Can you guys give me a quick sanity check please?
So out of the box, one problematic aspect of the stock FT-5 (R1) is the filament delivery.
The factory PVC pipe stub has issues with the filament drooping off the roll and tangling between the roll and the frame. It is also problematic in that the protruding socket cap screws securing the mount to the frame catch the webs of the plastic spools that FolgerTech sells, causing everything to bind up. Swapping those to button-head screws would solve the webbed spool catching, but still wouldn't keep the filament from escaping the sides of the spool.
There are quite a few alternatives for filament management - multi-piece guides to direct the filament over the top of the 2020 frame, reverse bowden setups, standard bowden setups, top-mounted spool holders, remote mounted spool holders, wall mounted spool holders, vertical posts that pull the filament off sideways, the FT-5 R2's top-rear-center mount, etc, etc.
One of the most popular alternative designs on Thingiverse is the triangular "A-Frame" style, which uses two triangular uprights on the top 2020 extrusions, with either a piece of conduit, threaded rod, or PVC pipe between them to suspend one or more spools of filament. These optionally have a separate guide arm that sticks out from the top front extrusion, to ensure that the filament is always pulled from approximately the centerline of the spool, not off the side, regardless of the print head motion. I'm talking about any of the dozens of designs that look generally like this one:
I thought these looked nice, so I picked one I liked and printed a set. They work fantastic for small prints, but I've had several failures with larger prints (larger in terms of X-Y dimensions), and after seeing the failure mode, I can't see how this design would ever really work well without being constantly monitored...
The theory makes sense. Locating the filament at the center of the build platform reduces the amount of filament that needs to be pulled from the spool when the print carriage moves to an edge or corner of the build platform. Or perhaps more accurately, it reduces the maximum amount of filament that is pulled, even if the average ends up being close to the same. That's the theory.
But when printing a large part in practice, a carriage movement to a corner will pull off a fair amount of filament, and a traversal through or across the build platform center point (or the point immediately below either the filament guide or where the filament exits the spool) will then cause that extra filament to bunch up. It's not going to rewind the spool, so that filament has to go... somewhere. Simply homing the printer and then moving to start a print in the center takes the filament from its maximum reach to its minimum.
On my printer, any significant lengthwise movement on the X-axis when the filament was unloaded (from a tension standpoint) and pushed like that would cause that extra length of filament to jump off the side of the spool. From there, it would bind up on the support pipe when pulled.
Maybe it was worse because my spools are relatively full, or maybe they have smaller flanges than others... but aside from some small item prints, I just couldn't walk away from the printer with this spool holder without coming back to a mess of filament hanging from the pipe beside the spool. I tried with and without a filament guide loop under the spool, and both had the same eventual result.
Did any of you encounter the same issue? I'll probably move to a reverse bowden setup to fix this, but I'm a bit bummed that this didn't work out, and surprised at how popular these are on Thingiverse if they are in fact fundamentally flawed in their operation...