Legal Rope Material for Spin Up?

Just curious if there is any restriction on what kind of rope we can use since R7 simply states “An unlimited amount of rope / string, no thicker than 1/4” (6.35mm)”. Would this open the door for teams to use steel rope for structural elements on robots?

If it has rope in the name its rope right? :sweat_smile:

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This came up in the Tipping Point Q&A and the answer was yes, steel cable counts as rope:

Previous seasons’ Q&A responses do not automatically carry over, but given that nothing about the rule has changed there is no reason to think the answer would be different if the same question gets asked this season.


Thanks for the reply! Didn’t know that there was a Q&A over at robotevents.

Best of luck for Spin Up!

I was wondering if theyd allow us to use polychord and melt the ends together.

I believe that melting is listed as an illegal modification, however, it was written under the legal/illegal modifications for plastic sheets, so I don’t know how if if it would carry over. Honestly I would just tie the ends together. The knot shouldn’t get you dq’d, because it’s still just two pieces of rope tied together, and they can both be separated.

Look at <R22> d:

d. Fusing / melting the end of legal nylon rope / string (see ) to prevent fraying is permitted.

So the only permitted use of melting is to prevent fraying - not connect segments of rope together.

Hope that helps.

You can find the 0.1 version of the manual here:


the typical usage of polychord, at least within my team, is to form rounded belts with superior grip to string, with near seamless uniformity due to melting together the belt and cutting off excess. I think that the usage of polychord with pulleys would require this seamless-ness which can only be gotten from melting two ends together.

I think trapping/blocking will be big tactic in the endgame.