Orion Delta: Extruder Jam Fix (With Photos)

The Problem

The Orion Delta extruder drive assembly relies on a single drive gear which moves the filament to the extruder. The filament is held tight to the driving gear by a wheel that pushes the filament into the drive gear with a spring.

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      Click images for higher resolution

Every once in a while, it is too hard for the drive gear to pull the filament from the spool. This can be due to the Orion Delta’s less than favorable feeding system, or to tangles in the spool. Either way, the printer will eventually stop extruding. It will look something like this:

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These specks are small amounts of plastic being pushed out, but this is clearly not going to work. This may happen part way through a print, and can usually be seen a few layers after as the extruder will be printing several millimetres above the part.

What’s happened is the drive gear has sort of chipped away at the side of the filament, causing it to become thin and filling the extrusion assembly with bits of plastic. The filament is now too thin for the drive gear and wheel to create a large enough force on it to push it up into the extruder. This will be visible when you take the machine apart.

Quick Fix

If you’re short on time, or part-way through a large part, it may be worth it to perform a quick fix. This can be done by spraying some compressed air at the drive gear, then pulling up the red handle, releasing the pressure from the gear and the filament, and pushing the filament up the extruder manually. This may get things moving, but if the part is already damaged or if the problem persists, you will need a more permanent solution.

 

The Real Fix

The real way to fix this is quite simple. We’re going to open up the extruder drive assembly. clean out the affected parts, and replace the filament.

Before we do anything, we’re going to ensure the hot-end is ready by preheating the machine for PLA. This is under Printer Settings > Preheat PLA.

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While that’s heating, we’re going to pull off the white gear attached to the stepper. This might feel like it’s not going to come off, but it will! Don’t pull too hard, and use a tool for leverage if it’s really stuck.

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Once that is off, remove the assembly cover. This screw is different than the others, so keep it separate.

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Once removed, remove the rest of the assembly. Be careful, as once the screws are out, the spring tends to jump out!

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Once removed, clean the drive gear with a metal brush or similar. If you miss this step, the problem will surface again quickly, as the teeth of the gear that are usually used to push the filament through will be filled with plastic, giving the drive gear less grip on the filament.

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Once it’s clean, cut the filament so that any damaged filament can be removed.

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Ensure the printer is preheated for PLA. Then, gently pull the filament out of the hot end.

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If the filament breaks, don’t worry! You can always unscrew the tube from the top of the extruder drive assembly and remove it from there.

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Once the filament is out, you should be able to see where the damage was. I’ve included this photo that shows the end of the filament that has been ground up by the drive gear, but it might be hard to see. I will upload a better photo next time it happens.

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Then, reassemble the drive assembly and perform a normal filament spool change to get the plastic flowing again. Hope this helps! If I’ve missed anything, or if you’ve found a way to prevent or improve this problem, leave a comment below!

 

 

Dynamically Changing $PATH for different Node projects

When I started working with Node, I did a lot of the work locally. I was working on several local projects and was having trouble keeping my $PATH up to date. I’ve recently found a solution that dynamically sets your $PATH to include node_packages/.bin in whatever directory you’re working.

Add the following to the bottom of your .bashrc or .bash_profile.

This takes advantage of the PROMPT_COMMAND environment variable, which runs an assigned function before your BASH terminal displays a prompt. Large functions may slow down the shell, but I haven’t noticed a performance issue at all using it.

1C03 – Printing in the lab

Preparation


Before you enter the lab, you must have previously prepared everything you need. Here is a checklist you can follow to make sure you’re prepared.

  I have designed all my gears using the Design Accelerator and created a hole in their centres.
  I have created files that contain several gears, all constrained to a single plane. Spur gears are in separate files from all other gears.
  I have all exported all my gears in the .STL format.
  I have all the files I need on a USB drive.
  I have also backed up my files to Dropbox, Google Drive, my email, or another reliable webservice.
  I have made a valid booking online.

Printing

When you arrive on the day of your booking, you will have half an hour at the computers, and half an hour at the printers. It is imperative that you use this time wisely, as you will be cut off from the printers at exactly one hour.

If you are late for a session, it will be given to someone on the waiting list. If you fail to attend a session, there may be a penalty to your final grade.

Scaling Your Files

Before printing, we must ensure our files are scaled correctly. You can follow these instructions to ensure your files are ready to print. Remember, it is your responsibility to ensure that the measurements are correct before printing.


Step 1

Open Netfabb Basic from the Desktop. When prompted, select “I accept the terms of usage”, and click “Later” when it becomes enabled after 10 seconds.

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Step 2

Open (one of) your .STL file(s) in Netfabb Basic.

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Step 3

Take note of the measurements of the part. Is it the correct size? Inventor often exports .STL files ten times too small. If this is the case, we will have to scale it up 10x. If it is not that small, we do not have to scale it.

Right click part > Scale part

After scaling by 10 times, we also must scale our entire design by 1.5 times (150%). This gives us a total scaling factor of 15 (if we had to scale up by 10 times first). For spur gears only, we are not going to scale the z axis by 1.5, but instead leave it (assuming our face-width is reasonable and does not require scaling). This is because we can scale the face-width differently than the rest of the gear without impacting the gear’s performance. This is not the case for all other gears, which must be scaled uniformly.

At the end of this step, your designs should simply be 1.5 times larger than they were initially designed to be, with the exception of spur gears, which should be 1.5 times wider in the x and y directions.

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Step 4

When we’re happy with our scaling, we can export the .STL file for printing.

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Printing Your Files

Step 1

We will be printing our files on SeeMeCNC Orion Delta printers. The software we’re using is called Repetier. Open it from the Desktop or Start menu. If you’re doing this at home, please use MatterControl and follow the instructions I’ve provided on the Avenue FAQ.

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Step 2

Add the file that was previously scaled in Netfabb Basic to the Repetier queue.

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Step 3

Navigate to the Slicer tab and click “Slice with Slic3r”. This will slice the .STL into many layers, and write directions that the printer needs to print them.

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Step 4

Connect to the printer and Start the print. The Connect and Start buttons are located at the top-left of the interface.

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Step 5

The printer will begin heating, and will start as soon as it is ready. It is the responsibility of the student to watch the printer during operation and alert a TA or IAI of any problems. The screen contains lots of data about the current status of the print. When the print is done, allow time for it to cool before removing. Only remove the part if a TA or IAI has indicated it is safe to do so.

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EPIC Game Challenge

Looking to expand your Python skills? Want to put everything you’ve learned in 1D04 into something you can play and share with friends? Join the EPIC Game Challenge! The Game challenge runs twice a year and gives students the opportunity to create a Python based game to submit for competition. Your IAI’s, TA’s, and other students will attempt to complete these submissions at the end of the term.

Getting Started

Be ready to get creative and get your game on! Making a game in Python can seem intimidating at first but with the skills you already have and some extra research you too can make a fun and interactive game!

A great resource to start off on is PyGame, a library with extensive documentation that makes Python game making easier by laying down a foundation for you to work off. Check out the PyGame website to download the library and learn more!

Note:
PyGame offers a lot of graphic capability which can be intimidating but do not feel like you need to make a game that has complex graphics for it to be good. A text-based game can be just as fun and innovative, and often can be equally or more complex in terms of how the user experiences the game!

Submitting a Game and Deadline

Think you have the next best game? Want to share your game and compete with other students to win the challenge? Submit your entries via email with the subject “Epic Game Challenge” to the EPIC IAI at jamiecounsell@me.com.

Submission deadline is December 1, 2014.
Those from last semester can still submit! If any students are looking for assistance on where to start, you can contact me to arrange a short tutorial.