Pneumatic port size 2020

Technical Pneumatics
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My team is wanting to use a pneumatic cylinder, NCDQ2WB50-50D-F79W-XB9, and want to know if it is legal to use. Could you help us?

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So long as it has the correct pressure ratings as stated in the manual, and it is under the maximum cost per item also defined in the manual. Then you should be fine. A quick look up didnt find much myself, so you’ll have to look a bit more than I did.
Also make sure that yours isnt moddified at all from its original state.
The one other thing is making sure you can use the right fittings to connect to legal size pneumatic tube

(Quick edit, make sure you look through the entire manual to make sure its legal as I might have missed something)

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The rules for pneumatic parts are listed on page 32 of this part of the manual. I don’t see any rule that would prevent you from using this.

I would question why you’re using it though. This cylinder is great if you need to move a 180 pound object about 2 inches (or two 90 pound objects, since it’s double-sided). It’s large, heavy, discontinued (so you can’t buy it from SMC anymore), and way more industrial than anything required in FRC. The only reason I would use this cylinder on a robot is if I already had it and couldn’t afford a more appropriate one.

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To speak to your thread title, if there is confusion over the wording of the manual’s port size rules, I’ll point you toward this portion of the FAQ section of the basic pneumatics guide I put together:

Is [particular valve or actuator] legal?

  • Highly dependent on a given year’s rules; Restrictions in the past have been based around Cv or flow rating, port size, tube size, etc.
  • It should be noted that pneumatics components are generally considered “sacred” by the manual, i.e. they are not allowed to be modified like some other COTs components may be
  • Please read the rules from a given year closely
  • In 2019, some confusion was caused due to this portion of the manual:


Image: A screenshot of rule R84C from section 10.9 of the 2019 FRC Manual Robot Construction Rules

  • The text in parentheses led people to believe that ⅛”, and therefore 3mm, were diameter dimensions to look at in regards to port size. If you were to actually measure the diameter of a ⅛” NPT threaded port, it would measure at approximately .4”, depending on where you measure along the tapered thread. This is because the ⅛” refers to the nominal pipe size of hard pipe that would be used in a fitting, which is based on the pipe’s inner diameter. No, it’s not intuitive. Yes, it is an incredibly mundane topic to try and research. Looking up the dimensions for a given pipe thread size will help you find your answer.

By my reading the rule has not changed this year.

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