Hydraulics?

[s_forbes]

Originally Posted by Ian Curtis

A look inside the wheel well of a 737 gives you an idea of how awful it is to manage all the tubing for hydraulic lines. It's also pretty heavy.

Fortunately we don't build such complicated systems for the FRC... although if a team showed up with something like that they would become an instant favorite of mine!

I think it's interesting that teams are allowed to compete with some dangerous and failure-prone electromechanical mechanisms year after year, but for some reason the thought of a hydraulically actuated device is thrown right out the window for safety reasons. I understand the oil-on-field issue, but if we're using something that's field-safe like water, is there actually a serious risk? (reference some 2008 catapult robots when making your comparison. )

[Andrew Schreiber]

Originally Posted by s_forbes

Fortunately we don't build such complicated systems for the FRC... although if a team showed up with something like that they would become an instant favorite of mine!

I think it's interesting that teams are allowed to compete with some dangerous and failure-prone electromechanical mechanisms year after year, but for some reason the thought of a hydraulically actuated device is thrown right out the window for safety reasons. I understand the oil-on-field issue, but if we're using something that's field-safe like water, is there actually a serious risk? (reference some 2008 catapult robots when making your comparison. )

My objection wasn't safety related it was related to not wanting my robot sprayed with water because someone else couldn't be hassled to prevent their system from leaking.

Originally Posted by s_forbes

Fortunately we don't build such complicated systems for the FRC... although if a team showed up with something like that they would become an instant favorite of mine!

I think it's interesting that teams are allowed to compete with some dangerous and failure-prone electromechanical mechanisms year after year, but for some reason the thought of a hydraulically actuated device is thrown right out the window for safety reasons. I understand the oil-on-field issue, but if we're using something that's field-safe like water, is there actually a serious risk? (reference some 2008 catapult robots when making your comparison. )

I love how we are limited to certain parts and mechanisms due to "safety", yet half of the games wield robots who can majorly harm people and objects. Two examples are from 2008 and 2010. Some robots in 2008 could shoot the track ball so high and far at such high speeds, if one shot out of the field it would damage something, or severely injure someone if they get hit. Same with 2010. Some robots in there could fire soccer balls off so hard that it could be serious injury to anyone, and could be life or death if it hit someone in the head (Maybe a little exaggeration.....).

[s_forbes]

Originally Posted by Andrew Schreiber

My objection wasn't safety related it was related to not wanting my robot sprayed with water because someone else couldn't be hassled to prevent their system from leaking.

I'm guessing this is a greater risk than a team jamming their arm into your electronics board, right?

With all of the water game hints, you've got to be ready for it some day!

[Andrew Schreiber]

Originally Posted by s_forbes

I'm guessing this is a greater risk than a team jamming their arm into your electronics board, right?

With all of the water game hints, you've got to be ready for it some day!

I can shield that from an arm. Short of waterproofing my entire electronics system there are few things I can do to prevent water from getting into my CRIO.

[sanddrag]

In last year's rules for example, would it have been permissible to concoct your own hydraulic setup? Or was there something disallowing that?

[MrForbes]

Oh, I guess it depends on the definition of "is"

<R02> ROBOT parts shall not be made from hazardous materials, be unsafe, or cause an unsafe
condition. Items specifically prohibited from use on the ROBOT include (but are not limited
to):
...
J. Hydraulic fluids or hydraulic components

I suspect they are referring to an oil type of hydraulic fluid, but you never know.

[davepowers]

Originally Posted by SuperNerd256

I love how we are limited to certain parts and mechanisms due to "safety", yet half of the wield robots who can majorly harm people and objects. Two examples are from 2008 and 2010. Some robots in 2008 could shoot the track ball so high and far at such high speeds, if one shot out of the field it would damage something, or severely injure someone if they get hit. Same with 2010. Some robots in there could fire soccer balls off so hard that it could be serious injury to anyone, and could be life or death if it hit someone in the head (Maybe a little exaggeration.....).

So you're refering to something like this happening? Poor Dean, why'd it have to happen to him? .

-Dave

[Tristan Lall]

Originally Posted by SuperNerd256

I love how we are limited to certain parts and mechanisms due to "safety", yet half of the games wield robots who can majorly harm people and objects. Two examples are from 2008 and 2010. Some robots in 2008 could shoot the track ball so high and far at such high speeds, if one shot out of the field it would damage something, or severely injure someone if they get hit. Same with 2010. Some robots in there could fire soccer balls off so hard that it could be serious injury to anyone, and could be life or death if it hit someone in the head (Maybe a little exaggeration.....).

There's a bit of interesting backstory behind the safety-related restrictions over the years. Basically, FIRST has had different concepts of what is adequately safe from year to year. As safety enforcement is generally implemented by interpretation of the catch-all safety rule (typically <R01> or <S01>), there is great discretion given to officials. While there are efforts among the referees and inspectors to standardize their rulings within a year, and FIRST gives this thought between years, the outcomes of this process aren't always adequately communicated to the teams.

In 2006, in particular, FIRST pushed hard for safety, both in terms of ball speed (they tested it against a limit) and in terms of mechanism design. They instructed the inspectors to require significant shielding of rotating machinery on shooting mechanisms. This standard was a bit more restrictive than teams had been used to, and there were a few teams, 188 included, that got tripped up by it. There may have been a Q&A response about it, but perhaps the most prominent documentation of such a standard was the (official but non-binding) inspection checklist, which read "Safety and Wedges: No sharp protrusions or edges, no entanglement risks, no wedge-shaped robot bases that may potentially affect other robots, shooter mechanisms (if used) must be shielded (3/4” dowel test)". This was also discussed at length among inspectors, and the directive was to draw upon industrial practices for guarding of machinery.

So, returning to your original point, this was an attempt to avoid the possibility of serious injury (pinch points in shooters), and yet it was unhappily received by the teams, who were too disappointed at the onerous interpretation to care that FIRST was trying something new to promote more safety across the board. I don't hold this up as an example of great policy—after all, there are very few opportunities for a person to make contact with a robot (protrusions excepted) during a match—but I do think that FIRST probably deserves credit for trying to be safety-conscious when it comes to mechanism design.

And incidentally, let me reiterate that the hydraulic ban is not mainly a safety concern—it's a cleanup concern. It's the pneumatics rules that are primarily safety-driven—and they're conservative to a fault.