The Bearin Winder - A Universal Spool Rewinder

This is an automatic filament rewinder core that is designed to be mounted in the Bearin Winder stand. 

After purchasing the RepKord rewinders I found that they were not always compatible with the filament spool I was using. I also had some issues feeding the filament through the back ports on the RepBox to feed down into the MMU2s if 5 spools were loaded. I then decided to design an automatic spool rewinder that was easy to replace and was modular.

Hence, the Bearin Winder was created. This filament core can be used on a range of spool sizes from 70 to 100 mm. It is modular so you can easily add a spacer to extend the length of the core without the need for much extra re-work. It is compatible with 1 kg and 2 kg spools. In total 5 spools can be loaded into the RepBox, they can also be used standalone. Also, the frame with the filament loaded can be slid forwards on the rail track so you can reach behind to easily feed filament down the back ports on the RepBox. 

You will need these non 3d printed parts:

It uses the 2 springs from the RepKord RepWinder: 

• Clutch Spring(s) 18mm Diameter x 18mm Free Length
• Tape Measure(s) for Main Spring Cartridge(s) (Found inside 10ft/3m Tape Measures)  

Link to page: 

https://www.repkord.com/products/the-repwinder-a-spool-rewinder-solution-for-repbox-and-prusa-mmu2-integration

and 2 of the bearings that come from the original Prusa filament spool holders:

Link to page:

https://help.prusa3d.com/guide/7-spool-holder-and-buffer-assembly_46160

Bearing Part number: 608RS 

If you already have the MMU2s and the RepBox/ReWinders then you should have these parts.

An exploded view of the Bearin Winder is shown in the picture (Bearin Winder exploded picture) it shows the relative order of how the Bearin Winder needs to be constructed. 

Tip: When adjusting the tension with the pirate wheel I recommend 4 full turns. This should be enough to make good contact with the spring. Try not to put too much force on the pins on the wheel as they may break. 

An assembly video for the Bearin Winder can be found here:  

https://youtu.be/hMe9urXhYAQ

A video for mounting the Bearin Winder into the frame can be found here:

https://youtu.be/ZuTMUBQwMVg

Caution: The compression nut is a left handed thread, this is so that you when you hold the front plate when tightening it doesn't get loose. Try not to overtighten this part I normally go finger tight then a turn with the tool. There is a (+) and a (-) indicator on the compression nut to indicate the direction for tightening (+) and loosening (-).

A video for spool installation can be found here:

https://youtu.be/127RDOGCB1I

Tip: I recommend pre-winding a new filament spool by 2 rotations as heavier spools tend to struggle with the weight, this is especially true for 2 kg spools. If the spool re-winds then you should be set to go. 

A video for pre-winding the spool for loading to the MMU2s can be found here:

https://youtube.com/shorts/re2RID1M53E?feature=share

When combined with the stand it can be installed in the RepBox or used standalone. It is possible to fit 5 complete sets into the RepBox. 

Note: This is only possible if the max width of the spool is comparable to or less than the width of the Prusa spool dimensions. 

I have also made a second frame that can support 1 kg Filament PM spools or wider spool types > 70 mm. However, only two of these can be installed in the RepBox with a Prusa sized filament in the middle. 

It is also possible to use this rewinder for 2 kg spools, I have not made a stand for the 2 kg spool but there is a very good 2 kg spool holder by Vincent Groenhuis that can support the Bearin Winder with a 30 mm spacer. I have made a rod that can be used for installing the Bearin Winder in this frame. 

link: https://www.thingiverse.com/thing:3369189

I have provided 3mf files for the following:

Complete set with keys - contains all parts for the Bearin winder including the keys. Ideal if this is your first print, or if you don't have the keys.

Complete set - contains all parts for the Bearin winder without the keys. Ideal if this is your second print, or if you already have the keys.

Spacers for wider spools - Allows you to extend the length of the core by 30 mm or 20 mm. Useful for wider spools. 

Important Printing Note:

It is important to print the parts using a layer height of 0.1 mm. This helps to increase the quality of the threads and also gives a smooth finish for the top of the main body. Due to the overhangs on these parts a layer height of 0.2 mm tends to give rough edges and more chance for stringing. However, the first layer can have a 0.2 mm height. 

Tip: I highly advise using the Keys (Tightening tools) for assembling the Bearin Winder it saves your fingers. 

For mounting 5 Bearin Winders in the RepBox you will need to print 4 of the standard frames and one of the middle frames. The middle frame is designed to slide over the lock (I recommend using support enforcers for the bridge). I would recommend putting some grease/lubricant on the rail to improve its slide ability. 

Note: The bottom base frame for the standard and middle type frame is slightly different. The middle base frame has a lip to hold the top more firmly.

The Filament PM/wide spool frame only contains the top part of the frame. It is assumed the RepBox already has 5 of the standard bottom base frames installed. For this frame you will likely need the 20 mm spacer too. 

Note: Useful assembly and installation guides are included as pictures. There are a few parts that need to be reworked after printing. 

Update:

To improve the flexibility of the Bearin winder for a wider range of spool sizes some new parts were designed. These include:

an extra large top plate (Top_plate_larger_v2_with_supports.3mf), an additional spacer (spacer_for_5_mm_extension.3mf), a larger wing nut (wing_nut_v4_60mm.3mf), a thinner top lock nut and bearing cap (Top_lock_nut_slim_tension_wheel_slim.3mf), and a new rod for the frame (frame_rod_wider_spool_v2.3mf). 

Using these parts with the rest of the Bearin winder parts will allow you to use filament spools with a length of up to 76 mm and an ID of 58 mm on the standard frames.

Additional frames with taller mounting arms for the middle location were designed as some spools would make contact with the cross bar. 

Frame_Middle_5mm_extended.3mf 

The 5 mm extended frame fits into the RepBox, but might be tight. 

Frame_Middle_4mm_extended.3mf

Updated the screw to more tightly secure the base to the rods in the RepBox.

screw_v2.3mf

Thanks to Morpheus31@Morpheus31_120960 for testing and feedback on the new parts.

Complete_end_cap_set_V3 (No supports print for larger support plate)

I made an extra design to remove the need for supports for the extra large end plate. It improves the overall finish of the piece. Some assembly required but it should click in place. 

UPDATE 7/5/2024:

Added some extra washers/improved designs

I have updated the lock washer for the Prusa spools to be slightly wider incase there are slightly different spools with a similar diameter.

modified_lock_washer_for_prusa_spools

Improved wing_nut_v4_60mm.3mf to be less sharp and easier to handle new part:

Extra_wide_thin_washer_for_wide_spools

Added a whasher for creality spools

lock_washer_for_creality_spools

Finally added a washer for Prusa refil spools: 

lock_washer_for_prusa_cardboard_refill

Currently untested for the cardboard refills as I don't have any refill spools, will confirm if it works when I have one, but sharing it anyway for feedback. 

Currently tested for the smaller 400 g spools that come with a MMU3 upgrade kit. Pictures included.

Again recommend printing with 0.1 mm layer height due to the threads and overhangs.

UPDATE 7/20/2024:

extra_wide_thin_v4-original_style

Included an original style lock nut just incase anyone prefers this look for extra wide and large ID spools.