What colors do you have loaded?  

The correct answer is none - unless you are printing from dryboxes.

All of the common filaments absorb moisture to some extent and this impacts print quality.  Some filaments deteriorate so fast that the later parts of long prints are degraded even though the filament started dry and the early layers are perfect - and that's with just a single colour.  When printing full multicolour the filaments are all absorbing water at the same rate but the outer, dampest  layer is only used up at about a fifth of the speed on average so damp filament is a frequent cause of problems.

Therefore the wise user unloads all the filaments at the end of each significant job and puts them in the dryer.  Consequently it's no extra chore to load exactly what's needed for each particular print - and nothing remains 'installed' when the machine is not printing.

Cheerio,

RE: What colors do you have loaded?

OK, thanks Diem.

Being new to all this, I have been overwhelmed with all the options for dry boxes and haven't settled on one yet. And quite frankly, I haven' noticed a problem yet.

Dennis

To some degree it depends where you live - but it will matter sooner or later...

We always see seasonal peaks of humidity problems in the spring and autumn as people live for a while without heating or aircon.

For run of the mill filaments most dryboxes are fine, printing from any box that restricts air changes is enough as long as filements go in dry.  PVA, BVOH and nylon though, always need protection the whole way to the print head, especially so if they are being used intermittently and waiting periodically while something else is used.

Most people won't need dryboxes for sub 12 hour prints and many will manage much longer prints in PLA; PETG is something of a test, right now I expect to see the first signs of damp after 6 - 8 hours but in midwinter with the heating running I might get away without a drybox for 48 hours.

Your milage *will* vary.

Cheerio,

RE: What colors do you have loaded?

Diem,

What are some of the effects of humidity damage? Currently I am only using PLA & PET(G). I do have a spool of ABS & TPU still in sealed packaging.

I'm actually in a worse situation for excessive humidity, I live on a lake (in Michigan, USA) and due to dry skin, I have a powerful steam humidifier on my furnace for the winter.

I'm confused on the use of the dry box. Is it expected that all filaments be stored in an environmentally controlled location? This seems unrealistic.

Or is it ok to have the filament in the dry box for a period of time (1 hour ?) prior to printing?

So, I have 2 MK4S's (just did the MK4 > MK4S upgrades this week) 1 with a newly assembled MMU3, would I want one dry box large enough to hold 5 filament spools for the MMU3 printer and one to hold one spool?

Can you recommend some dry boxes?

Thanks for your help,
Dennis 

All moist filaments will ooze and string.  People complaining about 'zits' on the printsheet from bed leveling are using damp filament.   In bad cases the extrusion goes haywire as water boils and steam pulses upset the internal pressures. You may even hear popping as steam pockets escape, there may be pits on the surface of the print at these points.

Support adhesion may become a problem.

PLA filament will get brittle and snap easily in PTFE tubes and can even break in the open air if it only lightly stressed.  The surface texture may change. 

PETG stringing is worse and might include blobbing 'though it's not the only cause.  Surface texture changes and pitting are common. I routinely dry new PETG before printing.

TPE's, including TPU *MUST* be kept dry, moist TPU will string to the point of unprintability.  Always dry TPE's, including new spools, before printing.

ABS is very little affected but you will find an externally ventilated enclosure necessary to evacuate the noisome fumes.

All that said, you *may* be able to print PLA for a few days before it gets too bad.

Is it expected that all filaments be stored in an environmentally controlled location? This seems unrealistic.

It's not so hard; remember that a ziplock back with a few dessicant packets is an environmentally controlled location.

Can you recommend some dry boxes?

Practically anything that protects the filament from air changes will do - even a cupboard or, at a pinch, a closed cardboard box.

Or is it ok to have the filament in the dry box for a period of time (1 hour ?) prior to printing?

As long as you have a dryer so that you start wiith dry filament, and the box prevents air changes, you will be OK.

Cheerio,

RE: What colors do you have loaded?

Diem,

Thanks so much for your replies. The information you provide has been and will continue to be very helpful.

Dennis

RE: What colors do you have loaded?

I will just underline one thing here - I have found the food dehydrator (dryer) an indispensable accessory. Typically, I would dry the filament in the dehydrator *prior* to printing - my chamber keeps ambient humidity around 40% - 50% during the print cycle and my prints are typically under 12 hours, so I have not encountered issues with dry filament becoming wet in the midst of a print.

RE: What colors do you have loaded?

Thanks HappyKatz.

Dennis

RE: What colors do you have loaded?

Just for the record: In professional practice, when injecting plastic into molds, drying plastic granules is, with a few exceptions, a vital necessity. ABS is dried at 80 ° C, PC even at 120 ° C, PA is dried at the same temperature, all for several hours and the granules go into the press hot directly from the dryer.

RE: What colors do you have loaded?

Orange, black, white, sometimes purple and sometimes blue!

RE: What colors do you have loaded?

Dont have my MMU3 yet, but I intend to install Black, White, Yellow, Red, Blue.

I dont intend to change filaments often and want to just keep them loaded, even though I can go for long periods without printing anything as I'm just a hobbyist, so my intention is to create the filament storage boxes using the airtight cereal containers - lots of examples on Printables to choose from. 

That just leaves the filament in the buffer cassette that's out in the open, which isn't too much when considering the whole setup. Or maybe that could be installed in another airtight container too.......

RE: What colors do you have loaded?

You can eliminate the buffer by using an automatic spool rewinder.  A popular one is the Filamentalist.  I have had some good experiences with that.  The Nextruder filament gear is perfectly capable of driving the rewinder action.  And as a bonus, it makes loading spools way way easier (if you use the "rear loading" version of the Filamentalist).  I have 4 spools sitting in a dry box using those rewinders.  The 5th is a Filamentalist sitting on my bench, to be used as a wildcard.

RE: What colors do you have loaded?

I’ve set up five spools in a drybox (with desiccant), which feed to the MMU through a set of PTFE tubes — I’ve found that a rewinding device has been unnecessary, as the filament buffers itself in the two or three inches at the front of the box as it unloads. (I will occasionally take up the slack in the others when changing one of the spools, but I find this is not anything I need to pay close attention to.)

I kinda knew when purchasing the MMU3 that I probably wouldn’t do much multi-color printing — but I had no idea how convenient it would be having multiple spools pre-loaded.

(To answer the question: Black PLA, Black ABS, White PLA, Black PETG, Orange PETG.)