User:Klcooper11/weeklyupdate2

Project Preference
1. MakerBot

2. Smart Shoe

3. Hallway Robot

Problem Statement
Determine a value for the modulus of elasticity for PLA and discover which factors have an effect on it.

Project Plan
Week 1: Determine if and how the color of PLA affects modulus of elasticity.  Week 2: Determine if and how fill direction of PLA affects modulus of elasticity.  Week 3: Determine if and how temperature affects modulus of elasticity.  Week 4: Determine how there variables affect PLA's yield stress and ultimate stress.

Week 1 Narrative
My goal this week was to dry run a 2 point test and complete the 3 point test for the red beam.

3 Point Test
Dimensions: L = .189 m  w = .0099 m  h = .0052 m

Beam Color: Red

Beam Fill Direction: Cross section L x w

I set up the test according to the directions on the procedure (https://docs.google.com/document/d/1TwFxADqyHYukzMuZ9NvqfPN5nt1JfFwynR5VVa8iXDg/edit3 Point Bending Test Procedure. During the procedure the objective was to add weight in increments of 200g until you reached 1450g.  At each increment you would mark the slip of paper to record the data of how far the beam is being pulled below. After all data is collected you are able to get the calculations below.

2 Point Bending Test
This week would be the first time for me to test the 2 Bending Procedure that I designed last project cycle. I was able to construct a beam with the dimensions of L = 280 mm w = 10 mm and h = 5 mm. I used the drill press to drill a hole into the beam for the weights to hang property. The plan was to use the 2 Point Bending Procedure 2 Point Bending Test. I started with 10 lb weights and would increase to by 10 lbs until I reached 30 lbs Then after reaching 30 lbs I would increase by 5 lbs. There was still no visible deformation to the beam. Once I reached 50 lbs the beam became unstable to the surface that it was attached to. I tried this experiment several times but the tools I had available to me where not conducive to what I needed to achieve with the procedure. So next week cycle I need to find a better way to make the beam more stable against the surface while testing the 2 point bending test.

Week 2 Narrative
2 Point Bending Test

This week my goal for to complete the 2 Point Bending procedure that was drafted last project cycle. I was able to setup in the engineering lab at campus. I also had the assistance of Samantha Small with the project as well. During the first test I started with a 10 lb weigh and hung it on the setup. Then we increase the weigh to by 5 lb increments until we reach a 25 lb mark when the beam had reached it stress point.



I didn't expect the beam to reach it stress point at 25 lbs because of the previous test that were done at my home. I think by the beam being used multiple times might of effect the strength of the beam. It easily snap when placing the 25 pound weigh on the beam.

Then I decided to test the shorter part of the beam with the 1 kg that were available in the lab. Again the 1 kg of weight was place on the beam and increased by another 1 kg. That would equal a little over 4 lbs of weigh. I think the testing again was again a little faulty because of the different results I received. My goal is go back and re-access the 2 point test. Hope to make another bean this upcoming week to complete the 2 point bending test.

3 Point Bending Test

Also this week we decided to retest each beam to collect enough data to statically analyze the affect of color on PLA's modulus elasticity. The test was done in the engineering lab as a group. We were able to test each beam and collect data as need for each beam.

Beam Dimensions: L= .189 m   w= .0099 m   h= .0052 m       Beam Color: Red            Fill direction: L x w cross sections



Week 3 Narrative
This week's goal was to test the cross section of the beam. Each beam can be created in a different directional pattern.

Beam Dimensions: L= .19 m   w= .01007 m   h= .00505 m       Beam Color: Blue           Fill direction: L x h cross sections





Week 4 Narrative
My goal this week was to correct my previous calculations for the 3 point bending test in week 3. My teammates and I discovered that my deflection of the beam was higher than Seth Vinson. Seth Vinson and I performed the same 3 point bending test on the same beam. We remeasured my deflection on the data I collect. In the measurements the average deflection was measured incorrectly.

I perform the entire 3 point bending test over and had much better results. I believe that he height of the experiment placement effected my results due to incorrect levels what I can see when placing my markings. I move the experiment to a better height and position so my marks would be more precised. After my experiment my measure where pretty close to Seth Vinson data which concluded that the experiment was done correctly.

Beam Dimensions: L= .19 m   w= .01007 m   h= .00505 m       Beam Color: Blue           Fill direction: L x h cross sections

My results went from 2.917 Eavg to a 2.415 Eavg