I had some requests on the World Coaches facebook page for a less expensive field riser made with wood construction (compared to the 80/20 aluminum field riser that we use for VEX Team 3547:Virus. Here are the plans, a 12’x12’ stationary riser, and 3 “portable” variations: VRC WOOD FIELD RISER PLANS.pdf (438.7 KB)
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Plans for all the VEX Team:VIRUS field risers, VRC and IQ, aluminum and wood, can be found here: https://drive.google.com/drive/folders/1ov2NzN39V26Id_NbbsVL0HFcHCcRHfrX?usp=sharing
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We have built a riser to test practice on.
When we built the riser with double layering it with sheet-wood, and despite there being double layering the sheet-wood started to have bowing towards the unsupported areas. The only way to prevent this likely would be to construct a rule that you must step on the field in areas that are reinforced (i.e. where a beam goes across). But if you want to prevent all doubt of bowing, you’re probably gonna have to buy the risers that are used at VEX Worlds.
Choice of design and materials is critical for a successful field riser. The last thing we want to see are issues with fields that are unlevel, sagging or poorly fit, as illustrated by forum threads such as this one:
Leveling of fields.
Sadly, some of these events rely on rented commercial field risers, so the quality of the platform is outside the control of the event organizer. If you seek commercial platforms, here is a sample of what is available: http://www.stagedrop.com/store/Search.aspx?SearchTerms=12'x12' For sturdiness, I would recommend the Biljax riser, which will set you back about $2,100 for a 24” platform.
Back to “home-built” risers: we have been using our aluminum field risers, topped with a single sheet of ½” OSB, for over 5 years of continuous use, including both local events at the Michigan MS State championship, and have never had issues or complaints about the field from any visiting teams. ½” OSB has a of “32/16 APA span rating, 70 psf allowable live load,” which means with joists on 16” centers, the material can adequately support 70 pounds per square foot. This is certainly enough for VRC robots, and perhaps a little springy for people to walk around on the platform, but then, people are not on the platforms during competition. Our aluminum risers are actually 24” on center, so it is a bit more springy than rated, but again, perfectly adequate for VRC robots. To have platforms that would meet residential floor standards, simply increase to 23/32 thick OSB (and add 50% to the weight that you have to move around for a portable riser!). OSB is recommended over plywood as it is more uniform and flatter than plywood, which tends to warp and have soft spots. MDF is not “span rated” for flooring, but it is a nice material for VEX IQ fields. Particleboard is not recommended at all (although span rated, it is not durable).
Here are our aluminum field risers at the Michigan MS State Championship:
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Super mad props for making the wooden plans. I am hoping to build the 6x6 version at some point this year and will post a finished assembly when we get there.
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Can confirm. My organization built a field riser from a few pieces of 4x4 for the legs, a bunch of 2x4 for support, and some 3/4" plywood and its not quite perfect.
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What were the main issues? Were the different platforms not flush?
one of the legs is half a millimeter too short so it bounces a lot. other than that, its just not as perfectly even as it could have been.
Flex, warp, and twist will be a general problem with wood construction. Advantage is that it is MUCH cheaper. We have been fortunate on Team VIRUS to have the funds for all our risers to be aluminum (it didn’t hurt that our first 80/20 aluminum riser was made almost entirely from scraps from a previous employer, either). If building from wood, the 6x6 risers will actually be better than the 12x12, and the 4x4 will be about the best of all.
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@kmmohn - an old post, but still very relevant; thanks again for putting up the plans for the wood field riser! The team put one together a few months ago and it’s been GREAT! Super sturdy and easy to keep level. Even with wood prices increasing, still a good value for a reasonable cost. Thanks, Team 3547:Virus!
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The ones that are generally used for the Tennessee state championship are super sturdy, field resetters can walk on them easily. I’m not sure what they are, I’ll have to check, but I also think that they are pretty pricey, too.
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