Days 6 & 7: A Bird is Being Born

A compilation of the final versions of the pieces we drew 

   The next days were filled with many exciting and puzzling events. We eventually settled down to a routine of drawing and re-drawing many SolidWorks parts and printing iterations. Our first goal was to build the mechanism that would move the hinge up and down. We had drawn the parts necessary for this and we put them all together. We tried, at least. The fits were not correct and we would need to do them again. We cut many pieces out of Delrin rod using the saw and built some muscle. We made ourselves a cubby from one of the little red boxes for Lego parts and put all our pieces in that. We had to reiterate all of our pieces, except the wings and the base. I got certified to operate the Laser cutter, which would become useful during the late nights we spent in the Engineering Studio.

The moving parts before the support parts were added

  The main problems we had were with the sizes of pieces and finding the right radii for the holes to achieve the desired fits. We also had a hard time finding the right size of washers. We ended up printing out 4 different samples before finding the perfect fit. Once we got the radius correct, we printed out about 16 of these. We thought we had more than we would ever need, but we were proven wrong quickly.

 

The wrong-sized support pieces

   Not having a Lego model became a problem at this stage as half of our model was in Delrin and half in Lego. After we had attached the wings to the now working mechanism, we started building the supports and the base. However, due to a lack of model, we horrifyingly ended up building our supports in the wrong plane, which made connecting them impossible. Not only were they on the wrong side but they were half the size we needed. We really depended on these pieces since they were holding up our normally loose wings and the wings were supposed to bounce off of them. They were forming the lowest level that the wings could go. This mistake was unacceptable, ridiculous, and hilarious.

Our bird with its foam case

 We did not get to correct this mistake and put our moving parts together with the support parts before our presentation. So we ended up building a foam skeleton in order to demonstrate how our bird worked. It was ugly and tilted, but it did the job.Our presentation was successful but not flawless. We agreed on meeting later to build its proper casing and finishing the assembly. With EJ's help, we also press-fitted some of the parts together with piano wire so that it could stand the drop test.

Here are the final results, with a video of our bird in action.

The assembly of our bird

Our actual bird: made out of Delrin and fully functioning

Our bird after being decorated by Marie: Everything looks prettier in pink

Day 5: From Model to Solidworks

  On Tuesday we were supposed to start building our birds on SolidWorks based on our Lego models. However, we weren't sure about either of our models. The first model wasn't reliable on creating a smooth flapping motion because it depended on gravity to move the wings up. The bottom parts of the wings that we would be pushing up with our mechanism would be falling down with their weight on the way back. We weren't quite sure if we were going to build this model or not. We then asked Lyn what he thought of our other model and he was concerned that it might not be robust enough. We had already run into issues with the tape that constituted our conveyor belt. Thus, we decided to abandon the second model and look for another mechanism that would allow us to control the upward motion, as well as downward, of the wings. We thought that attaching both of the wings on a hinge and moving the hinge might work better than hitting a part of the wing. We were given an example of a mechanism that moves a rod up and down. We were impressed and inspired by this design and started to draw our bird again, using this mechanism.

The piece that inspired us

A sketch showing the list of parts we will need and their estimated sizes.

The sketch of our mechanism with the Delrin rod connectors represented by dark  cylinders, used for choosing how to fit the pieces together.

  We tried to decide on the dimensions of our parts on our sketches. We also had learned about tight and loose fit that day, so we also specified what fitting would be loose or tight on our sketches. That made it easier to see where we would nee a washer and how many washers we would have to make, as well as what the radii of various holes in parts need to be.
  The last thing we did was to start building some of the parts on SolidWorks:

Day 4.5: Continuing With Wings On Friday

   After we were done with our bottle opener presentation on Friday, we started working on our " Bird Wings". We had been introduced to PicoCricket and different motions that can be achieved with Legos earlier. I still couldn't see how these movements could be translated to flapping. My partner Marie and I decided to look at the different gear mechanisms in the 507 Mechanical Movements for inspiration. Then, this little mechanism drew our attention:

   It was simple and straightforward; you turn a handle, a rod goes up. We started to think how we can connect the wings and attach this mechanism to make the wings move. We counted on gravity to bring the wings back down. Here is a sketch I drew:

Here are Marie's sketches:

    Both of these ideas are based on the assumption that the two wings will be connected and one rod will be moving their connection point. On the left, they are linked by a middle piece loosely and the middle piece is attached to the end of the moving rod. On the right, they are connected to each other and the rod hits their connection point directly. Another idea we explored -but that isn't represented by the sketches because we weren't able to decipher each other's sketches easily and started to show with Legos- was having two separate rods, attached each to one wing.We presented our sketches to the class and started working on two Lego models. By the end of the day, we had one working model that we used to compare one versus two rod mechanisms. We decided to meet up outside class to build a second model. Here is the result:

We used a conveyor belt to achieve motion but it's questionable to what degree it would actually look like flapping. We decided to see what Lyn thinks about it.

Day 4: Bottle Opener for Breakfast, Wings for Lunch

   Bryn and I met up early in the morning to finish our design. We ended up using the same file to combine our design because creating an assembly wasn't feasible at this point, since we had no idea how to do that. I rebuilt the four on her file and we finished up the 2. We turned it into a drawing and cut it out of Delrin. Here it is, being used by Bryn. Go Purple Pride!!!

Day 3: Bottle Opener & The Bird

  Tuesday started with a crash: My computer died! Me being me, I hadn't saved the four or the latest version of 0 and 1 anywhere, so there went hours of work. After accepting the final decree from the help desk that there was nothing else that could be done, I made my way to the engineering studio few hours early.
  My plan was to rebuild the four and adjust the one. Lyn was there and he suggested that we try out the zero by itself first, to see if our design works, before we build all the extra parts on something that may or may not work. While trying to build another oval attached to a rectangle for this experiment, we found out that there is an 'ellipse' template. Lovely! If only we had known that last week...

   
  So here is the part for the 'rectangularly handled elliptical bottle opener'. And it worked! Well, in the end. It needed a bit of filing because it was a little too thick but there was nothing majorly wrong with it. The dimensions were correct and the handle was comfortable.
  During class, we started a new project. Now, we need to build a mechanism that will move like bird wings out of Lego. We looked at different machines made from Lego and how they worked. Then, we partnered up to come up with 5 different designs. We're still working on that...

Day 2: Bottle Opener Cont'd

  On Friday, we started to use SolidWorks to design our bottle opener.
  We had watched a tutorial on building a part and we dived right in. Bryn and I shared the 2014: I was building 4, while she was making the 0. Problem: No oval in template. This meant that she would have to build the oval 0 using (lots of) splines. In the meantime, I was considering carving out a four from a rectangle by splicing and adding lines. After a few minutes of tinkering with a rectangle, I decided to start from scratch and build it using lines. We had to figure out how to define all the lines of our sketches. We also don't know how we are going to combine the 01 with 4 and then 2.
  This is how far we had gotten at the end of the day: