Well Windlass

For our second project, my partner, Tiffany, and I had to build a well windlass that could span 12cm. We needed to be able to hoist a 1 liter bottle of water 10cm above the top of the tables with one hand. The structure had to be stable and be able to lift the load easily. We were also only allowed to use 500 cm^2 of delrin, 50cm of delrin rod, and 120cm of string

We started the project by brainstorming various well-windlasses that would work.

There were various ideas, but we decided on this one.

The idea, called Crank, is that there are two triangular bases on both sides of the table. The delrin rod goes through two of the bases and has a handle attached to it. The delrin could then be rotated so that the string would wind around the delrin and pull up the bottle.

However, we soon realized many flaws with the plan. The delrin rod was not going to be able to support the weight and the bases were going to use too much delrin. Instead, we modified our idea to have rectangular bases, with only two of the sides actually in place and we added a rectangular delrin casing for the delrin rod for added support. In addition, we made the handle longer on both sides for easier turning. Our final model looked like this.

Our next step was to make a physical mock-up out of foam core.

We changed the handle to a rod eventually because we found that it would be easier to turn the handle with one hand that way as opposed to a circular handle. After, we needed to make each piece of our design in solidworks. We started by drawing out all of dimensions we would need, including test pieces.

We then made up all of the pieces we needed in solidworks. When everything was to our specifications, we made a drawing of the solidworks.

We started by cutting out test pieces to make sure all of our notches would fit into each of our holes. When we got the test pieces to fit correctly

We printed out our final project. The first thing we noticed is that our notches in the bases were too small to fit the delrin rod casing, so we changed the dimensions on solidworks and printed out new delrin bases. We also noticed that some of the pegs in our delrin rod casing did not fit into the holes. This was because the laser cutter needed to make two passes to cut the delrin, so part of the delrin would melt. We fixed this by sanding down the pegs and then the rod fit together very nicely. We put the delrin pieces together.

My lovely partner demonstrating our Well Windlass!

We tried it out, and it worked (thought it was a little shaky)! It lifted the piece without too much difficulty. 

Engineering Analysis

We picked this design because we thought that the delrin rod casing would prevent the delrin beam from bending and allow for the delrin rod to pick up more weight. We also tried to make the base wide enough to support the height of the base without using too much delrin. We attached delrin squares in between the two sides of the base to strengthen them. These design implements were important since we could not control the material that we used.

However, the windlass was not as sturdy as we hoped it to be because the notches that held the delrin rod casing in place to the base was not tight. Therefore it did not hold on to the rod casing tight enough to make the rod casing stay in place

Materials Usage

Delrin Rod Casing: 2cm x 22cm x 4 pieces = 176 cm^2

Bases: 12cm x 4 cm x 4 pieces= 192 cm^2

Base Connecting Pieces: 4cm x 4 cm x 2 pieces= 32 cm^2

Handle: 1.5cm x 20cm= 30 cm^2

Total Derin: 430 cm^2

Delrin Rod: 27 cm

We used Delrin of width 3/16 and inch.

Summary

1) Brainstorming many different ideas

2) Choosing the best idea

3) Making the piece out of foam core

4) Iterations while making the foam core- We realized that it would be impossible to make pieces fit or sturdy enough in 3d.

5) Making the pieces and test pieces in solidworks

6) Laser-Cutting Delrin test pieces- We used smaller pieces of delrin to make sure the holes and pegs would fit together correctly

7) Iterations to the test pieces- We had to keep changing the dimensions of the pieces until they fit snugly together

8) Print out the whole piece

9) Reprinting out some pieces- We realized that some pieces didn't fit together, so we needed to change the dimensions and try again

10) Putting the piece together- This involved filing down some pieces as they melted in the laser cutter.

11) IT WORKS!!

Results: In class, the Well Windlass lifted the bottle, but it was pretty shaky while doing so. I believe this is because the Delrin rod casing was fit too loosely into the notches on the bases. It might have been better to heat stake or piano wire the pieces together to make them sturdier. I might have also improved the design by making the delrin rod casing smaller so the delrin rod would have fit better in the casing.

I also would like to experiment with completely different ideas as they seemed very sturdy in class.