Build Rules 2011

[RogueTwoRobots]

New rules are looking pretty good, especially the battery section with its new clarifications concerning lithium batteries.

Just a couple of things I want to raise; it's more likely probably wording than anything else and that is something that can come down to the opinion of the person interpreting the rules but:

4.2.5 Servo Control
It is not advised you use servo/ pot/ micro-switch interfaces, as these will remain in their last position with loss of power leaving the weapon active.

I know this is only advisory so it probably doesn't matter too much but the servo/switch remaining in its last position upon loss of signal can simply be remedied by connecting a failsafe between the servo and the receiver (or using a tx/rx's built in failsafe setting) and setting it so that the servo or switch returns to a preset 'zero' position, just as explained in the general failsafe section.

4.4 Remote Kill (Advisory)
Robots should incorporate a €œremote kill€ that should bring the robot's failsafe device(s) to the pre-set 'off' or 'zero' position via a switch on the transmitter. This is to allow for de-activation of robots from outside a fully enclosed arena and prevent accidental operation of controls.

Again this is only advisory, and again this may just come down to my interpretation of the word 'remote kill'. To me a remote kill switch is a radio-operated switch that, when switched, removes all battery power from the drive and weapon systems. Effectively you're removing your link by remote control. Contrast that with setting radio signals to zero (in failsafe) so that your robot won't move under radio control but power is still being supplied to all systems in the robot.
The description in the rules is of a switch on the transmitter that brings the failsafe devices to their pre-set/off positions. This can be achieved by turning off the transmitter (as is done during tech checks) rather than having a designated channel switch. So by that reckoning, every robot already has a remote kill incorporated and this rule becomes a little redundant.

That's also something I try to make sure I do after the end of every fight before the marshal enters the arena, turn off the transmitter so that the robot is in failsafe mode and shouldn't drive anywhere/activate weapon when the marshal is among 'live' robots. I don't know who else does this (several people I'm sure) but maybe something to try and encourage for those who don't? Discuss.

Also, is it worth putting the kilobot/beetleweight category into the weight limits? I know Kenny and Tom started it up as a fun, unofficial class, there haven't really been any fights yet and a specific arena isn't yet completed but there are a few of these machines surfacing now and I reckon several more are on their way. Just a thought (although may be best to leave it just now until the class has grown a bit)

Anyway, that's my tuppence worth. May just be rambly rubbish but at least the thread's here if anyone wants to raise some more valid issues

[typhoon_driver]

Jamie, the servo advice mentions loss of power, not signal. And on loss of power, failsafe or not, the servo will remain in it's last position.

Re turning off transmitter - The transmitter should be kept ON at all times whilst the robot is active and especially whilst someone is in the arena. Failsafes should be a back up secondary option and never the first line of defence for the potential of a runaway bot.

Could someone clarify the reasoning behind the increase in hydraulic pressure allowed? Someone correct me if I'm wrong but the previous value was 4000psi? or thereabouts. Increasing this to 10 000psi seems needlessly dangerous and completely pointless.

My reasoning is as follows,

- Hydraulics are used almost entirely in the heavyweight class. Hate to say it but this class is a lot more cuddly than the days of old or the featherweight class. Punching through armour is seen as somewhat of a no no with damage being something to be avoided. Where is the need for an increase?

- 4000psi is dangerous enough but 10 000psi?! One of those lines get damaged thats a very dangerous steam of fluid you have coming out there. I don't have the engineering experience to say definitively what would happen should someone be on the wrong end of that but I can imagine and have heard stories.

Hydraulics obviously isn't my area of expertise, but I'd like to know some of the logic behind the sizable increase in pressure?

[grant_ploughbot]

For the hydraulic's there was a proposition put forward to increase the pressure to 10,000 psi.
The discussion about it was very reasonable and the outcome was that hydraulic compionents are available off the shelf rated for 10,000psi and so perfectly rated to do so and safe at those pressure's.
Secondly, if for any reason it help's pursuade people to build hydraulic robot's and its perfectly safe then there's no reason to not allow it.

Hydraulic's arent like pneumatics if a pipe is broke. Unless you have an accumulator (which are banned) then a leak in the pipe will just squirt a tiny smount of fluid out untill the pressure is gone (being as the oil is non compressable then it is only a tiny amount comes out).

[typhoon_driver]

Fair play. Like I said, not my area of expertise

[RogueTwoRobots]

Jamie, the servo advice mentions loss of power, not signal. And on loss of power, failsafe or not, the servo will remain in it's last position.

So it will; that's what I get for reading stuff when my eyes were just about needing propped open with matchsticks :P

[Mouldy]

I'm guessing heavyweights moving to 80kg got laughed of as a stupid idea?

[Scorpionbuilder]

Hi Jamie

Gary is right and as you are now aware servos stay in their last position when power is lost, however you are correct that this is only advisory and servos are allowed. The only adviceI can give to anyone wishing to use servos & microswitches is to be careful. I've just got back from Portsmouth having suffered from this exact problem with Scorpion's weapon - a battery pack broke free breaking the connections to the receiver, hence the servo lost power and was unable to return to the off position. Scorpion's axe is electric, if I had not had a clutch in te mechanism there would have either been a battery fire or it would have cost me a Lem motor (I believe they are about £800 plus new!!)

Hydraulic pressure - thank you Grant for explaining the reasoning

[kane]

The description in the rules is of a switch on the transmitter that brings the failsafe devices to their pre-set/off positions. This can be achieved by turning off the transmitter (as is done during tech checks) rather than having a designated channel switch. So by that reckoning, every robot already has a remote kill incorporated and this rule becomes a little redundant.

The principle of the remote kill is to prevent inadventently operating controls while having the transmitter switched on. This is particularly important with PPM and PCM transmitters where it is very possible to receive interference from a close channel as this becomes more likely when the receiver is not receiving a signal. Newer DSS transmitters are paired to the receiver so this is extremely unlikely however a remote kill can still be beneficial as switching a DSS transmitter off and back on can take as long as 15 seconds to reestablish a connection.

I'm guessing heavyweights moving to 80kg got laughed of as a stupid idea?

While a change in weight limit would not be easy to implement, especially given the number of robots built to the current limit, the reasoning behind a change are very valid and these will be discussed going forward. Most notably creating exciting action packed events for the public that everyone can enjoy.

[Mouldy]

So the future plan for keeping heavyweights alive is to tell people who already have little interest to loose 20kg or they carnt fight? Meaning if theyd have to take a lot of armour off to get in weight... while crushers are allowed to run an exstra 6000psi?... Yeah makes sense

[kane]

No