Chain and sprocket mechanism

Why you should print it:

• The assembly is very easy and only requires one drop (more like a dab) of glue

• There is an ergonomic grip and handle to maximise rotating speed

• It can be printed on an a1 mini and has a very portable form factor

• I iterated the gears and chain several times to reduce jamming

• It's very satisfying (in my opinion :))

   

Print settings - if you use a different slicer to Bambu Studio, follow these settings:

• Disable prime tower for the handle colour change

• No supports

• Keep the layer height at or below 0.2mm so that the screw threads can be printed to a high quality

• Paint brims under each end link for the chain (see picture below)

Assembly guide:

For a visual guide, see the gifs at the top of the page.

1. Rotate each link in the chain so that it can articulate. You'll probably need pliers to free the two end links, but be careful not to crush them when gripping them with the pliers.

2. Rotate the chain into a loop so that the side on the build plate is on the outside. Use a dab of superglue on the dovetail joint where the chain needs join and push the dovetail pin into the socket. I'd recommend using a cocktail stick or something similar to apply the glue to avoid gluing your fingers or jamming the chain.

3. While the glue is drying, rotate the square axle in the base and the rotating cylinder in the handle to allow them to freely rotate.

4. Once the glue is dry, insert the gears into the chain one after the other, making sure the teeth are meshing with the chain.

5. Pick up the gears at the same time while keeping them apart so that the chain is taut and doesn't fall off. Place the gears onto their respective axles on the base part. 

6. Put the top part on, making sure the big hole goes on side with the longer axle. Screw one of the nuts onto the shorter axle

7. Put the handle on the longer axle, and tighten the second nut down over it.

    

8. FINISHED! It may feel a little stiff at first, but it should be buttery smooth after a few turns of the handle

Troubleshooting:
1) If there are a couple of printing errors or minor breaks (similar to the picture to the right) in the chain then it'll probably still work, so test it with the full assembly before reprinting

2) If your parts are jamming and there are no visible errors them (e.g. stringing, splits, heavy warping), it will probably be due to tolerancing errors caused by differing printers and environments, so comment if this is the case and I'll add more print profiles with different tolerances.

3) For general errors or adhesion issues, make sure your filament is dry, keep your build plate clean, add brims, and switch to a cool build plate (if you have one).

4) If your issue hasn't been covered above or hasn't been rectified by the advice, comment describing what it is and include a picture if possible.

I hope you enjoy it!