Sunday, March 8, 2015

Limit Glue Layer Buildup to Minimize Start Up Clogging

I'm guilty.

After many complaints to the Cube3 engineers about my printer working for job after job only to fail when starting a new print job did it dawn on me that the user, in this case, might be to blame.

I believe that I was applying glue over old glue too many times and finally closing the critical gap.  And, since I was letting the glue completely dry, it was acting as if it was the hard surface of the print plate and stopping the flow of filament.

My bad!  :(

Now, you would think that with several years of 3D printing experience, I would know better.  However, with the Cube2, the first layer of glue over a newly cleaned glass was less successful than a second coat of glue over a dried previous coat.

But, the tolerances for the gap was greater in the Cube2 than with the Cube3 gap.  You can get away with one thin second coat and maybe even a third.  But, beyond that it's probable that you will hear the dreaded "click, click, click".

Please don't let Cubify Support or the engineering team know that I made this confession.  Who knows what they might do to me the next time I stop by Rock Hill next time I travel down to South Carolina to visit our Youth ChalleNGe cadets!  If I suddenly disappear, you'll know somebody tipped them off.

Hmmmm.... I think it might be wise to start using an alias when contacting 3D Systems support with vociferous complaints.  

Saturday, March 7, 2015

Possible Cubify v2.22 Quirk

I don't know if this is widespread; but, the Cubify client is now choking on my STL files. 

It tells me that it cannot read the file.  However, if I persevere, it will eventually read the file and print it.  I notice some new functionality related to updating the Cloud version of the Shelf.  So, it may have to do with that.  Or, it might be related to error checking the STL.

It would be interesting to know if anyone else is running into this as it may or may not be related to the way my STLs are built.

UPDATE 

As has been pointed out in the comments the above situation seems to be related to te time it takes to sync the new design with the Cloud.  Once the 'Syncing' symbol disappears from the top center of the screen, the file is available.  Apparently, the file is locked while syncing.

Friday, March 6, 2015

Some Insights Into the Latest Updates (Cubify 2.22 and Firmware 1.10A)

More than a few of you probably wondered why I didn't panic in the face of clear evidence of clogging issues with the Cube3 3D printer.  The number one reason is that I have been watching the Cube team since the very first Cube 3D printer was released back in 2012.  And, I was certain that they not only could solve the problems; but, would not rest until all of the issues were behind us.

Now, I know that is small comfort for those who have had a Cube3 languishing on the shelf as we waited for the solutions to be found.  But, with this latest combination of Cubify Client software and firmware updates I'm trusting that your faith will be at least a bit restored and that mine will be proven justified.

Getting a 3D printer to work is a LOT more difficult than it may seem on the surface.  Just go back through countless countless Kickstarter campaigns to see how many actually delivered to happy doners.  And, in the case of the Cube3 there was an added wrinkle.

That wrinkle was the desire to create a long term solution to be able to deliver a true consumer 3D printer.  That this was an important design consideration was obvious to me the very first time I tool my Cube3 out of the box.  The 3D Systems' designers had gone over all of the impediments for widespread consumer 3D printing and created a platform that answered each of those impediments.

Unfortunately, in my opinion, they may have taken on too many challenges in a single generation by introducing BOTH the self contained cartridge/guide/printjet system and two color printing.  So, it, no doubt, complicated a total solution taking more time to get to the point where I believe we are with these updates.

I print a LOT.  It is rare that my 3D printers aren't going day and night.  So, I've had opportunity to make some observations.  The first was that incorrect gap could not have had anything to do with failures that would occur well after a print had started.  The updates address this issue.


NEW TEMPERATURE TABLES

Temperature for each combination of material type and material color is controlled by a table of values in firmware.  These have been refined in this update.  I am told that "...the new temp tables have proven to be very effective for cartridge reliability." It also explains why we found a reliability difference between colors. 
NOTE:  If your printer continues to repeatedly clog in the upper layers of a print job, it may have a bad heater block.  Contact Cubify Support to troubleshoot
It will take some more observations to understand the behavior of the new temperature tables starting, running and ending a print job with different colors, etc.

REFINED FILAMENT FLOW CONTROL

As you, no doubt, have observed, the extruder gear both pushes and pulls the filament.  It pushes while feeding out filament and then pulls to retract the filament as it travels over distances without printing.  While it has not been officially confirmed, it is my understanding that the push/pull process has been refined to prevent pulling the heated filament too far back into the guide assembly where it could cool and create a blockage.   I'm making an assumption here that this is also addresses in these updates.

REFINED LEVELING

While a permanent fix is still in the works, these updates begin to address an issue where Auto-Level goes into an endless loop.  What is happening is that the firmware is seeing a value that is right on the edge of acceptable limits.  It's like finding yourself sitting right on top of a fence and not being able to decide to move to one side or the other.

If you have this condition, simply move the plate to the font of the printer, loosen the front knob and turn it 1mm to the left or right.  You should then be able to properly level.

They are aware of this and a future firmware update will address it.

ADDRESS YOUR PRINT JET LEVELS

None of these updates will solve your printer's issues if you install both cartridges and the print jets are not level.  I suggest testing the update with only one cartridge installed to verify that clogging is eliminated before adding the second cartridge.  Only then would I suggest moving on to two color printing AFTER ensuring that both print jets have the same gap.

WHAT I WILL BE LOOKING FOR

My fifth grade teacher would be horrified by that sentence; but, I can't think of any other way to say it.  One of my as yet unconfirmed observations is that a cartridge would print just fine for multiple print jobs and then fail right at the beginning of a new print job.  To me, that only made sense if something in either the Cubify Client or the firmware miscalculated the position of the print jet to be lower than a proper first line of print.  In other words, it seemed likely that the printer was told to raise the print table higher than it should.

I will be paying close attention to this issue.  I BELIEVE it is supposed to have been found and fixed.  But, I have no confirmation that either is true.

BOTTOM LINE

While I do not have a comprehensive list of improvements, those that I do know about seem to go a long way to addressing the clogging issue.  Let's hope we can concentrate on producing beautiful 3D prints time after time.  :)

ALERT!!! Quick (and Important) Reminder for Cube3 Owners.

I have to rush off this minute to an appointment and will have to wait to post what I JUST learned a bit later today.

But, I want to once again urge ALL Cube3 owners to update BOTH their Cubify Client to v2.22 and update their firmware to v1.10A (It will simply appear as 1.10) as these, for most of us, probably contain the breakthroughs that we have been seeking!

Don't forget to go through the entire process of recalibrating, leveling and setting gap.  Check the final gap before printing just to be safe.

In a couple of hours, when I get back, I will provide more information as to why this is so important to all Cube3 usewrs.

EKOCYCLE USERS

You are not being left out in these new improvements.  But, you'll have to wait just a bit longer for final firmware testing to be completed before it's available online.  I have no idea how long that might be.  (After all it IS in final TESTING!)   So, keep watching for your new firmware update on an hourly or daily basis!

Thursday, March 5, 2015

Critical Cubify Cleint and Firmware Updates

Cubify client 2.22 and firmware 1.10A are available for download.

I believe the combination of these two new updates will reduce our clogging issues.  While I have not been told that directly, when I reported that I thought that sometimes the Cube3 would start print jobs one line too low, I was told that 'the next update should fix this."

I took that to mean that there might have been instances where the print jet would be positioned too low on start up and, if so, it had been spotted and fixed.

I suggest downloading and IMMEDIATELY applying both updates..

When finished, the update still showed simply v1.10 on my Cube; but. 


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!