Re: What is the best spool holder alternative?
My own setup:
IMG_0021.JPG
Mash-up of:
https://www.thingiverse.com/thing:508896
https://www.thingiverse.com/thing:1754587
and a custom bracket I made to bolt it to the back of the z=top with some longer screws. I made the bracket after finding out the 6mm frame adapter is more than likely to kill your filament sensor connector if you do anything at all that makes the printer move to a high Z height.
That's pretty slick!
RE: What is the best spool holder alternative?
@thomas-s37
I like your modification to the spool holder and would like to use it, but cannot find the referenced .zip file. Nor can I export from Onshape since it's view only. Can you make these available either on Thingiverse or Prusa forum?
RE: What is the best spool holder alternative?
Hey there!
I'd say that as far as spooler solutions go, the stock one on the MK3S is more than adequate and pretty optimal eh? IMHO and just my 2 cents.
I mean, I don't have this unspooling problem if I print high parts. I do have an unspooling issue though when I unload the filament then let go of it where it springs back over and around the spool. I fixed this issue by creating/printing a piece that I slam on the frame and that allows me to "snap" the filament to and stops it from moving until the next time I want to load it. Mind you I'm only mounting 2 spools at a time where the filament from 1 is loaded while the other remains snapped into position by that snappy thing until next time I need it.
However, have you considered a "filament guide" for your problem instead? It kind of would constraint the filament from going too much to the left or right, and with the right kind of guide, address the issue with the unspooling that you mention when you print higher.
Here is an example of what I'm talking about: Filament Guide example on Thingiverse .
Note that I have not used/tested that particular model; it's just an example.
Cheers!
Flood
RE: What is the best spool holder alternative?
I stand next to my printer with the spool in my hands and gently unfurl the filament as it prints. No bearings, no tangles.
RE: What is the best spool holder alternative?
Here is an example of what I'm talking about: Filament Guide example on Thingiverse .
I do like this design. I need one that is less tall.
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Chuck H
3D Printer Review Blog
RE: What is the best spool holder alternative?
Here is an example of what I'm talking about: Filament Guide example on Thingiverse .
I do like this design. I need one that is less tall.
Ignore that - this one flexes. Perfect!
--------------------
Chuck H
3D Printer Review Blog
RE: What is the best spool holder alternative?
@cwbullet
That's great news! Hope it helps with the issue.
Cheers!
Flood
RE: What is the best spool holder alternative?
I designed a spool holder that handles the issues you mention. You can find it here on prusa prints site Smooth Roller for Mk3s | PrusaPrinters
This was the result of downloading a low profile spool holder ... and then not liking how the spools had friction on the bar, like others here, and then looking for a rolling alternative. I wanted something that suppresses backlash when the head moves a lot, that rolls smoothly, and doesn't become a fidget spinner that unwinds filament when there are large head movements.
I also wanted it to fit into my enclosure, mount to the prusa Mk3s frame, and not make me have to unscrew anything to mount a new spool of filament. The result is the smooth roller - 10 bearings per side, internal to the filament spool, and a left/right orientation that gives you two spools at a time to work with inside your enclosure. For over-run, the design employs a felt clutch - allows spin smoothly, suppresses overspin. Adjustable clutch are the end caps for the spool holders. For unwind/rewind, the spool is actually offset a little bit so it will rock back and reclaim some filament, and the offset further allows for a low profile that gives plenty of head room in the enclosure.
RE: What is the best spool holder alternative?
For unwind/rewind, the spool is actually offset a little bit so it will rock back and reclaim some filament
How much is it able to re-claim? For instance, if I were to raise the hot-end height from zero to maximum as a "rapid", would it be able to re-coil all the slack, only only a small fraction of it? In the past I've encountered instances where doing this would actually unloop some filament from around the edge of the roll, resulting in a tangle followed not long after by a jam once enough filament was consumed.
RE: What is the best spool holder alternative?
It's a different application, but this guy uses some laser beams to sense and maintain a fixed amount of tension of the filament coming off (or, in his case, going onto) the roll of filament.
RE: What is the best spool holder alternative?
Repkord has a rewinder that he talks about here (starting at time index 14:41):
He says parts are available to download for free.
RE: What is the best spool holder alternative?
@dimprov
So far, even on tall prints, I'm not having any filament get so loose on the spool to unwind. The forward lash that causes the free spinning spool to spin too much (loosening the slack) is suppressed by the felt clutch, and fact that the spool doesn't rock any more (spins smoothly but attenuated by the clutch) seems to do the trick. Before I added the clutch to the design the spool would definitely spin too far on a fast hot end movement. Now with the clutch, no more.
RE: What is the best spool holder alternative?
Keeping an eye on responses I just want to say I'm a bit baffled by the situation some of you find yourselves in. Now I might be missing some details hampering my full understanding - and I'm no expert - but I can't help but wonder why the stock spool holder works for me 100% of the time with no fuss whatsoever. My setup is really plain Jane, too, other than my sound dampening solution that, aside from slight additional wobbling brought on to the print by the rubber pads, which actually you would think would trigger or worsen spooling problems described - has not been causing any problems to me whatsoever.
So, if I'm getting all of this right, wouldn't it be worth investigating aspects of your setup a bit more before investing time, money and energy into a patched and involving solution? I mean, a filament guide is somewhat good to have but that, even in my own regular setup, hasn't been necessary yet - let alone needing more fancy solutions.
I've been printing every day, about 8hrs a day for the last couple of months.
Perhaps the spooling/filament problems described here are just waiting for me around the corner...
RE: What is the best spool holder alternative?
Immediately above the enclosure I have a spool rack of two sections of plastic pipe and 3d-printed brackets. This holds the filaments I use regularly. PLA to the left, PETg to the center, ABS to the right.
Above this is a shelf on which I have four of the Prusa MMU spool holders. I use these mostly for filaments I use for projects but not regularly. (Paramount Castle Limestone Gray, Sky-Blue Pink, etc.)
I also have one of the 3d Upfitters clear plastic holders which I can place on the enclosure if needed.
RE: What is the best spool holder alternative?
@flood
When I put my printer in an enclosure, the stock spool holder was too tall and the spools would hit the top of the enclosure. That lead me to the low profile spool holder - which worked as you say, fine. But I was bothered by the spool rock... and woke up with an idea for a low profile internal bearing roller. That worked great, but the spools spun too fast and would tend to unwind. So then I added the clutch and I have no rocking, fits in enclosure, and easy to change the spools as the original was. Mostly about geeking out and then incrementally solving problems in a design for me. There is NO best solution of course 🙂
RE: What is the best spool holder alternative?
@dan-rogers
Now I understand a bit more, thanks!
RE: What is the best spool holder alternative?
@dimprov
So far, even on tall prints, I'm not having any filament get so loose on the spool to unwind. The forward lash that causes the free spinning spool to spin too much (loosening the slack) is suppressed by the felt clutch, and fact that the spool doesn't rock any more (spins smoothly but attenuated by the clutch) seems to do the trick. Before I added the clutch to the design the spool would definitely spin too far on a fast hot end movement. Now with the clutch, no more.
Maybe you're printing at stock speeds with the stock gcode post-amble? I am/was printing at much higher speeds and also raising the print head to the top at the end of the print to make access to the nozzle easier. Also, unlooping/tangling is more likely to present itself on a full spool of filament. If may (?) also have to do with the type of filament: some is more springy than others.
RE: What is the best spool holder alternative?
@dimprov
Ah yes, good considerations to keep in mind indeed. On my end I'm printing at 3x speed when the prints give themselves well to it, if not, 2x. Also been printing PLA only. The filament will want spring far back onto the roll if I'm not careful after I unload it and it slips out my fingers before I get a chance to snap it in place to that doodle I made. It's quite manageable so far. I don't have an enclosure but I may have to consider this, based on what I'm reading, if I'm going to print certain kinds of filament types like ABS. So we'll see. Knock on wood.
RE: What is the best spool holder alternative?
@flood
A couple years ago a few of us set out to determine just how fast we could push an i3 MK3 to print, and the speeds got pretty high! https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-hardware-firmware-and-software-help/does-someone-want-to-know-how-fast-they-can-print-extrude-look-here/ So, maybe that had something to do with it, because at those speeds the hotend could yank relatively hard on the filament due to the high speed/accelerations.
Anyhow, for whatever reason, some people see a need for it, like the repkord guy above , which is why he developed his spring-driven filament rewinder.
Of course, the easiest way to prevent unlooping would be to use a spool with a wider diameter, but there also seems to be an argument for keeping the filament nicely wound, as one finds on the prusament filaments, rather than more randomly as with cheaper filaments. Maintaining that seems to require maintaining tension on the filament, with rewinding being one way of achieving that.
RE: What is the best spool holder alternative?
@dimprov
Warning: Long late night rambling post ahead, supported by a few drinks.
TLDR: Happy printing, let's roll!
Holy smokes, that is quite the in-depth diving into print speeds; and I only read the last 2 of the 17 pages !
I'd expect there to be many factors that can come into play, too, such as vibrations of the printer, enclosure or not, quality of filament even within PLA and within the same company and batch, to name a few.
I have not ventured into manually tweaking the gcode for any of my speed tests because when I reached out to Prusa Support via their quite venerable and effective chat function they confirmed to me that if I use the live print speed adjustments of the printer, it will try to auto-adjust other related parameters on the fly, such as flow rate as just one example. So that's what I've been doing since, only adjusting my print speed early on in the prints and only after I was satisfied that it had adequately printed the first layer at stock 1x speed.
Mind you, I've been printing on demand and mostly for myself. Plus the printer is just a foot from my pc desk and I'm at my computer almost the entire day anyways.
And then, there are the particular goals/expectations, obviously. For example, since successfully printing at 3x speed with consistent results I was surprised by my choices when one day I wanted a really high quality print so I picked the "0.05mm ULTRADETAIL" preset in the PrusaSlicer, loaded the gcode in pronterface, send it to the printer, got a good 1st layer, was prepared to live-increase the speed and thought, well wait a minute, if I increase the print speed I might do so at the expense of detail, which would counter my goal of a high quality print. In this case I chose to leave it at 1x speed. I would assume I would make a similar decision when aiming for precision instead of aesthetics, say a piece intended for applications in small electronics or requiring small mechanical capabilities.
There would probably come a point where, say, if I'm looking for printing a large number of pieces in a small amount of time where a low failure rate was imperative, say when fulfilling orders for my Business, I may chose a balance leaning more towards reliability over print count by keeping print speeds on the lower end but still increasing my print count with buying more MK3s = Some print farm.
Here's another scenario to conclude on that: If you don't particularly aim for high precision and you don't need a whole amount of detail and it's a straight forward print that gives itself well to fast printing having very few jumps and retractions in its travel path, such as with a vase in vase mode, but it is however a huge print that will take many hours and will test the limits of your printer in terms of height and width of the print; well, who wants to see their print suddenly fail 24+hrs in using half a spool of filament because of overconfidence in the printer's performance based on print tests using smaller parts? Not counting how in this scenario you may successfully print a few parts, then a see a fail, whereas if had you lowered the print speed you might have gone on with several more successful prints before seeing a fail. There is also the fine performance and tolerances of your particular MK3 - the luck of the draw.
There's a point where it's highly subjective, too, of course. Then there is the printing experience for the heavy tinkerer and modder versus the hobbyist printing doodles once in a while.
And then, what is a fail exactly? 🙂 I've had prints that were technically fails, but that I satisfactorily fixed with pliers in just seconds. Others looked more than adequate, but I was looking for super fine detail and it didn't quite deliver. Case in point, near perfect pieces with lots of stringing. Or an even better example: Prusa MK3 kits with seemingly acceptable looking printed parts but where, as I painfully found out myself, their function isn't quite up to par until you try to insert a nut in the hole and it doesn't fit.
I'm noticing the underlying IFs, mays, mights, shoulds, coulds and ought tos in this writing here as I re-read myself.
It's very much a necessity even beyond the 3D printing landscape to try and push the boundaries with each iteration of the technology in order to see how far it will take us. This is to be very much appreciated, whether coming from the lab or the community. Many years in the future there will many facepalms - and hopefully mostly deep gratitude for this kind of work - when our kids and grand kids are printing complex, multicolored pieces at 20x speeds with ease, after they read what we put ourselves through with our extreme tests.
Anyhoo, I think it's time for me to print another version of my latest prototype 🙂
Happy printing!
Flood