3D Printer Extruder Jams

Extruder Jams are a frequent and perplexing problem with FFF 3D printers. The gears can get clogged with plastic, the hot end can get clogged in many distinct ways and your EPROMS might not be accurately telling your machine how much its motors need to turn in order to push out 100mm of plastic.  But FFF 3D printing is still a great option for prototyping your ideas if you have free time and want to save money.


I’m not enough of an expert on extruder jams to feel that my advice is a better guide than some of the other guides out there already but I am enough of an expert to hold your hand or fix it for you (if you are willing to pay for my time).

Customer: I’ve been having trouble with my printer.  This is the printer I have https://www.amazon.com/Monoprice-113860-Select-Printer-Filament/dp/B018GZBC3Y/ref=sr_1_3?ie=UTF8&qid=1465878994&sr=8-3&keywords=monoprice+printer

It is not extruding any more.  I was able to print things smoothly for a little over a month then I started having trouble.  I print on painters tape and occasionally used glue sticks if parts weren’t sticking to the bed.  When it stopped extruding I was able to get it working again by reloading the filament but then it seemed to strip the filament so I wasn’t able to feed it through or remove it.  I removed the end of the extruder to try to clear the filament.  I cleared some but I have not been able to load the filament since then.  I have tried using a guitar string to clear it but I haven’t had any luck.  What other things could I try?  Thank you for any insight or advice!

Pintstein: You are describing one of the hardest and most common printer malfunctions.  Your printer probably has multiple issues but only one root cause.  To get your filament to clear again try setting the temperature 20ºC higher than your normal printing temperature.  Once the hotend is hot, depress the spring and pull up on the filament. If the filament is too stuck to change filaments, try not depressing the spring, pulling up on the filament lightly, and using your print software to have the extruder retract filament. If you still can’t change your filament you are going to need to disassemble the extruder.  I can help people do that in person faster than I can describe how to do it.
If you can change the filament we can diagnose the root cause of your problem.  Clean every part of the gears that you can before putting in the new filament.  That stripped plastic inside your gear teeth could be your problem. Extruder jams can be caused by the temperature being too low so why not increase your extruder’s temperature 5ºC above your normal printing temperature.
Now use a micrometer or ruler to measure 125mm of filament.  Open your software and ask the extruder to push out exactly 100mm of filament.  If you are left with an amount of filament other than 25mm write back to me with a description of what the extruder looked like when it was trying to push filament out. https://www.youtube.com/watch?v=YUPfBJz3I6Y

Many make and models have a spring that can be tightened or loosened.  If the spring is too tight, it can cause that filament stripping that you described.   My Monoprice dual extruder’s spring cannot be tightened and loosened so I will assume that your Monoprice Maker does not either.

If your printer is now able to extrude accurate amounts of filament, let’s make sure the printing temperature is set to the right temperature for your filament. Download this file and print it.  changing the temperature as it prints.  If the print becomes “beady”, as in looks like a string of beads, your temperature is too low and the optimum temperature is probably 5ºC above that.https://www.youtube.com/watch?v=POaL2GGBHGM
My Printrbot develops extruder jams after I have done A LOT OF PRINTING on it and the steps I just described above allows it to work for a little while but buying a new hotend has been the most successful way to get it back in good working order.  I now have 3 old hotends for my printrbot and am putting off buying the 4th in the hopes that I will find a magic way to revitalize one of them by spraying teflon inside the hot end or something.
Keep in touch and pay it forward! The additive manufacturing revolution is about giving people with free time, the information and skills to make plastic objects from their dreams.
I struggle to generate social media content. Is It alright if I use our conversation on my blog similar to the way I posted another conversation on my facebook page? https://www.facebook.com/Pintstein/posts/1738226519775217

Customer: You can use this conversation on your blog.

I think I have actually tried all of that before.  I gave it another shot but still no luck.  Are there parts I should look into replacing?  On your website it says you can send a tech to look at the printer, is this the kind of problem a tech could take care of and maybe also show me what I’m doing wrong?  I work as a maintenance tech so I feel like I should be able to fix basic things but I’m very new to 3D printing.

Pintstein: Yes, this problem could be solved by having a technician come out to your location and run through everything but Pintstein’s technician is not able to carry every single part for every single make and model of 3D printer. So you should order a replacement hot end before I come to your location.  I’m 90% certain that the replacing the hot end will get the machine back to good working order if another step does not.  My labor costs $50 for a 2 hour visit and $15 for each hour after that.

I have been struggling to find a replacement hot end. Could you send me a photo of your extruder so I can confirm that it looks a lot like this but is black instead of blue? http://www.aliexpress.com/store/product/12V-0-4mm-Single-Nozzle-3D-Printer-mk10-Print-Head-Extruder-Extra-Throat-Tube-0-3mm/1737229_32311314664.html
Where are you located? I’m in Saint Paul on Grand Ave.

I Needed to do my Part to Save the World.

A year and a half ago I was confused why I was not happy. I believe that the meaning of life is “love and work”. In 2015 I finally had a stable job that paid $27,000+ per year and there was a strong potential that I would get promoted. I also had recently met the lovely Maria Hull. I had filled the huge holes in my life created in 2013 but there was still something missing.

As I thought about what I was missing I realized that my world was burning. Wars, extinctions and other catastrophes seem to be happening with increasing frequency and what was I doing about the catastrophes? I worked in a Pacemaker Battery Factory which is actually one of the more meaningful jobs I’ve held (HR says my labor saves an average of eight lives a day). But I was unhappy because I knew that I could do so much more to make the world a better place. I began prototyping a series of toys that are going to make it much easier for students to become literate in the language of life.

dna-a-summaryI started reading everything I could about 3D printing and design. I tried to find local resources teaching about 3D printing but short of enrolling in a course at a university, there was nothing. The Twin Cities Makers and Nordeast Makers did not respond to my emails for weeks so I resolved to buy my own 3D printer. It took me a week to assemble my first printer and then another week to calibrate all the settings and get useful prints out of it. In that third week after my Printerbot had arrived I was amazed at how much I could accomplish. Many of the more complicated things that people had been telling me I should do when 3D modeling were irrelevant if you were not using an SLS printer.

TonyStarchIn these early days I was certain that if I just put in enough time, all of the mysteries of 3D printing would reveal themselves to me and I would be able to lead the manufacturing revolution. My goals have had to become more realistic since then but I am two or three months away from being free to publicly disclose the bioinformatics toy that got me started on this whole journey.

I am prototyping a series of kits that will make it much easier for students to become literate in the language of life. Organic molecules interact in complicated ways that I was able to understand fairly well by just reading textbooks and looking at pictures but I saw a lot of my fellow students struggle with complicated topics in protein folding and DNA mutations. Textbooks try to depict 3 dimensional structures and forces in 2 dimensions. Printing 2D representations of organic molecules was the most cost effective method of teaching at the time I was in school but 3d printers have become really cheap. In biology, the 3 dimensional structures that molecules fold into determines the way that those molecules function.   Having a kit that models the shape and charge properties of DNA and other organic molecules will allow students to understand how tiny differences in genetic coding can result in big changes in function. Give me your contact information if you would like to hear about the launch of my kickstarter campaign to get the DNA kit made with injection molding in two or three months.

This might sound obscure or nerdy to laymen but trust me, students trying to learn how genes become proteins will find my bioinformatics kits very useful and the possible inventions that can come from a better understanding the language of life are endless. The first thing I am going to use my bioinformatics toy to invent is “new RuBisCo” a protein that will stop global warming in its tracks.

The Cambrian Explosion of 3D Printing


542 million years ago most of the known animal diversity came into being in the geological blink of an eye! If that sounds like creationism rather than Darwinian evolution it is only because I was being dramatic in my word choice.   The Cambrian Explosion was a period of less than 25 million years where all animal phyla are suddenly distinctly recognizable in fossils. I personally believe that the cause of this dramatic “leap” in evolution was that HOX genes made body design complexity more easily modified by mutation but this blog is not about my mad theories or the Cambrian explosion. I want to use the Cambrian explosion as a metaphor for this period of rampant creation in the 3d printing market place. To make that metaphor, I need to tell you one more thing about the Cambrian Explosion. Not only did the recognizable ancestors of sponges, starfish, worms, coral, lobsters and a tiny worm-like organism with a backbone, that would give rise to humans and all other vertebrates appear in the geological blink of an eye, there were also many organisms that clearly have no descendants in our modern day life. For instance, Opabinia, a lobster like organism but with 5 eyes and a clawed proboscis (like an elephant’s trunk).


Okay there was a lot of diversity, but what does that have to do with 3D printing? Well, right now there is a dizzying number of 3d printer manufactures in the market place. 3D Systems and Stratasys are the giants in the 3d printing market but I am not sure they are going to weather the turmoil of this rampant creativity. If you were in the Cambrian period that five eyed Opabina would have looked like it was winning the evolutionary arms race because they were a lot more common than that funny little worm that gave rise to humans and all chordates.


I have been weighting if I want to buy a higher quality printer, Flash Forge Creator Pro. I feel fairly confident that any 3d printer that I buy now will be obsolete in 5 years. My printrbot simple maker has already been made obsolete by the printrbot play. I find myself telling people that I like my printrbot more than my M3D but I can not fully endorse the printrbot play because I have never actually seen one in action. But don’t take my word for it, Make Magazine rated the printrbot play best for schools.

My 3d printers allow me to prototype the designs and teach myself 3d modeling but I feel fairly confident that in 5 years any FFF printer will be seen as an old clunky machine that you only use if you don’t have access to the nicer CLIP systems. I feel like I know that buying new nicer is hardware not going to pay for itself by improving how many people ask me to print things for them. My current hardware allows me to test my ideas and motivate myself to model objects that I want but can’t find at the store. The software skills that I am developing might generate more revenue for my company than any of the actual designs that I am prototyping and considering patenting/copyrighting.

Delta Printer Experience 

I have been teaching myself 3d printer calibration for 8 months and until recently, all of my experience has been on Cartesian FFF printers. Cartesian printers have a single motor responsible for all of the x axis movement. A single motor responsible for all of the y axis movement and a single or sometimes couple of motors responsible for the z axis movement.

Cartesian Vs Delta

In contrast, Delta printers have 3 towers with motors that impact the X, Y and Z coordinates of the print head. My membership at Nordeast Makers gave me access to a Rostock Max and I have not regretted the $200 I spent on a one month membership at Nordeast Makers.

Delta Printer MathFor the most part, The extra complicated math of delta printers is handled by firmware and slicing software. However, if you are the person first setting up a delta printer or recalibrating it, you will have to calibrate the EPROMs to make the print head move level across the print bed.

Today I ran into a problem with one of the towers on the Rostock hitting a boundary and skipping a couple steps on the rubber belt that the C motor is attached to.

After it skipped the steps, the print head was elevated when it came near the C tower. The printer tried to print outside of the its maximum dimensions and thus skipped some steps.  Most consumer 3d printers lack encoders or some other method of tracking where their motors are actually located after they leave a “home position”.  Any time that a motor tries to move and it cannot, the motor gear skips on the rubber belt and the position of your print head shifts from where the software expects it to be.  On my Cartesian printers a little bit of skipping, especially on the skirt (an outer boundary of the print) does not result in a failed print.  On a delta printer, having just one motor skip a couple steps moves the print head’s location in all 3 axises and that z axis shift is going to result in a failed print every time.

 The problem was easy enough to solve by just scaling down the print to 95%, repositioning the digital model and making new Gcode. Now the printer never tries to print outside of the boundaries that are possible.  Thus it never skips a step on the C belt and the print head stays in the position.

   But there still was a little bit of unevenness to the print heads location near the print bed.  In the photo below you can see some gaps in the first layer when the print head is near the C tower. These gaps are a result of the print head being ~.05mm millimeters higher off the print bed and the filament not being squished as flat.

   I have offered to take a stab at recalibrating the EPROMS for each tower but I need to wait for Micah Roth’s approval before attempting it.

Tangent: when I had only read about Delta printers I read that the delta design allowed for faster movement of the print head.  Nordeast Makers has a Cartesian Creator Pro that is easily 1.5 times faster than the  Rostock Max. So my limited experience does not support the idea that delta printers are faster than cartesian printers.  However my limited experience might not be representative of the potential maximum speed of the printers because I am printing at movement speeds that Micah Roth determined were the best balance of speed and quality.  Just because you can drive your car at 120 mph doesn’t mean that you will like the result if you do. Similarly, reducing your print speed can be a very helpful way to increase the quality of your print.

A Very Hack Factory Christmas

Scan 11Well, I am still not as good at fixing and recalibrating 3d printers as I would like to be but nothing worth doing is easy. I do at least have a functional prototype of the educational toy that motivated me to found a business (you can only see it in private meetings). Starting Pintstein LLC has taken up a lot of time and money so when I was making my Christmas list this year I tried to think of people that I could make presents for in order to conserve money.


The Hack Factory runs their laser cutter calendar on a Raspberry Pi and the case for the thing is appropriately, laser cut.

2013-07-07_07.47.17_preview_featuredMy Father also happens to run a website off of a Raspberry Pi and his Pi has just been dangling from the wires plugged into it. So, cutting out a version of this thingiverse file got added to my christmas to-do-list. I got some 1/8 inch Baltic Birch from Young Blood Lumber and cut him out a couple of Raspberry Pi cases because it is good to have spares.

My Brother is an architect so this bizarre sculpture/puzzle seemed like a good gift. IMG_2432I tried to assemble it without complete success. IMG_2434My failed attempts to solve the puzzle just made it all the more fun to watch my Brother put the puzzle together in under an hour.

I am still trying to figure out the best way to turn this image of my soon to be Sister-in-law’s cat


into a laser cutting design. But when I finish it will be a gift to Jacki, my Brother’s Fiancee.IMG_2355


The Love of my Life, Maria Hull will eventually receive a “surprisingly swishy Maple wand with phoenix feather core” 

 I had never used a lathe before undertaking this project and I am quite satisfied with my success. I finished hand carving the design from Ginny Weasleys wand into the handle. Now I just need to put some stain on the wand.


I got to show off my printrbot simple maker to my family and help my Cousin design 3d printable key chains and coins for her startup, the Core Clothing Company.


I even brought some 3d printed and laser cut objects to the white elephant party my friend Micheal Anderson hosted.

White Elephant

Aaron Sinner took home the laser cut Mayan calendar and has collected on his IOU by requesting a sign for his apartment door. 

 The joy of the technologies that I have been delving into is that they make customizable gifts easier. If you really want something that you can’t find in the store, do a quick search of Thingiverse, see what kind of free designs are already available, Then go to my website and ask me for a quote on making the design.

3D printing 101

The following is a handout for a class designed to help people go from knowing nothing about 3d printing to being able to start a print and design simple objects for printing.

What is 3D printing? 3D printing has a lot in common with 2D printing. Imagine that your 2d printer made thin pieces of plastic in any shape instead of ink in any shape. Now imagine that you could move up and put multiple layers of thin plastic on top of each other. The technology for 3d printing has been around since the 70s but recently cheap microprocessors made it possible to sell 3d printers for $400 or less.

What are you going to 3d print? Printers that fuse filaments of plastic together can make objects of virtually any shape. The printed object might not be as smooth or high resolution as you would like and it might require support material to ‘defy gravity’ but all of those limitations change if you go away from Fused Filament Fabrication and try one of the more expensive printing technologies. What is the plastic object of your dreams?

Download a file from Thingiverse.com a large, user friendly database of printable files. Nature doesn’t reinvent ‘the wheel’ very often, why should 3d modelers? STL files are some of the most universal 3d models but OBJ files will work too.

Repetier is one of several software options for turning digital .stl files into physical objects. Repetier is not the most user friendly but its complexity allows experts to control more aspects of the printing process

Click the “load file” button. Once the computer has processed the file you will see the object displayed inside of a digital box that shows the limitations of your print bed. You can load several STL files at once and drag them around the print bed however you like. Some files need to be rotated so that a large area will be in contact with the print bed. If an object is not strongly attached to the print bed the next layers of plastic will end up in the wrong place.


Click the “slice with slic3r” button. Slic3r is taking STL files that you arranged in repetier and generating the instructions that the printer will read to print each thin layer of plastic. These instructions are called Gcode. Gcode is not easy to modify and run on other machines because it often has coefficients that have been calibrated to a specific machine. IMG_2271

I wish I could say just click the “start print” button but our printers are still a little quirky.

  • The Velleman K8200 doesn’t turn on its extruder heat when you click the “start print” button so it will sit there waiting for the extruder to heat up. If you click the manual control tab before starting a print then you can turn on the extruder heat

Screen Shot 2015-11-04 at 10.55.18 PM

  • The Prusa i3 doesn’t have a sensor to tell it what height its print bed is located at and it assumes that its print bed is located at whatever height the extruder was at when it turned on. The way to work around this is to always lower the extruder back to the print bed before turning the machine off after you have finished with your print.


Changing Filament color:

  1. Open the manual control tab in repetier.
  2. Heat up the extruder.
  3. After the extruder is around 190º C, pull up on the filament while clicking the retract filament manual command.
  4. The extruder gears should spin in reverse and eventually the filament will come loose and allow you to push in the desired color.
  5. Insert the new filament and push the extrude filament manual command. The extruder gears should grab the filament and pull it in.
  6. Keep extruding until the desired color is coming out of the extruder nozzle.

TinkerCAD is the most user friendly 3d design software that I have found. It is free just go to www.TinkerCAD.com and log in.

Drag objects onto the work plane

drag objects

Resize objects


Change the location of the work plane

Change Workplane

Make holes

Make Holes

Download your design

download design

I do the majority of my 3d modeling in Blender, a free animation software. I will be hosting a class on modeling with Blender on December 3rd.

My Company, Pintstein L.L.C. is a startup 3d printing and education company or as I like to call it, a “Mad Scientist Toy Company”. Pintstein will print things out for you, teach you how to design your custom object and, hopefully some day, Pintstein will be able to send a technician out to your house to fix/recalibrate your 3d printer. 3d printing is resource cheap but time expensive. Children are the most time rich members of society so Pintstein wants to get kids access to 3d printers by making it easier for schools and libraries to keep their printer in good working order. www.PintsteinPro.com

3d Printing Objects for Lost Wax Casting

I am preparing for a class as part of the Metal and Glass Symposium of the Society for Creative Anachronism, a gathering of Medieval Reenactment enthusiasts that recreate art or utilitarian tools from some time period between 600-AD and 1600-AD.

Schedule:  September 4th, 7:30pm to 9:30pm hosted by the Metal and Glass Symposium 19848 East Bethel Blvd NE East Bethel MN 55011

7:30-8:00pm Demonstration of 3d printing and lecture about the hardware involved in 3d printing and lost wax casting.

8:00pm-9:00pm 6 Participants will get to 3d model a 2d design onto a simple geometric object.

9:00pm-9:30pm Question and answer. Feel free to ask questions during the class but I might put off complicated explanations until after the class is over.

The hardest part of every design is getting a clear vision of what you want. These instructions are going to show you how to digitally model a coin with some sort of simple 2 dimensional design on its surface.

elizabeth-sixpence white Back pencil-black-and-white-drawing-nTX979LTB

Once you have the black and white image that you want to put on a coin or stamp, open Inkscape. Inkscape is a free Vector Drawing program easily downloaded and installed on Windows, Macintosh and Linux.

In Inkscape open your desired image.

  1. File> Open
  2.  Select the image by clicking on it. If a dotted box and black arrows appear around the image, the image is selected.
  3. Path>Trace Bit Map>Ok There are a lot of buttons that you could play around with here but for the purposes of mapping a black and white image, the default settings are perfect.
  4. Now we just need to save our design as a .svg file. File>Save.

SVG files are known as scaleable vector graphics and 3d modeling software can use them in fun/useful ways.open image inkscape not selected Selected Inkscape Bitmap Inkscape Save


Blender is a free, powerful and complex animation software.  Today we are just going to learn the bare minimum. When you open blender you might have a cube, a camera or a point in the startup file. Feel free to delete these by left clicking on them and hitting the x key. It is not control x, just x and then you will need to confirm that you really want to delete it by left clicking the delete button that appears.

Blender Delete 

  1. You can drag objects around by right clicking them and holding the right click while you move the mouse. If you left click, the object getting dragged will stay at the new location. If you right click, the object getting dragged will return to its original location.
  2. In blender you are looking at a 3 dimensional space on a 2 dimensional screen. Changing your view of the object is a little bit like flying a spaceship or submarine while looking out a wind shield. The scroll wheel on your mouse is forward and backward (or zoom in and zoom out). Clicking down with the scroll wheel while you move the mouse allows you to rotate the direction that you are viewing the object from. Now try holding down the shift key, while clicking down with the scroll wheel and moving your mouse: I am not sure how to describe this third method of moving your windshield other than to compare it to side thrusters on a space ship.

Design a coin in blender

  1. you can import your design in form of an SVG file. File>Import>Scaleable Vector Graphic. Select the desired file and hit Import SVG.
  2. For some reason the SVG file always imports so tiny that it looks like nothing is there. Hit the n key and information about the location, rotation and dimensions of the selected object will appear. Entering X and Y dimensions of 20 will make the design fill a 20mm x 20mm square
  3. A great way to make imported SVG files centered in the axis’s is to transform the origin to the center of its geometry. Object>Transform>Origin to Geometry
  4. Now we need to set the thickness of the SVG design. You will need to click on the curve button and then set the Extr: thickness to half the desired thickness (.5 if you want 1mm thick design).
  5. In order to make the simple cylinder part of our coin select Add>Mesh>Cylinder.
  6. A 2mm diameter and two millimeter cylinder should appear. In the dimensions panel change the x dimensions of the cylinder to 23, the y dimensions of the cylinder to 23 and the z dimensions can remain 2 or maybe you would like a coin that is 3mm thick.
  7. Adjust the placement of design and coin until you like the result by right clicking them and holding the right click while you move the mouse. If you left click, the object getting dragged will stay at the new location. If you right click the object getting dragged will return to its original location. Changing the locations to x=0, y=0 can be a great start.
  8. Once you know that you have everything correctly placed in relation to each other, select the design and the cylinder by right clicking both with while holding down the select button.
  9. You can export this design as a .stl file for 3d printing File>Export>STL
  10. Stl files can be given to someone with a 3d printer and loaded into a gcode generating software like Repetier or Cura
    Blender Import SVGBlender Import SVG2Blender ImportedBlender Imported nBlender ImportedBlender Point of origin  Blender Thickness 2 Blender RotationBlender Origin to Geometry  Blender Add Cylinder2  Blender Add Cylinder3  Blender CoinBlender Coin 2Blender Export

My Company, Pintstein L.L.C. is available to print wax designs within the dimensions of 85mm x 85mm x 95mm.


A startup 3d printing and education company or as I like to call it, a “Mad Scientist Toy Company”. Pintstein will print things out for you, teach you how to design your custom object and, hopefully some day, Pintstein will be able to send a technician out to your house to fix/recalibrate your 3d printer.

More 3d printing classes coming to the twin cities:

  • Blender Basics for 3d Modeling: Accelerate your learning curve with this introductory class! I will be focusing on making sure each student understands 7 commands necessary for good 3d modeling. Blender is free open source software but it is not the most intuitive.
  • Comparative Anatomy of 3d Printers: a show and tell experience. I own three printers with different approaches to “FFF XYZ” designs