Printable View
XT90 is what I'm using, I think most of it's in how you mount it really - if you keep it fairly recessed back from the access point and make sure it can't move too much (with foam, cable ties, padding, not having it just waving around on the end of some wire, etc.) it should prevent 90% of link failures due to impact.
Would something like those Dzus fasteners you get with ring attachments be okay? It's over-centered when in place so it wont come out, but one quarter turn will bring it out? If it has the ring attachment and not the allen key, it can be done tool-free...
What did typhoon use gary? I have a faint recollection of wanting to make something to pull that bloody flag out.Quote:
Originally Posted by typhoon_driver
"6.1.1 Removable Link
The main power cut-off MUST be a removable link, which must NOT be in place unless the robot is in
the arena or under the supervision of a technician. A key or switch is not allowed.
6.1.2 Accessibility
The link must be positioned in a visible part of the robot's bodywork, fitted away from any operating
weaponry or drive, and this position must be clearly marked.
6.1.3 Covers
The link may be fitted under a cover, but the cover must be able to be opened without the use of tools.
6.1.4 Kill Switch
If the robot uses an internal combustion engine(s), the "Power" cut-off must take the form of a clearly
labelled "Kill" switch. See Section 7 for further details on engines.
6.1.5 Inverted Link
Robots in the heavyweight class that are capable of being driven inverted, having a removable link fitted
that is only accessible when the robot is the right way up, must have a duplicate link fitted in the
opposing panel, so as to allow the robot to be disarmed when inverted."
It's all there in the FRA rules :)
Poles are not used to remove links, even if a robot is out of control, they are just left to run out of power. These machines are far more dangerous than a boat with a propeller on it.
Using the custom link is fine, but far more effort than necessary IMO. In a FW a XT90 or EC5 work fine, and an 100/200A Anderson in a HW. Putting them under a small door held down by a wing nut is pretty common (We even use industrial velcro to cover ours). While people tend to bury their links inside their robots, the links on both our spinners are easily accessible and on the outside of the robot and we have never lost a link.
Side thought, if your custom link breaks and you can't fix it then you may be in trouble fitting a new link if you have some custom housing. Sticking with the standard links like everyone else has its advantages.
Can I ask a question then.
If I was to run a low voltage system say around 5 or 10V with 2 Nmos Fets attached to it in series could I have a removable link that drops the voltage to the NMOS fets and cuts the power? This way the removable link wouldn't need to be rated to the current that you were pulling through the whole bot and it would make everything safe.
Will pop a circuit diagram up later.
Typhoon 2 used a military grade 1000amp connector that was worth a few thousand pounds which was well slotted in. The middleweights used a screw mechanism that had to be unscrewed.
From reading through this, it does seem as though you are overthinking the problem. The link isn't all that big a deal and there will always be the odd one or two that pop out.
Not totally overthinking it just don't like the thought of handling a live 150A connector and if I can have a low voltage low current link then I can use a military connector that isn't succeptible to vibration or shock
Thanks for the replys, i read the rules and have them as my bible for creating my machine, but again there is nothing in there to state that custom devices can't be used, which was the main point of asking for clarification on using a custom part.
in regards to damage to the link, first off it would be built in using tough materials i'm experimenting with the use of 3D printed nylon so it should be a strong unit for the purpose, but i'm also looking into molding's ( something that i do regularly) so there is no reason for it to fail providing it can be mounted in a way to reduce damage.
However damage can occur even in the most unlikely of places regardless of planning but with all machines of doom carrying spares is somewhat of a necessity and i see no reason not to carry 2 or 3 spare parts of the link, which again the way its designed allows for it to be unscrewed/bolted and replaces in only a few minuets (whats 4 retaining screws and 2 contact screws really?)
Again i was looking to do something different keeping the unit contained and more professional looking without causing issues with the tech check.
I know none of you know me or my work in other hobbies but if you did you would understand that my work i treat as art as well as functionality so if it looks just hashed together it get scrubbed and i find something better.
Please keep suggestions coming, input is always welcome.
Wearing gloves is the easier option.Quote:
Originally Posted by higgeh
Similarly my heavyweight link has a pull cord
I think there was something in a ruleset (I can't recall the precise one off the top of my head but it indicates the thought process) that it had to be a direct disconnect rather than going through a relay or regulator of any kind, and since relays can weld shut/be damaged by shock and FETs can go open crcuit if you look at them funny, you can see why a direct disconnect is safer. You can get anti-spark connectors to minimise the risk and it's honestly not something I'd ever be concerned about grabbing. Plus more components always means more parts that can go wrong...
I think of combat robotics as a sort of art too, gods know I fuss over the placement of parts and making it all look logical, but if you're trying to make every single part fit artistically you're going to have your work cut out with the rest of the electronics!