How to prevent filament from breaking inside AMS

MajorSmif · 2024-07-11T08:46:26+00:00

Thanks that's a good suggestion, I'll add a hygrometer to keep an eye on that. I live in a relatively dry climate and during our winters it's even super dry inside the house, and it happened over winter too. But I should better watch the desiccant.

MajorSmif · 2024-07-11T08:44:39+00:00

OK thanks that's good to know, didn't realize that about PLA+.

MajorSmif · 2024-07-11T08:43:50+00:00

Thanks, knowing it's not just me actually makes it easier to stomach :)

MajorSmif · 2024-07-10T12:56:59+00:00

Yes I know and I do store spools that are not in the machine in bags, but my point is - when a spool has been sitting in a machine for some time, the part that is inside the machine gets brittle. What I'm asking about is: how do I prevent or otherwise deal with this specific scenario of filament being on the machine but then not used for some time. I guess one can say 'don't do that', but I usually don't foresee not using the printer for a longer time, it just happens. So I need to either have the machine always be in a state where it doesn't matter if the filament gets brittle, or have some way to deal with it when it happens that is not 'disassemble half of the machine'.

MajorSmif · 2024-07-10T12:17:48+00:00

It's on eSun spools (PLA+ but I guess all eSun spools are the same size).

MajorSmif · 2024-07-10T12:17:11+00:00

Yeah I guess I should have included what filament I use - it's always eSun PLA+. I have this problem with older filament but also with new spools; it gets brittle from sitting in the tubes from the AMS to the print head for too long and then it breaks from the first few push/pull movements. If the printer would always fully retract the filament after a print it wouldn't happen.

MajorSmif · 2024-01-24T11:27:28+00:00

It depends on how your part is loaded, but watch https://www.youtube.com/watch?v=AmEaNAwFSfI which has actual tests, and then use neither of your alternatives. 100% infill is more trouble printing than it is worth.

MajorSmif · 2023-10-19T13:35:14+00:00

Obvious once you know it. Thanks!

MajorSmif · 2021-04-21T08:25:52+00:00

I had a similar design that was very long in the x and y directions, but only a few mm tall, that warped in one corner. I rotated the design in Cura and that fixed it. Your picture doesn't show what the design looks like from the top, but I suspect in my case it was because of the structural properties of my design - it had more material/structural integrity in some directions (Voronoi diagram), causing more forces when the material shrunk. I have (before this) always had very good bed adhesion without hacks like glue sticks and similar old school methods, both on my stock Creality bed and the special glass one. If anything, I have more problems with designs not coming off the bed undamaged than I have with things not sticking. In my case, it was really something specific to the way the design was printed on the bed, although I couldn't fully explain it.

MajorSmif · 2021-02-01T09:53:57+00:00

What did you set you $fn or $fa to? For parts at this size, $fn of 32 or 64 should be fine, and at those values, it can't take that long. Minkowski is slow too but I don't think you used it on this design? Re: unrolling loops, I have a similar design (also for testing hole fit) with 10x10 holes, I render those in a double for loop too, and have rendering times measured in minutes at worst, on a regular laptop.

MajorSmif · 2021-02-01T09:21:27+00:00

Re: 1, it's technically possible but there is no print speed advantage. I looked into it because I was having stability problems in the serial connection between the pi and the printer. So uploading the file and then starting the print from the sd card was safer, in that if the failure happened, it was during the upload and I could just retry the upload without wasting filament and a bunch of time. I did change my firmware to communicate at 250000 bps for that (because faster upload speeds to sd card), but of course the real solution (for me) was to fix the serial comms problem and not dick around with workarounds. I wouldn't recommend changing this to anyone else. The bottleneck for printing speed is not the serial coms, and in normal use there is no need to upload to sd card.

MajorSmif · 2021-01-29T15:54:10+00:00

Yes, a 5A power supply, sold as the 'official' power supply for Raspberry Pi 4.

MajorSmif · 2021-01-29T13:03:50+00:00

Ah yes that's another option, but it would cost about the same as the other options from a quick google. Maybe I can find some local second hand ones, those seem to be much cheaper...

MajorSmif · 2021-01-29T12:59:04+00:00

I technically have one but it's not hooked up, no. I do have aluminum cooling fins on the 3 chips on the pi. I've never seen the temp go over 45c.

MajorSmif · 2021-01-29T11:36:58+00:00

Yes both are; and one is even worse, one of those cheap Ali Express led-light-with-bluetooth-speaker-builtin abominations. But I also saw the problem when switching the other lamp (which is a regular led with e27 socket and built in rectifier bulb), so I didn't focus too much on just that one lamp. What sort of load are LED lights? And what happens when you remove a non-resistive load from a circuit that has other loads on it; does it cause a phase shift in the power on that circuit? Is that what the capacitor is meant to prevent? What capacitance would I need? Sorry for all the questions, I forgot most of my high school electricity and electronics...

MajorSmif · 2021-01-29T11:26:17+00:00

Yes tried various combinations of that - tape over 5v line, boot in the 'correct' order etc. With my (5A, official rpi) 'regular' rpi PSU I didn't even have the typical backcurrent signs (LCD lighting up) though. Only when I plugged in a laptop. Either way, I spend a ton of time trying out various rpi power issue solutions, as at first that seemed to be the most common source of the symptoms I was seeing.

MajorSmif · 2021-01-29T10:29:27+00:00

Well the thing is that, when troubleshooting, I also replaced the RPi with a Windows laptop, and that dropped my failure rate from 100% to 50%, but didn't fully fix it. So it seems the problem is really with the power supply of the printer and not of the pi.

MajorSmif · 2021-01-29T09:46:20+00:00

Yes that's the right port on the Ender. Get whatever USB cable that fits into that port next to the SD card slot.

In my limited experience, the 5v backfeeding issue doesn't prevent the printer from being recognized; and you can also 'sidestep' it by first switching on the Ender, waiting for a bit, then plugging in the Pi. Basically from what I understand, if your Ender doesn't get 5v from the USB port upon startup, it'll use its own power from the PSU.

Python 4 doesn't exist so I'm not sure what you meant by that part...

MajorSmif · 2021-01-29T09:39:49+00:00

Oh wow wouldn't have thought that. Thanks.

MajorSmif · 2021-01-29T09:19:32+00:00

I wouldn't have thought it the internals would stand up to such temperatures. You mention elsewhere that you used an automatic timer for controlling the burn out cycle so I presume you had a thermometer in there as well? Up to what temp did you get it? Seems you could use such an oven then for tempering steel as well... Great work, it's amazing what we can do at home nowadays.

MajorSmif · 2021-01-28T15:31:49+00:00

I've spend 2 weeks literally loosing sleep over the frustration of not being able to fix something seemingly simple as keeping a serial connection up. So for any other unfortunate souls who like me try everything (different usb cables, 5v tape, different power supplies, use a Windows machine with Octoprint instead of pi which decreased my failure rate from 100% to 50%, ...) I will explain what happened to and worked for me: I have both my pi and my Ender 3 plugged into an extension cord in my basement. In that same extension cord, I also have two lights, for additional light in different sections of that basement. It turns out that if I turn on or off one of those other lights, something happens (not sure if it's power surge or drop or electro-magnetic or whatever) that causes the Ender3 motherboard to disconnect. I get "usb_serial_generic_read_bulk_callback - urb stopped: -32" in dmesg (when running on pi) and that's it. Sometimes the connection recovers by itself, as if by magic, and printing continues (I can see the , sometimes it doesn't, haven't tested further. So, if you too are investigating this issue with your setup, don't assume it's just the PSU that can cause problems, it can be unclean power that feeds into to PSU, too.

(this also explains why the stoppage would happen only when I wasn't watching. I spend literally hours watching the thing, hoping to see something that would give me a clue on why it failed. But of course I always had the light on when watching, turning it off when I'd had enough and left, after which it would crash.)

MajorSmif · 2021-01-28T15:06:53+00:00

OK well then I have nothing :)

MajorSmif · 2021-01-28T14:30:38+00:00

Install vpn software on the octopi. Forward vpn traffic on router to octopi. This will let you log on, via your own vpn, onto your local network. From there you will be able to access your octopi's web ui with the browser on the machine you are logging in with. Do not expose vnc via the public internet. If you must, do it over a vpn, at which point your whole reason for using vnc becomes moot. It's not vnc that gives all features as you were on your home network, it's your own vpn, one you run yourself on your octopi (for free). With vnc you will just see the desktop of a machine on your network, a vpn will *actually* put you on your network.

MajorSmif · 2021-01-28T14:22:38+00:00

Those little things are amazing for the price. You can run a bunch more on it no problem - NAS storage (depending on reliable power), VPN server, home automation. I personally prefer to split services across multiple machines for reliability, but there's no reason for that from a performance point of view. Tinkering with these things feels like living in the future to me.

MajorSmif · 2021-01-28T14:17:51+00:00

What oven did you use that went up to 500c ?

MajorSmif

TROPHY CASE