Prusa USS Drybox  

RE: Prusa USS Drybox

They seem pretty well constructed.  

RE: Prusa USS Drybox

I am assuming the pop out panel would be for a future heater, but on my XL 5T the plumbing would be like a Ducati exhaust manifold (without the beauty) or a heater per, which would be wires everywhere. 

also slightly worried about cardboard spools, which I use a fair number of. Seems a bearing roller on the hub would have been a nice touch.

RE: Prusa USS Drybox

Posted by: @henryhbk

It’s a smoked gray so harder to see exactly, and I suspect it would be hard between close colors  

Posted by: @jurgen-7

Quick question for those with first-hand experience: How transparent/translucent is the material of the USS box? Can you still see the color of the filament clearly enough?

 

Well not just the color, but it will be hard to see (I think) how much filament is remaining on the spool. 

RE:

Well I got a bunch of them since I needed drybox storage and rather than explore other options of which there are many ...

I *think* it was a good decision ... boxes are well made, and should indeed keep filament dry for as long as it remains in the box.  The plastic is a tad dark (smoked) and the hygrometers need reasonably good light to read them.  The internal slot for labels (PVA, ASA etc) might be usable for some folks, but again too dark.  Personally I think I'm going to ignore it and design a small external label with (eg)  "PETG // Matt Black // {sample}"   where the 'sample' will be a small postage-stamp sized swatch of the filament so that the colour can be easily spotted. 

I do have some questions and tips though so here goes ...

Questions: 

1) Do we reckon we need to install a slightly longer external PTFE tube (and I'm talking about CoreOne here) to the machines's side, SO THAT the tube can reach all the way INTO the drybox?   And that way ONE TUBE will rule them all ... getting carried away .... that one tube can then be used with any drybox(es) you own?    If so I think that could be neat.  At least, neater than having a separate tube(s) and having to join/unjoin it each time a drybox is used.

(Since each drybox comes with a good length of PTFE tube, maybe we could sell it back to Prusa ?? !) 

2) How long do Prusa think the dessicant will last?  AND can (instructions?) it be reactivated, AND if not are they going to sell it , or suggest a supplier?

Tips

1) As noted the dessicant sack is a tad difficult to install. By the time you've got to your 10th (yes) you'll get the knack.  So, what you want to avoid is the sack tangling with the spool. Prusa have deliberately left cut-outs in the 'dessicant corner' so that you can use a finger through the small windows to rotate the spool to take up any slack filament. But if the sack pokes through that gap it runs a risk of fouling the spool with consequent performance issues.  So ... FOLD the sack into a triangle shape: very approximately take 1/4 of the total length at each end and fold it over. So you end up with a longish (nearly square) central bit and the two ends folded back. Now you need to get the sack into the dessicant corner in that shape.  With the open bit of the triangle in the very corner and the flat bit facing the spool.  It doesn't go easily, but push gently (and the material does seem very tough) and the beads can be pushed around until - success!  A bit of thin card can help the thing slide in a bit more easily. 

2) There are 6 large catches to close the enclosure, plus the 2 small windows on the dessciant corner.  It is VERY LIKELY you will find that one of those is not properly closed.  Check and check again. 

3) The two halves push together and there's a large soft plastic 'gasket' that is supposed to seal the two halves in the centre.  On one of my boxes the seal had been slightly deformed when factory assembled, so it might not have been airtight if I had not spotted that and straightened it.  All I can suggest is that when pushing the two halves together, just rotate the two ever so slightly and gently back and forward, as you close them up, all the while observing that central gap. 

4) I thought (and still think) that mounting the drybox the 'right way up' in the printer is a reasonable idea, BUT it would need a longer PTFE tube and more excess filament to wind back into the box each time it's removed.  So 'on it's side' - as pictured in the  shop: https://www.prusa3d.com/product/prusa-uss-drybox/   is probably best.  But good ol' Prusa don't actually TELL us to how to mount it, we're left to spot it in that picture.

5) I have some non-Prusa spools that are narrower and which 'rattle' in the box, possibly making (re)winding a bit tricky. So I found a plastic tube with a diameter quite a bit more than the central hole and cut sections (mine are 17mm wide) which I insert on top of the spool(s) before finally closing the box. Initial use suggests it works well. 

6) Prusa should have told us about the USS 'accessories' on Printables: https://www.printables.com/model/1605113-prusa-uss-drybox-printable-accessories      I'm not sure there's anything there that I'll be using, but we'll see ...

RE: Prusa USS Drybox

Oh and Prusa make it SO difficult to find info (searches don't find this stuff) ....

Essential reading I guess:

https://help.prusa3d.com/article/prusa-uss-drybox_1014382

Put a link to that too on the shop page Prusa!  

RE: Prusa USS Drybox

I happened to be with the Marketing Manager at Prusa at Rapid+TCT yesterday and discussed the dry box with the XL. First off correction for the instructions as posted by @Dmartin, the "Unscrew the spoolholders with an M4 Allen key." at least on my XL uses a 3mm Allen key, so that took a moment (as my Allen key set was not next to the printer as usual).

1. The first thing you need is of course the "new" spool holders which I printed, but you need to dig through the Core 1+ files to find the spool holder parts. Not like there is a handy link (He said he'd mention it to get them linked). 

2. On the right side of the printer (Tool 4,5) the dry boxes mount inverted to keep the filament path straightest, which of course means the hygrometer is facing away from you. Sigh... And on the left side (tool 1,2,3) the rear rail gets mounted backwards as well, again same issue.

3. With the new spool holders (regardless of dry box or not you need to decide 1KG or less, or big spools. Annoying on a big machine but that is what it is.

4. I'm worried about switching filament since now the filament runout sensor is 15cm in the tubing so it's going to stop there, so when it expels the old filament there is no way it's coming out the end, unless there is something I missed? There will need to be a firmware update with a setting for how long the filament tubing is before the sensor.

Posted by: @dmartin

Oh and Prusa make it SO difficult to find info (searches don't find this stuff) ....

Essential reading I guess:

https://help.prusa3d.com/article/prusa-uss-drybox_1014382

Put a link to that too on the shop page Prusa!  

 

 

RE: Prusa USS Drybox

Posted by: @henryhbk

4. I'm worried about switching filament since now the filament runout sensor is 15cm in the tubing so it's going to stop there, so when it expels the old filament there is no way it's coming out the end, unless there is something I missed? There will need to be a firmware update with a setting for how long the filament tubing is before the sensor.

In that link, it looks like there's a coupling you can use to join two PTFE tubes together.  It seems like the idea is to allow the printer's existing tube to remain in place, and have an extension connected to it leading to the drybox.

If you did it that way, it would mean you could "break" the PTFE tube open at the point where it was originally, so presumably accessing the filament then would be no different to before.

Good question to ask though, I was thinking of running the PTFE tube straight from the printer to the drybox but as you've pointed out, if the filament runs out it won't be possible to eject it far enough to pull it out.

I have however on my Core One+ disabled the side filament sensor, and just left the print head filament sensor enabled.  This way when it runs out of filament and pauses printing, there's nothing to retrieve from the PTFE tube as the filament has been completely used up.  I just cram more filament in and purge until the extruder grabs hold of it, then it seems to resume the print without much issue.  I did this because I wasn't so keen on losing the last metre or so of filament every time a spool runs dry, so this allows every last millimetre to get used up (purge waste excepted of course).

I don't know if the XL has a filament sensor in the print head but if it does, using that instead could also be an option, perhaps.

RE:

Call me a sucker but I just noticed Partsbuild.com had 10 of these in stock. I got just one!!! 6 bucks more than Prusa cheapest shipping. I’m a fan of Polymaker myself

Guess a link might help: https://partsbuilt.com/prusa-uss-drybox-original-prusa/

RE: Prusa USS Drybox

Have you noticed any drag issues when using paper spools? On my XL printer, which has two paper PLA spools, the tool heads are now frequently jamming. It’s extremely difficult to pull on the filament, especially at the toolhead. The PTFT tubing is about 2 inches inside the drybox. I haven’t encountered any issues with plastic spools. The only solution I was considering was printing a liner for the inside of the spool to see if the friction reduces. The spool is the same size as a plastic one from Prusa.

RE: Prusa USS Drybox

Posted by: @knightofcarnage

[...] On my XL printer, which has two paper PLA spools, the tool heads are now frequently jamming. It’s extremely difficult to pull on the filament, especially at the toolhead. [...]

Assuming you have a spool made completely with "paper" (cardbord): Cardboard has more drag as plastic. Maybe a printed  inner tube like -  https://www.printables.com/model/1589881-polymaker-cardboard-spool-insert - will help.

RE: Prusa USS Drybox

Well my dryboxes arrived a few days ago (in an MK4S box no less!) and they are quite nice indeed.

However I have just encountered my first problem.  It seems they are not compatible with the MATT brand spools sold on the Prusa web site!  I put one of these in and the lid closes and all seems fine, however you can't actually mount it to the machine, and it's very difficult to pull the filament out as there is so much friction, it's like the spool is clamped in place.

After some back and forth with support I realised that the spool is just a couple of millimetres too thick, so the box closes but the hole in the middle doesn't fully seal, which makes the middle of the drybox a few millimetres thicker than it's meant to be, and that prevents you from mounting it as the spool holder ends up being too short to accommodate the increased thickness.  (Not that you'd want to anyway, it takes way too much force to get the filament to come out.)  Prusa support said those spools are supposed to fit, so they're going to investigate and get back to me.

Hopefully Prusa will add some more details on the product page about the maximum dimensions of spools, and which ones will/won't fit, as there isn't much detail there at the moment.

FWIW these MATT spools are 197mm in diameter (which leaves 2-3mm spare so plenty of room in that dimension) and the width is around 75mm, but my calipers say the middle of the spool is 76.1mm thick, and that's too much for the drybox.  At a guess, 74mm is probably pushing it and 72-73mm is the thickest spool you'd want to use.

Here's a photo of what the middle is supposed to look like when it's sitting flush:

And here's the same shot with a MATT spool showing how the two halves of the drybox won't fully come together.

RE: Prusa USS Drybox

I bought one also.  I am impressed with the quality and surprised that quite a few of my filaments will not fit.  Not upset about it because spools are so variable.  

I wish there were a dryer available for purchase for them.  

RE: Prusa USS Drybox

I bought one also.  I am impressed with the quality and surprised that quite a few of my filaments will not fit.  Not upset about it because spools are so variable.  

I wish there were a dryer available for purchase for them.  

RE: Prusa USS Drybox

RE: Prusa USS Drybox

The video doesn't really cover anything we haven't already discussed here.  It would've been nice to see it a few weeks ago when we were all asking questions about it though!  Also in the video it says the little cover in the corner is for replacing the desiccant but this isn't the main reason, it's primarily there to allow you to rotate the spool (e.g. to wind in the excess after unloading it) otherwise you'd have to open the whole box in order to turn the spool even a little.

And yeah I'm not too upset either about the MATT brand spool not fitting (Prusa offered me a small discount off a future order as an apology but I declined), as I'd rather they just made it clearer what the maximum dimensions are for the spool, and listed which common brand do and don't fit.  At the time of writing there's no information at all about what spools do and don't fit, so I think you could be forgiven for assuming that it would at least fit all the spools available for sale in the Prusa store.  But as it turns out, quite a few spools they sell won't fit, so that was a bit of a surprise.