Removing FP motor outside sleeve legal?

[Rob]

Hello,

Does anyone have a hunch about whether removing the steel sleve around the outside of the FP motor would be legal under <R54>?

It seems to me that this would meet the "intent" portion under modifying the mounting arrangement of the motor (we would like to remove it to facilitate mounting).

We are posting to Q&A but I was interested in seeing what people's opinions of this are.

On a more academic front, does anyone have an estimate of how much power the motor could lose by removing the sleeve?

Thanks,

Rob

[Mike Betts]

Originally Posted by Rob

Hello,

Does anyone have a hunch about whether removing the steel sleve around the outside of the FP motor would be legal under <R54>?

It seems to me that this would meet the "intent" portion under modifying the mounting arrangement of the motor (we would like to remove it to facilitate mounting).

We are posting to Q&A but I was interested in seeing what people's opinions of this are.

On a more academic front, does anyone have an estimate of how much power the motor could lose by removing the sleeve?

Thanks,

Rob

Rob,

Obviously you realize that it is there for a reason and that you will lose power if it is removed. Good...

In the past, this question has been asked many times and the GDC's response has always been no.

However, to get this year's response, you should post this to the official FIRST Q&A.

In reply to your last question, since the GDC has never allowed the sleeve to be removed, I'm not sure that anyone has ever done testing on it in that configuration.

Regards,

Mike

[Rob]

Well it looks like history is not on our side here. I guess we will start to plan for finding a way to mount the motor with the sleeve on.

If we don't like the Q&A answer can we ask them to go back and try again!?! Just kidding

[Mike Betts]

Rob,

The GDC has reversed itself on many occasions. For example, they ruled pneumatic check valves were legal a couple of years ago and this year they are illegal.

You really should ask...

Good Luck.

Mike

[gorrilla]

Originally Posted by Mike Betts

Rob,

Obviously you realize that it is there for a reason and that you will lose power if it is removed. Good...
Mike

Why does it lose power if the sleeve is removed?

What does the sleeve do?

[Joe Johnson]

Originally Posted by gorrilla

Why does it lose power if the sleeve is removed?

What does the sleeve do?

The sleeve redirects the magnetic lines of flux to make a stronger magnetic field inside the motor where the armature is. This is a common trick used when the can of the motor is not thick enough to redirect the flux all by itself. Removing it will definitely adversely affect motor performance.

Joe J.

[Mark McLeod]

That was quickly answered:
http://forums.usfirst.org/showthread.php?t=14681

[dlavery]

Originally Posted by Mike Betts

The GDC has reversed itself on many occasions. For example, they ruled pneumatic check valves were legal a couple of years ago and this year they are illegal.

Oh. Really? Can you provide examples of where the GDC has "reversed itself on many occasions" this year? To the best of my knowledge this has only happened once, which was documented in this Q&A thread, where they realized there was a conflict between Q&A answers, and a correction was quickly provided.

I do not consider a change in the rules from year to year to be a case of the GDC reversing themselves. Time and time again, FIRST has repeated one of the most fundamental tenets about the FRC game - RULES FROM PRIOR YEARS DO NOT APPLY TO THIS YEARS GAME. Each year is an independent effort, with different constraints, different requirements, different inputs, different restrictions, and different opportunities. Each set of rules should be viewed with a fresh set of eyes and an open mind, not clouded or confused by experiences from other competitions that may no longer be relevant. It is hoped that all the teams, and in particular all the inspectors, would understand this.

-dave



.

[EricH]

I can think of two occasions where a GDC ruling underwent a lot of tweaking or a reversal, Dave. "In" the loading zone in 2005 (can't remember if touching was originally a requirement, but it sure became one by the end of build) is one. The other was in 2002 with tape measures. Admittedly I wasn't around that year, so I don't know all of what went on, but from what I have heard from those who were around, it was "No tape measures to contact the home zone" and then became "You can use tape measures to contact the home zone".

This year, there has only been that one conflicting Q&A set, and a bunch of clarification on electromagnets vs solenoid actuators which was apparently unclear to some people for a while but is now quite clear.

Regardless of what reversals there may/may not have been in Q&A, the rule stands: Don't modify the motors, except as specifically allowed.

[dlavery]

<sigh> Since some apparently don't read entire messages before responding...

Originally Posted by dlavery

Oh. Really? Can you provide examples of where the GDC has "reversed itself on many occasions" this year?

[Ian Curtis]

Originally Posted by EricH

I can think of two occasions where a GDC ruling underwent a lot of tweaking or a reversal, Dave. "In" the loading zone in 2005 (can't remember if touching was originally a requirement, but it sure became one by the end of build) is one. The other was in 2002 with tape measures. Admittedly I wasn't around that year, so I don't know all of what went on, but from what I have heard from those who were around, it was "No tape measures to contact the home zone" and then became "You can use tape measures to contact the home zone".

2005 was a long time ago, but I don't recall anything near a reversal. IIRC, it came down in the final week (through a Q&A, I think) that you had to be touching the triangle. Again going off memory, but whatever the original condition wasn't defined and we just assumed that being over it was good enough. In my humble opinion, that's hardly "reversing itself on many occasions."

[EricH]

Originally Posted by dlavery

<sigh> Since some apparently don't read entire messages before responding...

Same to you, Dave.

Originally Posted by EricH

This year, there has only been that one conflicting Q&A set, and a bunch of clarification on electromagnets vs solenoid actuators which was apparently unclear to some people for a while but is now quite clear.

Note that that clarification was not because the GDC reversed itself, but because people had a hard time figuring out what exactly they meant.

[mathking]

At the risk of putting words in Mike's mouth, my reading of his post was clearly that you should always put the question to the GDC because what was a rule one year may not be a rule in other years. There are many rules that we have now that didn't exist or were different in years past. Don't assume, check.

[Rob]

Not to bring this thread back on topic, but Q&A has ruled that this part can't be removed per <R54>.

I guess it's another late night with the dremel...

Rob.