Design of a Manual Cattle Chute - Project Report | BAE 4012, Study Guides, Projects, Research of Engineering

Download Design of a Manual Cattle Chute - Project Report | BAE 4012 and more Study Guides, Projects, Research Engineering in PDF only on Docsity! Design of a Manual Cattle Chute Joe Biggerstaff William Ryan Haar Matt Kilker Taylor Miller BAE 4012 May 2, 2006 Design of a Manual Cattle Chute Joe M. Biggerstaff William R. Haar Matt S. Kilker Taylor F. Miller Biosystems & Agricultural Engineering Department Oklahoma State University Submission Date: May 22, 2006 Joe M. Biggerstaff Biomechanical Option May 2006 Graduate Medford, Oklahoma William R. Haar Biomechanical Option May 2006 Graduate Elkhart, Kansas Matt S. Kilker Biomechanical Option December 2006 Graduate Brighton, Colorado Taylor F. Miller Biomechanical Option December 2006 Graduate Carney, Oklahoma Dr. Paul R. Weckler Senior Design Advisor Dr. Ronald L. Elliott BAE Department Head iv List of Figures Figure 1. W-W Livestock System "BEEFMASTER" Current Chute Design...1 Figure 2. Misalignment Due to Single Squeeze .....................................................2 Figure 3. Breast Plate Patent ..................................................................................7 Figure 4. Headgate Lever Detail...........................................................................11 Figure 5. Neck Access Door...................................................................................12 Figure 6. Symmetrical Squeeze.............................................................................13 Figure 7. Top Squeeze Locking Mechanism………………………………….. 14 Figure 8. Bottom Squeeze Details .........................................................................15 Figure 9. Squeeze Panels Fully Open and Fully Closed.....................................17 Figure 10. Larger Animal Neck Access ...............................................................18 Figure 11. Small Animal Neck Access..................................................................18 Figure 12. Finite Element Analysis ......................................................................19 Figure 13. Guillotine/Slider Tail Gate..................................................................20 Figure 14. Scissor Tail Gate ..................................................................................21 Figure 15. Bottom View of Conceptual Floor......................................................23 Figure 16. Top View of Conceptual Floor ...........................................................23 Figure 17. First Large Bull Tested in Chute .......................................................24 Figure 18. Branding Interference Problem .........................................................25 Figure 19. Working Cattle at Jim Kinder Farms ..............................................26 Figure 20. Testing the Chute at Rolling R3 .........................................................27 Figure 21. Notch in Neck Access Panel ................................................................28 Figure 22. New Kick Panel Design .......................................................................29 v List of Tables Table 1. Suggested Chute Dimensions. Source: OSU Fact Sheet F-1738 ........16 Table 2. Rumber® Specifications. Source: www.rumber.com.........................22 Table 3. Cost Breakdown .....................................................................................31 Table 4. Retail Cost Comparison.........................................................................31 1 Problem Statement W-W Livestock Systems has been a competitive manufacturer of livestock equipment since 1945. They have produced a quality manually operated cattle restraining chute for many years. However, their current design the “BEEFMASTER” needs updated in order to stay competitive in today’s market. Custom Agricultural Designs (CAS) accepted the task of improving the design of a manually operated cattle chute while considering the manufacturing and design constraints set forth by W-W Livestock Systems. The design must improve ease of operation and reduce stress on the animal. Figure 1. W-W Livestock System "BEEFMASTER" Current Chute Design Statement of Work Representatives of W-W met with CAS in September to establish the design objectives for a new manual chute design. They have asked CAS to develop new ideas in compliance with their design constraints in order to help meet their objective of staying competitive in the 4 imposed on it during operation. When developing the structure of the concept tailgates, CAS should explore ways to reduce noise that can be attributed to metal on metal contact. Miscellaneous Issues W-W is addressing the issue of noisy operation in cattle equipment. In order to reduce the noise levels while working cattle, W-W wants to incorporate a Rumber floor. They suggested designing a new floor support that will allow the steel C-channel to be replaced by common sized Rumber. The cross members must be close enough to support the Rumber and restrict the Rumber from deflection. Noise will be reduced by reducing the number of metal on metal contacts. The use of polyurethane bushings along with rubber on all contacting surfaces will be implemented. This particular model of chute uses a special yoke trailer for transport. The design of the trailer simplifies transportation of the chute from one location to the next. Changes to the yoke trailer are needed in order to accommodate the concept unit. The trailer must balance the chute properly. Height of the chute on the trailer is also a consideration so that clearance does not become an issue. Testing and Observations In order to find solutions for the problems with the current W-W chute, CAS interviewed ranchers from all over the state of Oklahoma. These ranchers expressed many of the same concerns as W-W. One aspect that CAS quickly learned was that every rancher preferred something different. Ranchers with large cattle breeds such as Simmental and Chianina breeds complain about the small size of the chute. Ranchers with smaller breeds indicate that the size is fine. Some ranchers like a guillotine gate, some a slider, some a scissor-type and so on. 5 CAS went to Rolling-R3 Ranch to work cattle and witness the problems of the, “BEEFMASTER” firsthand. CAS met with Jason Shepard, the cow herd manager for Rolling-R3 Ranch. At the meeting, the team began by discussing the changes which W-W had already suggested. After all the aspects already covered between CAS and W-W were discussed in detail, Mr. Shepard began to explain, and show the team members the problems with the chute which he had encountered in his six years of experience with the “BEEFMASTER” manual chute. Eleven areas of concern were pointed out by Mr. Shepard:
The rubber floor in the headgate- The two rubber planks in the head gate raise up out of placement from time to time due to material build up and cattle impact. Once the pieces are out of place, the head gate catches on the floor and restricts movement resulting in failure to open and close the head gate.
The latching mechanism on the headgate latch- The mechanism uses a round bar with an ear on the end to restrict the latch from moving upward; hence, locking the headgate shut. The round bar must move laterally through two sleeves. The bar catches in the sleeves and does not move freely, causing difficulties in unlocking the headgate latch.
Tailgate- The guillotine type tailgate is in the way when using the palpation gate and performing artificial insemination on cattle. A slider type tailgate would be more desirable for the applications used by R3 Ranch.
Latches on the kick panels- The nuts which attach the pull cables to the latches back off and the cables come unscrewed. 6
Emergency Exit Latch- The latch on the exit is not reliable. Nearly 25% of the time, the gate does not latch; therefore, the operator must go around the chute and manually push the gate shut.
Emergency Exit Gate- The gate does not swing open on its own. The gate must be pulled or pushed open manually, which is very inconvenient for the operator.
Bottom width Adjustment- The movement of the squeeze panel becomes very restricted after time due to material build up and steel rust.
Squeeze Pull Handle- The handle is very hazardous to tall operators due to the low placement. The handle height should be adjustable to accommodate all sizes of operators.
Releasing the Squeeze- In the situation of downed cattle, the release of the squeeze is very difficult due to the low resolution of the gearing on the latch. In some cases, releasing requires more than one person; which is very undesirable.
Transporting the Chute- The current design on the yoke trailer requires a bar to be place all the way across the back of the chute. When placing the chute in work areas, this is very inconvenient. The chute must be dropped forward of the desired working location and moved back into place. After Mr. Shepard had completed his discussion, the team worked a few 1500 lb Angus cattle and encountered many of the problems described. This experience gave CAS a much better understanding of the problems. With this knowledge, CAS can design a chute more efficiently. 9 Dr. Temple Grandin, assistant professor at Colorado State University, published articles on animal welfare and restraint. Grandin (2000) discusses many significant points to consider when restraining animals. She indicates that cattle become excited and agitated in a squeeze chute and will have lower weight gains and are more likely to have dark cutting meat. Dr. Grandin gives suggestions on chute design:
Encourage slow steady motion to calm an animal, as opposed to sudden jerky motion.
Engineer equipment to minimize noise
Use solid barriers on sides so that the only exit the animal sees is the headgate
Use optimum pressure. Provide enough to make the animal feel restrained but do not apply so much pressure that the animal is inflicted with pain.
Provide non-slip floors Design Specifications W-W told CAS that they would entertain any design concepts. However, if the following criteria are not met in the concept design, the design will not be implemented. W-W indicated that these criteria are very strict and cannot deviate.
Break down the chute into components. The components must be small enough to fit into their powder coating booth which has an opening of approximately (36” X 120”).
Saddle pipe to meet their current practices.
Squeeze from both sides.
Maintain emergency or side exit.
Reduce noise. 10 Design Concept CAS has designed a livestock chute that is more versatile than any other chute on the market. With the proposed design, the operator will be able to run an 1800 lb. bull through the chute and then be able to run a 200 lb. calf directly after that bull and not have to stop to make adjustments. With a design this versatile and safe, the operator will save a significant amount of time and labor. The controls for this chute can be installed on either the left or right side of the chute depending on the operator’s preference. All controls are accessible while the operator stands in one place, and are placed in a safe position. Headgate To obtain a reliable headgate latching mechanism, CAS has designed a two lever latching system. The design has a front and rear latch which restricts the headgate panels from forward or backward motion. The latches are spring actuated to insure that each latch closes without operator input. Each latch can act independently with a selected lever. Figure 4 shows the positions of each latch while the head gate is restricted to forward motion only. This design allows the latch to have a significant amount of downward motion to secure the headgate which solves the problem with the current W-W headgate latch design. As illustrated in Figure 4, this design has a great deal of versatility allowing the operator to work quickly and efficiently. 11 Figure 4. Headgate Lever Detail CAS utilized experimental data from Maghirang (2001) for the stress analysis on the vital components of the headgate. CAS used the data to size the pins and structure that support the members absorbing the force of an animal hitting the head gate. When consulting with many chute operators, a primary area of concern on the head gate was access to the neck of the bovine. The neck area is a location where large amounts of medications are administered. CAS has developed a removable neck access door that swings open or can be removed in order to address this issue. The neck access door of the head gates are easily opened by pulling on a latch and swinging the gate forward toward the front of the head gate as illustrated in Figure 5. The neck access door can then be removed if desired by pulling the gate out of the bottom pivot and then the top pivot. Nine inches of room allows Lever Allowing Head Gate to Swing Forward Only Lever Allowing Head Gate to Swing Backward 14 set of notches as shown in Figure 7. With this many degrees of rotation and the fine pitch of the locking notches, the operator has a fine tuned adjustment on the squeeze of the animal. When the operator wants to release the animal, they simply pull the squeeze lever downward; lift the lever on the locking strap, and the squeeze releases. Figure 7. Top Squeeze Locking Mechanism With this type of squeezing motion, the narrower the squeeze, the farther forward the squeeze panels are positioned toward the head of the animal. This feature solves the problem of the squeeze panels only restraining a small portion of the rear of a small calf while keeping the spine aligned with the central axis of the chute. When a smaller calf is in the chute, the squeeze panels will restrain more of the calf’s body as compared to the current W-W design. When a larger animal is in the chute, the squeeze panels will be further back which improves neck access where many vaccinations are administered. Top Squeeze Release Lever Locking Notches Top Squeeze Actuating Lever Locking Pin 15 The ability to conveniently and independently adjust the bottom portion of the squeeze is crucial. The CAS bottom squeeze design is a first for manually operated chutes. With most manual chutes on the market, the bottom squeeze cannot be adjusted once an animal is in the chute. The bottom squeeze on this chute is operated independently from the main top squeeze by simply actuating a lever as shown in Figure 8. This lever is hinged on a bolt and will conveniently fold out of the way while not in use. Figure 8. Bottom Squeeze Details When the top squeeze is actuated, the bottom squeeze is linked so that the squeeze panels are parallel. Once the operator has the animal squeezed, they can use the bottom squeeze lever to obtain more squeeze on the bottom if they so desire. Operators like to make the bottom narrower than the top because this provides a lifting action on the animal and will prevent the animal from “choking down.” The operator also has the option to initially set the bottom squeeze and leave it when restraining the animal. A lever and a ratchet gear shown in Figure 8 lock the bottom Bottom Squeeze Actuating Lever Bottom Squeeze Release Lever Cross-Over Cables 16 squeeze. The release latch is conveniently located near the front of the chute where the rest of the actuating functions are operated. A set of cross-over cables, similar to the current head gate design, are used to actuate the bottom squeeze on the other side of the chute. Squeeze Mechanism Dimensions and Further Analysis CAS consulted beef producers, OSU fact sheets, and ASAE standards to determine the operating dimension of the squeeze mechanism. Dimensions of cattle vary from breed to breed. This variation complicates the decision for the squeeze dimensions that will have the optimum effect on restraining the animal. Information from the three sources will determine the dimensions of the squeeze panels. All of the beef producers consulted agreed that the current W-W design squeeze panel dimensions are fine for smaller animals or smaller built breeds such as Angus, etc. but the chute is not large enough for large cows or larger breeds such as Simmental or Chianina. The squeeze panels need to open wider at the bottom and the squeeze panels need to be longer. Table 1 from OSU Fact sheet F-1738 outlines suggested dimensions for different sizes of cattle. Table 1. Suggested Chute Dimensions. Source: OSU Fact Sheet F-1738 Animal Size to 600 lbs. 600-1200 lbs. Over 1200 lbs. and cow calf operation Working Chute with Vertical Sides Width 18'' 20-24'' 26-30'' Working Chute with Sloping Sides Width at bottom, inside clear 13'' 15'' 16'' Width at top, inside clear 20'' 24'' 28'' 19 Figure 12. Finite Element Analysis The member in this analysis is 1.5’’ schedule 40 pipe. There are two 5/16’’ holes near the bottom of this member. The loads applied were estimated by adding the downward force of a 2000 lb animal in addition to the dead weight of the side panel. The maximum stress on this member is approximately 10,000 psi, which can be seen in figure 12. This gives a factor of safety of approximately 3. This member is more than strong enough for this application. Tailgate In order to meet the desires of a larger range of W-W chute purchasers, CAS has employed multiple tailgate designs. Each tailgate design can be removed by simply removing eight bolts. This will allow each customer to have a choice between tailgates. When CAS approached W-W with this design, they indicated that the number of stocked parts may become a Member Analyzed Max Stress Point 20 problem with multiple options for tailgates. W-W suggested that the tailgate options should be limited to only two in order to keep stocked parts low. CAS developed two conceptual tailgates. The first is a guillotine/slider combination. The type of motion of the tailgate can be changed by simple rotating the tailgate and attaching or removing 4 extensions. The guillotine/slider combination is a very powerful tool for a cattle operation facing many different tasks when working cattle. The guillotine portion of the gate is very convenient when working a large amount of cattle due to its easy actuation and ease of access. The slider portion of the tailgate is convenient when performing tasks such as artificial insemination. Figure 13 shows the concept guillotine/slider gate. Figure 13. Guillotine/Slider Tail Gate 21 The scissor tailgate is the second option designed by CAS. Figure 14 demonstrates the major components involved in the conceptual design. The gate is actuated by pulling down on the actuation handle. The cross-over cables and parallel linkages make the scissor gate travel at a constant speed and position. Due to the placement of the linkages, the scissor gate will stay opened when fully open due to the linkages breaking over center. When the gate is closed, the lever is rotated past center and gravity will naturally close the gates quickly. Figure 14. Scissor Tail Gate Cross Over Cables Parallel Linkage Break Over Linkage Actuating Handle 24 chute adjusted for this wide range of animal size very well. The chute constrained the steers very well but it also opened up enough for the large bull to comfortably enter and exit the chute. Figure 17 displays one of the first animals tested in the chute. Mr. Flores was very pleased with the operation of the chute. He liked being able to run the headgate, top squeeze, bottom squeeze, and scissor tailgate all from one position and with only one operator. Figure 17. First Large Bull Tested in Chute This initial test proved to be very successful; however, CAS noticed some aspects of the chute that needed to be corrected. The first was the height of the fold down bars on the side of the chute. The pivot point for the fold down bars was too high on the hip of the 450 lb. steers. This interferes with the branding location on the steers. This is not a problem on larger animals but since most cattle are branded when they are smaller, this problem needed to be corrected. Figure 18 displays the problem. 25 Figure 18. Branding Interference Problem Following the initial test, CAS lowered the fold down bar pivot point five inches. Jim Kinder of Carney, OK tested the chute next for CAS. He ran approximately forty head of cows through the chute. Mr. Kinder was very pleased with the operation of the chute. The only problem encountered was when the side exit latch “popped” out of the notch. CAS immediately corrected this by making the notch deeper. Figure 19 displays the chute in operation at Kinder Farms. 26 Figure 19. Working Cattle at Jim Kinder Farms Rolling R3 Ranch located near Guthrie, Oklahoma tested the chute with about 200 head of cows as well. The slider/guillotine combination tailgate was used for this test. Cow herd manager for Rolling R3, Jason Shepard, provided his thoughts on the chute:
He liked the ability to adjust the top and bottom squeeze independently.
The two latch system on the head gate is convenient.
The slider/guillotine combination tailgate worked well.
He like the ability to control the chute from either side Figure 20 displays Jason Shepard working cattle with the prototype chute. 29 Figure 22. New Kick Panel Design Recommendations After constructing and testing the concept chute CAS was able to identify some areas for improvements on any future prototypes.
Using two linear gears on top squeeze to add resolution
Lengthen pivot connections for easier assembly
Make neck panel self catching for easier operation The first change involves using two linear gears on the top squeeze in order to improve the resolution. By staggering two gears on the rotating top squeeze lever the resolution of the top squeeze will be doubled. In order to implement this type of system a new release and latching mechanism would need to be developed. Lengthening the pivot connections on the frame by ½” will make it easier to assemble the chute due to increased clearance. In order for this change to be made the sub frame will need to be shortened by ½” so that the panels will have adequate clearance on the floor. This change 30 should be monitored carefully as it increases the moment experienced on the pivot connection and torque on the frame. The final change is that of implementing a self latching mechanism on the neck access panels. Placing self latching mechanisms will make it a quicker process for the operator to close the panel. It also helps put a preload on the latch to insure that an unwanted panel opening will not occur. Cost W-W has stressed the importance of cost to CAS since the beginning of the project. In today’s manual chute market, there are a number of competitors that build a cost effective chute. If the cost of a manual chute is too high, the customer will simply by another brand or they will purchase a hydraulic powered chute. Realizing that the manual chute market is such a niche market, CAS has avoided the use of unnecessary material and high manufacturing costs in the design. After the conceptual design was completed, CAS created a bill of materials in Microsoft Excel. The entire chute is categorized by sub-assemblies. Each part in the sub-assembly is listed below that sub-assembly. Each individual part is labeled with a description, material price, and labor price. With the cost information categorized in this manner, CAS and W-W can analyze the cost very precisely. Table 3 summarizes the manufacturing, labor, and material cost for the fabricating the chute and all of the tailgate options. 31 Table 3. Cost Breakdown ITEM TOTAL # TOTAL COST Cuts 379 $94.75 Saddles 32 $8.00 Punches 138 $34.50 Welds (in) 1530.5 $505.76 Total Labor Cost $643.01 Total Material Cost $536.28 Total Cost of W-W Material $906.21 Table 4 summarizes and compares the retail cost of the new chute design chute and the old chute design. CAS used a retail mark up of 120% for the retail cost analysis. The new chute design is more expensive than the old design. CAS feels that this extra cost is justified by the additional features and improved performance of the new chute design. Customers will witness the improved performance of the new chute design and decide that the chute is worth the additional cost. The Excel spreadsheet with the cost information is on the attached compact disc. Table 4. Retail Cost Comparison ITEM COST COMBINATION RETAIL VALUE (120% mark up) Basic Chute $1,599.53 Guillotine tailgate $74.35 $1,673.88 $3,682.54 Combo tailgate $221.98 $1,821.51 $4,007.32 Scissor tailgate $189.64 $1,789.17 $3,936.16 Existing Chute $1,386.24 $3,049.73