1418 Vae Victis | Pit^2 Build Log

[Jungler]

Howdles!

This thread is a showcase of the design and build process of 1418’s new pit which has been so amazingly named “Pit Pit”. I admit that I probably could have come up with a better name, but this one just has a nice ring to it. This post will be about defining the constraints and requirements of the new pit, as well as providing an overview of the current state of our pit.

The current pit isn’t really anything spectacular, however, our newest addition was a Milwaukee Packout System which has served us extremely well. Beyond that, all we have is a large husky box for our bumpers, our wooden battery cart, and a generic folding table. In the past, we had a scaffolding system from our school’s theater department but after it viciously attacked a mentor and left him with a cut down his forearm we have since decided to relegate it to extra storage.

This meant that we needed a new pit, but what does that look like? Despite knowing literally 0 amount of Onshape I threw myself at my laptop trying to create a model to convince our head mentor and school system (we’re largely reliant on our amazing high school) that this was a great idea. I took immense inspiration and reference from team 4414’s Pit, so a huge thank you to them for being super detailed and open about their fantastic pit! Additionally, team 1339 has an amazing Road Case Pit which is super useful when determining the placement of the latches, so other huge thanks to them.

Unfortunately, our team doesn’t have a massive trailer or truck to transport our equipment, instead, we have a school facilities van, it’s a Ford Transit 350 with a medium-height roof. Thankfully though, we do have a liftgate installed on the back so we can load cargo and equipment. What this means is that whatever I design needs to fit in the back of the van and on the liftgate, which as it turns out is easier said than done. The liftgate has a capacity of 1100 lbs and a 47 x 49 in lift area, while it is possible for the pit to hang over the edge a little while lifting I would Like to avoid doing so for obvious safety reasons. When I saw 4414’s pit writeup I instantly fell in love with the idea of a road case design. While I knew that I would have an insanely small space to fit the pit in, I wanted to have a longer and more consolidated single case rather than 3 separate ones. Initially, I had designed a prototype case with the intention of just renting a Uhaul trailer. But after conversing with my mentors I understood that it would be unsustainable to need to rent a trailer for every event we go to, especially after I graduate this year. The initial design combined the two parts of other road case pits (the tool chest and the battery charger/ command center) into one seven-foot-long road case. The advantage of this is that we can still bring our other equipment (the folding table gets to stay!!) as it would only occupy one side of the pit dimensions. Additionally, it would mean that all of the equipment would be consolidated to a greater extent, we wouldn’t need to unload 3 cases, a robot, and the packout system.

This first design didn’t fit within the liftgate -or even through a doorway as it turns out but most critically it was going to be too awkward to move. Weighing at around 1800lbs fully loaded it would easily exceed the liftgate weight and likely require the entire team to move it as it would be incredibly awkward to go through any doorway (if it fit at all) or make any turn. So I went back to the drawing board (or the Onshape board in my case). I decided that I really wanted to keep the oversized long road case which combines the multiple workstations, but I wanted to make it more transportable. To solve this problem I followed the Flex Tape™philosophy and just cut it in half to make two four-foot sections joined together by latches. This would also allow the liftgate to hoist the weight in two separate sections of just under 1000 lbs, below the 1100 lbs max (barely).

Some of the key features of the design include:

• Split Road Case Design
• Room for DSR 127 Battery Charger
• 46” Husky tool chest
• Hidden rising shelf
• Cable organization Panels
• Removable window above the workbench
• 1.5” Maple worktop
• Metal plate inlaid to prevent freshmen from destroying worktop with drills
• 6 Sortimo brand (hopefully) small parts boxes
• 32-inch monitor to aid in scouting and documentation (programmers love this! [maybe])
• 20 Amp internal wiring in case the venue allows it
• Sturdily overbuilt wheels with a max section capacity of 2800 lbs
• 17 handles around the perimeter to allow even the smallest of freshmen to maneuver it

As we keep working on this I will keep this thread updated with the progress, please by all means feel free to post questions, comments, or concerns. Our collection of resources, including our semi-okay CAD model and parts list, can be found below.

Sponsorship Goals/ Parts List

Aforementioned Semi-Okay CAD Model

[Jungler]

Howdles!

With the winter break and kickoff happening the past month has been a perfect description of the calm before the storm. Before we went on break we received all of our final pieces for Pit^2, woohoo! This means that all of the aluminum extrusion, wheels, and a couple of miscellaneous pieces were accounted for. Unfortunately, I made a goof when obtaining the quote and forgot to order the appropriate bolts and nuts to attach the caster board and wheels. Thankfully, these hex bolts and t nuts are arriving today! I’ll attach the complete order form below but keep in mind all of these parts will be on the shared spreadsheet I shared in the previous post.

On Tuesday, January 10 we laminated all 6 sheets of plywood with the ABS material. To do this, we brought sheets of 4x8 ft Sande Plywood to our outdoor garden area since the adhesive comes in an aerosol can. We used 1-1.5 cans per sheet. We sprayed the laminate and plywood after we lined them up and clamped them to ensure they would fit perfectly. We tried to spray an even coat but it was difficult with the draft from the open door and the wind so some of the adhesive got stringy and wrapped around the laminate to the exterior side. Because of this a couple of pieces have some adhesive on the wrong side but it should be simple enough to get rid of with a solvent (fingers crossed, haven’t tried yet). We rolled the laminate back onto the plywood in half sections working from the middle out with our hands and a J roller. We squeezed out as much of the air bubbles as possible and after we finished each panel we laid them on the ground to make a stack that would weigh the laminate down to hopefully squeeze any excess or remaining bubbles. At the end of the day, we moved all 6 panels inside onto 3 folding tables to be stacked and weighed to let sit for 24-48 hours as they fully set.

On Thursday, January 12 we measured and cut the caster board, this is the very bottom piece of sande plywood that will distribute the weight evenly and hold extra thickness to mount the massive 5 lbs wheels. From cutting these pieces I learned how to improve the workflow: don’t use the table saw, the pieces are far too large (8ft wide) to cut in half perfectly and quickly. Instead, we later found that using our track saw would provide the best clean cut while still being relatively quick and painless to manage and set up. I had a little bit of a drain bamage moment when I was ordering some of the parts and forgot to order the bolts and t-nuts, I ordered them that day and they actually got here today! (Saturday).
Here are some pics of the caster board

On Saturday, January 14 we began cutting our first laminated panel, panel 1 comprises both back walls for each half of the case. At this stage we used the track saw to cut each half so that we could split the work between the two of us (we really do be short-staffed man). Unfortunately, in my rush to cut the halves, I forgot to check below the cut, and even tho I didn’t cut the table I did cut one of the caster boards almost cleanly in half in addition to the back wall. No worries tho because it is load-bearing in a way that requires continuous support I will fix it! To fix the board I am going to cut it cleanly in half then create a lap joint using a router and jig to allow me to lay a piece to bridge the new gap. I have scrap material that will allow me to bandage the board back together with wood glue and some wood screws. This isn’t strictly necessary but it does (somewhat) prevent my peers and mentors from roasting me into ashes for mistakenly chopping a piece of wood in a dumb way. Regardless of the joint working, I will be attaching the caster board with the aforementioned forgotten (but now delivered) t-nuts and bolts. 32 of these bolts will be for the 8 wheels and will bear the most force and weight while an additional 18 will attach the caster board itself to the floor panel. 9 bolts on each half should be all that is necessary but my anxiety argues for more. On this long Saturday meeting, I also began planning out the layout of our logo on the back panel, one issue however, is that the logo should be centered but if it is it will be split down the middle by the seam of the two halves of the road case. I considered putting the logo on one side and the words “1418 Vae Victis” on the other side but decided against it. To complicate things more I received a suggestion/ demand from our coach that we have the sign be LED-backlit (for added annoyance and flare). I think I will just embrace the seam and split the design in half, it shouldn’t look terrible, right? I am open to any input. We managed to install 2 pieces of hardware into the back wall though, a small access door and a perforated ventilation dish.

Tomorrow, Monday, January 16 we will work on finishing the entirety of panel 1, including the hardware mounting, cutout panels, and riveting metal extrusion on the sides.

That’s pretty much all for this post, progress has been a little slow but it should be picking up soon enough, will keep this thread updated from now on, I promise.