I'm embarrased to say I forgot to measure it before I installed it. Tired of breaking my acrylic idlers, I had my father help me rig this up in his machine shop. Yes, it's been done before, but it's SUCH a better solution. I'll upload the measurements at a later point, like the next time I have to rebuild the head. Which is hopefully never.

Plastruder MK5, Do or Die!

After strenuous testing which logged hundreds of hours of continuous extrusion, we are supremely excited to offer the all-new Plastruder MK5.

Designed for reliablity, low maintenance, and ease of use, the next-generation MK5 revolutionizes the MakerBot's extrusion mechanism.

Hot End Reinvention:

This story begins with the complete redesign of the extruders' heating element, barrel, and nozzle. Our goal was to take user feedback and our experiences the MK4, and return with the most robust, most reliable, and longest lasting extruder possible.

In close consultation with our manufacturers, we opted for precision machined stainless steel throughout the hot end. Every part was totally redesigned and pushed to the limit before we included it in the final product.

Each component screws tightly together, creating rigid connections and no room for leaks or loosening over time. The result is an all-stainless hot end that feels heavy and strong, and extrudes smoothly for hours and days without issue.

The heating element has been reinvented too: Nichrome wire has been replaced by two matching power resistors that screw-mount directly to the stainless steel MK5 Thermal Core. The resistors receive current straight from the Relay Board, and they heat evenly to produce a consistent temperature perfect for reliable extrusion.

Sayonara Idler Wheel:

You may notice the reduced footprint and profile of the MK5 Plastruder. It's thinner, sleeker, and the motor housing is smaller. The reason for this is the complete "Paxtruder" inspired redesign of the filament guide mechanism. Now simply twist the thumbscrew to push the Delrin plunger into place, and your filament guide is set. No moving components, and the low coefficient of friction and high strength of Delrin means that the filament will slide over it smoothly and meet with the MK5 Drive Gear with no variation. It's a simple design, and it's simply effective.

The Gear that Drives It:

The MK5 Drive gear, released earlier this year, has become the defacto standard drive gear for MakerBots around the world. It's custom machined stainless steel, lasts ages, and is easy to clean without removing from the plastruder body. The MK5 Drive Gear grabs filament with 100% greater push strength than the MK4 Extruder Pulley. The proof is in the pudding for this item- it's already in successful use around the world.

Power Play:

With the larger surface of the MK5 Thermal Core to heat, the extruder needed more juice to get hot. For this reason the MK5 is powered by our Relay Board Kit, already in steady use with our Heated Build Platforms.

The Relay Board comes standard with enough outputs to run the Plastruder MK5 and the HBP simultaneously. By using the relay, the MK5 doesn't draw the power load through the Extruder Controller. Translated- Steady power, without wearing on sensitive circuits or microcontrollers.

The combined effect of our innovative new components, redesigned filament guide, and stainless steel construction is tremendous. It's a totally reinvented extruder that mounts easily to existing CupCake CNC Z-stage, and makes your machine better instantly.

This is a new and improved drive gear for the upcoming Plastruder MK5. It is backwards compatible with the MK3/MK4 plastruder designs and provides 200% increased push force.

For more information, see the blog post: blog.makerbot.com/2010/05/21/mk5-drive-gear-now-with-science

To purchase one for yourself, visit the MakerBot Store: store.makerbot.com/mk5-drive-gear.html

An idea to take nophead's stepper-driven worm gear extruder and extend it to drive pinch wheels on both sides of the filament.

The ultimate spare parts kit to keep your extruder printing day in and day out. Enough parts to make a complete heater barrel assembly, or replace replace other key components.

Our idler wheel kept cracking so we made one out of aluminum. Works great!

this is still a work in progress, it has none of the mounting holes established yet but i wanted to share the idea so anyone else that was thinking on it could contribute.
this current object is more to fabricate the drive shaft without the need for a lathe or mill.
I got the general idea from the side tapped drive pulley's.

Here is a modified version of Zach's Plastruder design. These layers replace the ones inside the MK4 plastruder to help guide the Idler Wheel. This keeps it straight and on target. I have managed to crush filament without so much as a crack on the acrylic idler wheel.

I still wouldnt recommend crushing filament just because you can...but this will atleast keep you from replacing an idler wheel every so often.

NOTE* The rendering engine on Thingiverse makes the files appear wobbly, but when loaded into the proper software they should show perfectly round.

The Plastruder MK4 is the latest extruder design for MakerBot machines. We've fixed a couple of bugs, and improved the design to be more robust. A quick summary of the changes:

* Motor shaft support bearing
* Fully attached dino supports
* Better machined parts (heater barrel, nozzle, etc.)
* Motor is more firmly attached to housing

Fixed up a non-printing version which had a lot of double verts.

However, in the spirit of teaching fishing, I've prepared a quicktip on this subject:
blog.thingiverse.com/2009/05/13/bonus-blender-quicktip-vertex-doubles/

This is the plastic extruder that we have developed over at MakerBot Industries. It is a primarily lasercut design which uses a pinch-wheel filament drive system and a nichrome heating element. It is heavily based on work we've done with the RepRap project and is compatible with the RepRap mounting system.

You can buy kits for this at the MakerBot Store: store.makerbot.com/featured-products/plastruder-kit-presale.html

This is a minor update of the previous pinch wheel extruder. I've logged about 40-50 hours on the previous design and have discovered some areas that could use some improvements. This design should be easier to use. For example, the smaller gap between the wheel and the Filament Guide will make it less prone to jamming during inital filament loading.

This is a new and improved version of my pinch wheel filament extruder design for the RepRap project. It works pretty darn well, and I'm quite happy with it. More details coming soon.

Parts List:
1 x Lasercut Parts
1 x M8 x 30mm socket cap screw
1 x M8 nut
4 x M8 washer
3 x M3 x 50mm socket cap screw
4 x M3 x 40mm socket cap screw
2 x M3 x 18mm socket cap screw
6 x M3 x 8mm socket cap screw
1 x Skate Bearing
1 x 2" washer
15 x M3 nut
9 x M3 washer
4 x 7/16" plastic spacer
1 x Heater barrel assembly
1 x Kysan 1156006 DC gearmotor
1 x Magnetic Rotary Encoder v1.x Board
1 x Extruder Controller v2.x Board
2 x 5mm LEDs
1 x 1K ohm resistor
various wires / etc.

This is an experimental extruder design for RepRap based on the awesome work by Lou Amadio at ooeygui.com/?p=187

It's still a bit of a work in progress, but the filament feed portion works great.