Making Printing Cabinet with Dry Boxes - Some Questions
Note: Some of this applies to using an MMU (specifically the MMU3), but there's other questions that aren't about just that one piece of equipment, so I'm posting here. (Also, I've asked about this in some places, but not about the same issues.)
I live in a seriously humid area and I'm making a print cabinet so I can keep my filament dry. I'm rethinking my original design. My plan has been 2 compartments, a lower one for storage, then a row or two of drawers (for tools, supplies, parts, and so on), then, above that, at a level I can comfortably access when standing, is a 2'x4' (about 60x120cm) surface for the printers. Both the print compartment and the storage compartment would have their own powered dehumidifiers and I can easily add drains so I don't have to empty their water trays every day. The rows of drawers between them are not dry boxes. Both the print and storage dry boxes are independent.
Above the printers, in the print compartment, my design included printing hangers that would come down from the top and hold filaments spools, which would make it easy for the filaments to feed into the MMU and would provide a place for quick access to filaments I was using the most often. One reason for this is that, in my humid environment, using the MMU has been seriously frustrating. If the filaments are not dry enough, there are problems with the feeders in the MMU grinding down the filament instead of pushing it through and, often filament that's been in a humid setting, would break in the PTFE tubes and cause problems with the feed in the MMU. (And the control software doesn't allow for "accidents" so if something goes wrong, I have to power cycle my printer too I can deal with the mechanical issues.)
Yesterday, when I was doing maintenance on one of my printers, I realized I would often have the doors to the print compartment open for a while. I have to open them to remove prints from the printer, to clean the print bed, for maintenance and for feeding the filament into the printer. So I figure I can count on that compartment being open a decent amount. That would be a problem for the filament stored above the printers, since it's in the same compartment.
Also, one last detail: I have not started printing with ASA or ABS yet because I've heard about the smell issues and often need to be able to do other work in my workshop while I'm printing. So the compartment with the printers would be vented, as part of a vent system I've designed, so after a print, I could give it a few minutes to cool down, then turn on the fan and vent it to outdoors before I open it. (And I would have a valve or gate so the humid outdoor air does not come in through the vent.)
Also, I do have a filament drier that dries 2 spools at a time. But one thing I'm trying to cut down, with this cabinet, is the need to do extra things, like unload filament, cut it, then reload it (especially with the MMU), or having to dry a filament for 4-8 hours before using it. That kind of thing seriously upsets my workflow and thought process.
I'm thinking of redesigning for 3 dry boxes: Main storage (down below), Frequently Used storage (above), and printing (above, but below the Frequently Used. The dehumidifier I've been using successfully to dry out some other spaces has worked well and is not that expensive, so if I have to use 3 of them, that's not a major expense or burden. I can feed the filaments from the Frequently Used storage to the print compartment through grommets or something else to keep humidity from getting into the storage area.
So this leaves questions and thoughts I'd like feedback on:
* The MMU3 is designed to mount on top of my frame for my MKS3.5+. Is there any real issue with moving it to inside the upper filament storage area? That'd put it about 8" farther from the printer, but I'd still be using PTFE tubes from the filaments to the MMU3, and from the MMU3 to the printer. That way the MMU3 is in a dry box that will be drier than the print compartment.
* If I have a PTFE tube coming out of the upper storage area to the print head, will that do a good job of keeping the filament in it fairly dry? (I would think so, since the tube end goes right into the print head and leaves only a VERY small space for moisture to come in, and a lot of that is filled with the filament.)
My main concern is keeping the filament dry on the run from the storage box, through PTFE, into the MMU (and 2-3" of filament is exposed within the MMU), or into the print head without any issues.
I don't want to get into what materials to use, construction methods, or design details. I mainly want to get comments and thoughts on the issue of keeping filament from getting too saturated for the last few inches (or feet, if you include the MMU and cassette) of the trip to the printer.
(For reference, it's spring now where I live and inside the workshop, the hygrometers are reading about 35% humidity, which is close to average for outside this time of year. During the summer, outside can be 70% or more.)
RE:
I personally feel the MMU should be enclosed like the AMS and clones and I don't understand why it isn't. Anyhow enclosing the MMU would solve the problem you are having.
Is it cheaper to build one of the clone AMS (bigtree tech has one) than enclose the MMU?
Regarding cabinets, down the road from us there is a 3d print shop that uses the CC3D "HDRY" filament drying cabinet. It's a 3d printed design, and you can get the plans and parts from their site. Will save you a lot of trouble, and it is known to work. Do not use 2020 because it will expand at a different rate to the plastic doors. (I mention this because almost everyone with a 3d printer who walks in asks them, why did you print the whole cabinet and not use extrusion?)
RE: Making Printing Cabinet with Dry Boxes - Some Questions
Did some quick searching. Apparently AMS is well liked, but I didn't find anything clear about using AMS on a Prusa printer. I did find some material from about a year ago saying AMS is closed source and there are attempts to make it work with Prusa. Has that changed? I do see the HDRY system works with AMS, so I would think there's progress there. (One thing I noticed about the HDRY system was the size of the doors - they look like they're done in one piece, but they're far bigger than what I could print on my Mks3.5.) I do see the AMS uses 4 filaments and the MMU uses 5. That may seem like a picky point, but some of the stuff I want to print will work better with 5 colors over 4. (Plus, one of my plans was to often have 3 PLA in the MMU and 2 PETG, so I could easily switch between them for a print. Since my printer is in my workshop, in the barn, and I'm usually in the house, that makes things a bit easier for me.) But if the AMS is easily used with Prusa printers now, I might be interested in using it in the long run.
I had a lot of trouble setting up my MMU3 and getting the filaments to feed through it and have only printed a few test prints with it (like the sheep), but haven't used it in over a year. I've repeatedly told tech support about the issue of how the UI doesn't allow for hardware problems and there's no way to exit the load loop if you're getting repeated errors, other than rebooting the printer. I've made the point, many times, that needs to be added to the firmware - but it hasn't. I don't know the humidity around Pursa's base company, but I question if they're truly aware of just how serious an issue humidity can be. I agree, that the MMU should have been designed to allow for humidity issues. I chatted with Prusa support last night and they've told me there's no problem with moving the MMU off the printer frame and into a dry box. The one issue is to be sure I change the length of the PTFE tube from the MMU to the print head in the settings, so it retracts enough filament when making a filament change.
When you talk about using extrusion instead of printing, what kind of extrusion? I'm working only with a couple printers now, but am interested in other smaller scale ways to manufacture items. (Smaller, as in not mass, as in making dozens or hundreds of something, but not thousands or millions...)
RE: Making Printing Cabinet with Dry Boxes - Some Questions
The DIY AMS clones are open source. I have seen a "BoxTurtle" connected to a Prusa but there are several designs to choose from. While they generally have 4 spools, you can build one with more, and you are supposed to be able to chain multiple units together (I am not sure if that last feature is working yet in the open source versions).
By extrusion I was referring to aluminium profile e.g. 2020, although i think 3030 might be more appropriate for something large enough to take the size and weight of an MMU plus filaments. But the hard part will be solving the different thermal expansion rates of all the parts you use so that it can remain airtight when heated.
RE: Making Printing Cabinet with Dry Boxes - Some Questions
Okay, I wasn't sure what 2020 was referring to. I'm not looking to use aluminum or extrusion on what I'm doing now. I have plans for a cabinet. (I do my plans for 3D printing and wood work in Blender - which means when the plans are done, I can easily make a copy, take it apart, and figure out just what I need in lumber.) I know wood sounds odd for a dry box, but I saw Adam Savage built his out of wood and he's in a humid area (San Francisco) and I'm going to include active dehumidifiers in mine (not just desiccant). (Also, as a side note, I've been spending so freaking much time at the computer, I desperately need something like a woodworking project I can spend a few days on for a break and change right now!)
In the long run, learning how to work with extrusion would help. Are you talking about something that an individual can get for a decent price and use? Aside from "aluminum" and "extrusion," what other terms would help me find more info on using this?
The one thing I can see immediately that I don't like about the AMS and Box Turtle (after checking links) is the roller system - putting the spools on rollers. I've had issues with that kind of setup in the past. One time the filament somehow got tangled (odd - I'm careful about that!) and when it got stuck, the printer actually pulled it off the rollers and down onto the printer! It was a mess! I prefer hangers so I can slip a dowel through the spool and slide it in place, so it rolls on the printed hanger I make. (But I'm betting that if I got files to print AMS or something similar, I could modify them to fix that for me.)
What about AMS working with Prusa? Is there an issue with getting firmware files to work on the printer for those? Or is it something I can easily use with OctoPrint? (If that's the case, does OctoPrint handle loading and unloading into the AMS system and loading the AMS output into the print head?) I love the idea of being able to chain some together!
RE: Making Printing Cabinet with Dry Boxes - Some Questions
Plywood is very good for insulation. When I lived on a boat we had plywood everywhere.
Aluminium profiles are the X shaped metal "bars" a prusa mark 3 or 4 is made of. It's very common in industrial machinery. 2020 refers to the size (20mm across). You should be easily able to find information.
RE: Making Printing Cabinet with Dry Boxes - Some Questions
I completely interpreted your post wrong - didn't realize that until you pointed out it's the channeled bars! I didn't know the numbers for them, but with what I was thinking about when I read everything, my brain just went in the totally wrong direction.
I have tried to find info on using AMS with Prusa printers and can't find anything, even after several searches. Have you heard about anyone using AMS with Prusa?
RE: Making Printing Cabinet with Dry Boxes - Some Questions
The DIY AMS clones are open source. I have seen a "BoxTurtle" connected to a Prusa but there are several designs to choose from.
Are you sure this has actually been done and is not just "wouldn't it be cool" thinking? Please give a specific reference, which includes a description of the integration into the xBuddy firmware. This seems like a hard project to me, and I have not come across such an implementation.
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I did see it operating. Did not physically do it myself. Hard part was probably installing Klipper on the Prusa, which is possible and documented. Probably voids your warranty. Exercise caution.
RE: Making Printing Cabinet with Dry Boxes - Some Questions
I did see it operating. Did not physically do it myself. Hard part was probably installing Klipper on the Prusa, which is possible and documented. Probably voids your warranty. Exercise caution.
Installing Klipper... which involves installing a Raspberry Pi to drive the printer, and ending up with a printer that is no longer compatible with anything Prusa on the software side? This looks like a seriously deep rabbit hole. Given that the OP already has an MMU and is just interested in better filament management (compact and dry), I think the "forget about the MMU and build your own AMS" idea is leading him in the wrong direction.
It would be nice if an off-the-shelf AMS -- sealed and with a dryer, like the Bambu AMS Pro -- could be used as a pure filament store + rewinder for the MMU. But given the closed nature of Bambu's products, that would require a fair bit of reverse engineering, and maybe a homebrew microcontroller PCB replacing Bambu's controller. Has anyone come across such a project?
RE: Making Printing Cabinet with Dry Boxes - Some Questions
Yeah, I'm not going to install Klipper, especially if I can't re-install Purse's firmware over it. I've learned that, while I love hacking, sometimes a hack is a rabbit hole that goes far, FAR deeper than imagined. Assuming I follow a tutorial and get Klipper up and running on the first try, then I have issues like how I configure the new setup in Prusa Slicer and I'm sure there are a half dozen other issues I'll run into.
I was hoping there might be some hacks that have been developed to make the two (Prusa and AMS) work together, but I don't see that. It might be something I would use on my crappy Creality printer (crappy - yes - I got the CR Probe with the printer and later found out the reason I couldn't get it to work for 5 months was because Creality had changed their CPU and their own software would not work on the new CPU without division by zero errors - and yet they were not doing a thing to help customers deal with that issue!). I don't mind experimenting on that, but I need to keep the Prusa functional and reliable.
I'm sure, at some point, if not already, someone will work out an open AMS, whether it's like the MMU, the AMS, or something different.
At this point, I'm changing my plans. The bottom half of the cabinet is like I had it: Storage general filament storage with 2 doors with (easily replaceable) plexiglass planes in them. Above that will be a table surface. Instead of making it monolithic, I may make storage boxes for the printers (one box each, for 2 printers), and storage boxes above them for the filaments. I may work out another level for the MMU and the cassette for storing the loose filament. I'm not sure. But I have decided the printers and the filament in the "frequently used" or "in use with the MMU" storage needs to be in a separate box from the printers.
I'll make sure the closest any in-use filament is to full exposure will be when it's inside PTFE tubing. That should help quite a bit.
The hard issue I have now, as I plan this, is working out the PTFE tubing path so there are no sharp turns or kinks from the filament spools to the MMU and from the MMU to the print head.
RE: Making Printing Cabinet with Dry Boxes - Some Questions
If you are printing from a dryer, be aware that the heat from the dryer can sometimes soften the filament enough to change the extrusion parameters. You might want to make any drybox for printing separate from any dryer.
I'm sure, at some point, if not already, someone will work out an open AMS, whether it's like the MMU, the AMS, or something different
Unfair to say they don't exist since klipper and some of the AMS units are fully open source ... I think what you wanted was an open system that was straight plugin compatible with Prusa hardware.
RE: Making Printing Cabinet with Dry Boxes - Some Questions
If you are printing from a dryer, be aware that the heat from the dryer can sometimes soften the filament enough to change the extrusion parameters. You might want to make any drybox for printing separate from any dryer.
I'm sure, at some point, if not already, someone will work out an open AMS, whether it's like the MMU, the AMS, or something different
Unfair to say they don't exist since klipper and some of the AMS units are fully open source ... I think what you wanted was an open system that was straight plugin compatible with Prusa hardware.
Well, one question I asked (or topic I brought up) was whether the Prusa firmware could easily be re-installed over Klipper later. No answers, so it would seem not possible, meaning to use that system means to basically change the functionality of the printer in a major way.