Furled Leader Twister

This is a mostly 3D printable leader twister allowing you to make your own furled leaders. 

• Printed BOM:
  • Baseplate x 2
  • Sun gear x 1
  • Planet gear x 4
  • Hook adapter x 4
  • Table mount x 1
  • Static end base x 1
  • Static end taper x 1
  • Post Base x 1
• Hardware
  • Bearings (16mm OD x 5mm ID x 5mm thick) x 12
  • M5 bolt 35mm thread length x 5
  • M5 locknut x 10
  • M5 washer x 16
  • Teacup hooks x 4

I designed this using hardware that I had on hand. I had a lot of bearings left over from 3D printer parts. You could also use simpler metal sleeves (that would require redesigning the baseplate). I tried an all 3D printed version of this twister but the plastic parts would friction weld themselves together. 

See the attached pictures and CAD assemblies for more detailed views of the device. In essence the twister has a central sun gear surrounded by planet gears. Each gear is mounted using bolts and bearings. The order of components goes as follows:

Bolt>washer>bearing>baseplate>2 washers>nut>gear>nut>washer>baseplate>bearing>washer>hook adapter>hook

This unit is repeated 4 times for each planet gear and once for the sun gear. The gears all get nuts press fit into them (the first nut in the sequence) and then are secured by the second nut. Originally I used captured nuts in the hook adapters but in the most recent version I have simply used 3D printed threads.

There are holes in the corners of the baseplates that correspond to holes on the table mount. This allows the twister to be secured to the bench top. The holes are sized for ¼-20 bolts. I used them mostly as pins rather than securing the bolts permanently. 

The twister allows thread to be twisted in the same direction facilitating the furling process. these threads are anchored on the static end. The static end is designed to have a stationary hook mounted on the opposite side of the bench but at the same height as the two middle hooks. I used a tapered mandrel to hold the hook and tension is set by hanging weights that are draped over the back of the mount supported by bearings. As you twist the cords the length of the cords shorten. The mandrel is pulled from the base while tension is maintained by counterweights. 

This video explains the process of making furled leaders and will help illustrate the functions of the components in this design.