Power/failsafe LED

[blazerbotics]

Power/failsafe LED

but if you are powering the led off the RX supply then the RX may be off yet the link still be in. In THEORY nothing should happen, it should be in failsafe, but theres still the chance of a valve firing etc.

[andy_kane]

Power/failsafe LED

Very difficult to get rovs to scoop robots out of the pit.

This thread is going around in circles.

For the record the ruling for external lamps is now required.(FRA members and Events)1/1/04
The reason for having these lamps was to aid arena operatives to stand a chance of knowing when a robot is dead or alive when disarming in an arena, and not for roboteers themseves. Arena operators are extra careful when disarming robots when there is no light on.
A roboteer must has as always done, only rely on the link for safety disarming purposes.
It was envisaged that link in/ light on, link out light off, and should be powered off the main battery and not off the receiver battery.
It is very easy to wire up. As for colour I use green for go!

[ukrobotics]

Power/failsafe LED

Robots stuck in the pit are less of a hazzard as they cant move too far anyway. The ROV would ovbiously be for removing robots that are no longer working but are still on the arena floor, not in the pit.


Dominic

http://www.ukrobotics.comhttp://www.ukrobotics.com

[babeth]

Power/failsafe LED

And no matter how knowledgeable you are of your robot or professional training... always be wary. You may also not know every roboteers professional or experience status, do not rely on that anyway as we all make mistakes now and then, but also do not suppose firsthand that one is not knowing what one is doing. A difficult thing maybe.
I would advise caution at all times.
(Knowing very well that people will become complacent anyway but Ill think of wake-up calls...)

[geoff]

Power/failsafe LED

Thank you Andy,
I hope that covers it for everyone!
Very sound point there too, Babeth

[big_nipper]

Power/failsafe LED

Daniel counldnt have said it better my self.

Andy. I think people should read the FRA rules before commenting anymore so they dont keep making fools of themselves (Says just printing a new copy out).

Dominic, Think theyre safe in the pit. Next time theres 7 robots in jonnos pit (sheffield) well let you stick your hand in there and disarm them all, youll soon change your mind and as for being able to see them in direct sunlight you dont know what your on about take alook at ours, done right its easy to see (LEDs less than 50 pence and a couple of resistors). Even lights the floor up when upside down so you can still see them.

I think Ill put a link on every side of the robot that way anyone who comes near us will get disquilified .

Roger, you dont know Daniel then do you. If memory serves me right you had wooden barriers last year and no enclosed arena, only 4 or 5 robots turned up so as far as I know you have no where near the experiance in running events as roaming robots and are not in a position to insult people on the matter.

[Guest]

Power/failsafe LED

As long as theres a rule stating how everything should be done, Im satisfied! But as Geoff said, the rules doesnt forbid you from using more than a single LED.

[maddox]

Power/failsafe LED

1 big thing that goes in favour of the Power On led.
All the machines and electrical equipment,that I know of has one way or another to indicate they are on

Anyone an amplifier, a car radio, TV and lots of other things?


Mark, I would call Roger Plants use of words gruff at least. Maybe the mans way.

[tim_jones]

Power/failsafe LED

I personally have no problem with LEDs, but feel that it ia absolutely essential that we achieve some degree od standardisation from the beginning.

This should cover the colours and locations of LEDs, for instance red for main power, green for Rx and yellow for failsafe all in a standard location maybe centre rear of the robot.

Surely the FRA could produce a simple stripboard schematic that we should be working to and list were each LED/lead should be connected. Without some serious uniformity of this standard it is likely to achieve very little and maybe throw in extra risk by creating complacency, yet with just a little more thought and careful regulation it could be a major aid to safety.

Regards

Tim Jones

[ukrobotics]

Power/failsafe LED

I was certainly not implying that robots are safe in the pit. But given the choice of removing the robots around the pit with an ROV before approaching the pitted robots has to be a safer way of doing it.

I actually thought that there were plans to make the RR pit open and close hydraulically like the RW one does, in which case that problem would not be an issue.


Anyway, it was only a suggestion


Dominic

http://www.ukrobotics.comhttp://www.ukrobotics.com

[blazerbotics]

Power/failsafe LED

RR does have a electric operated pit now. it was used at aber...thingy, it broke just before our fight but it did work well.

[m2xt]

Power/failsafe LED

The inclusion of this link light has caused me some concern and those concerns have been discussed with the FRA. I can only accept that this light is a warning light and does not have a safety function. Its purpose surely is to assist the event officials in their management of the arena / pits. If the majority of event organisers wish to have this light, then it is only right that the FRA adopts this as a requirement as a service to the roboting community.

If an event organiser has alternative procedures to manage the arena / pits then that is their call. If these alternative procedures require specific alterations that are not within the FRA build rules then they may run the risk of having limited numbers of robots attending or having to turn away non-compliant machines.

If I hear an event official say something like €˜that bots safe, the light is out€™ then I will be campaigning for the removal of the light requirement from the rules.

Do not start using relays to drive this lamp, apart from being unnecessary; keep it simple as stated by Geoff. I do support the standardisation on colours, lamp type and circuit.

Just one more thing to say and that is in response to a comment from Roger, just because a ram has been tested to a static pressure test that exceeds the operating pressure does not necessarily make it suitable to use. Consideration has to be given to the dynamic forces that stress the ram when it strokes at violent speeds - the ram assembly on WBC has failed at an open air event and a more recent example is Spawn Again. My recommendation to event organisers is not to accept low pressure rams on high pressure service unless there is a pressure test certificate and action taken to ensure the ram can cope with the dynamic forces.

Paul

[Guest]

Power/failsafe LED

Roger, there€™s a huge diffrence between static and dynamic force. For example, take a small hammer and gently put it on one of your fingers. Does it hurt? I doubt it€¦

But what if you would have swung the hammer at high speed? The results speaks for themselves!

[roger_plant]

Power/failsafe LED

WBCs ram has never failed.
The only thing that failed was the knuckle joint where it attaches to the flipper. Nothing came off, the flipper stayed attached by its massive reinforced hinges as it was designed to do.
The ram stayed intact, the full pressure gas charge stayed in it and vented correctly as soon as I released the transmitter €œflip up€ button.

The knuckle joint has been replaced by a stronger one.

If people want to make a fuss about a piece of metal failing on a robot then we must all give up building robots now.

For those of you who keep pointing out WBCs €œterrible€ ram failure and assume I am ignorant about ram design and use, I used to design and use them for the aircraft, offshore oil and submarine industries.
I have also used 50,000 psi hydraulics, 6000 psi gas and liquid oxygen military aircraft and professional diving systems, as part of my normal daily work.
I do know about HP gas and fluid systems. It was a requirement for the job.


I did all the calculations concerning the strength of the cylinder wall and other parts, rod, seals, retaining bolts, flow rates, energy and safety margins.
The energy calculations were confirmed as accurate by a professor of applied mathematics using data taken from WBC flipping Axe Awe in RW series 5.
I was 2% out on the energy calculation, everything else, force, speed and acceleration was spot on.

WBCs ram has adjustable dynamic gas cushions at both ends to decelerate it, and its load, well within the safety limits of the materials it is made from.
They are not just bits of rubber or springs as I have seen on several other robot flippers.
These are regularly inspected and serviced as is the whole ram and gas valves.
The person most likely to get hurt if WBCs ram goes wrong is me, when I am testing it in my workshop, so you can see I have a particular interest in its integrity.

The general attitude seems to be to €œnit pick€ at peoples work and highlight their failures without knowing much about them or the failure itself.

If we all made robots that never broke we would be making boring dinky toys.

Robots do fail and fall apart, that is what makes the entertaining.
If they never broke then every battle would end in a draw after five minutes.

It is only when they nearly hurt people that we must question their design.

When they fly apart in the RW fight box they are doing exactly what the RW producers wanted them to do.

WBC and most of the top robots were designed to work specifically within the RW bullet proof fight box.
That was designed to contain them whatever failed, or was smashed, and always has.
WBC has rarely been used in public outside of RW and only when I considered it safe to do so.
I withdrew during one event as I considered its arena unsafe to use.
I have not gone to many more for the same reason.

Nothing has ever flown off WBC or hurt anyone so I have judged it right so far.

WBC is now retired from active service because I am fed up with the whimpering of those who are afraid of it.

Christian Fredriksson lecturing me about the difference between static and dynamic force in a hammer is just the sort of un-called for sniping that I am getting fed up with.
Its often called €œteaching your Granny to suck eggs€.
In my workshop I would tell him where to go in no uncertain terms, but this is a public forum.

I even had a telephone complaint that a WBC pull back toy hurt some little boy€™s finger when he fired its flipper.

All machines with moving parts eventually break and those like robots, which are pushed to their limits, generally break the soonest.
If you want an example of the worlds finest machines too often going wrong and bits falling off then just look at F1 motor racing.
If they, with their multi million pound budgets, can€™t get it right then it€™s a bit much to expect robot designers to.
Plenty of people watch F1, many of them just to see them crashing. As soon as they make them super safe their audience will get bored and stop watching.

Those who €œcry wolf€ every time something breaks on a robot are just showing their ignorance and fear of things mechanical.

We must be safe and not hurt anyone, but for heavens sake stop your boring niggling complaints and get on with the real safety issues.

If you keep sniping at people they will get fed up with you and just give up on RW.

[ewan]

Power/failsafe LED

I personally think Roger is entitled to his point of view, as are we all. His robots are almost as safe as you can get, its just us that people seem to want to point out the weak bits. Why doesnt Roger point out the weak bits on everyone elses robots, well he doesnt because hes got some brains unlike some of you...
But Roger, I wouldnt give up WBC because of the odd swine, come-on you know your better than most of em...
Cheers, Ewan