I spent the day at WPI helping build the practice field there. Here are my initial thoughts:
Reef
The reef base has a lot of oddly shaped pieces of plywood. The majority of the time was spent cutting plywood.
The team element plans come with two sets of plans, one for building just the base so you can buy the branches, or a monstrosity of wood that holds pvc pipes in place. I can’t imagine anybody would go for the monstrosity. It will be easier to manufacture your own branches out of pipes.
I’m thinking of making my own branches out of 3/4" electrical conduit. I don’t think the diameter of the branches matters that much for game play, so smaller diameter is easier to bend (and cheaper!) Bending it to match the dimensions of L4 shouldn’t be a problem. L2 and L3 can be made of separate pieces with enough extra length to bend down and attach to the main stalk with hose clamps. At most I would pad the diameter with PVC in the three locations that the robot can hang coral on it.
For our team’s home practice field, we need to modify everything to be able to taken down after each use, put on wheels, and maneuvered through a 30" door frame. I think the branches will have to be removable for us. I’m hoping that all six sections of the base will be light enough to tip sideways onto a dolly.
I haven’t combed through the materials to find the answer yet, but I’m not sure if the branches are able to swing side to side in their holes or will need to be fixed so the branches face the robots.
Barge
At WPI, team 190 has truss for their practice field. It is pretty easy to assemble the barge from the truss. Two of the three feet of the truss sit outside the walls field. So you need extra width next to your field to accommodate this.
For 1073’s home practice field, the team plans won’t work without modification. The unit is just to large to fit through doorways. I’m still evaluating how to deal with this. I’m thinking of making the top of the barge removable from the uprights.
I just assembled this Branch out of half inch electrical conduit. Thicker would be sturdier but I had a piece lying around of half inch and the bending tool for half inch. I think this basic premise will work fine. The hose clamps seems sturdy and keep things aligned well.
I’ll report back about the advantages and disadvantages of each.
Our field build will be on Saturday. We have parents volunteering to come in and help. At this point, everything is as ready as I can make it. The shopping is done, the wood and pipes are unloaded into the shop, the plans are printed, and the tools are laid out.
If you are trying my design, definitely go with the version that has a 3/4" EMT conduit core for the vertical section. I finally made a set last night and it is night and day better than only PVC
We did a print last night. I recommended that version, but I’m not sure which version actually got printed. In any case, I’ll have to buy some conduit. Thanks for following up with the tip.
Team update 002 change algae inflation tolerances such that the minimum inflation is 16" rather than 15.5".
The sizing tools have been removed and replaced them with an algae inflation jig. The jig could be replicated from a 1/2" thick plywood with a 16.25" hole cut in it. It would need legs to stand such that the top is 8.125" off the ground.
Creating sizing tools for 16" and 16.5" would be way easier, but maybe making a jig would give us more accuracy.
We made two algae sizing tools out of the scrap piece of plywood that was cut from the processor opening. One has a 16" claw, the other 16.5". I think that is good enough and we won’t make the new inflation jig.
It was good that we made the sizing tools, all of our algae was underinflated before we measured it.
Unlike the official team elements plans, they have to be able to stand fully on their own as we lift the barge onto the tops of them, so they have feet coming out in four directions.
They are on homemade furniture dollies so that we can wheel them to the practice field when we roll out the rugs.
I ended up chopping 3 inches off the bottom compared to the plans I posted earlier. This is so that the piece can fit through a 36" doorway if we turn it sideways.
Overall, I am very pleased with how well the barge came out. It is very sturdy. It doesn’t need pins to hold it together, gravity holds it together well enough.
These are two of the four styles of branches we had planned.
The one in the front is 1/2" conduit that I bent in a post above. I added the PVC to make the parts that the robot interact with the correct size. It has closed cell foam packing wrap between the conduit and the PVC to keep the PVC in place. Overall this one works pretty well so are.
The one in back is the Geometrically Accurate 3D Printed Reef Pipe Fittings. We had some trouble assembling it. Like other teams we had to do some sanding on the 3D printed connectors. It has a 3/4" conduit inside to make it stiffer. I suspect that the robot will occasionally break the twigs off these branches.
The 3D printed connector sleeves that we tried didn’t work out. The sleeves cracked when we inserted the PVC pipe into them.
Our official pipes that we ordered haven’t come yet.
