Well Windlass

Coming into this project, we were given very specific tasks that our windlass had to be able to complete:

1. It had to be able to carry a water bottle from the ground to the height of the table
2. It had to be able to fit across a gap of 12 cm
3. It had to be able to carry the bottle up in less than 30 seconds
4. The total amount of material used had to be within 500 cm^2 of delrin sheet, 50 cm of delrin rod, and 120 cm of string

My partner, Chloe, and I started off the project with a few ideas in mind that we definitely wanted to incorporate. Firstly, we decided to orient the windlass in a way that our crank and handle was positioned over the gap so that

1. we could minimize the shearing that would occur when we would be cranking the windlass
2. we could allow more room for our had movements

Notes and sketches of designs before creating foamcore and solid works models

In the process of creating our design we first made a foam core model to be able to visualize how all the parts would sit together and how the weight might be distributed. During this process we decided that it would be most efficient if we cut the 50 cm delrin rod we were given into 4 seperate sections, two pieces would be used to brace the mounts, one would be used as the main support to hold the weight of the bottle, and one would be used in the handle.

Foamcore model

Before finalizing our solid works designs for the main components, Chloe and I decided to test out the different sizes and tolerance of the laser cut machine in order to create almost perfect push-fit bushings in order to prevent any unnecessary movement of the parts.

Solid works design of peg test sheet

solid works design of slot and bushing test sheet

We decided on creating mounts for the crankshaft that were triangular in order to provide the most amount of stability and weight distribution. In order to prevent shearing, we decided to outfit the mounts with two push-fit bushings around the midpoints of each of the legs, as well as designing the feet of the mounts to also fit inside a push fit slot along the base.  We created into the design a loose fitted bushing into the top of the mounts in which one of the delrin rods would sit while we cranked the handle and pulled up the bottle. We did not alter the design of our mount much since after the first prototype we found minimal flaws in our design and found it to function incredibly well.

Solid works design of mount

We then designed a base where the mounts would be able to fit into push fit slots to reduce shearing. We initially designed our base to be a rectangular frame which would fit two of the mounts into it, however after testing out our first prototype, we noticed that we needed to brace our windlass with once hand due to the entire structure sliding. So we decided to insert additional slots into the base that we then thermal pressed pegs into that would jut out of the bottom of the base and frame the sides of the desk.

Solid works design of base 1.0 without pegs

Base 2.0 with pegs thermal pressed

Next we design the spindle where the string would wrap around. We decided that it would be easier if we designed it to be a rectangular box with two sides missing in order to save material and make it easier to tie the string to the delrin rod. As well, we thought that there would be better weight distribution with this model, as the stress from carrying the bottle would be split between multiple points of contact rather than the one point where the string would be attached.

solid works design of spindle (part 1)

Solid works design of spindle (part 2)

Finally, we designed a handle that consisted of two delrin rods being attached to a long rectangular sheet of delrin in order to make it easier to turn the crankshaft.

solid works design of handle

While testing our first prototype we noticed some slipping of the delrin rods push-fitted into the bushings, so we decided to thermal press the rods into the handle to prevent any slipping. We also noticed that the crankshaft would sometimes slip from the loose-fit bushings on the mounts, so we designed a push-fit bushing stopper in the shape of Navi, an annoying fairy from the Nintendo game Legend of Zelda to add a bit of personality to our design.

Final design of windlass (excluding fairy bushings and pegs)

In the end, we had around 40 cm^2 of left over material that we didn’t use. I am very pleased with the work Chloe and I did to make this windlass. We furthered our knowledge on how to use solid works and the laser cutter, as well as how to use the thermal press, which can be noticed in the quality of how the pegs were thermal pressed as they become progressively better attached and cleaner.