Re: Al's Annual Inspection Thread 2015
 

Taping a white piece of paper onto it would work for me.

Haha well that would kinda take away from the work I did to make the number plates to begin with.

Re: Al's Annual Inspection Thread 2015
 

Ben,
Thanks for the report, it would seem that the hose is doing it's job.

Even white gaffer's tape works for extending the border. It is ugly but it satisfies the rule.

Any changes that you think are minor may be a major change in the eyes of other competitors. Please check with the RI's before you make the change. We had some great teams who constantly worked on their robots in Duluth this weekend. They were coming and weighing parts that they were planning for modification. If we see it first, we can tell you if it is legal and a good way to attach it to your robot so that re-inspection will be painless. Thank you to all the Duluth teams who were re-inspected prior to the end of qualifying.

The procedure for calibrating the pressure relief valve will not overly stress your pneumatic system. Many parts, tubing included, list the 'working' pressure. "Burst' pressure is far above that. The tubing at room temperature is generally rated for 150-165 psi as I remember. The relief valve is in circuit as you would expect. It the software, pressure switch or compressor controller were to fail and the compressor was running constantly, the pressure would never exceed burst pressure for any components. Under certain conditions, a second pressure relief valve is required for components that have a reduced burst pressure. See R66.

Re: Al's Annual Inspection Thread 2015
 

Al - I meant to ask up in Duluth, but forgot while we were up there... could you explain the reasoning behind R66D?
I'm just wondering what the second pressure relief valve does that our relieving regulator doesn't already do. Is it required incase the relieving regulator fails to relieve? The first pressure relief valve is required to be attached to the compressor through hard fittings, but the second one can be anywhere on the low pressure side, connected through tubing.

Re: Al's Annual Inspection Thread 2015
 

Jon,
There is some solenoid valves that are designed to be run at 25-45 psi. The rules allow a team to use a second regulator that is down stream from the main regulator to supply this much lower pressure. The rules do not require that secondary regulators be relieving. So to protect a failure in these low pressure components, FIRST Engineering decided to add the secondary relief valve should a failure occur. Such a failure could cause pressure in excess of the burst pressure of these other solenoid valves. I think in the past few years I have only seen one or two robots with these valves. They may be more common in other countries than here in the US.

Re: Al's Annual Inspection Thread 2015
 

It definitely makes sense if it's downstream of a non-relieving regulator when the pressure rating is that low. I had been thinking more along the lines of solenoids like these that are rated "0.15-0.8 MPa / 22-116 PSI" - per the letter of the rules, they need a secondary pressure relief valve even though we're talking about just a couple of PSI away from 125 PSI.

Re: Al's Annual Inspection Thread 2015
 

Jon,
We have used these valves in the past and some robots this weekend had them installed. The 'recommended' working pressure range is published but when asked the manufacturer has said the working pressure is greater than that. The recommended pressure is that range in which valve life is optimum. Above that range, internal items wear a little faster and below the range, the valve cannot be guaranteed to operate. Burst pressure, (which is rarely published anymore) is greater than 150 psi.

Re: Al's Annual Inspection Thread 2015
 

I am not Al, but. A large number of industrial solenoid valves have a working pressure of 110-120 PSI. They would not be legal prior to 2011 when the provision of the 2nd relief valve was added. The second relief valve with lower set pressure than the valve rating protects the valve if the primary regulator breaks or is turned to higher than the working pressure of the valve. Since the set pressure of the relief valve is lower than the allowed stored pressure it has to be on the working pressure side. It is a back up to a back up.

Re: Al's Annual Inspection Thread 2015
 

At Georgia Southern Classic this past weekend, we formalized the re-inspection process. When a team came up for re-inspection, we recorded this on a separate form attached to their original inspection form. We noted what was changed, got a new weight if necessary, signed the form, time stamped it, got the team to sign it, then put a dot sticker with the re-inspection number on it by their original sticker. Took only a minute to do and EVERYONE could verify that the r-eispection had been done. This keeps everyone out of trouble later.

Don't know why FIRST doesn't institutionalize a similar process, especially after the incidences last season.

Re: Al's Annual Inspection Thread 2015
 

There's an old thread around somewhere - I have an email from SMC Tech Support in 2010 stating that their SY3000 series valves (rated operating pressure of 100 psi) "will not catastrophically fail at or below 125 PSI due to air pressure alone". They use the JIS standard proof pressure definition of 1.5 times maximum operating pressure. I researched it back then to show that we were in compliance with the rules and didn't required an additional relief valve.

Re: Al's Annual Inspection Thread 2015
 

Rule 66D: The rule says for valves with working pressures below 125 a secondary relief valve is required. While I agree the SMC would be safe without the extra relief valve, unless the email said to effect that working pressure or operating pressure is greater than 125 psi, by rule you need the extra relief valve.

Re: Al's Annual Inspection Thread 2015
 

This one?

Re: Al's Annual Inspection Thread 2015
 

I am a little surprised & pleased by this Q&A. If this is in your plans, I would have the drivers keep a print out of this with them.

Re: Al's Annual Inspection Thread 2015
 

No, this one

It also includes a link to the GDC answer to Q&A that year that said it was sufficient, I don't think any circumstances have changed since then even though that ruling is obviously not binding this year.

Re: Al's Annual Inspection Thread 2015
 

It would be nice if the GDC would reword the rule to what they actually accept. The SMC response clearly says the valve can malfunction at 125 psi. It just will not blow up at that pressure. :]
(emphasis mine)