This stand accommodates large or small filament reels, any width up to about 70mm... in fact, any reel I've ever come across. (I believe there are wider ones, if you want more than 1kg of filament on one reel, but really? On a Tina2??)
My new design includes unique features which address problems I had with the Mk2: warped prints, fragile parts, non-rotating rollers, and its tendency to be dragged across the tabletop or for the reel to get pulled off it. As an engineer, I decided what was needed is a properly engineered solution (click through to see the full-size photos):
By threading the filament between and under the rollers, the reel is pulled down onto the rollers rather than off them, which greatly reduces the likelihood the reel will come off, and the pressure ensures the rollers really do roll (instead of the reel slipping). Three positions are provided for the feed – centre for wide reels and the outer positions for narrow reels.
Feeding the filament through PTFE tubing serves two purposes: the radius of bend at the input to the extruder is controlled, and the tube acts as a stand-off so that the reel and stand stay where they are rather than drifting across the tabletop. The tube is a press fit into the stand (and also seats nicely into the extruder at the other end).
Combined, the under-passing filament and feed tube provide greater tension in the filament coming off the reel, so that minor tangles are overcome when otherwise they would often lead to the reel on the floor or feed failure.
The stand comprises two of each of four parts, plus some hardware. The rollers themselves are in two parts (not shown separately), so that the flange can print in contact with the build plate and prevent the warping the Mk2 roller flanges suffered from. The dovetailed stretchers, being a quick print, are included as a pair in the print files. The trunnions (supporting the rollers) are orientated on the build plate in such a way that warp does not affect the function of the finished stand.
I find it beneficial not to try printing everything at once. This way, a failed print only means reprinting one part not all of them, so it's quicker overall to get to the finish line of all parts printed.
These are the parts shown post-slicing in Cura. They're printed with a brim to improve bed adhesion, plus minimal support:
(Actually, I imported the gcode back into Cura to create these illustrations, which is why they also show the nozzle wipe at the front of the plate.)
Construction involves removing the brims and support, super-gluing the parts of the rollers together, and assembling the trunnions and stretchers (more glue). The only support is for the nicks which seat the axles on the trunnions, because any holes are orientated and chamfered so that no support is required. You can probably get away without the glue, but...
Being an engineer, I chose to use 3mm diameter x 10mm long steel dowel pins as the axles, which ensures a low-friction contact between the axle and the trunnion, and then M3 washers to separate the end of the roller from the trunnion itself. The dowel pins are press fit, but the washers are best glued onto the roller end so they don't fall off (but see below).
The only problems I've had have all been attributable to the steel pins working loose, resulting in a roller falling off the trunnion. Just recently, I found an overnight print had failed because of that: the reel got jammed so the filament jammed and the print was incomplete. The moral here is not to leave anything to chance and glue the pins into the rollers - don't just rely on them being a tight fit, because (being smooth) there is no such thing as a tight enough fit!
The PTFE tube is the usual 4x2mm tubing used as the Bowden tube between the extruder and the hot-end.
The attached free download zip contains the Gcode files for printing on Tina2 or Tina2S. It is made available for personal non-commercial use only. When printing on Tina2S, set the bed temperature to 50 or 60 degrees manually before commencing the print.
Download HERE
Print times are:
- Roller part A: 21m (2 required)
- Roller part B: 1h 11m (2 required)
- Trunnion: 2h 2m (2 required)
- Stretcher x2: 31m
You could print pins (and do without the washers), so I have included a Gcode file for them in the download, but don't expect them to perform as well as the steel pins - I do not recommend it.
If you print this, let me know by posting below. If you find it useful and would like to reward my effort, buy one of the upgrade packages listed in my shop (see previous paragraph).