Robot Plastics

[TEACH]

The rules state we can use a 24x24" sheet of certain plastics. Is it legal to purchase a already formed tube that falls within the legal amount of square inches? If this isn't the proper place to post this type of question, can you tell us how to post correctly. Thanks

[Billfred]

This isn't the right place, actually--the official word comes from the FTC Q&A forums. (Being an FRCer, I don't know where you get the credentials to post your question there; perhaps someone else knows that process.)

Also, I'm nudging this into the FTC forum here on CD.

[JesseK]

My first guess is that the GDC will say no, that a pre-formed tube is illegal. The 24"x24" is stipulated as a sheet by definition. Hence, you'd have to come up with a legal way to join opposite edges of the sheet in order to make a tube. You may argue that you can melt the edges together so why isn't a pre-formed tube allowed, but the GDC may fire back that melting things together is a form of illegal soldering/welding. It's best to make a holistic interpretation to the rules rather than a case-by-case basis.

Hence, the best legal way to make your tube is to drill holes, overlap the edges, and put bolts or zip ties through. Or you could bend the edges backwards creating a crease, then lock the two creases together -- though something tells me that the creases will crack.

It's very possible that my interpretations are completely off, so I too suggest asking the GDC yourself.

[qwertyuiop[]\]

Coming from my teams experience in already having made a tube, you should heat the plastic, drape it over a cardboard concrete form of appropriate size (available at homedepot) while it is still soft to form half of the tube. make two of these. you can do this in basically any oven that is big enough. our school happened to have an oven that hadnt been used in probably 20+ years but still worked great! after you have the two halves cut two 1 inch wide strips that are the same height then use these to glue the two halves together with polycarb or abs or whatever kind of plastic you are using glue. you also can do it with out heating the plastic and just have it be flexed but it is much more difficult to do. if you do heat, set the oven at about 300 degrees F and put the tube and plastic in the oven for about 4 minutes or until the plastic drapes over the tube. its safe to put one of these cardboard tubes in the oven but build a rack for it so it doesnt roll around.