Spike mechanism.

[glen]

hello,

im looking at making an active spike that thrusts out the front of the robot.

im looking at the moment at using a huge spring that will be compressed with two over volted drills, but the problem is i am unsure of how to release the spike after its wound back.

would any body have an idea for a simple mechanism that would allow me to electrically wind back the spike yet allow it to fire and repeat?

also would pnuematics be feasible for this type of weaopn. im talking low pressure 100-200psi pnuematics.

any help would be greatly appreciated.

Pneumatics could certainly do this on 10bar (145 psi) - for example a 50mm bore cylinder at 10 bar will have over 400lbs of thrust. If the spike tip is 2mm x 2mm (unlikely I admit) you have a penetrating force of over 100 pounds per millimetre and Ill let you do the maths to turn that into psi or whatever.

I think the springs may be more work than its worth, althought it may be worth talking to the Diotoir team to find out how they did it for their scoop.

-- Kev

I think the spring idea might be a little risky for two reasons:-
1)If the spike is unable to complete its stroke then when the motors are winding it back in it may cause problems.
2)If the spike penatrated polycarb or the likes of and got stuck, this will burn out your motors especially if you are over volting them.

Go pnumatics....
Grant

[fwsorg]

Re.Pneumatics- whilst large force is all very well, the make a brake for this design would be speed- flow rate would be all important for this.

Er guys...hello...reality check...Havent you forgotten a very simple law from that Newton bloke. You know, the one about every action having an equal and oppersite reaction?
Think on this...You fire your spike into a bot that is sitting against the arena side wall..with me so far?..good! and because this bot is armoured like a proverbial brick built s**t house your spike doesnt penatrate but just comes to a standstill...see were Im going yet?? Let us say you go for a pneumatic spike with reasonable thrust...12Kg robot goes flying backwards having recieved nearly all the energy intended for its victim!!..Ok, extreme example but it holds for all situations. You only have 12Kg to hold this weapon on the arena floor. The moment you impart more than this into your opponent you will recieve an equal amount in return!
Just a passing thought on reading this thread

Geoff.

It would be silly to apply the force perpendicular to the surface of the floor. Id want it angled up a bit to provide a bit of lift, and keep you on the floor slightly better. Im thinking of one of the spawn bots which had such a wepon a few series ago.

That should read parallel instead of perpendicular.

Yeh, a wedge at the front of the bot. The spike would fire once under the opponent. Simple but effective.

Anyone who remembers Spawn of Scutter from Series 4?

[fwsorg]

Thats what I mentioned in my post. Ty for clarifying.