Within the first two weeks of May, the Equest team focused on finalizing the remaining components of the portable mounting ramp to ensure that a fully-functional ramp and the final CAD assembly are available to showcase at the Spring 2022 EPICS Expo.
On the week of May 1st, the team visited the North Lab Machine Shop to assist Andrew Bittner in the preparation of the final ramp components for him to machine and weld onto the main ramp assembly. All the expanded metal panels were cut to size during the last week of April, leaving us to remove sections of the ramp frame’s paint for Andrew to sitch-weld the panels onto the frame. In addition, the two hinges and lower-ramp hooks (described in the April 2022 update) were welded onto the ramp components—enabling the ramp’s functionality of the desired folding and hooking mechanisms. Thus, a fully-functional ramp was produced on May 5th, 2022.
The fully-functional ramp with flooring, hinges, and lower-ramp hooks.
Additionally, the team worked on completing the final CAD assembly of the portable mounting ramp which includes all components and mechanism features.
Full CAD assembly of the portable mounting ramp using Creo Parametric.
[Describe the socket holders once they’re welded on]
[Show image of the handrails attached to the main assembly]
[Describe miscellaneous attachments—safety features & storage mechanisms]
[Show image(s) of feature(s)]
[Describe delivery status to the project partner]
[Show image of the completed portable mounting ramp]
This month, the team worked on finalizing the remaining designs/features of the portable mounting ramp and, additionally, put forth the effort to physically prepare all components and assemble them to the ramp.
With the handrails selected, the team focused on drafting a handrail holder feature that fixes the safety handrails to the appointed sides of the portable mounting ramp—as depicted in the March update. To achieve this, we decided on fabricating side socket holders—consisting of a tube and a bent plate—that act as outer tube sockets for the handrail ends to slide into. Quick-release spring pin are included with the design, which assist in keeping the inserted rails in place.
Socket holders for the handrails.
Four of these socket holders were created using 1.875″ OD X 0.120″ thickness, 1026 Mild Steel (DOM) round tubes from Metal Supermarkets cut to length of 6″. The 0.100″ thick plates were water-jetted and bent at the North Lab Machine Shop by Andrew Bittner.
To satisfy the folding mechanism requirement of the middle-ramp and the platform, the team ended up going with welding two 1′ piano hinges (purchased from McMaster: 15665A195) on each end of the platform, as shown in the previous update. McMaster doesn’t provide load rating of these items, so we gauged an overall rating—13.9 kip—for two hinges by identifying the shear-force capability of the hinge’s pins.
Estimating the overall load rating of the two hinge’s pins.
Additionally, the team finalized the designs and selections of several miscellaneous safety features. For example, we decided to incorporate an edge-guarding plate along the loading side of the portable mounting ramp to ensure that wheelchairs can’t roll off during the loading process. Also, we implemented two rubber stoppers (McMaster: 9541K44) at the front edge of the platform to dissipate energy from the middle-ramp in cases where it falls and impacts the platform. To guarantee that the lower-ramp stays in place during the loading process, we also designed and added lower ramp hooks (bent 0.100″ plates) that attach to the middle ramp.
Depiction of the edge-guard plate.Threaded rubber bumper inserted into the front edge of the ramp.Depiction of the lower-ramp hooking onto the middle-ramp.
Finally, the majority of our worktime this month went towards physical labor—for instance, painting the lower-ramp, tidying up the wiring for the brake lights, cutting the expanded metal, and testing the motion of a wheelchair on the ramp, as shown in the following images.
Covering the lower-ramp with Black Rustoleum paint.Cutting the expanded metal sheets to size.Testing a wheelchair as it moves up the inclined middle-ramp.
Going into the month of May, we plan to hurriedly complete the final components of the portable mounting ramp and assemble them together. This includes the fabrication, welding, and/or painting of the expanded metal flooring, the hinges, handrail sockets, edge-guard plate, rubber stoppers, and lower-ramp hooks. By the end of the school semester, we aim to have completed the project altogether and delivered to our project partner, Bobby Valdez.
Our main objective this month was to complete our final design choices and prepare purchases for immediate machining/installment.
Starting out, the team focused on finalizing our choices for the main ramp components—namely, the expanded metal flooring, handrails, and ramp hinge(s).
For the expanded metal flooring, we considered McMaster items that heavily reflected the preferences laid out by previous teams. These preferences include a carbon steel composition of the expanded panel, a raised panel style, openings of 2.5″ width and 1.19″ length, and overall sizes that satisfy the top dimensions of the platform and ramps. Thus, three McMaster 9302T66 Carbon Steel Expanded Panels were selected for purchase.
Raised carbon steel expanded metal panel.
Considering that a detachable handrail is preferred for the mounting ramp, a Uline 6′ Steel Safety Handrail was selected due to it having circular slot ends for sockets and an overall length that is within the length-wise [Insert length] dimension of both the platform and middle ramp. Along the platform and middle ramp edges, the team plans to install custom-designed sleeve sockets to attach to the handrails’ circular slot ends. So far, our team is leaning on purchasing circular tubes on McMaster to serve as the sockets, however, difficulties arise due to the elevated costs of inner-diameter-based tubes. As we purchase and install the components, we simultaneously consider potential solutions/designs for the sockets.
Uline handrails attached to the ramp assembly.Uline 6′ Steel Safety Railing.
Initially, the team planned to purchase a piano hinge that spans along the width of the mounting ramp. However, this option leads to unnecessarily large costs and excessiveness. Thus, we decided to run with two 1 ft. removable-pin piano hinges attaching to both ends of the platform—middle-ramp joint by welding. A load rating isn’t provided by the McMaster website, thus we gauged a shear strength rating of the hinge pin by performing calculations.
Hinges attached to the ramp.
In addition to these main components, we decided to also include several miscellaneous additions. Firstly, we looked into implementing rubber stoppers on the mounting ramp’s front corners to absorb shock in case the middle ramp suddenly drops during the folding process. Websites like McMaster provide stoppers with threaded ends, which we are currently considering purchasing. Additionally, we plan to install an edge-protecting lip along the mounting edge of the platform. With this, we will use a long, flat metal plate to weld across this end.
As described in the previous section, we were considering installing an expanded mounting edge to prevent horses from tripping over the wheels and the side frame tubing. However, the team decided not to go with this idea due to the project partner agreeing to the terms of the previous team’s final design (which didn’t include this feature).
Going into next month, we plan to quickly make our final purchases and begin machining/installing the mounting ramp components. During the month of March, all team members acquired the basic machine shop certification, so we can assist Andrew Bittner during this final assembly process. As of March 31st, 2022, we’ve completed installing the ramp’s trailer rear lights, removed the trailer wheel fenders, and purchased most of the components.
The team installing the rear trailer lights and removing the wheel fenders.
In this month, we began looking into the finalization of the portable + foldable mounting ramp and began preparations for the conceptualization, selection, and purchasing of the remaining components—which includes the hand-rails, expanded metal flooring, hinges, and (a new item) the flooring extension. To ensure a clear understanding of the project, we met with the project partner, Bobby Valdez, and Andrew Bitner to discuss the details, complications, and feasibility of certain components.
In our first meeting with Bobby Valdez, we discussed the initial state of the project and the major goals for this semester. Here, we learned that the frame, designed by previous teams, had already been fully manufactured and welded together, leaving the finishing touches (e.g., the flooring, handrails, hinges) for our team to complete. Bobby mentioned including additional features for the frame such as extending the flooring over the wheels and implementing side-covering panels to prevent the horses from getting injured by kicking the wheels or by having limbs get stuck in the frame, respectively. However, as implied by Andrew Bitner, these additions may not be feasible for the scope of this semester since the costs for the project had already gone over budget in the previous semester.
The completed portable mounting ramp frame.
A few weeks into February, our team further organized this semester’s goals with the completion of our Project Charter and Project Plan. Here, we highlighted our main tasks and produced a Gantt chart timeline for us to keep track of time.
Spring 2022 semester timeline for the Equest project.
Since then, we’ve started looking into the conceptualization of this semester’s additions. As mentioned earlier, we met with Andrew Bitner to discuss these concept topics and, subsequently, we were left with a general understanding of how we could approach these various components. Starting off with the handrails, we decided that they would be inserted into sockets on the side of the frame and be removable—allowing users to easily detach the rails and, thus, be able to fold the ramp when needed. However, for the component itself, we could either design the rails ourselves or look into potential online options to save cost and time. For the flooring, the previous semester had already ordered the necessary amounts of expanded metal for the completed frame, though additional material may be required to satisfy the added dimensions from an included flooring extension (which is discussed later). The previous semester introduced piano hinges as a potential option for the ramp hinge, which spans the width of the ramp. To save cost, we are looking into other options of smaller sizes that we can use in numbers to attach the frame components. However, the derivation of force ratings for these other options becomes necessary to ensure zero mechanical failure can occur. These derivations will depend on how we attach the hinges to the frame (either bolts or fillet welds). Finally, we conceptualized how we could approach the platform extension which covers the outward protrusion of the trailer’s wheel and fender. The likelihood of implementing this depends on the budget we’re provided for this semester.
CAD for the platform extension.Aerial view of the platform extension
For next month, our plan is to: 1. Complete the selection/design of the components (Before Spring Break) 2. Purchase the necessary material and components (Before and After Spring Break) 3. Begin machining/welding at the UTD Machine Shop and assist Andrew (After we complete the machine shop training)
