Abstract Our Senior Design project was based on the design and manufacturing of a devise capable of testing the physical properties of the main housing of an AR-15 modern sporting rifle. The main housing of an AR-15, as well as any other firearm, is known as the lower receiver; the lower receiver houses the springs, hammer, trigger and magazine. As a third party, we were commissioned by Lively Machine to test the physical properties of these lower receivers that the shop was producing. The purpose of the design of this devise was to test the tensile properties of the components upper receiver attachment pin holes. We also performed a compression test on another critical component of the lower receiver, the magazine well. The newest design in the firearm industry calls for lower receivers to be made from magnesium, as opposed to the old models of aluminum. We will display the data we received from the tensile and compression testing of the magnesium component, and then compare it to a theoretical testing of the currently used 6061-T6 Aluminum Alloy.

The Modern Sporting Rifle There are many widespread misconceptions about the modern day sporting rifle also known as the AR-15. The most popular misconception is that the AR-15 sporting rifles are military grade weapons, this is a false accusation. Cosmetically the AR-15 sporting rifle is nearly identical to its’ military counterpart the M16, the functionality of the sporting series is much different. A military grade M16 is a fully automatic rifle that will disperse rounds as long as the shooter is holding the trigger making it the modern term of assault rifle. The AR-15 sporting rifle is a semi-automatic rifle dispersing only one round each time the shooter pulls the trigger, this means that this firearm cannot be classified as an assault weapon and is available for civilian ownership. Not only is the AR-15 sporting rifle completely legal to own in all 50 states but it is among the most popular firearms on the market due to its modular platform and ease of customization. The modern day AR-15 sporting rifle is a lightweight, 5.56 mm, magazine fed gas operated semi-automatic rifle. It is currently manufactured out of aluminum alloys which are the successor to the previous steel made models. The current AR-15 design comes from its predecessor the AR-10 developed in the early 1950’s by Eugene Stoner for the Fairchild ArmaLite Corporation. The AR-15 was designed as a smaller caliber, 5.56 mm compared to 7.62 mm, lighter weight version of the AR-10. ArmaLite patented the design giving credit to Eugene Stoner and naming the rifle AR for ArmaLite Rifle. In 1959 ArmaLite sold their rights to the AR-15 model to Colt Industries. Colt took this design and began to market it all over the world, making a strong pitch to the U.S. government. In the early 1960’s the U.S. military adopted the AR-15 design, renaming it to the M16. The design was modified and made automatic and first used in the Vietnam War by our military. The design was chosen because of its lightweight and short range accuracy characteristics for jungle combat. Colt also began to market the semi-automatic AR-15 version for civilian use. Colt, being a household name in quality firearms, made the AR-15 one of the most popularly owned civilian big game hunting rifles in the world.
Project Conception The idea for our project came about from our Academic Advisor Keith Benedict. Having strong ties in Evansville in both the machining and firearms world, a project was presented to him and passed on to us. Jeff Hoefling of Lively Machine in Evansville, Indiana was commissioned a project through a local firearms component distributor out of Newburgh, Indiana called MAG Tactical Systems LLC. MAG Tactical is a local manufacturer and distributer of firearm suppressors as well as the AR-15 lower receivers’. The lower receiver of an AR-15 is the most key component of the firearm without it you have nothing but scrap metal. This lower receiver houses all of the key components of a firearm including the firing pins, springs, trigger guard and trigger, as well as the magazine. Because of its important nature in manufacturing a firearm these components are highly regulated by federal law and must be serialized. Each receiver has a unique serial number imposed upon it and is registered with the ATF for monitoring and tracking of the firearm. Currently MAG Tactical die-casts the AR-15 lower receivers from high strength lightweight magnesium. MAG Tactical’s end product was then being sent to Jeff Hoefling of Lively Machine for finishing touches and serialization of the product. Jeff was in charge of taking the component and doing some simple yet intricate machine work on the pin holes, spring housing, etc. to get the receivers to their finished state. While these were simple enough tasks no physical properties were known of these newly made magnesium receivers. Jeff knew that Mr. Benedict had the capabilities of running such test asked if he could be of assistance, which is where we came in.

Designing Our Mechanism When designing such a customized mechanism as our tensile tester we had to be sure to truly measure twice, cut once. Our design hinged upon not only the design of the lower receiver obviously but also the universal tensile tester located in the BE building. Using these two things as our guideline we were able to come upon a strict set of specifications on which to design our mechanism. When looking at the lower receivers specifications we were lucky enough to have acquired a detailed SolidWorks file that we could pull proper measurements from. This was provided by our industry advisor Jeff Hoefling in order to aid us in the task commissioned by him. The drawing we received was not pre-dimensioned, so we were required to go back and use the skills that we had acquired in SolidWorks in order to acquire the dimensions necessary. The biggest things that were looked at were the overall length, width and depth of the lower receiver to know the minimum allowance needed by our mechanism. We were able to find these dimensions to be 4” x 7” x 2”. From this we were able to find an approximate starting area to work with of 56 in2. The next major component of the lower receiver that had to be dimensioned was the upper receiver attachment pin holes or what we called the “ears”. We determined these to be the major component which we were to test and so accuracy was of the upmost importance. The measurements given to us from the SolidWorks file was the finished inside diameter of the ears were 0.25 inch inner diameter. The third and final crucial dimension was that of the inside of the magazine well of the lower receiver. We knew that in the design process that this component of the receiver would be crucial in getting a proper pull on the ears by placing some sort of a support through the magazine well to keep the entire receiver straight during testing. The original design called for a simple thin support going through the middle of the magazine well that would as said before act as a counter pull to the force of the tensile tester upon the ears of the receiver. Upon further consideration it was decided to go in an entirely different direction and make the piece of our mechanism that went through the magazine well to be as big as we could make it. This was decided because we determined that the closer our tolerance was to the actual dimension of the well the less room the receiver would have to move during testing. And because the receivers were in limited supply factors such as these had to be made with the upmost care. The dimensions of the magazine well and insert to be used were found from the SolidWorks file and found to be, 2.398” x .890” x 4”

Figure1-1: Lower Receiver Bottom View
Figure1-1: Lower Receiver Bottom View
Figure 1-2: Lower Receiver Side View
Figure 1-2: Lower Receiver Side View

2.398”
2.398”
.890”
.890”

0.25”
0.25”

Figure 1-3: Enhanced View Receiver Magazine Well
Figure 1-3: Enhanced View Receiver Magazine Well
Figure 1-4: Enhanced View Upper Receiver Attachment Pin Holes “Ears”
Figure 1-4: Enhanced View Upper Receiver Attachment Pin Holes “Ears”

Now that we had all of the dimensions needed from the lower receiver itself we had to look at the universal tensile tester and determine the key dimensional issues that we would face during testing. There were many things that we looked at within the tester itself such as what pieces were available to us prior to creation of our mechanism, the thickness of the pulling plates of the tester, the manner in which devises are attached to the tester and the maximum length that the tester’s plates could spread. One of the first things that we noticed was how our theoretical mechanism would attach to the bottom plate of the tensile tester. There is a circular indention under the bottom plate which will hold any piece of testing equipment that can be used. Available to us were many circular fittings of different sizes that would allow us to secure the main portion of our devise to the bottom pulling plate. We decided upon the fitting that had a one inch hole in the center of it to base our design on because we initially intended on using a piece of 3/4 inch all thread rod to go through the opening of the bottom plate of the tester to secure our mechanism. Next we focused on the thickness of the bottom pulling plate of the tensile tester. We found our minimum distance from top to bottom to be approximately 9 full inches. Knowing this we could determine the length of 3/4 inch all thread rod that would need to be sued to allow for maximum securing of our mechanism to the bottom pulling plate. Below are the initial photos taken that have been dimensioned giving us our usable specifications of the tensile tester:

7”
7”

Figure 1-6: Tensile tester Equipment used to anchor mechanism to lower pulling plate
Figure 1-6: Tensile tester Equipment used to anchor mechanism to lower pulling plate

Figure 1-5: Underside of Tensile Tester Lower Pulling Plate
Figure 1-5: Underside of Tensile Tester Lower Pulling Plate

9”
9”

Figure 1-7: Thickness of tensile tester pulling plates
Figure 1-7: Thickness of tensile tester pulling plates

We then looked at the top pulling plate of the tensile tester to determine how we would design the portion of our mechanism that would attach to the ears of attachment pin holes in order to successfully pull them off. We immediately noticed that if we were to use any of the circular attachments available to us we would have to pull directly from the center, which would have been nearly impossible given the unusual dimensions of our receivers. Having noticed this we determined that a customized slotted plate would have to be created in order to slide our pulling devise on our mechanism to the appropriate distance to line up with the ears on our receivers. This we determined would be a crucial design and creation aspect. Below is our initial drawing and representation of our slotted plate:

0.75”
0.75”
5.25”
5.25”

2”
2”

Figure 1-8: Slotted Plate Design
Figure 1-8: Slotted Plate Design

Now that we had a very good idea of the specifications that needed to be met in order to create our mechanism we were ready to create a dimensioned SolidWorks file. Below is the initial rough finished design of our mechanism.

Figure 1-10: Finished Mechanism Stand Alone
Figure 1-10: Finished Mechanism Stand Alone
Figure 1-9: Finished Mechanism with Receiver
Figure 1-9: Finished Mechanism with Receiver

From Conception to Creation The very first thing that we did in the beginning stages of the creation of our mechanism was to find suitable materials that would withhold any of the stresses that would be put upon it during our testing procedure. Taking note of the fact that our receivers were made of a lower strength more brittle material in magnesium we were aware that just about any steel material that we used would suit the needs of our mechanism and not be overstressed during testing. Another requirement that we wanted to meet in choosing material was the possibility of using recycled material. Since our material list was small we were easily able to accomplish this task. We were able to secure a piece of ¾” sheet steel, along with many small pieces of square or flat steel that with some simple machining efforts would suit or mechanism very nicely. The only thing that had to be purchased out of pocket were our all thread rods (3/4” and 1/2" dia.) cut to size and our washers and bolts that would secure our mechanism to the tester as well as the receiver to our mechanism.
The following steps are the machine work or labor duties that went into creating and assembling our mechanism: We began by creating the top and bottom plates of our mechanism. The top plate is the slotted plate that would fit into the circular opening of the top portion of the tensile tester and hold our pulling fork. The bottom plate had the three holes to hold the support bars of 1/2" all thread that would align to either side of the receiver holding our magazine well counter pull. And in the center is a hole just over 3/4" that would fit our 3/4" all thread rods which hold our mechanism to the bottom pulling plate of the receiver.

1. The first step was to cut our plates oversized from a piece of sturdy but scrap 3/4 inch steel plate using an oxyacetylene torch cutting tool as seen below. (Due to weather conditions no we were unable to get any quality photos of this process)

Figure 2-2: Cutting Tool Used in Procedure
Figure 2-2: Cutting Tool Used in Procedure
Figure 2-1: Identical Cutting Procedure
Figure 2-1: Identical Cutting Procedure As one can imagine an inexperienced cutter would have a finished product that was rough just a little rough around the edges. So after the completion of our cutting process we were able to put our two plates into the mill to mill off the rough edges to get a good flat 90° edge on the plates. 2. Using the appropriate spacers we placed the our plates into the vise of the milling machine and using a 1 ½ inch ceramic cutting tool insert were able to mill down the roughest edges easily. Taking approximately .005 inches per pass with the milling cutter. We were able to find the center of the plates and center the cutter over that allowing ample hangover to ensure a full surface cut with each pass, moving the mill table in the X- axis we took as many cuts as were required to reach our specified dimension of 5.25 inch square plate.

Figure 2-3 and 2-4: Milling process on the two 3/4 inch steel plates down to 5.25 inch square
Figure 2-3 and 2-4: Milling process on the two 3/4 inch steel plates down to 5.25 inch square

3. Once the steel plates were milled to specification we took them over to the bench and used a hand grinder to get a good even edge and knock any remaining burs off to create a smooth flat plate.

Figure 2-5: Hand Grinding Edges of Plates
Figure 2-5: Hand Grinding Edges of Plates

4. The next step in our process was to cut the different holes in each of our two plates. Using first a 1/2 inch drill bit put into the milling machine we put two holes through the bottom plate each approximately 1 3/8 inches from center. In the center of this plate was drilled a ¾ inch hole for our all thread rod that is used in the attachment of our mechanism to the tensile tester. In the other plate a ¾ inch slotted hole was created using a ¾ inch drill bit and a small milling cutter to extend the slot as far as needed.
Figure 2-6: Side to side cutting for slotted hole plate
Figure 2-6: Side to side cutting for slotted hole plate

Figure 2-6: Drilling Holes in Bottom Plate
Figure 2-6: Drilling Holes in Bottom Plate

5. Once the plates were cut and drilled to our required specifications we took the bottom plate of our mechanism and bored, chamfered each of the three holes. The 1/2 inch holes were then taken to a hand tapping machine and given a coarse 1/2 inch thread in the hole. This was done to allow our 1/2 all thread rod support bars to be manually screwed in to the finished mechanism.
Figure 2-7 and 2-8: Operating the hand powered tapping machine to thread ID of holes
Figure 2-7 and 2-8: Operating the hand powered tapping machine to thread ID of holes

The next portion of our design that we focused on creating was the magazine well insert. The purpose of this insert was to act as a counter pull to the load put onto the receiver by the tensile tester. It would be made of steel and machined to fit as snuggly as possible through the magazine well of the receiver being tested. Attached to the support rods on either side of the receiver it would also keep the receiver stable while the test was being performed. 1. The first thing that was done was to find a piece of steel as close to our necessary dimensions as possible to reduce our amount of machine time. We were able to acquire a piece of 2 inch by 2 inch square piece of steel approximately 5 inches long. Using the dimensions mentioned before of the receivers magazine well to work off of we marked the piece accordingly and cut it to length. We first cut a small portion off using a horizontal band saw, reducing its length to approximately 4 inches. This would give us plenty of room to drill holes through the piece that would attach to the support rods. We then loaded the piece into the mill and using the same 1 ½ inch ceramic cutter as before milled away at the width of the insert until it was to our desired specifications.

Figure 2-9: Milling the width of the magazine well insert
Figure 2-9: Milling the width of the magazine well insert

2. The next step in preparing the magazine well insert was to drill a hole on either side of the insert for the support rods to slide through. This was accomplished using the mills drill press and drilling two oversized 1/2 inch holes straight through the magazine well insert. The 1/2 inch size is in accordance with the tapped holes drilled into the bottom plate of our fixture as well as the 1/2 inch all thread rod that would act as our support rods. The holes were then chamfered for a smooth finish.
Figure 2-10: Drilling holes in the magazine well insert
Figure 2-10: Drilling holes in the magazine well insert
Figure 2-11: Chamfering the holes of the magazine well insert
Figure 2-11: Chamfering the holes of the magazine well insert

3. The final step in preparing the magazine well insert was to attach a small piece of industrial strength rubber to the bottom. This was done in order to reduce a metal on metal contact giving the insert a soft and conforming contact point against the receiver during testing.

Figure 2-12: Rubber “cushion” on magazine well insert
Figure 2-12: Rubber “cushion” on magazine well insert

The next step in the creation of our mechanism was the manufacture of a pulling fork, as we called it, which would attach to the ears of the receiver and go up through our slotted plate fixed at the top of the tensile tester pulling plate. In our original design we accounted only for the fork piece and the slotted plate. During creation we decided to affix the fork to a 3/4 inch all thread rod by welding the rod between two pieces of 1/4 inch steel and drilling a 1/2 inch hole through the pieces allowing for the fork piece to connect by a 1/2 inch bolt and have a hinging motion. Like the slotted plate design this was another way in which we were able to get more of a straight pull on our ears.

1. After cutting the 3/4 inch all thread rod that we would be using to the appropriate length we started our welding process. We welded the rod directly in between two thin steel plates and then drilled the 1/2 inch hole in the plates that would enable us to connect our fork by a simple bolt.

Figure 2-15: Welding the rod between the thin steel plates
Figure 2-15: Welding the rod between the thin steel plates

2. The next step was to make the fork itself. In order to do this we took a piece of scrap steel that was left over from making our magazine well insert, and milled it down to the appropriate size of ¾” x 2 ¼” x 1 5/8” designed specifically given the dimensions of the welded piece as well as the ears of the lower receiver specimen. Two slots were cut into the piece using a small milling cutter, approximately 1/2 an inch deep from the surface. Through those slots was drill a hole approximately ¼ inch in diameter to match the pin holes on the receiver. A small steel pin was then fabricated at just less than 1/4 inch in diameter to push through the forks holes and the pin holes on the receiver in order to connect the two pieces together as shown below.

Figure 2-16: Machined fork piece
Figure 2-16: Machined fork piece
Figure 2-17: Pin placement in fork
Figure 2-17: Pin placement in fork

Once our mechanism was nearly completed we realized that our specimens were not going to fit in their current condition. The specimen had a threaded circular portion on the back end of it which is used for inserting a butt stock onto the finished firearm. Originally our support rod on that side was to go through this circular portion but when the mechanism was looked at closer to completion we began to realize that with this piece on there we would not be able to get a straight pull and that it would rest to much on our nut which held the mechanism to the lower pulling plate of the tensile tester. We made a decision that removing this portion of the receiver would not compromise our results and it would be fine to remove it. So using the horizontal band saw we clamped the specimens in and were able to simply cut this portion of the receiver off of each of our three specimens.

Figure 2-19: Band saw cutting butt stock insert
Figure 2-19: Band saw cutting butt stock insert
Figure 2-18: Comparison of post-cut and pre-cut receivers
Figure 2-18: Comparison of post-cut and pre-cut receivers

We also determined that in order to get the proper pull on the receiver’s ears, a small portion near the ears would have to be very carefully milled off. To do this we simply clamped the receiver to the milling machine vise and using a very small cutter took off approximately .001 inches with each pass until we were flush with the ears of the mechanism. We again decided that this would have no effect on the data acquired from the test’s.
The final portion of the creation process was acquiring our all thread rods, nuts and washers that would help us to secure our mechanism to the tensile tester as well as secure the receiver to our mechanism. The all thread rod was cut to the appropriate length for our mechanism using a horizontal band saw.
From a local hardware store we purchased the following items: 1.) One 36” piece of 3/4 inch coarse thread all thread rod 2.) One 36” piece of 1/2 inch coarse thread all thread rod 3.) Three 3/4 inch coarse thread nuts 4.) Two 1/2 inch coarse thread nuts 5.) Three 3/4 inch stainless steel washers
Below is the finished mechanism side by side with the original conceptual design. As one can see they are nearly identical meaning that our design was solid and we were able to stay on track in each facet from conception through creation.
Testing the Lower Receiver Specimens Now that we are finished with the conception and creation portion of our project, we are ready to start the testing and data acquisition. To begin we set up the universal tensile testers partnering program. To do this we entered in the appropriate data of our specimens that were to be tested such as the force with which we wanted to pull on the ears, the approximate area of the ears, and the material properties that we wished to test for. We found the approximate area of the ears at a perfect break to be .183 in2 and we were able to test for the tensile stress at break as well as the ultimate load that our specimen could endure before the break. After the specimen’s data was entered into the partnering software we were ready to place the mechanism into the tensile tester and hook up the specimen as follows: First we attached our mechanism to the lower pulling plate using the given circular fitting at the bottom of the plate which was fitted with a nut and washer to one piece of our 3/4 inch all thread at the bottom. The all thread ran through the center of the bottom pulling plate and through the 3/4 inch hole in the center of the lower plate of our mechanism where it was again fixed with a nut and a washer of appropriate size. We arranged our mechanism so that the specimen was fixated in a way that the ears and fork at the top would be able to get a straight pull and our hinging mechanism on the fork would work appropriately. The slotted plate design also worked how we wanted it to by allowing the specimen and hinged fork piece to align appropriately before getting a tight pull on the ears.

Figure 2-20: Specimen in mechanism loaded in tensile tester (pre-test)
Figure 2-20: Specimen in mechanism loaded in tensile tester (pre-test)

Once our first specimen was loaded we were ready to begin the testing, incorporating the tensile tester’s partnering software. We simply pressed the test button and let the tensile tester go to work. After about 3 minutes in the tester our specimen broke at the ears as expected and our mechanism remained intact throughout the process making test number one a success. We then tested our remaining two specimens and again they broke giving us different breaks yet similar data each time. The testing process went very smoothly taking only approximately one and a half hours to complete.
Analysis of Data and Specimens As stated earlier each specimen broke in a different manner but render very similar data including stress and load at break. We will now go through each specimen one at a time and examine the break that it endured as well as the data that was acquired by the tensile tester’s partnering software.
Specimen #1 Specimen number one broke according to the following picture. Though we had anticipated a break at the cross sectional area of the pin holes or “ears”, we were not too far off in our assumption. One ear of the receiver did break as anticipated while the other ear on the receiver came off entirely. While this was somewhat unexpected we believe due to a thinner wall of metal at the site of the ears and the fact that these specimens were molded may have attributed to the uneven break.

Figure 2-21: Specimen Test #1 break
Figure 2-21: Specimen Test #1 break

Above is the plotted data for specimen #1. As you will see from the results of the other tests, this test resulted in the highest ultimate tensile strength of 11,338 psi and the highest load at break of 2,075 pounds. While it was within a tolerable range to the other two it was by far the furthest away from the average.
Specimen #2 Specimen number two broke exactly as we had expected directly through the cross sectional area of the upper receiver attachment pin holes. This was the only specimen that we tested that broke according to our assumption.

Figure 2-22: Specimen Test #2 break
Figure 2-22: Specimen Test #2 break

This data was by far the most consistent, the curve was very even and it was our benchmark for data sine the break happened right where we had expected it to. The ultimate tensile strength at break for this specimen was 9,131 psi and the max load at break was 1,671 pounds.
Specimen #3 Specimen number three provided by far our most interesting break, but the data acquired was not far off from the data acquired from our specimen #2 “perfect break”. Specimen three broke the entire pin-hole group off of the receiver, the pin holes both remained undamaged but the magnesium behind the pin holes broke off of the receiver completely as seen below.

Figure 2-23: Specimen Test #3 break
Figure 2-23: Specimen Test #3 break

The data acquired from this specimen as stated before was very similar to the data acquired with our perfect break specimen number two. It had an ultimate tensile strength of 9715 psi and a max load at break of 1778 pounds. Average Tensile Strength of Specimens:
10,061 psi
Average Load at break:
1,841 pounds of force The test went as smoothly as we could have hoped for giving us some very interesting data and a number of different breaks of the receiver pin holes. The first thing that should be said about the strength and durability of the pin holes is that the breaks are inconsistent. To us this means that there is not one specific direction of load that could cause these pin holes to fail. It is not necessarily all in the strength of the pin holes themselves as can be seen by the specimens that did not break according to our assumed break. The strength of the magnesium around the pin holes also plays a large part in the overall strength of that part of the lower receiver. We believe that some of these inconsistencies in testing came from one of two possibilities. The first is the possible inconsistencies that come from die casting these specimens. This could theoretically cause a certain part of the specimen to be just a hair thinner than the original model causing it to fail in that thin spot. Secondly it could have been an inconsistency within our mechanism. Our mechanism may have incurred some elastic and our slight plastic deformation as a result of the test causing the pull to be just a little different each time we tested. Even the slightest variance from the designed pull could have caused the specimen to fail in a different manner than expected.
Comparison to a Theoretical Aluminum Sample At the beginning of our project we thought we were going to be able to test the newly manufactured magnesium receivers against the more frequently used aluminum receivers. Due to current political situations as well as high demand for these pieces we were not able to acquire aluminum samples. We instead are going to make an assumption of the amount of force that would be the same no matter which receiver one was testing so that is our constant variable. We found the ultimate tensile strength of the 6061-t6 aluminum alloy is 45,000 psi (ASM Material Data Sheet, Accessed April, 1 2013). Using this as our ultimate tensile strength we were able to find the theoretical load of an aluminum receiver by simply multiplying the tensile strength by our given cross sectional area of 0.183 in2.
45,000 lbs. /in2 X 0.183 in2 = 8,235 lbf We found the theoretical amount of force in a perfect break using an aluminum receiver to be approximately 8,235 lbf. Knowing that aluminum is normally stronger than magnesium anyway if you are looking for a receiver to be stronger aluminum would be your best option, in all honesty though neither an aluminum receiver nor a magnesium receiver would ever be subjected to such a force as this. It may under extreme conditions be subjected to a force of say 300 lbs. making either component acceptable in real life standards, so having said that the magnesium receiver is about 35% lighter than its aluminum counterpart making it the less heavy option. Another consideration is machining of the two metals. Aluminum can be machined by normal tooling while magnesium must be heated and then cast due to the dangerous flammability characteristics of its machined chips. So really in our opinion at the end of the day the choice is yours and both materials will meet the needs required to enjoy your firearm.
Compression Testing When testing our specimens in the universal tensile tester, 67% of the specimens were destroyed in such a way that would have made a compression test on those specimens inaccurate and nearly impossible. And again due to the current political situation as well as the high demand for these products we were unable to acquire another batch of specimens in order to run the proper testing to get compression data. This would be a great opportunity for future researchers to get into and find a way to test the specimens as well as accurate results from their testing.
Economic Analysis
Below is a tabulated representation of the economic analysis of our project. The three main components that we were able to put a price on were our academic advisors time, our time and cost of material throughout the entirety of the project. | Student Work | Faculty Work | | | | | | $15/hr | $100/hr | | | | | | | | | | | | | Shop Hours | Misc. Hours | Testing Hours | Total Hours | | | Student | 22 | 5 | 1.5 | 28.5 | | | Faculty | 10 | 2 | 0 | 12 | | | | | | | | | | | Total Cost | | | | | | Student | $427.50 | | | | | | Faculty | $1,200 | | | | | | Material | $30 | | | | | | | | | | | | | | | | | | Overall Project Cost | $1,657.50 |

Summary In conclusion and reflection we were able to successfully complete or project scope beginning with a design and ending with a finished product. We were able to follow the guidelines that we had laid out in our abstract and through careful planning and many revisions come up with a mechanism capable of testing all of the physical properties we wanted to examine. By looking at all of our data we were also able to make careful assumptions of the data and come up with a comparison of the aluminum alloy to the magnesium components. Due to the current high demand for these receivers we were unable to perform a compression test on the magnesium components. We would recommend that this testing procedure be looked at more in depth by future students as a project. We think these details may be vital to fully understanding the physical properties of the magnesium component.