Quote Originally Posted by grant_ploughbot
Hi Nick,
I'm the tech checker and Arena marshal for all the Robo Challenge events (i'm James' brother btw!).
Ideally the best solution would be to have a hollow shaft with the link in the centre, but it can be abit of a pain if they get flipped upside down aswell!
Dizzy tilly's link isnt in a particularly good position but there are ways of removing the links safely depending on the robots design.

Where ever the link on a robot is, or what the robot is, we always try to put in the locking pins in the weapon before I begin disarming them. This minimises any risks as soon as possible (unless for somereason theres more hassle putting the locking pin in ).
Once the locking pin is in, it is usually safe enough, especially with non-pneumatic robots to turn the robot over, or access the robot where it would normally be a risk.

Obviously, this isnt the prefered route but if no other method is do-able, then the above method can be acceptable aslong as i deem it safe enough during a tech check.

Main things I would check is that you locking pin needs to be able to easily secure the weapon under its full load at all times, and mainly that it is eay to put in and wont fall out easily. Then put your link where you think will be easiest to access it from there.

From your first post and precautions you have take, i believe your sensible enough to come up with a solution you believe is safe from what i have written above. If you have any queries let me know and i'll happily tell you if i'll put my fingers near it or not

Oh - the other thing, using something to hook the link and pull it out sounds a good idea, although the force required to remove most links would just pull the robot along with the link
The locking pin is a simple U shaped staple which fits over the blade and down through two holes through the chassis, so that's pretty easy to install and I'm sure will take the torque of the motors. I believe using a decent locking mechanism and an electrical interlock on the weapon will sort out any hazards when powering up - the drive system link goes in first, then the weapon link, then the weapon enabling switch (controlling the contactor which supplies the weapon motor escs) can be switched on and off to make sure the weapon live lights work and then go out when switched off - then the pin can come out and it should be ready to go.

As for pulling the link out from a distance, can I suggest just using one of those snooker cue rests? Should hold the robot at a distance while taking the link out with the hook...

Saves me all the gearbox redesign issues anyway