Sunday, February 15, 2015

Learning to Listen to Your Cube3 Printing.

As you have already noticed, 3D FDM printers, like the Cube3, produce a variety of sounds.  Paying close attention to those sounds is more important than might be first apparent.

The Cube3 and all printers of its type use stepper motors to move along the X, Y and Z axes and to control the flow of filament.  More often than not, more than one stepper motor will be working at any given time so the sum total of the frequencies can produce some very elaborate sound combinations.

We Can Learn What the Sounds Mean

If we learn to listen closely, it becomes easy to tell if a 3D printer is busy laying down a circle or a rectangle as they produce quite different sounds.  With experience, we sometimes don't even have to see the printer to know if a particular design is printing as it should.  The more we print with attention to sounds, the more we are able to monitor the progress of a printer with more than simply sight.

Some Sounds Alert us to the Progress and Order of Printed Features

Let's say that we have designed a table with four legs and are printing it upside down.  When the top is being printed the sounds signaling the printing of the table edges will be quite different from the sounds of the fill material.  And, the sounds of the first and last several 'surface' layers will be quite different from that of the 'fill pattern' sandwiched between those layers.


But, the real change in sounds will come when the top of the table is completed. The sound will abruptly change and something best described as 'screeching' might begin to be noticed as the print jet rapidly crosses over empty space from one leg to another.  Again, this is a common characteristic of stepper motors along with the belts, etc. used to move the print jet.  And, while it might seem to be due to a z-axis change, it's most likely a rapid return to an X/Y starting point.  (Although it may be compounded by a slight lowering of the print table to keep the print jet from hit obstacles.)

Extrusion Sounds are the Most Critical to Learn

The sweetest sound that any 3D printer can make is when the filament is being continuously extruded.  Generally, we hear this when the printer is laying down the border of our object. If the base of our object is a large circle, the sound from the extrusion system will be very smooth, with the gear pushing the filament forward in one constant stream.  We'll call this the 'Free Forward Flow' sound.

The LEAST sweet sound that any 3D printer can make is that sickening repeated click that alerts us to the fact that the gear cannot push the filament forward.  The quicker we respond to that sound, the more likely we are to be able to address the issues causing it.  We'll call this the 'Obstructed Flow' sound.

In between, these two sounds we have some equally interesting sounds as the extrusion system periodically reverses direction.  In the case of our table, it will be pushing the filament forward as it lays down a layer for each leg.  But, it will reverse itself and pull the filament back a bit to keep it from dripping as it moves across the empty space from leg to leg.  I think it is critical, with the Cube3, for us to keep our senses sharp to see if there is any correlation between a lot of reverse extrusion activity and clogging in our designs.

One of the things I am interested in studying is how the various fill choices might affect extrusion reversals to the point where one or the other choice might induce a clog? 

Right now, I don't know.  But, I do know that listening to the printers as these fill type experiments are conducted will be crucial to understanding the actions required to draw them.  I have a suspicion that 'hollow'+'lines' might sound quite different from 'solid'+'diamonds' and that, in fact, one or the other choice might help us complete more print jobs.  While this remains to be seen, it will be fun listening for the differences.  :)

Friday, February 6, 2015

Evaluation as we Enter February

This post is going to be a mix of great news and mixed news.

By now, I have had a chance to put the Cube3 to the test to the tune of probably a hundred objects,  Yes, I have had clogs with some of the newer filament.  But, overall the clog situation is not anything close to my first experiences with the Cube3 with the earlier PLA.

First, the mixed news.

Printing with ABS

I hear that people are successful with printing in ABS.  In fact,I have had little warping compared to earlier 3D printers I owned without a heated print table.  But, that assumes something will print at all.  And, I have had MORE clogging with ABS than with PLA.  The maddening thing is that what I call "EXTREME UNCLOGGING" tricks using a heat gun seem to work miracles... for a few minutes.  And, even the new PURGE function tantalizingly shows promise, only to have the cartridge fail early in the print.

So, at least for now I will stick with PLA until I hear better news from you.  All of my ABS was received because of the shortage of PLA.  So, it may be that the same issues affecting the early PLA also affected the ABS.  I don't know.  All I know is that at least for now I am having a LOT better luck with PLA.

Printing with PLA

As of now, I do not have a single PLA cartridge with the new filament that is permanently clogged.  Yes, I HAVE had clogs.  But, they have been easily cleared.  In fact, I have one design that I KNOW will cause a clog because of the way it is designed stresses the extruder.  But, each time I have brought a cartridge to a halt, the new purge function has been able to clear it up and get me back up and running.  I do now know if that is true of the initial version of the filament.  But, all the cartridges that I know have are running clean and free for now.

Printing with the Cartridge Open

I believe in being proactive when it comes to avoiding known issues with any technology.  This means that I now print only with the cartridge open so that if I hear the tell-tale clicking sound that signals a slipping extrusion gear, I can instantly push the filament past the trouble spot.  If you catch it fast enough there are little or no consequences.

But, I also make sure that the filament is stabilized before and after leaving the extrusion gear.

Filament Stabilizers for an Open Cartridge
This simulates having the cartridge top in place while allowing instant access.

Why this Pseudo-Top is Important.

With all the exprimenting that I've done, I've up close and personal with the Cube3 cartridge.  And, perhaps it is a better understanding of how it works that has made the different in the success I'm having now vs. what I faced when I first got the Cube3.

One of the most important parts of the cartridge assembly is the button like fixture that is held in place by the top at the point where the filament guide leaves the cartridge.  One of its functions is to keep the actual filament guide, a narrow tube, from being pulled out of the extusion housing.  If the filament is ubstructed, the pressure can actually pull the filament guide right out of the ferrule that holds it in place inside the extrusion housing.  Here is what I'm talking about.

Cube3 Cartridge - Extrusion Gear Housing

This is an extrusion housing, from the hub of the cartridge, that is opened.  Every part of the housing assembly is beautifully CNC machined to extremely tight tolerances.  In addition to the idler wheel bearing and gear, there is an small cavity designed to hold the filament guide in place using a pressed on metal ferrule.  What I am calling the 'cartridge exit clamp' is designed to take some pressure off the ferrule by holding back an outer spacer tubing.  The cartridge top provides the anchor for the spacer.

When we remove the top, the cartridge exit clamp is free floating and cannot take pressure off the filament guide and it can slip out of the ferrule.  That is why I use the 3D printed pseudo-top to hold the cartridge exit clamp in place.

I have begun to immediately remove the top and replace it with the 3D printed part each time I open a new cartridge.  If you wait until later it can be a bit more difficult to pull the cartridge exit clamp back into place due to the stresses placed on it during printing.

By the way, the object holding the extrusion housing is part of my 'Extreme Unclogging' system pioneered by Eric Albert.  :)

It consists of a 3D printed combo heat gun and tip holder along with a cartridge holder and the object you see, that allows me to heat the tip at a precise temperature while turning the extrusion gear with a T20 Torx driver.  I'm not sure how much I'll need it now that we have the PURGE feature in firmware.  But it has been very helpful up to now.

At any rate, things seem to be coming together nicely on the filament front as soon as they can catch up on the backlog.  I know that is frustrating; but, the good news is that the printer itself, with filament, software and firmware upgrades is doing a lot better in a very short period of time.

ACCURACY

The Cube3 is, hands down, the most accurate 3D printer I've ever used.  Moment of Inspiration lets me use one feature to cut away from a second object.  The little cover on the extrusion housing holder was created in this way.  Normally, I would not expect the printed parts to fit.  But, they DID!  Each part was so precisely printed that the fit, while tight, worked!





Thursday, February 5, 2015

A Quick Look at Cube3 Firmware v1.10 Purge function.

I had an opportunity to briefly try PURGE on two clogged ABS cartridges and one working PLA cartridge.

I was hoping for a miracle cure; but, unfortunately this wasn't it.  The PLA spit out a very long stream of filament that was long enough to make 3 or 4 coils on the print table.  Neither of the clogged ABS cartridges fared as well.  I think I know the reason why.

First, let's take a look at the print jet housing on each of the ABS cartridges.

Filament Guide Separation
Notice that the filament guide, which should be seated flush with the tip housing is pushed away by a substantial distance.  It was pushed from the inside of the print jet,  So, how does that happen?

Eric Albert sent me an image that gives us a clue.

Filament Block Taken From Print Jet Tip
As is apparent, this block of filament has not only taken on the shape of the print jet tip; but, seems to have moved out of the metal part of the print jet and backed up into the area of the plastic guide.  A part of the block of filament is beyond the range of the heating element of the Cube3's heating system.  It has solidified enough to block anything trying to get to the tip.  As the extrusion gear continued to feed material, something had to give  And, that something was the metal retaining ring that held the filament guide in place in the print jet housing.

In this case, the PURGE function is not going to have much chance of unclogging this particular tip since there is filament blocking the path that is not going to be heated.

My early conclusion is that we can probably predict the efficacy of PURGE by first taking a look at the filament guide as it enters the print jet housing.  I'd still try it; but, wouldn't hold much hope for a miracle cure.

On the other hand, if we catch a clog by being alert for that dreaded clicking sound, we may be able to avoid a total backup like we see above.  In these case, I think we are going to have very good results with purge.

I'll keep testing it.  I certainly have some good test cases.  An d, I'll let you know the results.  At least we now have a shot of recovering a mildly clogged cartridge.  And, that is a step forward.

Cube3 Firmware V1.10 now on Cubify Site

This is a VERY important upgrade.  Look under the 'Activate' tab for the Cube3.

IMPORTANT:  If there is an underscore in the name, REPLACE IT WITH A SPACE.

I have to go our now.  But, on my return this evening, I will discuss the ramifications of this firmware update and how to take advantage of the new features.

In the meantime, I would make a mad dash for the site and download the update.  :)

This update includes a new PURGE JETS function that promises to be useful in clearing clogs!

Cube3 Cubify Software Update - Version 2.19 is Available

As I started the Cubify client this morning, a notice appeared announcing an update to Version 2.19.

I have not idea about all of the improvements that have been incorporated into this update.  But, there is one that for those using the Cube3 in a classroom situation will be happy to see.   For, the first time, I am able to control TWO (and I suppose more) Cube3 printers from my computer.

It still is not at the point where doing so is absolutely reliable or under our complete control.  But, the fact that I am now able to send print jobs to two different Cube3 printers is a HUGE step forward.

Ultimately, controlling two printers should be as easy as selecting the printer from a dropdown list.  We're not there yet.  But, this development takes us a good way down that path.

In the current Cubify 2.19 version,, I had go down the following path to enter the second Cube3's IP  manually
PRINT > SETTINGS > CUBE INFO > Find a Cube manually
It did manage to find the second printer.  But, in my first attempt to send it a print job, the internal communication system switched back to the original printer before the transfer was complete.   Trying a second time worked.

The fix for that should be pretty simple.  The software knows it's transferring and can ignore any other actions (like refresh) until the transfer is finished.  So, that should be taken care of in the next update.  For now, I assume that bigger jobs may fail (longer transfer times) while small jobs may be safely transferred.

As I write this, TWO printers are happily printing away, oblivious of each other and, now that I have discovered some of my design characteristics that were inviting clogging... and avoid them... I'm confident both will complete successfully.

Cubify support and the designers on the Cubify team are listening to us.

It's a beautiful day in the neighborhood.  :)



Wednesday, February 4, 2015

3D Printed Cube3 Print Table Leveling Tool

Earlier there was a blog article about a paper printed table leveling gauge that was designed to help count the precise distance to turn the print table pads when leveling the Cube3 print table.

A 3D printed version has just been uploaded to the Cubify 'Design Feed" for free download.  This is the DIRECT LINK.

As you can see from this image, the tool simply fits over the print table pads.

Print Table Leveling Aid (Print table pads simulated)

The ring without markings fits over the back/left print table mounting pad.  That pad is not to be adjusted.  It is the pivot point for the front/back and left/right height adjustments controlled by the left/front and back/right mounting pads.

The STL is designed so that should you desire the 'tic' marks can be printed in a 2nd color as illustrated above.  Be sure to place a mark on the print table mounting pads with a permanent marker to create a dial to follow as you ake the adjustments.

This thing is super helpful.  It makes the job of following the leveling directions SO much easier and more precise.  The increments are in 1/16th of a turn.

A REQUEST

I create these items to make my life easier with my own 3D printers.  I have no idea how helpful you feel they may be for your own 3D printing experience.  If you choose to download any of the files I've uploaded please check the 'heart' so that I can see if there is any value in uploading them and what kinds of items are most appealing for Cube owners.

Thanks!


Monday, February 2, 2015

My Most Successful Colors

This post is designed to catch up on some observations, etc.

Filament Color MAY matter

I wanted to report that of the colors I have been able to obtain of PLA, the least troublesome, so far, have been black and tan.  That is not to definitively say that they are THE best colors; but, simply that I've had excellent results from these two colors.

I'm mindful that the colors may not be the issue at all.  3D Systems has instituted a rigorous testing program on all of their filament and it just may be that these cartridges were the first I owned under the new testing program.  Whatever the reason, I am grateful.

Storing Your Filament

As I've pondered filament, more than I actually care to over the last month or so, I've been impressed that it is going to be absolutely critical that we develop a more pro-activein our care of the filament we purchase.  The cartridges of the CubePro, for instance, actually have a little pocket to held a moisture reducer packet!

Both PLA and ABS deteriorate reasonably quickly in moist environments. 

So, I have decided that (1) I will not open a new color unless I am ready to use it immediately and (2) I will keep all opened cartridges inside a closed plastic storage box with a sizable package of moisture absorber.  The two I'm testing are DampRid and DryOut.  Both are available at The Container Store.  AirBoss is another option.


Print Quality of the Cube3 is Impressive

The print from the Cube3 is, by far, the best I've been able to achieve and I am not talking about printing in 70 micron layers.  I'm comparing the prints at 200 microns, and quite frankly, I like my Cube 3 prints better than the CubePro prints.  Of course, I get the CubePro prints considerably faster so it's a bit of an apples vs. oranges comparison.

One of the things I've noticed over the years about 3D Systems is that they are constantly improving a printer series within the same model run over time.  This was true of the Cube2 and I think I see that in the Cube3 printers YouthQuest has purchased that are of more recent origin than mine.  The differences are subtle; but, as much as I use all the printers, I can tell.

Multiple Cube3 Printers with Cubify Software

Aside from cartridge improvements, where I'm hoping big changes will come is in the Cubify software.  It doesn't appear to handle the existence of multiple Cube3 printers all that well.  So, that needs to be improved.  The first step might be to give us more manual selections like the ability to specify ANY filament type and color as we build a .cube file for export no matter what color is in a connected printer.  I have to unplug the printers to accomplish this now.

Remember to Check for Firmware Updates

Lastly, whatever you do, remember to check for firmware updates at least on a weekly level.  The Cube teams has been great about responding to our requests for features or refinements; but, we don't benefit unless we keep our Cubes updated.

I'd like to hear which colors you've found to be the best for your printer.