I’m considering a remix of my A350 filament perch ( https://www.thingiverse.com/thing:4597120 ) so that others could use it inside an enclosure on the A350, A250 and (maybe) the A150. Could someone who has each of these models in an enclosure tell me how much actual space they have between the top of the vertical column(s) and the top of the enclosure?
Adam
A350:
Would it work better as a bracket on the outside with a hole in the middle of the enclosure that tracks the centre of the top panel?
I did so, there is a other thread where you can see my setup.
I’m not sure what you mean. Are you suggesting the filament sit on top of the enclosure and feed through a hole in the top of the enclosure? If so, that’s certainly an idea, but it wouldn’t solve the problem of too much filament being pulled from the spool when the print head goes down and back up during calibration.
I’m just checking to see if there’s enough room inside the enclosure for my filament spool holder design. If there’s not, I was considering a remix to make it possible for those people who have enclosures. I’m not super motivated though, since I don’t have the enclosure. 
Thanks for the numbers, Chris. It looks like there’s no solution, at least for the sizes of filament spools I have. There’s no way to to have a vertical spool perch design that meets both of the following needs:
Oh well. It works great if you don’t use an enclosure. If I decide to get the official enclosure one day, maybe I do a remix. But I’m much more likely to make my own enclosure…
Adam
… unless it somehow articulates at the top and bottom of the travel. Oh, what am I getting myself into!!!
I’ve been thinking about this - dangerous I know.
What about a hole in the top of the enclosure with the spool on the outside feeding through the hole into a PTFE tube that’s connected to the print-head?
That way there is no “yanking” of the filament, the tube will contain the same amount of filament regardless of location in relation to the hole in the top of the enclosure.
Sort of like this, but on top of the enclosure?
Someone on FB came up with this exact method.
They said it worked fine. No reason it shouldn’t.
-S
Yeah, that!
– extra characters for fun and profit –
In my opinion, that just introduces a whole different set of potential issues. Using a PTFE tube and fittings to force the filament into a channel THEN flexing that channel over the entire vertical travel of the print head? Seems to me that it would change the dynamic of how the filament is fed into the print head. Maybe the feeder can handle the extra work. Maybe it can’t. Maybe forcing the filament to occasionally bend opposite of its natural curve won’t be a problem. Maybe it will. And you’ve still got that long PTFE tube traveling and flexing up and down as the print head moves “home” and back down to the print surface. Maybe it won’t get caught on anything. Maybe it will. It just seems like an inelegant solution.
I don’t think I’ll completely redesign a filament spool mount to solve that problem since I’m very happy with mine. But I think the best idea would be to mount the filament spool at an angle so you can provide clearance inside the enclosure while still letting the filament “ride” up and down WITH the print head…
Just my 3 cents.
You make good points about the potential issues. All I can say is in my experience with my Bowden printer (24" long Bowden tube) the PTFE tube is quite slippery and hasn’t been an issue. I also put a small section of PTFE on my enclosure to smooth the entrance through the side of the enclosure, the result was less, and more constant, force in drawing filament into the toolhead.
I’ve seen plenty of designs using full ptfe tubing from a container all the way to the print head on other printers to suggest that it would work fine.
Especially since it’s pulling it. If a bowden printer can do that pushing it, then it should have no problem.
I would think that you’d want a spool holder where it’s supported and allows the spool to spin freely as opposed to the SM design where it kind of hangs there and lurches.
-S
