id: 4883011345). The photo either does not exist, or is private

The Stepstruder MK6 goes together pretty easily, but you'll need a few tools to speed the process along:

  • Scissors
  • 1.5mm Hex Wrench
  • 2.5mm Hex Wrench
  • 13mm Wrench
  • Adjustable Wrench
  • Two Pliers
  • Soldering Iron
  • Sharp Knife
  • Tape

Strongly suggested

Parts You'll Need

Nuts and Bolts

Cannot fetch Flickr photo (id: 5393438070). The photo either does not exist, or is private

Custom Machined Parts

Cannot fetch Flickr photo (id: 4902422996). The photo either does not exist, or is private

MK6 Nozzle

Cannot fetch Flickr photo (id: 5632843766). The photo either does not exist, or is private

MK6+ Thermal Core

Cannot fetch Flickr photo (id: 5635205857). The photo either does not exist, or is private

MK6 Thermal Barrier

Cannot fetch Flickr photo (id: 4902422016). The photo either does not exist, or is private

Laser-cut Parts

Cannot fetch Flickr photo (id: 5430678983). The photo either does not exist, or is private

High Torque NEMA17 Stepper Motor

Cannot fetch Flickr photo (id: 5387990379). The photo either does not exist, or is private

Hookup Wires

Cannot fetch Flickr photo (id: 5426424922). The photo either does not exist, or is private

Heater Cartridge

Cannot fetch Flickr photo (id: 5632886800). The photo either does not exist, or is private

Thermocouple

This is not included in the extruder box. The Thermocouple comes packed in a white wax paper envelope that is included in the Gen4 electronics kit, with the 6 pin heads and rainbow cables.

Cannot fetch Flickr photo (id: 5471797277). The photo either does not exist, or is private

PTFE Tubing

Cannot fetch Flickr photo (id: 5387780123). The photo either does not exist, or is private

Anti-seize Paste, Heat Sink, Ceramic Tape

Cannot fetch Flickr photo (id: 4883617164). The photo either does not exist, or is private

Heat Shrink Tubing

Cannot fetch Flickr photo (id: 5321072453). The photo either does not exist, or is private

Thermostat

Cannot fetch Flickr photo (id: 5634366565). The photo either does not exist, or is private

Part List

Prep Work

Peel off protective coverings.

The acrylic parts come with a protective paper film that covers the surface. Use your fingernail or a small screwdriver to remove this film.
Cannot fetch Flickr photo (id: 4883010349). The photo either does not exist, or is private

Attach thumb wheel.

Locate one thumb screw knob. Using two pliers press the knob onto the longest M5 bolt as shown below.
Cannot fetch Flickr photo (id: 5245401293). The photo either does not exist, or is private

Filament Drive System

Add Plate A to stack.

Take Plate A and place it in front of you as shown in the picture.
Cannot fetch Flickr photo (id: 5388392288). The photo either does not exist, or is private

Add Plate B to stack.

Find Plate B and place it over Plate A as shown.
Cannot fetch Flickr photo (id: 5390928453). The photo either does not exist, or is private

Add Plate C to stack.

Plate C is three pieces of Black Delrin. Place plate C onto the stack as shown. Pay careful attention to the orientation of the parts.
Cannot fetch Flickr photo (id: 5387785353). The photo either does not exist, or is private

Add nuts to Plate C.

Add four nuts to Plate C as shown. This is where you can mount a Magnetic Rotary Encoder if you choose to add one in the future.
Cannot fetch Flickr photo (id: 5388391860). The photo either does not exist, or is private

Add Plate D to stack.

Plate D is the top of the sandwich. Place it on the stack as shown.
Cannot fetch Flickr photo (id: 5431640442). The photo either does not exist, or is private

Bolt stack together.

Insert M3x25 bolts

Insert four M3x25 bolts into the holes as shown. These are for securing the motor. In this step they help keep the layers aligned.

Cannot fetch Flickr photo (id: 5431641270). The photo either does not exist, or is private

Insert M3x22 bolts

Insert two M3x22 bolts as shown.

Cannot fetch Flickr photo (id: 5431641672). The photo either does not exist, or is private

Hand tighten nuts onto the M3x22 bolts

Cannot fetch Flickr photo (id: 5431642426). The photo either does not exist, or is private

Insert plunger.

Insert the plunger into the stack as shown.

Cannot fetch Flickr photo (id: 5431035633). The photo either does not exist, or is private

Insert thumbscrew + nut

Prepare nut and bolt

Place a nut on the thumb screw as shown.

Cannot fetch Flickr photo (id: 5431035769). The photo either does not exist, or is private

Insert nut and bolt

Insert the nut and bolt into the stack as shown.

Cannot fetch Flickr photo (id: 5431036285). The photo either does not exist, or is private

Attach thumbscrew retainer bolts.

Insert two M3x22 bolts as shown. Hand tighten nuts onto the M3x22 bolts.
Cannot fetch Flickr photo (id: 5431644076). The photo either does not exist, or is private

Tape nuts on filament drive housing.

Place an M3 nut into each of the four holes and tape into place as show.
Cannot fetch Flickr photo (id: 5431702321). The photo either does not exist, or is private

Attach drive gear to motor shaft.

Bolt the gear onto the motor shaft as shown. The bottom of the drive gear should be 4.9 mm from the top of the motor. Use an M5 bolt to set the height of the drive gear as shown. Ensure the set screw contacts the flat part of the shaft.
Cannot fetch Flickr photo (id: 5431644840). The photo either does not exist, or is private

Fan mount assembly

Remove the fan connector

Using wire clippers clip off the fan connector as shown.
Cannot fetch Flickr photo (id: 5432303188). The photo either does not exist, or is private

Strip the wires

Strip the ends of the fan wires and the black/red cable.
Cannot fetch Flickr photo (id: 5431693823). The photo either does not exist, or is private

Add heat shrink

Place 1 inch of large heat shrink around both fan wires and 1 inch of small heat shrink around the black fan wire as shown.
Cannot fetch Flickr photo (id: 5432304390). The photo either does not exist, or is private

Solder wires

Ensure the heat shrink is a few inches from the cable ends. Solder the fan wires to 24 inches of black/red wire as shown.
Cannot fetch Flickr photo (id: 5431695435). The photo either does not exist, or is private

Shrink the heat shrink

Place the small heat shrink tube over the solder joint and heat as shown.
Cannot fetch Flickr photo (id: 5432305568). The photo either does not exist, or is private
Place the large heat shrink over both solder joints and heat as shown.
Cannot fetch Flickr photo (id: 5431696645). The photo either does not exist, or is private

Mount the fan to the bracket

Using two M3x16 bolts, two M3 nuts, and two M3 washers bolt the fan to the bracket as shown. Ensure the fan cable is oriented as shown. Ensure the fan label is facing the inside of the bracket.
Cannot fetch Flickr photo (id: 5431697925). The photo either does not exist, or is private

Bolt motor to filament drive housing.

Add the motor

Place the motor on a flat surface. Ensure the wires are to your left when facing the motor.
Cannot fetch Flickr photo (id: 5431698531). The photo either does not exist, or is private

Add the fan mount

Place the fan mount on the motor as shown.
Cannot fetch Flickr photo (id: 5431699325). The photo either does not exist, or is private

Add cork gasket

Place the cork gasket as shown.
Cannot fetch Flickr photo (id: 5431699957). The photo either does not exist, or is private

Add drive housing

Place the filament drive housing as shown.
Cannot fetch Flickr photo (id: 5432311202). The photo either does not exist, or is private

Tighten bolts and align the pulley

First, let's check the alignment of the pulley. Hold your motor assembly in place as shown and compare its position to the black delrin layer. The cork gasket will compress a bit, so remember to allow for that.

Cannot fetch Flickr photo (id: 5751161619). The photo either does not exist, or is privateTighten the bolts evenly. The cork gasket should be evenly compressed on all sides as shown.
Cannot fetch Flickr photo (id: 5432310476). The photo either does not exist, or is private
Tighten the bolts such that the drive gear is symmetric in the filament slot as shown.
Cannot fetch Flickr photo (id: 5431526918). The photo either does not exist, or is private
Slide the 606 bearing over the shaft of the stepper motor. It should just fit into the round opening in the acrylic plate. It will stick out of the acrylic but should be flush with the tip of the stepper's shaft. This will allow you to apply more pressure to the filament against the hobbed pulley and prevent slippage.
flickr:5864846922

Pre-load all the t-slots with nuts.

By doing this before the assembly, you will save yourself countless trips to the floor to find dropped nuts, and other headaches. We use a simple three-step process:

1: Tape to "top" side of the acrylic

Cannot fetch Flickr photo (id: 4883008381). The photo either does not exist, or is private

2: Flip it, and insert nuts into the slots

Cannot fetch Flickr photo (id: 4883612828). The photo either does not exist, or is private

3: Tape over the nut

Cannot fetch Flickr photo (id: 4883006853). The photo either does not exist, or is private

Attach supports to one arch.

The supports are two of the same part. The tabs are asymmetrical though, so make sure the bottoms of the supports are flush with the bottoms of the tabs as shown. Tighten the bolts to finger tight for now.
Cannot fetch Flickr photo (id: 4883602642). The photo either does not exist, or is private

Attach other side to supports.

Take the other support and attach it on the back side. Tighten the bolts to finger tight only.
Cannot fetch Flickr photo (id: 4882996509). The photo either does not exist, or is private

Attach top to supports.

The top plate will bolt onto the arches as shown. Bolt it into plates and only finger tighten the bolts.
Cannot fetch Flickr photo (id: 4883601102). The photo either does not exist, or is private

Attach bottom to supports.

The bottom parts bolt onto the arches as shown. The hex nut cutouts are slightly off-center for mounting purposes. Make sure you keep them on the same side. You will also want to ensure that a line drawn through the hex cutouts will pass through the large circular cutout in the top plate. This is where the filament path goes, and we want it to be in-line with the mounting holes.
Cannot fetch Flickr photo (id: 5388388192). The photo either does not exist, or is private

M3x40 bolts into top piece.

These bolts are how the hot end is attached to the filament drive mechanism. Drop them into place as shown.
Cannot fetch Flickr photo (id: 4883599498). The photo either does not exist, or is private

1" spacers + nuts to bolts.

These spacers will ensure that the hot end is separated properly from the filament drive mechanism. Put one spacer on each bolt and then thread a nut onto it. Feel free to tighten the nut to 1/4 turn past finger tight.
Cannot fetch Flickr photo (id: 4883598706). The photo either does not exist, or is private

Attach filament drive to support.

The tabs on the filament drive ensure that you can only bolt the filament drive in the proper orientation. Insert it into the slots and then bolt it in place. Tighten the bolts to 1/4 turn past finger tight with the hex wrench. This is also a good time to tighten the rest of the bolts to 1/4 turn past finger tight as well.
Cannot fetch Flickr photo (id: 5388583396). The photo either does not exist, or is private

Superglue spacer feet to support.

Using superglue, or ideally acrylic cement, you'll want to attach the spacer feet to the bottom of the supports. Make sure the hole in the spacer lines up with the hex cutout or you'll be in for a grumpy surprise. If you're using superglue, its a good idea to scratch up the surfaces to be glued for better adhesion.
Cannot fetch Flickr photo (id: 5387781167). The photo either does not exist, or is private

Tape M5 nuts into spacer

Once the glue has dried, you'll want to insert the M5 nuts into the cutouts. I like to tape over these nuts to keep them from falling out during the rest of the assembly process and during usage.
Cannot fetch Flickr photo (id: 4882990499). The photo either does not exist, or is private

New, Easier Cartidge-based Hot End Assembly!

Apply anti-sieze to threads.

If you ever plan on disassembling your hot end, it's imperative to apply the included anti-sieze compound to the threads. This stuff will protect against rust, corrosion, seizing, and galling that can happen at high temperatures. Simply smear a bit on your finger or a swab and apply it to the external threads. It should be applied to the nozzle threads and the thermal barrier tube threads.

Cannot fetch Flickr photo (id: 5622660562). The photo either does not exist, or is private

Bolt nozzle into thermal core.

To bolt the nozzle in all the way, get an adjustable wrench and your 13mm wrench. Screw the nozzle all the way into the thermal core by hand. Tighten them against each other with the wrenches. Use the 13mm wrench on the nozzle, and the adjustable wrench on the flat parts of the heater core.

Cannot fetch Flickr photo (id: 5622660874). The photo either does not exist, or is private

Thread in thermal barrier tube.

The thermal barrier tube is what provides the structural support for the PTFE as well as keeps the heat from travelling all the way up to the filament drive mechanism. Apply the anti-sieze and screw it all the way into the heater core. There isn't much to grip on, so just make sure you tighten it as much as possible with your fingers.

Cannot fetch Flickr photo (id: 5622661120). The photo either does not exist, or is private

Insert and trim the PTFE Tubing

Insert the PTFE tube into the thermal barrier tube with the pointed end at the nozzle. Ensure the PTFE tube is pushed all the way into the nozzle.

If you're having trouble fitting the PTFE insert into the tube, put your PTFE barrel into the freezer for 15 minutes or so. The PTFE will shrink and slip in easily.

Cannot fetch Flickr photo (id: 5622661308). The photo either does not exist, or is private

Using a razor knife trim the PTFE tube so that it's flush with the top of the thermal barrier tube as shown.

Cannot fetch Flickr photo (id: 5622074857). The photo either does not exist, or is private

PTFE tubing must be inserted all the way

This cutaway drawing shows the full insertion of the PTFE tube. Note that it extends all the way into the nozzle. You can check this by pulling it out and measuring it (should be roughly 80mm) or by unscrewing the nozzle with the PTFE tube in place.

Cannot fetch Flickr photo (id: 5238510988). The photo either does not exist, or is private

Put the heater cartridge in place.

* Be very careful handling the cartridge heater and wire lead. They are delicate and can be broken if stressed, bent, or pulled at the joint. *

The heater cartridge should slide easily into the hole we've had precision-milled into the aluminum hot end. Put it right in the middle like this; the ends will stick out a bit.

Cannot fetch Flickr photo (id: 5622663028). The photo either does not exist, or is private

Now lock in in place with the M3 x 4mm set screw. It will be the shorter of the two bolts in the MK6+ kit. Tighten down about a third to half turn past finger-tight. Do not tighten too tight and distort the heater cartridge body as this will damage it.

Cannot fetch Flickr photo (id: 5622663518). The photo either does not exist, or is private

And here we are with our heater in place. Wasn't that easy?

Cannot fetch Flickr photo (id: 5622076831). The photo either does not exist, or is private

Attach thermocouple

Use the thermocouple included in the Extruder Controller v3.6 kit for a MakerBot Thing-O-Matic. (Or purchased separately in our store.) This is the long, brownish wire with a metal tip on one end, and red/yellow wires on the other end. Attaching it to your hot end is very easy: we will be bolting it to the side of the MK6 thermal core.

Ensure that you use a layer or two of Kapton tape wrapped around the thermocouple end to electrically isolate the thermocouple from the metal extruder body (Picture does not show the Kapton tape isolation).

To attach it, use the M3 x 6mm bolt included in the MK6+ kit, along with a M3 washer. Thread the bolt into the tapped hole and tighten the thermocouple under the washer. You'll need to keep it in place as you tighten as it has a tendency to be pushed out before getting clamped down. It's a good idea to wrap the thermocouple lead around the block as we've done here, so both leads come off the same side of the heater block.

If you find that the tapped hole isn't quite deep enough, just add another M3 washer.

Cannot fetch Flickr photo (id: 5622664470). The photo either does not exist, or is private

And here we are, both heater and thermocouple installed.

Cannot fetch Flickr photo (id: 5622077983). The photo either does not exist, or is private

Insulate the thermal core.

The video below was intended for the MK5, but is relevant to the MK6 as well.

Prepare the ceramic tape

Cut one length of ceramic tape 70 mm long.

Cannot fetch Flickr photo (id: 5241276232). The photo either does not exist, or is private

Mark the center

Cannot fetch Flickr photo (id: 5241275786). The photo either does not exist, or is private

Use the thermal tube to press a hole in the ceramic tape.

Cannot fetch Flickr photo (id: 5239252356). The photo either does not exist, or is private

Your result should look like this

Cannot fetch Flickr photo (id: 5240680343). The photo either does not exist, or is private

Mark the center of the longer piece of ceramic tape

Cannot fetch Flickr photo (id: 5240679701). The photo either does not exist, or is private

Use the thermal tube to punch a hole through the longer piece.

Cannot fetch Flickr photo (id: 5238656537). The photo either does not exist, or is private

You now have two pieces that look like this.

Cannot fetch Flickr photo (id: 5241274574). The photo either does not exist, or is private

Slide the two strips onto the thermal tube.

They should go on perpendicular to each other. Then wrap them around the heater — most of the assembly should be covered by insulation.

Cannot fetch Flickr photo (id: 5622078453). The photo either does not exist, or is private

Now wrap it with some tape to hold it in place and insulate further.

Cannot fetch Flickr photo (id: 5622078703). The photo either does not exist, or is private

Slit the insulation and thread the bolts in.

Make a slit for each of the four bolt holes, and then thread a bolt into the tapped hole.

Cannot fetch Flickr photo (id: 5622666182). The photo either does not exist, or is private

Here we've threaded the first of the four bolts. I just use one bolt for this part. Right now, you just need to ensure that the slits are in the right position.

Cannot fetch Flickr photo (id: 5622079309). The photo either does not exist, or is private

Install the heatsink and retainer plate.

Put the bolts through the holes in the retainer plate and then screw them into the thermal core. You might need to give the heat sink a squeeze with some pliers to get it to hold on to the tube. Let it sit right on top of the retainer plate.

Some of these pictures show the heatsink below the retainer plate; instead, place this on the thermal tube above the retainer plate closer to the extruder motor.

Next, put the 4 M3 x 25mm bolts through the holes in the retainer plate, and then thread all four into their tapped holes.

Cannot fetch Flickr photo (id: 5622666820). The photo either does not exist, or is private

Attach the hot end to acrylic assembly.

Mounting MK6+ is slightly different than the MK5 and MK6 — there will be a slight space between the retainer plate and the nuts that hold the 1" spacers in place. First, tighten the nuts down against the spacers:

Cannot fetch Flickr photo (id: 5622667348). The photo either does not exist, or is private

Next, put the thermostat from the safety cutoff kit in place.

Note: DO NOT run a cartridge-based hot end without a Safety Cutoff Kit. The cartridges will reach much higher temperatures than our previous heater systems.

Cannot fetch Flickr photo (id: 5622667770). The photo either does not exist, or is private

Now, fit the four bolts through the holes in the retainer plate and tighten down nuts against the plate.

Note that the retainer plate is not symmetrical. The center hole for the thermal tube is closer to one edge, which will end up facing the front of the machine. It is recommended, altho not critical, that the wires from the cartridge and the thermocouple exit to the right when that edge is facing you.

The retainer plate will flex slightly and act as a spring. This will keep enough pressure on the nuts so they stay in place.

Cannot fetch Flickr photo (id: 5622668930). The photo either does not exist, or is private

If necessary, slide down the nut over the thermostat to hold it in place against the retainer plate. The thermostat should be in contact with the plate. Do not allow the thermostat to hang over the side of the retainer plate.

Cannot fetch Flickr photo (id: 5622668562). The photo either does not exist, or is private

Completed Stepstruder MK6+

All done! Now put your feet up and grab a beverage. Or take a brief moment to clear your mind before continuing your build.

Cannot fetch Flickr photo (id: 5622184875). The photo either does not exist, or is private

Next Step: Body Assembly

Unless otherwise stated, the content of this page is licensed under GNU Free Documentation License.