Locking bars and arming up!

[wendyshep]

At the end of the day, it is all about your safety guys. No-one wants to see anyone getting hurt for the sake of a preventative measure. That was the whole point of my post.

[Bacon Wizard]

If someone had already been hurt, I mean properly hurt, would we be having this discussion? And secondary to the tragedy that would be anyone's serious injury or death is also the not unlikely prospect of nailing-shut the coffin for this spobby with the same blow.

[JamesDavies]

What happened with the "roboteer nearly lost his head to a weapon as it fired accidentally in the pits"? Presumably this was someone not following the rules but has anything been done to stop someone ACTUALLY losing their head? The worrying thing for me is that it could have hit anyone, even someone not involved with that robot who was just walking past. If not extra precautions have been taken after this then I'm not sure how safe i'd feel just walking through the pits... Of course I don't know anything about this particular incident- just saying how I feel!

[grant_ploughbot]

These rules were put in place because in 2004 someone got knocked out after being hit in the head with a HW flipper. It could easily have killed him, and at the time thought it may have.
Since then the locking bars have been used and in the rules, and have cut down safety issues massively. Just sometimes the get overlooked and that needs to be enforced better.
It's up to roboteer's as much as it is event organisers to make sure your in the rules.

[mightymouse]

Not keen on having my (Meggamouse or Mini mighty mouse) flipper locked down. If the ram fires then you have a gassed up bot a ram under full pressure and someone has to stick their hand in to dump the gas and hope the ram empties. Having the flipper arm locked clear of the ram, if the ram fires nothing happens and the machine can be moved to a safe area.

The system used by Pressure and Maelstrom where the locking device is removed from a distance is far safer in my view, although I have had no issues with my robots, I may make a similar system.

Trevor

[leorcc]

I can see both sides of the argument for and against gassing up with locking bars. To me locking flippers in the upright position is safer, but that was ruled out after Mike's accident. But then I don't like the idea of having the flipper down with a locking bar under pressure either. Honestly I prefer John's method of gassing up slowly from the side of the robot and just let the flipper lift if the valve is open. With a screw valve that is easy enough to do.

[james...venom]

Thats fine if you want to arm up at home if your a capable person with lots experience (as most people are including the ones that have accidents) and nobody else around but not at a public event. My feelings are robots should be built and designed to the rules. If your machine design doesnt like a locking bar it needs re designing. I apologise for sounding harsh but we have a duty of care to our staff and arena marshals. maybe we need to come up with a new solution or a better method?

[leorcc]

James, Bullfrog has a locking bar, the design is not the issue here. If your response to a legitimate concern regarding a rule in place is "build your robots to spec" then you are not addressing the concern. For the same reason that I do have a power led in my robots, I still do not agree that power leds are a safety measure.

I am saying what I feel is safer. I am not convinced that a locking bar is a safer option, in fact quite the opposite.

[james...venom]

Hi leo thats why I said maybe theres a better option or a better wording for the locking bar. As an MD of an events company locking bar v no locking bar its certainly in.

Yes its in the rules but currently the rules can be interpreted in many ways to just scrape through. Thats why there are good locking pins like LF3's and indeed all the Big Nipper Teams robots and then theres people that give it no thought and just stick something together so it passes a tech check. My opinion is that the robot should be designed in a way to properly incorporate such a safety devise rather than it be an after thought. That way its a hec of a lot safer.

Your particular robot Leo you may feel safer not having a locking bar however you must appreciate EO's cant have different standards depending on the builders point of view (and I do respect yours as a veteran). There must be standard rules regarding safety and the robots must be designed to incorporate them. safety rules should never be an after thought once a robot has been built.

Maybe we should come up with some standards for the locking bars and test them in the arena for tech checking.

[Shakey]

The only problem I have with testing a locking bar is that to test it on my axe feather includes putting a speed 900 on 25V into a full stall probably blowing fuses potentially speed controllers etc. I can understand for CO2 systems where a robot may not be at risk from it's own locking bar but in an electric weapon the locking bar can actually inflict damage onto the motors and circuitry of the weapon it is meant to hold.

[typhoon_driver]

Two options in that case, pulse the weapon quickly to demonstrate that it will hold. If your electronics fail after a quick pulse then you may need to re-evaluate your design. Or have the tech checker do a sense check. Basically look at the pin, look at where it engages and determine if it is likely to hold it in place. With electrical weapons, unless they are of the order of Beta then chances are a small pin should hold an electric axe in place.

[Garfie489]

What i am about to suggest might sound totally wrong, and impractical. However, it could possibly be used to test electric weapon locking bars, without firing the weapon. According to my physics knowledge, it is correct. Real world however, it would need to be tested.

With electric weaponry you should be able to calculate the force produced by the motor.

Power = Voltage x Current

Work done = power x time

Force = Work done / distance

You can measure the distance with a ruler. Voltage and current with an ammeter. Time is a tricky one, as you will always undervalue it, unless you know the final speed, and acceleration of the weapon. But if the stop is at say 10 degrees from rest, and the weapon moves 180 degrees. Then the weapon will have an average time to the stop of 1/18th of a full fire. I would double this at least for safety, as in reality the weapon is accelerating in this phase, so takes longer. It is possible to accurately record the time, but there is no way to do it with what everyone has.

Anyway, take the force produced, and if the locking device can hold a replica of that force, then it should be safe to use.

Sorry if what i have said is really misguided in real world application. Currently doing a physics A-Level. Makes sense to me :P

[geeza]

All sounds good in theory, but its never that easy. The design of the locking system along with the sheer strength of the locking bar would need to be known. I.e. a data sheet for the material used for the locking bar.

Also something to note, if the locking bar is strong enough would the pivot point fail if fired during a test. There should be a tether to stop such an event but again this may depend on design.

[Ellis]

On the electric front, I may opt to design a locking bar into Tormenta 3. Even if not in the rules, I most definitely would not want my fingers trapped by the kind of weapon. I suppose once not dealing with spinners/pneumatics it's a matter of common sense. I'd definitely give an electric axe a locking bar - it's essentially what I am saying I wouldn't want to have my fingers under but heavier, faster, and with an extremely pointy bit at one end!

Edit: also a fuse should save a motor/speedo fairly reliably. In something like an axe where stalling is common you would need to rate it carefully, granted. A mechanical alternative might be a torque limiter.

[grant_ploughbot]

The problem with testing locking bars at events is time. Tech checking every spinner in the arena is bad enough to get done intime, let alone every robot with a locking bar. The rules are fine as they are, they just need to be used!
I have no issue with some of the lock open devices used in feathers as I can see they are very safe I case if miss fire, however I'm not sure I'd be comfortable doing it on a standard heavyweight incase something knock it and the flipper came down.