Dealing with Filament Aging

This post is relevant to all 3D printers using PLA, Nylon or ABS.  But, it may be increasingly relevant to Cube printer owners.  And, that is the subject of treating and storing filament in a way that provides the least difficulties during printing.

At the YouthQuest Foundation we have scores of Cube printers with an average inventory of 3 cartridges for each printer.  The printers are not used on a daily basis.  So, learning why and how filament degrades over time has been extremely important for us.

The problem came to the fore when 3D Systems first donated a number of 2nd Gen printers,   The printers had been in inventory for a number of years.  Even though the supplied filament was in sealed bags with packets of drying agent, all of the filament was brittle and easily clogged the printers.  Fortunately, 3D Systems replaced all the filament.  But, even this, too, showed some tendency to brittleness.  With this in mind, we began to explore exactly why we were seeing what we were seeing.  More importantly, we needed to find a solution that would minimize damage while the filament was being stored.

We THINK we have come up with the solution.  It involves combining a dehydrating system to proactively remove existing moisture from filament and a sealed storage system with a robust dehydration system.

DEHYDRATION SYSTEM

Since the problem of moisture affecting filament is common to ALL 3D printers, there are a number of new dehydration systems being developed specifically designed for filament.  But, the most interesting ones have yet to be released.  So, we looked for alternatives.  And, they came in the form of food dehydrators.  Here is the one that we recommend... the NESCO FD77DT Digital Food Dehydrator:

Nesco FD77DT Food Dehydrator

It is important to purchase a digital dehydrator that allows you to set a precise time and temperature as different types of filament require different times and temperatures.  This model can be found for under $80.   One of the main reasons we like this brand and model is the way air is distributed ACROSS each layer.  We open the Cube2 cartridges and only put the cardboard cartridges in the dehydrator.  For Cube 3 cartridges, we open the cover and put the uncovered base and reel in the dehydrator.  For our initial tests, we set it at 45C degrees and run it for 4 hours.  This could be refined as we gain more experience.

STORAGE POLICY

From now on, we will  no longer leave filament in the printers between print sessions... even if it only means leaving it in the printer overnight!  The only exception to this are the CubePro printers which we now treat as closed filament storage systems with their own dehydrator.

STORAGE SYSTEM

Some time ago, we had decided to store filament in large plastic boxes with sealed tops and single use moisture remover.  But, it turns out that using a simple 5 gallon bucket with a special sealed screw-on top is an even better solution.  We go right from the food dehydrator into a bucket.

5 Gallon Bucket

We pair the bucket with a special sealed screw-on top.  The Gamma Seal top is the key to the ability to ensure a moisture barrier.  Because we wanted to color code our storage, we have purchased both buckets and tops from both Home Depot (Red/White bucket and Black top) and Lowes (Blue bucket and white top).

Gamma Seal Top

The last part of the storage system is a cost effective way to ensure the lowest moisture levels in the bucket.  We could use packets, as we previous used with the plastic boxes.  But, we found what we believe to be a MUCH better solution, the Lagute Adenium L-A01 Renewable Wireless Mini Dehumidifier. 

Lagute Mini-Dehumidifier

The beauty of this system is two-fold.  First, it is a perfect size.  And, secondly, there is a window that allows you to determine when the beads in the dehumidifier need to be recharged.  To recharge the system you simply plug it in over night!  We use the same dehumidifier inside the CubePro.

So far, it looks like the dehumidifier takes the relative humidity under 22% in a single day.  It may ultimately go lower if I could only resist opening the bucket to check it!  :)

MODIFYING THE DRYING RACKS

In order to fit a cartridge into the food dryer, the standard racks with have to be alternated with racks that have been cut to remove the grill.  But, extra FD-77DT racks are relatively inexpensive and can be purchased locally at Bed Bath & Beyond.  I believe it cost about $14 for a set of two extra racks.

I would not buy the actual  NESCO DEHYDRATOR  model that can be found on the shelves in Bed, Bath & Beyond Stores.  It will work; but, it has no off-on switch or timer.  Buy online to get the digital model.  Sears seemed to have the lowest price.  But, shipping is not as fast as Amazon.

I fully expect that using these tools we may be able to save filament we otherwise might have had to discard.  But, at the very least it is going to protect our future filament investments.

The Care and Feeding of the Cube 3D Printer (Video)

I've been wanting to create some better videos about the Cube 3D printer, itself.  This is the first attempt in that direction.

I have received a number of emails from users that have described this or that issue they've had with their Cube printer.  Some have had clogged heads and others have asked about the using the CubeStick glue to best effect.  This video covers the following topics...

Setting the Head Gap

Nothing will clog a 3D printer faster than when the print jet is hitting the print bed.  Yet, we need a very small gap to ensure that the first layer of filament is properly laid down on the print bed.  A TWO STEP process for setting the gap is demonstrated along with the paper I've found that works the best for me.

Applying CubeStick

One of the most challenging thing for me, when going to the new 2nd Generation Cube from the 1st Generation Cube was the different behaviors of the two different glues.  The first generation Cube used a heat activated glue and, frankly, was a LOT easier to use both before, during and after the print job.

I found that I was having a LOT of trouble getting parts to stick immediately after I'd cleaned the print bed.  And, I didn't realize that by trying to solve the problem by applying thicker coats of glue only resulted in transferring glue to the little rubber cap over the print jet... essentially gluing the flowing filament to the cap and not the bed.

Finding the proper gap helped.  But, finding a more reliable system for applying the CubeStick was the real solution.

A Tip When Changing Cartridges

For a long time, I created some problems for myself because I did not understand the correct timing for pulling on the filament when removing it to change cartridges.  When the Cube team explained the steps of the process that the Cube takes when removing filament, I came up with a visual clue for myself that allowed me to more easily go with the flow when removing filament.  The result is no more instances of broken filament inside the print jet!

The Correct Way to Insert the Cartridge

While teaching a 3D printing class at Freestate Challenge Academy, we had two different instances where the little metal contacts in the cartridge slot were broken as the student loaded cartridges.  From this experience, we learned two things.  (1) The correct process for inserting the cartridge and (2) how to solder in replacement contacts.  We will show the latter later.  But, for now, this video demonstrates the SAFE way to insert new cartridges to avoid the potential for breaking the contacts.

The Video...

This is the first of the videos that I hope to bring you regarding the Cube 3D Printer, itself.  As will be clear, I do not write a script.  So, you will hear some obvious errors... such as when I talk about lowering the head when I really mean the bed.  But, I'm trusting that the information is useful enough that you will forgive my slips here and there.  I have to do these videos and tutorials in the limited time that I have to do them.  So, perfection is NOT an option.  :)

I have made the difficult decision to use the YouTube "Monetize" option to help offset the costs of the investment required to bring a higher quality of videos to you.  I know that it's annoying. But, hopefully you will find some of the products and services advertised useful enough to click on at least some the ads.

That investment, by the way, included a new Panasonic HC-X920 video camera and new LED 100WA-56 / LED 200WA-56 lights.  I mention this because these products have only recently been introduced and some of my fellow members of the DPReview forums have expressed an interest in seeing how well they perform. 

If you have the bandwidth, try viewing the video in HD 1080p, to see why I feel that investment was well worth it.  I love this combination!

Well... with that said... here is my first 2nd Generation Cube video!

Avoiding the Tug-o-War When Unloading the Filament

If you have changed a cartridge in the 2nd Generation Cube, you've probably noticed that it can be pretty difficult to pull the filament back out of the head.  Chances are, if you have experienced this, the cartridge you are trying to change was PLA.

PLA melts at a different temperature than ABS plastic.  And, that means that it also solidifies at a lower temperature than ABS.  And, THAT means that if the material is not thoroughly heated before having the mechanism back it out, it could cool too soon and break... causing a real clogging issue.

So, the unload strategy for the Cube when using PLA is to first drive the filament DOWN into the heating tip, bring the temperature up and only then reverse the gears to start backing the PLA UP and out.

But, the current LCD message we get does not accurately reflect that timing reality.

It tells us to pull NOW... putting us into a tug of war with the Cube.

My fight with the filament gear has been almost comical as I've dutifully followed the message to pull up on the filament while the filament gear is obviously trying to eat the filament!  Not one to avoid a fight, I've even tried using some pliers to exert my will over the seemingly recalcitrant Cube... to no avail!

Now I know what is really happening and why.

It's simply a messaging and timing issue.  Instead of immediately pulling, we can relax for a few minutes and let the Cube do its thing.  We need to be "one with the Cube".  And, that means that we should wait a bit before trying to pull the filament out of the print head.

But, how long?  Since the message on the LCD tell us to pull up right away, we need some clues as to when we should actually begin pulling up on the filament.

Sharpie to the Rescue!

What I now do is to make a little mark with a Sharpie on the filament just above the line where the filament enters the head.  I then follow the direction of the mark to give me the clue as to when the filament is finally being reversed back out of the head.  At first, it will be lowered into the filament channel for that extra heating we mentioned.  But, once the heating step is completed, you'll see the mark rising up and back out of the filament channel.

That is the time to start pulling.

3D Systems has been great about changing the user messages on the LCD to make the operation of the Cube ever easier for users.  Hopefully, we will see changes to the message concerning unloading so that we can simply wait for the appropriate message to tell us exactly when it's the right time to pull without fighting what is happening internally.  That is the beauty of the Firmware update process.

In the meantime, the Sharpie is my friend.  :)