User:MurphyTC/ENES-100/project 3

My Instructor's user page which points to this.

My Tasks

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Progress

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Proposed Next Steps



My Tasks

Find and record data of peoples' arms

Find correlation of data

Begin construction of rotary seal

Progress Arm measurement data

The task given was to record data of peoples' arms for the blood cooler seal. The largest part of the fist was measured, as that needs to fit through the blood cooler. That same measurement needed to be found on the arm, and then the distance between that measurement and the fist measurement is what's recorded. Afterwards, a spreadsheet(shown right), shows the twenty participants from smallest fist circumference to largest, was created. Then the average and Standard Deviant was calculated using Microsoft Excel.

(The height and weight ranges were asked of the participants, as they may be relevant, but without definite measurements, said measurements are considered unreliable.)

Correlation of Data

If someone's fist circumference (x-value) measured at 28cm, one would find 28cm circumference on their arm, and then measure the distance between(y-value). The graph to the right of the spreadsheet shows the smallest to largest fist circumference in relation to the distance between the two x-values.

Rotary seal construction

No progress made

Proposed Next Steps


 * Determine what sizes to use for rotary design
 * Begin construction of the rotary design

My Tasks

Test Blood Cooler vacuum

Find & fix issues concerning airtight seal

Fully test Blood Cooler

Progress Vacuum Test

During the first test, the air pressure gauge was not moving. After some careful listening, a small "hissing" noise was heard, and it turns out holes that were made and sealed with glue by a previous team had re-opened. After fixing that issue (explained next), it was re-tested. It passed, so it moved onto the full test.

(On a separate note, there is one other thing worth mentioning: During testing, the Blood Cooler was a rather loose fit on the participants' arms. The idea of different sized cones had been implemented for the first time, and it is worth noting that if this design is going to be be implemented, it needs to be refined and/or revised.)

Vacuum Fix

The small holes in the Blood Cooler were previously sealed with some type of glue, for whatever reason, and that glue had stopped working as a sealant. The first image shows a quick-fix to the problem, and the second one is solid proof that it had indeed fixed it.

Potential issues

Having worked with the idea of cones for a few weeks, there have been some issues that have risen in practice, and some that may arise if someone follows through with this idea.

1.) Abnormal arms This is a problem that has persisted the length of the entire project. One of the people working on the Blood Cooler itself fits into this category. His fist is rather large, but his arm is rather skinny. A cone big enough for his fist to fit through would be too wide for his arm to plug the hole.

No solution theorized.

2.) Length of the cones A potential issue is the length of the cone pieces. In theory, a petite person would have to stack a bunch of cones together to get their arm to fit properly. At that point, their arm may not be long enough to even reach the vacuum component of the Blood Cooler.

Potential solution: Create shorter cones - a personal guess for an optimal cone length would be 5cm long.

3.) Not being airtight The concern with the AutoCAD design is that the parts may not turn out air-tight. 3D printed parts are hard plastic - they do not conform to the shapes of our arms. Not only that, but there could be gaps in between the plastic pieces, letting air seep through.

Potential solution: Wrap rubber around the lips of the cone pieces. This could potentially solve the issues, and would likely be more comfortable against the arm. (Another issue arises, however. Past experimentation with rubber on this project has ended poorly - usually with the rubber ripping.)

Proposed Next Steps


 * Make a full set of cones in CAD
 * Print out set of cones using 3D printer
 * Test design