Plastruder Mk3 Assembly

Assembly

Estimated build time: 2 hours.

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Tools You'll Need:

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  • Wire cutters
  • Wire strippers
  • Soldering iron
  • Scissors
  • Needle nose pliers
  • M3 and M8 hex keys
  • M3 and M8 wrenches or an adjustable wrench
  • Super glue
  • A knife

Parts You'll Need

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Parts You Won't Need

The plastruder kit contains a few more pieces than most users will actually need. In particular, your kit may contain:

  • An additional idler wheel. Overtensioning your idler wheel can cause it to crack or break; we include a spare so you can replace it if it gets damaged.
  • A RepRap Insulator Retainer plate. These are special plates for mounting the Plastruder Mk3 on a RepRap machine. If you're building a Cupcake CNC, you won't need this piece. (Likewise, if you only intend to mount your plastruder on a RepRap, you won't need the big and little dino assemblies!)
  • Extra 5mm LEDs and through-hole resistors. These are included for experimenters who want to add more blinking lights to their extruders; they're completely optional.

Prep Work

The build process is much easier if you build all the sub-components first, and then assemble them all into a nice, working extruder in one shot. Things like the Dino's are easiest to make beforehand, and other things like the Idler Pulley need time for the glue to dry.

Peel off Plastic

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We ship the acrylic pieces with their protective plastic intact. This prevents them from getting scratched or scuffed during shipping. Use your fingernail, a small flat-head screwdriver, and/or your teeth to catch and edge and pull the blue film off. The parts are actually clear acrylic. Both sides have the film on them.

Small Dinosaur

Parts You'll Need

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  • Small Dino Left
  • Small Dino Right
  • Dino Support
  • Small Dino Bottom Mount
  • Small Dino Top Mount
  • 5 x M3 Nuts
  • 5 x M3 x 16mm Bolts
  • 2 x M5 Nuts

Assemble the Parts

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The dino brackets lift the extruder housing up so that you get the maximum build height possible. They are very simple t-slot assemblies. It's easiest if you slot everything together, and then insert the nuts/bolts.

First, assemble the neck of the dino. Put the left and right sides together over the Dino Support piece.

Next, plug that assembly into the Build Base. The text should be facing towards the bottom.

Assemble T-slots

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Now, insert bolts into each of the t-slots. You'll also want to screw in M3 x 16mm bolts as well. Don't tighten things down yet, the dino's need to be a bit loose to fit over the extruder housing later.

Attach Bottom Mount

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Now is a good time to attach the bottom mount. Put a dab of superglue in the middle of the plate and snap it on over the bolt heads that are sticking out. Let it sit for a few minutes and they'll be permanently connected.

Insert Captive Nuts

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The dino brackets use captive nuts to make attaching them to the base easier. Take two M5 nuts and drop them into their respective places. They may fall out, so feel free to hold off on this step until you're ready to attach the extruder to the build base.

Big Dinosaur

Parts You'll Need

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  • Big Dino Left
  • Big Dino Right
  • Dino Support
  • Big Dino Bottom Mount
  • Big Dino Top Mount
  • 5 x M3 Nuts
  • 5 x M3 x 16mm Bolts

Assemble It!

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The big dino is just like the small dino, but larger. Follow the directions above to build it.

Idler Pulley

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The idler wheel is the part that rotates along with the filament and keeps things moving.

You'll need:

  • The Idler Wheel
  • A 608 skate wheel bearing
  • 2 x M8 washers
  • Superglue

Position Idler Wheel

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The first step is to position the idler wheel on the bearing in the exact right position. This is easiest to accomplish if you use two M8 washers to space the wheel off the table a bit. Position the idler wheel over the 608 bearing and push it down until it hits the washers. Also, use a permanent marker to write radial lines all around the idler wheel. This will help when testing the idler wheel (below) and also in case you get extrusion slow downs later.

Glue Idler Wheel Down

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Once you have it properly in place, it needs to be glued down. Apply some superglue around the inner edge of the idler wheel to glue it to the 608 bearing. Be very careful not to get any on the inside of the bearing. You only want to glue it to the outer ring of the bearing. Let it sit for about a half hour or so.

Retainer Washer

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The retainer washer is the part that holds the heater barrel in place. Its essentially a steel washer with two holes drilled in it. We provide pre-drilled washers in the MakerBot kit, but its easy enough to drill your own.

Apply Sticker Template

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The easiest way to drill the washer is to use your existing 2D digital fabricator (a printer) and apply a sticker template which marks exactly where to drill. I use common laser-printable stickers. Simply print out the sticker template PDF located at Thingiverse. Next, cut the washer outline out and apply the sticker to the washer. Take care to align it properly.

Helpful Hint

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Peeling the sticker backing off is easier if you score the backing with a knife or scissors. Take care not to cut through the actual sticker!

Drill Holes

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BE CAREFUL WITH POWER TOOLS!

Before drilling the holes, its best to use a center-punch for accurate drilling. The sticker includes an X exactly where you need to drill.

It's recommended that you use cutting oil (3-in-1 works) or something to extend the life of your drill bit.

Drill the holes out with a 3mm or 1/8" drill bit. You'll want to de-burr the holes as well. You can simply use a larger drill bit or a special de-burring tool.

This process is easiest with a drill press. You don't need an expensive one either. We have used a cheapo press from Harbor Freight and it works just fine. Best tool investment we've made in a long time.

Remove Sticker Template

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After drilling you should remove the sticker template. If it doesn't peel off, you may need to soak it in warm, soapy water for a half hour. You can try to use it with the sticker on, but the washer will get rather hot, so its best not to do so.

Heater Barrel Assembly

Step 1: Gather Parts

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In order to assemble the heater barrel, you'll need these parts:

  • 1 x Brass Heater Barrel
  • 1 x PTFE Thermal Barrier
  • 1 x Brass Nozzle
  • 300mm nichrome wire
  • Kapton tape
  • 150mm ceramic tape
  • 1 x 100K ohm resistor
  • two different color wire, 300mm each. 24-26 gauge is a good size. I like using red for hot, and blue for temperature.
  • some solder
  • 2 x crimp-on ferrules for wire
  • a multimeter

Step 2: Prepare the Wires

First up, you'll want to prepare the nichrome wire. Nichrome is nickel/chromium alloy with a set resistance. What that means is when you pump electricity through a length of it, it heats up. If you use the right length, and the right voltage you get simple, cheap heater. Thats what we're going to build now.

Trim and Strip the Nichrome

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The nichrome wire should have a resistance of ca. 6 Ohm. Usually this amounts to ca. 300 mm of wire, but use a multimeter to be on the safe side.
Cut the nichrome wire to a length which amounts to about 6 Ohm of resistance.
NOTE: It's difficult to measure the resistance of the nichrome until you strip the ends, so cut it long, then trim it down until you reach 6 Ohms.

Take your length of nichrome and strip the insulation. The easiest way to do that is to use the edge of a knife and drag it along the insulation. Don't try to cut the insulation, but instead scrape it off. Scrape both sides of the nichrome wire and the insulation will easily fall away. Do this on both sides of the nichrome so that around 3mm of wire is exposed.

Strip the Heater Wires

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Next, strip about 3mm from the ends of the wires you will use for the nichrome. Make sure you have a decent gauge wire as this will be carrying 2-3 amps for the heater. Its easiest if you crimp the ferrules onto this wire first. It is important you trim the exposed end of the wire to 3mm. That way it won't take up all the space in the ferrule. If you mess up, its okay. You only need 2 ferrules and we provide 10 in a kit.

The next step will depend on which crimp connector came with your kit. Some kits will contain cylindrical ferrules, and others will contain terminal crimp pins (which have a springy metal curl at one end). Follow the directions below which are appropriate for your connector.

Using the ferrule connector

Crimp the Ferrule (1/2)
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Place the ferrule on the copper wire with the 'bell' facing the insulation. Take your needle nose pliers and crimp the ferrule onto the wire. Make sure you only crimp that part of the ferrule that is on the copper wire, we'll be crimping the other end onto the nichrome next. Give it a good hard squeeze and do the same thing with your other wire.

Crimp the Ferrule (2/2)
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The nichrome is a bit smaller, but we'll be doing the same thing. Insert one end of the nichrome into one of the already crimped cables, and crimp it down. While you have it crimped down, I like to make the connection a bit stronger by folding the ferrule in half and then giving it another crimp. Be careful not to break the ferrule. If you do, you may have to start over. Thats why we provide 10 ferrules in a kit!

Solder the Connection
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Because I don't trust mechanical connections, I like to solder the whole thing in place. Nichrome metal is pretty much impossible to solder, but the ferrule and copper wire are easy. The solder will provide a bit more stability and make the connection nice and strong.

Now, skip ahead to the insulation step!

Using the terminal crimp pin connector

Crimp the nichrome wire to the connector
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Insert the stripped tip of the nichrome wire into the small hole in the back of the terminal connector as shown. A little bit will stick out at the top; bend it back over the connector.

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Now crimp the connection by squeezing the curled end of the connector flat with a pair of needle-nosed pliers.

Crimp the copper wire to the connector
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Insert the copper wire into the other end of the connector, as shown.

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Use pliers to crimp the connector to the wire.

Solder the Connection
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Because I don't trust mechanical connections, I like to solder the whole thing in place. Nichrome metal is pretty much impossible to solder, but the ferrule and copper wire are easy. The solder will provide a bit more stability and make the connection nice and strong.

Insulate the Connection

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You'll want to do this so that you have a wire-nichrome-wire assembly. Once you have that, then wrap a tiny bit of Kapton tape around the joint to insulate it. Your heater wire is now ready to be attached. Win!

Separate Thermistor Leads

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Next up: thermistor wire assembly. This is much easier. First, grab out the thermistor. The wires are un-insulated, so our first goal is to separate them to prevent shorts. Pull them apart so they are not touching and are separated by about 3mm. Don't pull too hard you pull it in half. The keyword here is 'gentle'.

Trim and Tin

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Once they are separated, you'll want to trim the leads to a length of 25mm. Take your soldering iron and apply a bit of solder to each end of the lead. This is called 'tinning' the leads. We'll do the same thing to the wires we'd like to connect and then we'll melt them both together at the same time to make a solid connection.

In order to do that, you'll want to strip the ends off the other set of wires you have. Make sure you're using different colors than the wires for the heater! Tin the end of these wires with some solder as well.

Solder Them Together

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Once both the wires and the thermistor leads are tinned, you're going to want to connect them. This can be a bit fidgety, so if you can weight them down with your pliers or something, it will be much easier. Place them together and heat up the solder on both of them. You may want to apply a bit more solder as you do this. When it melts, remove the heat and both wires should be soldered together.

Insulate the Joints

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After that is complete, wrap a tiny bit of Kapton around the solder joints. This will keep them from shorting out and may add a bit of mechanical stability.

Isolate the Leads

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Take two more short pieces of Kapton Tape and tape from the glass bead to the solder joints. The point of this is to keep the thermistor leads apart so they don't short (and give you bad temperature readings). Put tape on both sides so its completely insulated and safe, and then your thermistor is ready for action.

Step 3: Prepare Heater Barrel

Thoroughly Clean Parts

Sometimes the heater barrel / thermal barrier / nozzle will have debris from the machining process on them. You'll want to wash all of these parts in water and/or rubbing alcohol. The heater barrel especially will need cleaning. Once you've washed them, I also like to clean the barrel out with a Qtip or other long stick thing that you can jam down it to push out any debris (like metal shavings.)

Assemble Machined Components

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We don't want any shorts on the metal heater barrel in case the Kapton we used to insulate the solder joints falls off. The easiest way to do this is to assemble the PTFE Barrier, Heater Barrel, and Nozzle.
NOTE: Your barrel may have one end that is dressed/tapered, and one end that is simply sawcut. The "pretty" end is the one that goes into the PTFE barrier - the joint between the barrel and the barrier has to be clean and tight. As part of that, make sure that the barrel is screwed in tight, not just snug - need to make sure there isn't a gap at the top.

Insulate Heater Barrel

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Once you do that, put one layer of Kapton tape just below the PTFE barrier. This is where there would be a potential short, so thats where we're protecting.

Attach One End of Heater

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Now we're going to attach the nichrome heater to the heater barrel, and we're going to do that using Kapton tape. First, bend a right angle into the wire connecting to the nichrome just above the joint. Then, tape that end down to the heater barrel just below the PTFE where we just insulated the heater barrel.

Wind Nichrome Around Heater Barrel

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Next, you'll want to wind the nichrome wire around the heater barrel. The closer you get it to the nozzle, the better. Check the picture for a good indication of how far down the barrel to start. Make sure you wind it so the nichrome fits into the threads of the barrel. You may want to use some thermal paste here, but its certainly not necessary. I don't like it because its messy.

Finish Attaching Heater

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Once you've wrapped the nichrome around the heater barrel, carefully bring the other end back up next to the start of the wire and secure it into place with more Kapton tape. Now you'll want to secure the whole thing to the heater barrel using a decent amount of the tape. A good rule of thumb is to use enough tape so that the heater barrel + tape is even with the nozzle.

Attach Thermistor

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Now that you have the heater attached, you'll want to attach the thermistor. This is what measures the temperature, so you'll want to attach it directly to the nozzle. If you want to go super-custom, drill a tiny indentation into the side of the nozzle. If you're like me and want to keep things simple, just tape it directly into the side of the nozzle. Use one or two layers of tape, and also tape all the way up so that the leads/wires are attached to the heater barrel. It is a good idea to attach it on the opposite side of the barrel for ease of wiring.

Step 4: Insulate the Heater

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This step is not strictly necessary, but it does make things look tidy, keeps your heater warmer, and gives better startup times. I'd definitely recommend insulating the heater barrel.

Trim Ceramic Tape

The first step is to trim the width of the ceramic tape if necessary. You want it to insulate most of the heater barrel, and only go down about halfway on the nozzle. You can go further down, but it is possible it will interfere with extrusion and printing techniques like towering.

Attach Tape To Barrel

Once your ceramic tape is ready to go, take a short length of the Kapton tape and use it to attach one end of the ceramic tape to the heater barrel. Wrap it around the barrel and then use 2-3 layers of kapton tape to make sure it stays connected.

Finish it Up

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Can you tell we love Kapton tape? It's only the raddest space-age material for building robots EVER! No big deal.

Add Retainer Washer

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I like to save the retainer washer for last, because it makes it really difficult to do all the wrapping and rotating that needs to be done. To put it on, simply unscrew the PTFE Barrier, slide on the washer and then screw the PTFE Barrier Back on. Make sure you screw the PTFE Barrier all the way back on. You may have to bend the wires down a bit to make it fit, but thats okay.

Filament Drive Mechanism

Stuff You'll Need

  • The Motor
  • The tiny hex key
  • The small hex key
  • 4 * M3 x 8mm bolts

Step 1: Attach Pulley to Motor

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The pulley is the part that 'bites' into the filament and physically pushes it into the heater barrel. Its very important that the pulley is very firmly attached to the motor shaft.

This is fairly easy to accomplish with the pulley that we use. It has two set screws that lock the pulley onto the shaft. First you should position the pulley onto the shaft properly. The set screws should be on the bottom towards the motor. The pulley itself should be close to the bottom of the shaft, and one of the set screws should be directly above the flat side of the shaft.

Screw both of the set screws down and then tighten the proverbial daylight out of them.

Step 2: Attach Motor to Motor Mount

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Grab out your trusty M3 hex key and four M3 x 8mm hex bolts. You'll also need the motor and the motor mount acrylic piece. The easiest way is to put the four bolts on their proper holes, then put the acrylic assembly on the motor. Now just screw down all the bolts. Make sure you tighten down each bolt a little bit at a time so it doesn't get uneven and break the acrylic.

Also, its a good idea to have the wires from the motor coming off to the right towards the rest of the extruder housing as shown in the picture.

Step 3: Add Spacer Plate

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The spacer plate just adds space to the body. It only fits on one way, so just stack it on.

Step 4: Add Filament Guide Bottom

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This plate also just stacks up on top of the others. The text should be towards the top and legible from your point of view.

Step 5: Add Filament Guide Middle

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This is a two-part piece. There is a left side piece and a right side piece. The left side piece goes over the motor/pulley, and the right side goes over the big open space. The text should be towards the top as usual.

Step 6: Insert Captive Nuts

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These nuts are very crucial for attaching the heater barrel assembly. There are two little rectangle slots towards the bottom of each fo the filament guides. Simply place one nut in each and you're done!

Step 7: Filament Plate Top

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This plate fits on over the other plates. Lay it on top and you're done!

Step 8: More Captive Nuts

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These nuts are for mounting the optional Magnetic Rotary Encoder. Even if you're not going to use that board, you might as well put them in there. Ya never know when they'll come in handy. The nuts go in flat. I find it easiest to put them flat on the plate and then slide them over the hole. They should just fall into place.

Step 9: Insert Idler Pulley

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Take the assembled Idler Pulley that you made in a previous step. Put one M8 washer down on the inner area over the 8mm slot. Then place the idler pulley, and then place another washer over that. You'll want to do a quick sanity-check to make sure that the idler pulley can easily slide between the flanges on the pulley. If it does, you inserted it correctly. If not, try flipping the idler pulley over. If that still doesn't work, try juggling the washers around until you have it at just the right level.

Check the Pulley Alignment!

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Once you do, make sure all the washers/pulleys line up over the 8mm slot. You'll be putting a bolt through there very shortly to keep everything in place, but until then it will be a bit wobbly.

Step 10: Attach Retainer Plate

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The retainer plate is the top layer of the sandwich. Place it on the top of the stack with the text facing out and on the top. Be very careful not to disturb the idler bearing. If you manage to move them out of place, take the plate off and put them back in place.

Now, you'll want to put the M8 hex cap bolt through the back of the Motor Mount and then put a nut on it. You don't need to tighten it down yet, so just hand-tighten it so that nothing falls out. We'll be putting the M3 bolts on in a second, and those will align everything.

Step 11: Attach the Small Dinosaur

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The dinosaurs are the parts that elevate the extruder to give you more build area. This dino is a support dino to eliminate wobble. Grab an M3 x 50mm bolt, put a washer on it, and thread it through the 'Left' side of the dino. Fit the dino over the left side of the extruder housing and then bolt it all together. Use another washer on the other side and nut.

If you tightened up the dino, it will be hard to fit it onto the housing, so make sure all the bolts are nice and loose. You will be tightening everything down later, so don't worry about it for now.

Step 12: Alignment Bolt

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Take an M3 x 50mm bolt and push it from the back through all the bolt holes on the upper left corner of the extruder housing. Put some spacers on it, then an M3 washer, and finally an M3 nut. Don't tighten it down super hard, but enough to keep things in place.

Step 13: Attach the Big Dinosaur

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This dino provides most of the support, as he's much taller and holds on to two points. Grab some M3 x 50mm socket cap bolts, a bunch of washers, and some nuts. First off, put a washer on all of the M3 bolts. Then, put the tip of the bolts through the top hole on the back of the dino.

Now, fit the dino over the extruder housing. If you tightened all the T-slots, you'll want to loosen that all up now. Once you have the bolt-holes lined up, push the M3 bolt all the way through. Slide a washer on it, and then thread a bolt onto it.

Repeat the process for the bottom bolt hole on the dinosaur. Your extruder should be much more solid now.

Step 14: Add M3 Nuts

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You'll need to add a few M3 nuts to each bolt for spacing. Three or four nuts will do it. Basically, you just want them to extend past the end of the M8 bolt so that the electronics will not touch it.

Step 15: Tighten Idler Wheel

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If you're using the plastic that we sell in the MakerBot store, the slot is sized perfectly for you. Simply slide the pulley all the way in, and give it a good tightening.
NOTE: This shortcut doesn't work on Batch 6, and can lead to filament damage. Use the step below.

If you really want to be methodical, take a 2.5mm drill bit and insert it into the filament path. Push the idler wheel up against the drill bit and then tighten everything down. Don't forget to remove the drill bit when you're done. ;)

Attach Heater Barrel

You'll need:

  • 2 * M3 x 50mm bolts
  • 2 * M3 x 12mm bolts
  • 1 x Insulator Retainer
  • 1 x Heater Barrel Assembly
  • 1 x Retaining Washer
  • 4 x M3 washer
  • 4 x M3 nuts
  • 2 x zipties

Step 1: Fit Bolts

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Take 2 M3 x 12mm bolts, and 2 M3 x 50mm bolts and put them through the Insulator Retainer piece as shown. You may want to put some M3 nuts on the end of the long bolts to keep them from falling out.

Step 2: Attach Insulator Retainer

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The Insulator retainer bolts into the captive nuts in the extruder housing. Tighten them down with your fingers and then give them a quarter-turn with the allen key. Keep in mind that there is a proper orientation so that the heads of the long bolts do not cause problems with the housing and/or electronics. The short side goes towards the front.

Step 3: Attach Heater Assembly

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First, thread a single nut all the way up onto each of the two M3 x 50mm bolts.

Now, Grab your finished heater assembly. We're now going to bolt it into place, so make sure there is a drilled washer between the barrel and the PTFE insulator.

The washer has holes that are not symmetrical. These line up with the bolts coming down from the insulator retainer. Slide a washer on each of the M3 bolts, then slide the heater assembly, PTFE barrier first up into place. Fit the M3 bolts through the washer and then put a washer and nut on the end of each.

Tighten it down

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Rotate the nuts until they are holding the large washer snugly in place. Make sure there is no wiggle room between the extruder housing and the thermal barrier. Now rotate the nuts down from the top of the M3 bolts and tighten them all together. This will hold the whole assembly in place.

LightShiningThrough.png

Take extra care here. If everything has gone well you should have very good alignment between the channel running down the acrylic plastruder, the PTFE thermal barrier, the brass heater barrel, and the brass nozzle. In fact, if you hold the whole assembly up to a light you should be able to see light coming through the nozzle, exactly centered in the channel. Checking this will ensure that your plastic filament has a very easy time finding the path all the way down to the heater barrel and nozzle and that your extrusion will be very uniform. If you cannot see light coming through the nozzle then you should loosen the nuts, adjust, and retighten.

Step 4: Zip-tie the Wires

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This is a tidying step. Bend the wires out and around the large washer. Then zip-tie each set to one of the bolts. You can also use twisty-ties, or even a short length of solid-core wire if you do not have zip-ties handy.

Electronics

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You'll need:

  • Extruder Controller v2.x
  • 4 x M3 nuts
  • A small flathead screwdriver
  • needle nose pliers
  • M3 hex key

Step 1: Attach Extruder Controller

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The Extruder Controller board has mounting holes that line up exactly with the mounting holes for the extruder. Place the board with the RJ45 jack facing up. When you push it all the way down, it should NOT be touching the M8 bolt on the bottom. If it does, it could cause shorts which are bad. If you need more spacing, throw more M3 nuts on the bolts to make it happen.

Once the spacing is right, push it all the way down, and then thread a final M3 nut on each bolt to lock it into place. That board isn't going anywhere!

Step 2: Wire it all up!

Cut wires to length

The first step is to cut the heater / thermistor wires to length. If you forgot which wires are which, you'll want to grab out your trusty multi-meter to measure the resistance of the wires. The thermistor should read somewhere >50Kohms, and the nichrome wire should read somewhere between 5 and 10 ohms.

Run them closely along a path up to their appropriate screw terminals. Add a little bit of length to them, so that they hang over the back of the screw terminals, and then cut them to length. Now strip the ends of each of them and you're good.

Remember to twist the thermistor sensor wires around each other over the length of their path from the plastruder to their final destination. With four motors going in close proximity there will be plenty of opportunity for EMF-induced noise. Twist the heater wires together to keep things tidy.

Insert and Secure Wires

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The wires for the heater are non-polar (can be inserted in any direction) as are the wires for the thermistor. Put them in their respective holes and tighten them down. The thermistor wires should go into the block labeled 'Thermistor', and the heater wires should go into the block labeled 'B+/B-'. The motor wires are actually polar, so insert the red wire into 1A and the black one into 1B.

Plug in Extruder Controller

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Finally, you'll want to plug the Extruder Controller into your RepRap Motherboard. Grab an ethernet patch cable, and you're good to go. Please note: this is not ethernet. We use these common cables to cut costs and provide a robust connection that can provide both power and communications over a single wire.

Test your Plastruder

It is possible that you will need to spend some time fine-tuning the position of the idler wheel in your plastruder. Before mounting your plastruder in your MakerBot, it is recommended that you "bench test" the Plastruder and make any necessary fine adjustments.

Test procedure

  1. Set up the Plastruder above a surface that you don't mind covering with hot melted plastic.
  2. Hook everything up, but don't bother to mount the Plastruder in your MakerBot body yet. This means: connect the heater, thermistor, and motor to the Plastruder controller, connect the Plastruder controller to the motherboard, and connect your PC or laptop to the motherboard with the included USB cable. (All boards should have had firmware loaded on them in previous steps.)
  3. Turn on the MakerBot!
  4. Fire up the ReplicatorG software!
  5. Select the Machine->Driver menu, and ensure that "Cupcake" is selected.
  6. Select the Machine->Control Panel menu item to open the Control Panel. You should see a pop-up window that looks like this:
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  7. Set the target temperature to 220 degrees C, hot enough to melt ABS plastic. The heating element should switch on, and you should see the temperature shown in the Control Panel begin to rise.
  8. Wait until the nozzle temperature reaches 220 degrees.
  9. Set the motor PWM to 255 ("full on.")
  10. Feed a strand of ABS plastic filament into the plastruder.
  11. Click the "forward" button.
  12. The ABS plastic should now begin to feed slowly into the plastruder. Feel free to make marks on the ABS plastic with a sharpie to make the movement easier to perceive. Look at your previously done radial marks on the idler wheel. Look to see if the filament is moving down the barrel at a good rate and also how large the indentations are in the filament (see video).
  13. After a while, the Plastruder should begin to extrude a thin host plastic filament.
  14. Continue to extrude plastic for three or four minutes.
  15. When done, click the "Stop" button in the Control Panel. Use a hobby knife to trim the plastic filament from the nozzle of the extruder.
  16. Set the temperature back to 20 degrees, and wait for the Plastruder to cool down before switching everything off.

If everything works perfectly, congratulations! Go ahead and attach your Plastruder to your MakerBot.

Fine Tuning

Problems to watch out for:

  • Ensure that the nozzle heats up.
  • Ensure that you get a continuous, fast flow of plastic filament out of the extrusion nozzle.
  • Ensure that the ABS plastic filament feed works reliably. If the feeding motor slips or jams, you may need to adjust the Idler Wheel.
  • If the ABS filament slips to the side of the Idler wheel, you may need to disassemble your Plastruder to adjust the position of the Idler Wheel and the position of the Motor Pulley.

Attaching to Your MakerBot

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Now that your extruder is complete, you'll want to attach it to your MakerBot. This should take place after you have completed assembly of the MakerBot, so do that if you haven't already.

Grab four M5 x 15 bolts. You should have captive nuts in each of the dinosaur brackets. Replace them if they are missing. Place your extruder on the Z stage with the Extruder Controller facing the front of the machine.

Thread each bolt from the bottom up through the Z stage into the captive nuts. Tigthen them down and your extruder is now attached. If you need to remove it, simply unbolt them and take the entire extruder out.

Updating Your Firmware

Should you need to update the extruder firmware, instructions can be found at the following page:

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