FRESH – Friction Reducing Spool Holder for Mini A1

FRESH – Friction Reducing Spool Holder for Mini A1

Boost
25
71
17
GIF

Print Profile(1)

All
A1 mini
P1S
P1P
X1
X1 Carbon
X1E
A1

0.2mm layer, 5 walls, 25% infill
0.2mm layer, 5 walls, 25% infill
Designer
2.7 h
2 plates
4.7(6)

Boost
25
71
17
0
87
50
Released

Description

If you print TPU with the A1 Mini, the softer the TPU you use, the higher the chance that friction will stretch your filament on its way into the extruder, and that will result in under-extrusion. This will happen even if all other printing parameters are optimized. That stretch is caused by friction, and is an obstacle good TPU prints.

 

The FRESH spindle replacement eliminates most of the friction between filament rolls and the A1 Mini spool holder while preserving the position, size and location of the spool holder. FRESH particularly benefits softer TPU’s (Shore 80A to 90A), but also alleviates friction on cardboard spools (regardless of filament type). Here is a video that shows the difference: https://imgur.com/a/cYFpYqf

 

The FRESH spindle is a replace-and-forget option, which requires no maintenance, and no switching back for any other functional reason.

 

Details

The FRESH spindle has five individual components:

  • The base, which holds the spindle in the standard spool holder arm. The base is a printed component;
  • The rotating axle, which rotates freely around the core of the spindle, also printed;
  • An end cap, glued to the core to keep the spindle together, also printed;
  • The core, which work as an axle that runs the whole length of the spindle. The core can be printed or cut from a third party component such as a carbon fiber, steel or aluminum tubes. The third party tubes eliminate the need for post-processing to produce a smooth surface, while providing optimal performance;
  • The bearings, connecting the rotating axle with the core, and drastically reducing friction between the rotating axle and the core (which allows the filament roll to rotate with less resistance)

Fresh Drawing.png

Third party components:

  • Required: Two 8x12x10 mm Needle Roller Bearings (i.e., bearings with an 8 mm bore or inside diameter, 12 mm Outside Diameter and 10 mm width). You can find them in Amazon or such, search for ”Needle Roller Bearings 8mm Bore 12mm OD 10mm Width Chrome Steel Open End” to find them;
  • Optional: A 79 mm-long 8mm OD rod / tube (the “core”). I had some carbon fiber tubes left-over from a quadcopter project, and it turned out to be perfect for the application, but there are many possible sources. You can search for “8mm OD carbon fiber tube”. There are many to choose from, in both solid form (rods) and hollow (tubes), they all work well; all that matters is that the outside diameter (OD) is 8mm and that the surface is as polished as possible. It can be a tube or a rod, carbon, steel or aluminum

Photo on 12-25-23 at 2.36 PM.jpg

Why carbon rods and needle bearings?

  • Carbon fiber tubes/rods are amazingly tough, and can easily overcome the shearing stress of a full filament roll, weighting over a kilogram.If you have 8mm steel tubes (also common in other filament roller designs), you can use them instead, but they are tougher to cut than carbon rods. Finally, you can print your own rod (See note below).
  • Needle bearings are amazingly slim. By using these bearings, I was able to design an axle that looks identical to the one being replaced, with the bearings hidden inside it.

 

Finally, two optional pieces are included:

  • A solid cylinder which you can print as the core (in Yellow PETG above), in case that you rather not use a carbon or steel core. In that case, you can print this piece. I have included a simple model that you can use to print with very minimal supports, horizontally oriented, .12 layers, and redundant walls, so that you get maximum shear resistance and as polished a surface as possible. You will need to sand it to make it very smooth, but you will almost certainly add some slight friction to the mechanism.
  • A cutting jig that will help you make a cut through either carbon fiber (in Red above), aluminum or steel rods. Precisely because those rods/tubes have very polished (slippery) surfaces, they are hard to mark and cut precisely. By butting the rod against the bottom of the jig, you will have both a secure way to hold it and also a clear measure of 79 mm to use for the cut: now you just need to cut following the open face of the jig.

Documentation (1)

Assembly Guide (1)
FRESH - Friction Reducing Spool Holder for A1 printers_ac974e91-104c-4b4d-ac98-cea2cf671774.pdf

Comment & Rating (17)

Please fill in your opinion
(0/5000)

Hi, did you ever make a thicker one that uses 608 bearings to mount to your 2020 cage? That is exactly what I am looking for :)
The designer has replied
1
Reply
You are the second person to request it, I will put it in the queue. Slightly larger than a 608 bearing, right? Very busy right now but will do it in about 10 days. Thanks for your message!
0
Reply
Replying to @Zorzal :
608 bearing sized would be great but I am also VERY interested in being able to mount directly to 2020 extruded aluminum rail.
1
Reply
Replying to @prizoner06 :
I have a whole set of accessories for a 2020 cage I built for my A1 Mini, including two external spool holders, an AMS RAISER that sits on it, PTFE guides, etc. (See ohotos). Never got to publishing the files (busy), but I can share it privately with you for now; it’s thoroughly tested, and in use for over 4 months. If interested send me a PM :)
0
Reply
Print Profile
0.2mm layer, 5 walls, 25% infill
good but why not make it bigger. make it stronger with 608ZZ
The designer has replied
0
Reply
Thanks, Joe, putting in the queue a "fatter" version :) I will upload some other versions in a couple of days (one self-standing, another one for my 2020 aluminum cage), then will add that one. Thanks for rating and feedback!
0
Reply
Print Profile
0.2mm layer, 5 walls, 25% infill
Just printed this and it works well. The only issue I had is with the end cap and it being a little too snug against the rotating part which prevented it from spinning, so I had to back it off a bit and glue it in place to prevent it from moving over time.
The designer has replied
0
Reply
Yep, that happens specially when you choose to cut a carbon fiber or metal rod as the core. I have a few of these, and even with the cutting jig it's hard to tune the spacing. Thanks for pointing it out!
0
Reply
Print Profile
0.2mm layer, 5 walls, 25% infill
Nice!
The designer has replied
0
Reply
Thanks, Steve!
0
Reply
Great design I will order the bearings :D And then try it out! thanks!
1
Reply
Print Profile
0.2mm layer, 5 walls, 25% infill
1
Reply
Print Profile
0.2mm layer, 5 walls, 25% infill
0
Reply
Print Profile
0.2mm layer, 5 walls, 25% infill
Other Issues:The cylinder does not fit the hole
0
Reply
No more