RE: Buffers vs retracting spool holders
i am worried the outside part that snaps into the frame might become too big. i just uploaded a new model of both bearing inserts that should work. Try those instead....
RE: Buffers vs retracting spool holders
i am worried the outside part that snaps into the frame might become too big. i just uploaded a new model of both bearing inserts that should work. Try those instead....
You are correct, 102% was still slightly too big for the bearings, but it was also too big for the stand. I am printing the new ones now.
RE: Buffers vs retracting spool holders
The new ones fit better, still a little loose, IMO, but should be good enough.
RE: Buffers vs retracting spool holders
I updated them once again to make the section that goes into the 608 bearing just an additional bit larger.
While slicer did you use to print the ones that were loose, but good enough?
Do you have any other fit issues (large or small gear, bearing pockets, etc.).
Does it look like everything will fit in the rubbermaid container?
RE: Buffers vs retracting spool holders
They are still a bit loose on the inside of the bearing, I can easily pull them in and out. In fact, when I spread the holder arms so I can pull the spool out they tend to stick in the holes in the holder arms because the friction there is much higher.
Everything fits perfectly inside a Rubbermaid container. Once my PC finishes its Windows update and reload, I can post a picture of it inside the container for you.
RE: Buffers vs retracting spool holders
For anyone that might be interested I've been (unsuccessfully) trying Prusa's buffer since the auto-rewind spools aren't cutting it positioned above the printer. I modified the input side of the buffer to add hooks to hang off 2020 extrusion: https://www.thingiverse.com/thing:3703814
Much like when I reprinted my idler door I found that my reprinted piece here seems to fit better (PTFE inserts without force, retaining bolts go in easily, and the nuts weren't a battle to seat) than the original. That could be another source of binding (PTFE tubes getting crushed) people are fighting so it might make sense to reprint them. I'm currently printing https://www.thingiverse.com/thing:3545935 to see if that works better though.
RE: Buffers vs retracting spool holders
For anyone that might be interested I've been (unsuccessfully) trying Prusa's buffer since the auto-rewind spools aren't cutting it positioned above the printer. I modified the input side of the buffer to add hooks to hang off 2020 extrusion: https://www.thingiverse.com/thing:3703814
Much like when I reprinted my idler door I found that my reprinted piece here seems to fit better (PTFE inserts without force, retaining bolts go in easily, and the nuts weren't a battle to seat) than the original. That could be another source of binding (PTFE tubes getting crushed) people are fighting so it might make sense to reprint them. I'm currently printing https://www.thingiverse.com/thing:3545935 to see if that works better though.
gnat,
at the request of another user on thingiverse, i modified my rewinder to better support people who put their filament spools above the printer. Don't know if that will be enough to entice you into printing a unit, but I thought I would mention the change, just in case. : )
RE: Buffers vs retracting spool holders
I have mine above the printer.
RE: Buffers vs retracting spool holders
I have the Rubbermaid modified spool holder inside the 21 cup Rubbermaid container, and a desiccant container attached to the lid. I am also using a pass-through M10 festo with a downward angle to come over the top and down toward the printer.
Once I get everything set up and I know it works properly, I'm going to create a collection on fevers with all the parts in it I used for the mmu2s.
RE: Buffers vs retracting spool holders
Maybe if I uploaded them to tinypic...
RE: Buffers vs retracting spool holders
For anyone that might be interested I've been (unsuccessfully) trying Prusa's buffer since the auto-rewind spools aren't cutting it positioned above the printer. I modified the input side of the buffer to add hooks to hang off 2020 extrusion: https://www.thingiverse.com/thing:3703814
Much like when I reprinted my idler door I found that my reprinted piece here seems to fit better (PTFE inserts without force, retaining bolts go in easily, and the nuts weren't a battle to seat) than the original. That could be another source of binding (PTFE tubes getting crushed) people are fighting so it might make sense to reprint them. I'm currently printing https://www.thingiverse.com/thing:3545935 to see if that works better though.
gnat,
at the request of another user on thingiverse, i modified my rewinder to better support people who put their filament spools above the printer. Don't know if that will be enough to entice you into printing a unit, but I thought I would mention the change, just in case. : )
I might take a look if my current path doesn't work (better PTFE tubes and better entries and exits to the buffer), but my issue with the rewinders wasn't so much the holders themselves. It is the path the filament needs to follow and your holder isn't going to help with that.
RE: Buffers vs retracting spool holders
cybrsage,
looks good to me.....BTW, if the weights on your track touch the inside of the container at all, it probably will not work reliably.
RE: Buffers vs retracting spool holders
cybrsage,
looks good to me.....BTW, if the weights on your track touch the inside of the container at all, it probably will not work reliably.
It does not touch the sides, it looks like it in the pic because I leaned it on its side to take the pic better. I need to get a longer bolt and add more weight to it. I only have 40g on it right now and it needs another 10 or 20 more grams.
I am going to double sided tape it to the bottom of the container so it cannot move around any.
RE: Buffers vs retracting spool holders
I took inspiration from Martin (and Vincent before him) and designed something a bit more compact.
https://www.thingiverse.com/thing:3691892
I've been using these for a couple of weeks now without issue. But, I just put them on thingiverse today, so no one else has provided any feedback. In other words, use at your own risk... : )
So far, it is working like a champ! I am running only one color through the MMU2s for now until I get everything tweaked in and it rewinds perfectly. I used a 30mm screw to have enough length to get the right weight.
I was going to see if you could widen the center bottom support and put in M3 screw holes to mount it on the bottom of the Tupperware container, but it is actually better not mounted. It does not slide around or fall over at all, so it never touches the side of the container (and therefor get a lot more friction) as it is...and it makes it very easy to remove the entire spool holder to replace the spool. It is far harder to replace the spool with the stand mounted in the container than it is pulling it all out.
Thanks!
RE: Buffers vs retracting spool holders
posted the v1.0 release of my rewinder last night with many improvements over the initial version.
Design was modified slightly and some optional parts created to allow Vincent's spring rewind hubs and Martin's arm mechanism to work in the same stand.
My hope is that more MMU users will consider a rewind solution if they can evaluate three disparate mechanisms with a lower total cost in time and material.
RE: Buffers vs retracting spool holders
Spool rewind vs Buffer,
I havent used the Buffer yet, but i have a full set of rewinds
If you have a really slick filament route like i do sometimes my rewind spools can actually pull the filament out of the MMU2 that isnt being printed, which is a pain , to counter this i put a few bends in the PTFE tube ,
going to print the buffer supports and give that system a go this week
RE: Buffers vs retracting spool holders
Hi Greg,
I printed one of your holders 2 months ago and like it very much.One question though... Could you include some screw holes to be able to fasten the spool holder to a surface? Maybe this is changed in newer versions already, but after printing the first version I found myself drilling a hole in the plastic..:-)
Thanks for the great work!
--
MK3
RE: Buffers vs retracting spool holders
thanks for trying out the holder and for the feedback...
the current version (v1.3) of the stand posted on thingiverse has mounting holes in the bottom.
RE: Buffers vs retracting spool holders
Hi All,
My question is somehow connected to the MMU2S buffer question (therefore I ask in this thread..)
I have a MK3S running in a Network 19" case (metal, to minimize fire danger)
Now I consider upgrading to a MMU2S.
- Can I omit the Prusa supplied buffer, or is it not recommended? I have the impression it needs fiddling about to
insert the filaments. Above I saw the solution with the non bowden gap acting as buffer. And I have in mind an image of a
system based on two IKEA lack tables where the filament is located below printer and there is also some 20 cm between
tangling down tubes and filament spools.
- Is it better to locate the filament spools above (tubing exiting MMU2S has to bend up) or below(tubing might go straight down) currently I prefer down as I also plan to have a piping on top for removing the air in printing box. Below I have a high drawer in an IKEA STUVA cupboard
which I think can be sealed with some gaskets and would allow easy access to the filament spools. also this can hold some desiccant stuff to keep filament try.
What do you suggest?
Greetings
M.
RE: Buffers vs retracting spool holders
You do not have to use the buffer, but you do need to do something to control the excess filament after a tool change. Uncontrolled it can tangle and cause the print to fail.
As much as filament wants to return to a coil shape, I would not go with an open "buffer" like you referenced. I would be too worried about it twisting and then kinking. A proper buffer or rewind spool holder control the filament better in my opinion.
As far as where the spools are located, that doesn't make much difference. More important is making sure the path is as smooth as possible with any curves being as gentle as possible. You want as little friction in your filament path as you can manage.