Announcing the Highest-Numbered Extruder ever to be released by MakerBot: Lucky Number Stepstruder MK7

Posted by on Thursday, September 15, 2011 in Uncategorized


That’s right folks, it’s finally here: the monumental, extraordinary Stepstruder MK7.  It’s extraordinary in that this is our first extruder designed from the ground up for 1.75 mm filament, and monumental in the sense that it’s…well…smaller than any of our previous extruder designs.  So small, in fact, that it might just be possible to use two of them for experimental Dual Extrusion!  (Ssshhhh….)

They said it couldn’t be done, and we said they’re wrong.  We have the technology.  We knew we could make a better extruder, one that’s smaller, more reliable, and easier to put together.  And has a higher number.

So tell me: do you feel lucky, punk?  Well do you?  Because you don’t need to: the MK7 will make it easier than ever to get great results from your MakerBot Thing-O-Matic.  The Stepstruder MK7 takes care of the luck for you!  Just choose the normal complete kit or one with a stepper driver if you’re upgrading from a MK5.

In all seriousness, a lot of work has gone into the design of this new extruder, and we’re really excited to release it.  Head on over to the store and check it out! ¡Awesolenté!

Tagged with , , , , , , 41 comments

41 Comments so far

  • Ostrich99
    September 15, 2011 at 10:48 am

    Of course I just ordered a bunch of 3mm filament. 🙂

  • anin
    September 15, 2011 at 11:10 am

    Where’s the source? I can’t buy it without the source.

  • Josh Cote
    September 15, 2011 at 11:26 am

    wow i cant wait to see how fast people adapt the size and mounting for the dual extruders… now if only i had money to buy them (only 2)… maybe 3.

  • Eric Smith
    September 15, 2011 at 11:55 am

    If you have a lathe, maybe you can turn some of the 3mm filament down to 1.75mm. 🙂

  • Nicolas
    September 15, 2011 at 11:56 am

    Was searching for an extruder for my Prusa and this is realy cool !
    But only for 1.75mm 🙁
    I have so much 3mm that i will try to find something else…

  • MTO
    September 15, 2011 at 12:15 pm

    I’ve read a few times that the community is moving to 1.75mm, but why? What are the advantages?

    Looks sexy though! I don’t see why the same general design couldn’t be done with 3mm. Presumably 3mm needs more torque, and may need a larger heater…

  • Niu
    September 15, 2011 at 12:26 pm

    Is the Thing-O-Matic kit gonna include MK7 any time soon?

  • msmollin
    September 15, 2011 at 12:53 pm

    MTO – 3mm requires more torque, larger motors, bigger heaters, and because its nearly double the width, extrusion control is corser (more corse?) compared to 1.75. Overall its a good idea to move to the smaller filament. It’s just the investment the community has made in 3mm is high. I have 3 spools of 3mm filament myself that I would need to use before I could justify getting this. Also I just upgraded my cupcake to a mk6 >_<

    I'm curious to see if this is light enough to use in a moving-head setup, a la no bowden side-mount (which I consider a hack for the most part).

  • neoteric
    September 15, 2011 at 1:02 pm

    I am very impressed. A truly original idea and powerful in its size. The idea of two or more extruders, oh my!

    I am difficult to please, but I have to say BRAVO!

  • GeoDelGonzo
    September 15, 2011 at 1:03 pm

    ¡Awesolenté! will be added to my vocabulary 😀

    I feel this uncontrollable urge to drop everything and go to the NYC MakerFaire this weekend… I must go…

  • Joe Larson
    September 15, 2011 at 1:21 pm

    Is anyone going to make a way to melt your 3mm filament and extrude it at 1.75mm so folks back stock isn’t wasted?

  • CapacitiveMind
    September 15, 2011 at 1:22 pm

    Placed my order this morning. Cannot wait to try out the new MK7. My hopes are high for reliable 1.75mm printing.

  • ostrich99
    September 15, 2011 at 1:24 pm

    I wonder if I could just put some quick connectors on the extruder cables so I could swap out the MK6+ and MK7 easier so I can quickly switch between my 3mm stock with the MK6+ and the 1.75mm stock with the MK7 depending on what I’m printing.

  • stan
    September 15, 2011 at 1:46 pm

    Quick note: The assembly instructions for the MK7 linked from the store page don’t exist at the moment.

  • Andrew
    September 15, 2011 at 3:05 pm

    Provided I upgrade to the gen4 electronics, can mount this on my cupcake? Are there any other upgrade considerations I should make before purchasing (is a big investment, in its own way)

  • jeff ballard
    September 15, 2011 at 7:13 pm

    I just ordered one my self along with some 1.75mm plastic, I hope to mount it beside my 3mm Frankenstein extruder in my huge Makerbot clone.

  • BRockhold
    September 15, 2011 at 7:21 pm

    @Andrew: If you have the stepper driver needed for it, you could indeed. I want to see it!

  • Moceri
    September 15, 2011 at 11:26 pm

    I literally just finished building my TOM today. With the announced
    MK7 stepstruder, this makes me want to buy it instantly. Is it worth
    it? I know this will lead to support material/multiple colors (me
    want) with 2 side by side. But most importantly for me, how much will
    this increase the resolution?

    “The stock 0.4 mm nozzle allows printing at a layer height of between
    0.32 and 0.27 mm right out of the box, for the most detailed prints
    you’ve ever seen from your MakerBot®” – from the description page in
    the store. How much is the difference from the MK6+ 1.75??

  • StumpLifter
    September 16, 2011 at 2:39 am

    Would like to use the Makerbot for something USEFULL!!! So can it melt Acetal? (MP 375-400+ degrees F) Why Acetal (Duponts Delrin) – cuz thats what the engineers are using to replace aluminum parts in mechanical applications! Or is the Makerbot just the little boys version of the Easy Bake oven??????? Yeah, I’m in your face – Lets put the world back to work!!

  • Execcr
    September 16, 2011 at 2:47 am

    I want to know if the MK7 will be introduced into the kit too. I’ve to buy one 😀

  • Chris
    September 16, 2011 at 3:19 am

    It’s the UP! extruder? or heavily influenced by it. Anyway, it’s a good extruder! 🙂

  • bre
    September 16, 2011 at 11:02 am

    @Ostrich99 @Josh Cote, @Joe Larson. If you’ve got lots of 3mm filament, stick with your MK6 until you build through it. Go on a MakerBotting binge!

    @anin Our policy is to put the source out before it starts shipping. This is pretty common in the hardware open source space. I totally understand you wanting to wait for the source to check it out. You won’t have to wait long, we’re just out of “test the crap out of it so we can launch this thing” mode and we’re in “clean up the docs so that others besides us can understand them” mode right now!

    @Josh Cote Yeah, we’ve got dual extrusion marked as experimental right now. One of the great things about being open is that MakerBot Operators are part of the R&D team and you can help improve the software and the hardware. I’m really looking forward to the community getting it’s hands on the code for dual extrusion and improving it. We’re cleaning up the code now and will have it out before the MK7 ships so you can get your hands dirty.

    @MTO The main advantage of 1.75 over 3mm is that it requires less force to push a small filament through a small hole than a big filament through a small hole. Thus we get to use a nice and tidy nema17. We also took the time to redo a bunch of the internal geometry of the extruder to optimize for better flow. (just realized this is basically what @msmollin said)

    @Niu Thing-O-Matics ordered on September 15th and after will include the MK7.

    @neoteric Thanks! When we started, we had a handful of customers so we could just make things up and ship them. Now things take longer to make because we have to have the supply chain worked out and we do an absurd amount of testing. We’ve been waiting to announce this for months, but we had to check everything and make sure all the ducks were in a row. In other words, it’s a relief to have this out there in the world now! We’re proud of it!

    @GeoDelGonzo You should go. If Maker Faire were a country, I would move there.

    @ostrich99 You can make connectors for everything but the thermocouple. Don’t cut that, it has to go all the way back to the electronics!

    @stan We’re on it!

    @Andrew One of the things that I love about the cupcake is that we upgraded it as much as we could and then created the Thing-O-Matic, but MakerBot Cupcake Operators continue to come out with upgrades for it beyond what we imagined possible. Gen 4 and upgraded electronics are doable. It’s kinda like putting a V8 engine in a Honda. You’ll have to spend some time under the hood customizing your hotrod 3D printer, but it will be very cool. Go for it!

  • Bre Pettis
    September 16, 2011 at 11:17 am

    @Moceri The nozzle is the same diameter, but with improved internal geometry. Also, with thinner filament, you have much quicker control over pushing it out and sucking it back in. No gears to slow things down and you can push and pull more filament per revolution. Also it’s a billion times easier to put together and take apart since there are only a few parts.

    @StumpLifter Acetal would be awesome, those temperatures are out of spec for this machine though. Don’t diss ABS and PLA, those are legit plastics that engineers love!

    @Execcr Mentioned this above. Order away!

  • Kevin
    September 16, 2011 at 11:26 am

    @Bre: “@Niu Thing-O-Matics ordered on September 15th and after will include the MK7.”
    Well, that seals the deal. Placing an order today.

  • ostrich99
    September 16, 2011 at 11:37 am

    Hmm.. I’ve got somewhere around 6 or 7 kilograms of 3mm to burn through. Wonder if I should try and print every item that is printable on Thingiverse to start to burn through it before upgrading. 🙂 I’m sure that’s not enough plastic, but I’d sure have some bragging rights if I ever completed that quest.

  • Squintz
    September 16, 2011 at 11:45 am

    Is there a video of the new extruder in action?

  • nycdesigner
    September 16, 2011 at 11:54 am

    @Bre: Can I use the same Type K thermocouple I have for the MK6+? Or do you recommend the one currently shipping instead? Will that work for the MK6+ as well?

    I’d like to hot-swap the two extruders and only have to attach the thermocouple to the hot end. I’ve been running the hot end naked, and it’s just fine, so the connection is easy to unscrew.

    Loving’ the engineering! Thx so much.

  • nycdesigner
    September 16, 2011 at 11:56 am

    P.S. What about profiles for RepG and voltages for the board? Should I assume docs will be up in a week?

  • ErikJDurwoodII
    September 16, 2011 at 2:50 pm

    Will the Thing-O-Matic Prize from the MakerBot Mascot Challenge include the MK7? 🙂

    • Bre Pettis
      September 17, 2011 at 11:56 am


  • Erwin Ried
    September 16, 2011 at 4:55 pm

    Nice! Lighter extruder = smoother operation…

    I only assembled the 3 mm MK6 because the included plastic in the TOM kit was 3 mm 😛 haha but now I have to use all my ~3 kg plastic before I buy the MK7.

  • David
    September 16, 2011 at 5:06 pm

    Ordered! But where is the documentation?

  • Sleepykitty
    September 16, 2011 at 5:22 pm

    I have been tying to get TOMs in several classrooms here.. I finally got approval to order one and I just had to do it on the 14th. Sooo bummed.

  • Dave Lee (Crypto)
    September 16, 2011 at 11:01 pm

    Love it. Need side by side comparisons and video’s stat!

  • Sleepykitty
    September 17, 2011 at 1:23 pm

    @bre “@ostrich99 You can make connectors for everything but the thermocouple. Don’t cut that, it has to go all the way back to the electronics!”

    You can buy a few pairs of Thermocouple connectors from . Search for the words ” Thermocouple Connectors” and look for the Flat Mini style for the type K.

    It must be type K and it must have type K wire running all the way back to the electronics as Bre says. (no other type of metal can be in that circuit).

  • Kevin
    September 18, 2011 at 7:08 pm

    On double Mk 7s: What about using a standard 1.75mm ABS in one extruder along with a second extruder which has the water soluble 1.75mm in it? You could build up water soluble foundations to allow for overhanging pieces. Very exciting.

  • 3D Printing in Two Colors!? | Revolt Lab
    September 18, 2011 at 7:28 pm

    […] on the Stepstruder MK 7 here and more about the public beta of the dual-head version […]

  • Maker Faire « Project Blog
    September 18, 2011 at 7:57 pm

    […] get to see the dual extruder thingomatic for the first time. The next morning on the train to the Faire I design a two color version of the […]

  • G
    September 22, 2011 at 9:55 pm

    As soon as I burn through the rest of my 3mm Transparent ABS and the remainder of my standard color ABS. I will upgrading to 2 of the MK7 extruders. I cant wait…. I ability to print support will be awesome.

  • Makerfan
    October 2, 2011 at 11:23 am

    Since the extruder is so small now to have more printing area you should make the extruder move on an x + y axis not the build platform. It would speed up the printer and make the build area bigger.

  • Open Hardware Summit and Maker Faire Wrapup |
    May 29, 2012 at 11:10 am

    […] only communicated online. On Sunday, I worked at the Makerbot booth, demoing our exciting new MK7 Extruders. It was great to finally show these off, because I had been working with them for much of the […]


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