The screw hinge model is much tighter than the filament hinge version and will be more difficult to actuate the hinge. Keep that in mind while deciding which version to choose.

It would be impossible to improve on the original creator's description:

This uses a bondtech style gear set to push the filament, similar to a Prusa Mk2/Mk3 extruder. Along with a battery, a reed switch, and a mid-RPM gearmotor, it can push or pull rigid filament through a bowden/PTFE tube with ease and quickness. One user has even tested TPU successfully!

To use, just line up the filament with the oblique teeth of the gears and clamp down on it. It doesn't matter much how the motor is wired. If it pulls when you want it to push, just flip it over (rotate on long axis). You might need to apply a little extra pressure on the lever arm while using it to prevent the filament from slipping, especially as it gets further along the PTFE. 

Note that if your filament has multiple kinks in it such as from storing the tip in the side of the spool, or messy winding, that there may be too much resistance for the BSL to push it all the way to the tool. The straighter the filament is, the smoother it will load, but you probably already knew that, eh? :) Also, a 500rpm (@12v) gearmotor is slower, but has more torque for longer runs and/or bent filament.

Bill Of Materials

NON-affiliate Amazon links provided by original creator

1. GA12-N20 500rpm @12v gearmotor
2. MK3s+ style Dual Drive Gear
3. Hinge Lever Momentary Push Button Micro Limit Switch
4. 9V Battery Clip Connector (original creator's link is unavailable so I found an identical item)
5. Optional: 9V Rechargeable Battery

AliExpress links (verified 9/4/25… sometimes it will say page not found but if you refresh the page the item will load)

1. GA12-N20 500rpm @12v (make absolutely sure you select correct RPM and voltage!)
2. MK3s+ style Dual Drive Gear
3. Hinge Lever Momentary Push Button Micro Limit Switch
4. 9V Battery Clip Connector
5. Optional: 9V Rechargeable Battery

You'll also need 3 M3x10mm socket head cap screws to hold it together, or whatever you have that will work with the provided screw holes. Oh, and probably a piece of wire or two, some solder, and a soldering iron. And a 9v battery. And a screwdriver. ;-)

Check your switch to make sure it's like mine, but the two contacts nearest the hinge point are what I used to make the connection when the lever is pressed down. Use a piece of filament as the hinge pin. Drill or ream out the holes if needed, then melt the ends to keep it from working itself out. The new screw hinge option is designed for M2x8mm socket head cap screws, but something close in size would probably work fine, so long as the lever arm is secure and rotates easily.

Assembly Guide by Teaching Tech

REMIX NOTES:

To remix the model I changed the top pieces to have smooth faces so that you can include whatever logo you would like on them. I also integrated the arrow indicating motor direction into the model so that it can be printed with AMS without having to print an additional piece that is glued on later however YOU MUST BE SURE WHICH DIRECTION YOUR LOADER IS FEEDING BEFORE PRINTING. If your motor is turning the opposite direction, I have included a plate with either top on which the arrow is facing the other way.

Each plate (excluding the arrow) is a complete project that includes all the printed parts that are required to build a speed loader. 

Thank you so much to @MrFlippant for such an amazing project