Remodel of Pastamatic - Filament Spool Winder for Bambu Lab and Others

Edit 15-Sep-2025: A maker notified my that I posted the wrong motor, he was right. I am sorry for that. I corrected the right motor in the following description. It must be a ø8mm shaft with flat area, so-called D-type. Sorry for any inconveniences. ;  (( 
Filament-Guide was revised completely: Now is M3 Screw for fine adjustment of the filament track. After tightening the cam you will be able to fine adjust the track more to the right or more to the left. Therefore, a M3 screw a M3 square nut (like in Prusa used) of 1.8 x 5.4mm is used. Now you can adjust the cam and fine adjustment with only on M3 allen key, instead of M3 AND M4.

Edit 07-Sep-2025: A request from a maker was that the cams cannot be put far enough towards motorside, thus Sunlu / Bambu spools cannot be served on the motor side far enough. I added (see files directory) a V3 version that gains approx. 7mm, still bayonet version. Note that gear and axle are only applicable pair wise, don't mix them Versions V2 and V3. Version V4 has axle and 50teeth gear as one part, gaining total of 11mm, Both versions V23 and V4 should be compatible with Sunlu / Bambu spools now.
For axle and cams fitting too tight I grinded the axle a bit, so they slide over each other quite smoothly. A hair of coffee-machine grease would not hurt.
Created a derivate of 6b-Spindle_Male_NonDriven=(V2) for slightly different spool mounting. I expect a bit more space at the brake-contact. That was a bit tight depending on which spool I used.

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First of all I like to kindly thank @GekoPrime for his development of the base machine. Many parts are also used or were modified which based on @GekoPrime's design (“Original”). THANK YOU!

The stl-files in the files-directory show approx. 58 files! I tried to sort them i.a.w. the structure described below. Now describing the features of enhancements, improvement or just “my-style-wishes” which I realized:

1. Basic structure: Is almost same as original. I call them Main-Frame_Side A1-Structure, …A2… B1… B2…  A1 ist the side with motor mount, B1 opposite of A1, carrying the upwinding spool. A2 and B2 are on the unwind side, having the brake-system. Two different Crossbars (indicated with "Drive" and “Brake”, come under the beforementioned large pieces. The will be slided in from the side, this is a big change to the Original, as you now can screw the crossbars with aid of 4.5x1.8mm square nuts which will be slided in into the provided holes. 
   STOP! No you should make a little sidestep to the section “Brake”. Assemble the brake spindle and sides, the return back to this place! With that said, you do not need to dissassemble the crossbars again.
   Four screws M3x20mm are used for the fastening. Btw. I preferred this method to the Original as the machine will be much more sturdy. Also I glued the frames A1+A2 resp. B1 and B2 with glue together, aligned, used clamps and let the dry over night. 
   14 ball bearings type 608 are used to be positioned into the provided places. This can be looked up in GekoPrimes post. Nothing changed until how to secure the ball bearings. 
   Use the quick and dirty solution of the original or my redesign. My redesign consits of: 
   A)   Axle1 (4x) and Axle2 (4x)  used for one front, two rear and leadscrew bearings in connection with the reinforced SpindleClip. Axle1 is for the fixed hinge, Axle2 is for the opening hings. All Axle1+2 come with a fastening clip. (Axle1_Clip).
   B)   Axle3 (3x) is for the gearside to fasten the bearings, come also with the Axle1Clip. 
   C)   Axle4_Cam is for the large gear.
   D)   Axle5_Motorblock is the axle for supporting the motorblock, comes also with an Axle1Clip. 
   How to arrange the clips and axles see the photographs!
    
2. The gears are arranged like described in the Original. Just watch the related YouTube Video of @GekoPrime and you'll understand it immediately. Better than a thousand words. As for the gears you should print one more of the 20Teeth gears, in total 6 instead of 5. One Extra! I describe later.
   For the motor I used a DC gear motor 12V 250rpm. Source "Amazonas".  
   
   
   
   
   
   
   For fastening the motor to the structure, in regard to obtain main designs of the "Original" I used two M10 hexhead screws (heavy stuff!!)  with M10 nuts. Length of thread 35mm or larger. Use some threadlock before you fasten the screw and nut too tight, as the gears will not move then. 
   The “2b-MainFrame_SpindleLock” part is simply hinged with a piece of PETG filament. Make sure it swivels easily. Use ø8x4mm Neodym magnets for a certain locking effect. MotorMount I printed lying flat, nose for the magnet showing up. The hole for the magnet is recatngular at the upper side, so you can eaysily insert the magnet during print pause. …"SpindleLock" gets a Neodym Magnet same size, this part is printed with “fork” showing up. So the magnet is inserted while part is lying on its back.
   MOST IMPORTANT thing is to check the polarity of the magnets before inserting. This could be helpful: https://www.printables.com/model/671057-north-and-southpole-of-a-magnet 
   If you do wrong, then sacrifice a new …"Spindle Lock". Also important: When you have inserted a magnet, use some glue so the printhead / nozzle don't fish the magnet out and you wonder about a non-magnetic effect. Happened to me, LOL. Wrong polarity happened to me also, LOL.
   Maybe this sketch helps:
   
   
    
3. The brake has been re-engineered, a spindle is screwed in in the “Brake_Nut for Lock”. Pay attention: One spindle left winding gears, the other right winding. Assemble the two sindles into the “Nut for Lock”. Spindles go in until half, then they stop! Don't use too much force. A drop of glue may help to hold them together. I never took them apart afterwards. 
   Screw the double-spindle into the holes of the “Brake_Side_L and -R (from behind left and right). Screw in one side until spindle comes ”flush", the screw in the other side (other turning direction). Get used to it! 
   Best is now to slide this correctly oriented over the crossbar (indicated below "Brake") and slide this into the Main-Structure “A” or “B”.
   Slide in the TPU Brake Flaps. I printed them standing position for better stability, therefore, I added some support structure, which you just cut off.
   Install the lever for the Nut-Lock by using two M3x14 or 15 and two square nuts M3x4.5x1.8mm. 
    
4. Leadscrew: This is the most modified part. Instead of one sturdy axle with 50teeth gear I divided this into pieces:
   -  Gear 50 Teeth with bayonet link.
   -  Hexrod with bajonet link, which goes into the 50 teeth gear.
   -  Opposite side a roll with hex core supports the rod and runs on the ball bearings, freely in length direction.
   -  Leadscrew block has the key (for cam), which is locked from underneath be a new part, this is a sqaure with ring cutout. First print the ring (here: Prusament Orange PETG), then print the black square. Before closing the lid (printer prints a bridge) you make a print pause and put the orange ring in, then continue printing. Matching shapes in the leadscrew block help the black square with orange ring to snap in and stay in place and hold the key (for cam) in engagement position.
   -  On top of the leadscrew I drilled two additional holes, right and left, in order to quickly reposition the PTFE tube without changing the cam position, if it fits….?
   - A further development is the rolls under the leadscrew, they had 2mm "air" till bottom, all this played a certain (more or less) roll for some misalignments. Maybe the rolls that are now easily touching the bottom help for some improvement. But you can also use the old leadscrew-block.
   -  On top another guide that I promise myself a better and stable feeding of uprolling filament, instead of flipping right and left too much. Maybe this helps, it is experimental status yet.
   -  Now the crucial change of the machine besides the motor: I created a couple of cams, indicated with numbers like 32, 35, … 52, 58. 60. 62. 64. Those cams are provided for different spool widths. So in case you need to wind up a filament on a smaller spool with e.g. 40mm instead of 60mm, just exchange the cam, adjust the position, then fasten the screw for secure hold on position and wind up. At this stage I cannot exactly say, whether a “60-cam” is best for a 58mm inner width spool as there are system based tolerances that have big influence. 
   I honestly spent over a hundred hours of engineering, printing on top and spent kilos of filament
    to reach this stage. Now I am tired with this project. It works, and maybe YOU need to figure out, which cam-width runs best for which spool-width. 
   - To change the cam is easy: unscrew the screw of the cam, disconnect the hex rod-bajonet CCW some degrees, open the spindle-clip and take the leadscrew-system out. Take the black square with orange ring out, then you can cautiously take the cam out, don't lose the key (cam)! Put another cam in and put the key back and lock with the black square (LeadScrew-3-Cube.stl). Now put the “HexAxle-Bearing” back on the hex rod, insert the hex rod back into the bajonet and lock it in, close the spindle clip. Now drive that the cam reaches on left or right turning point and pre-fasten the cam screw. Drive to the other side and check the distance of both end positions, balance it out if needed. Now you are perfectly ready for your next spool. 
   -  Usually the first 2-3 layers I achieved perfectly, then because of unrolling or misalignment it got worse, but in all of my cases it was good enough for seamless usage in my printers.
    
5. DC-PWM Control: I used this one:
   
   
   
   It is built in in a small cabinet. Holes for screws therefore are prepared. I just put a bit thin foam underneath the controller. Trick: The axle “MainFrame_PWM-Box-3-AxleTopPWM.stl” is inserted from behind (from the cabinet towards the holes. Open end showing to the inner of the machine, this hollow axle is slided over the PWM potentiometer! 
   
   
   
   This axle holds the ball bearing of the gear in place and comes out of the frame. Part “2-MainFrame_PWM-Box-4-HubToPWM” is press-fitted to the 20-teeth-gear which we printed additionally, this sandwich is fastened with a screw to prior mentioned axle. Thus the gear operates as operator knob. This came out of my fantasy. LOL.
   
   
    
6. Power Supply Unit PSU: 
   I used a Meanwell PSU Model DR-15-12
   
   A case where this fis in is also attached. I had this PSU. After one or two rolls upwound it gets a bit warm, so for 24/7 opertion this is maybe not the right size. The motor as well, btw.
   As you can see, my cable management is still WIP. 
    
7. Operation
   If you run the machine, do not really fasten the brake too much, as the motor is not the strongest AND a too tight filament roll may cause problems, like too loose too.
   Set the rolls up, adjust the brake, it is "swimming" so same brake force is applied left and right. You can adjust the force during running also by turning the knob. This is an advantege of a spindle that runs left and right different drives. I mentioned it already before.
   Before staring you need to flip the magnetic held flap over, note that the strength is not very high, but I think it does what needs to be done. In case of any motor problem you can use the Original Screw part (Soindle Male Driven) with your cordless or cordfull drill.

I hope I haven't forgotten anything, it was a long journey till here.

Have fun with this solution, happy printing!

Explore my other Printables: https://www.printables.com/de/@Tritschi 

Revisions:

2025-08-30: parts “2-MainFrame_PWM-Box-3-AxleToPWM_V2.stl” and “2-MainFrame_PWM-Box-4-HubToPWM_V2” replace earlier versions. Now hex-shape instead of round. Better grip for PWM-poti.

2025-09-02: 
A) Added revised Lead mechanism, can be exchaned against prior one without problems. Features lateral correction with M4 screw for fine adjustments. 
B) Revised the 90 teeth gear bajonet for better hold, slight improvement. Use either pair exchangeably.
3-Gear 50Teeth_Bayonet(V2).stl  AND  4-HexAxle_Bayonet(V2).stl
C) Added 5b-SpindleClipReinforced_L.stl  AND  5b-SpindleClipReinforced_R.stl for holding the HexAxle better down, gives less distortions of filament movement
D) 8-Axle4_Cam(V2).stl holds 90teeth gear better in place, just exchange.

2025-09-15: Motor type was corrected. I earlier declared the wrong motor type. Must be ø8mm “D” shaft.

Developed for a DC-geared motor. Many improvements, many new features, see description.