Flipper blades on flippers

[Jackpietrzak1]

how come the flipper blades that rests flat on the arena floor like kronic's flipper blade isn't lowwer than say manta's flipper from team shock where's theirs just bit of metal on top of the flipper? or it it how people drive their robots?

i found this out when i keep watching a recording that i saw at the europian championship, UEA, Norwichwhen kronic got flipped out of the arena by manta.

[Garfie489]

There are so many variables which determine who gets under who. There are three main factors to consider.

The robots speed
The robots attack angle
The robots ground clearance

If we assume the ground clearance is the same for two robots, and they hit each other head on (ie no attack angle). Then in theory the slowest moving robot will get underneath.

If one robot now hits the other at 45 degrees to being straight on, at the same speed. Then the one which strikes the side of the other should get underneath.

The last scenario is where the robots drive at equal speed, straight on. Here, the robot with the lowest ground clearance wins.

In each scenario there was 2 constants, and one variable. In real life all of these can vary. However, the advantage Manta has is related to its speed, and ground clearance. Lets assume Manta and Kronic have the same ground clearance when still. As we increase the speed, the flipper goes over bumps in the floor, causing it to gain a temporary ground clearance as it clears these bumps. The flipper can only be as low, as the highest bump along its length. Thus, since Kronic has a solid blade, this bump could be anywhere along the flippers width, and where this bump does not occur, there is a ground clearance. For Manta, if this bump happens between its blades, the flipper will not have an increase in ground clearance, and thus it will get under Kronic if this bump is at the point of impact.

It gets even more complicated than this as we introduce more robots with different designs. For example, Titan and Dystopia can have the same ground clearance, same speed, and same angle of attack. Yet Titan will still get under Dystopia, even though both have the three blades of near equal width. The trick is, Titan does not get under Dystopia at all, but its only when we watch in very slow motion that we can see what is happening at all. I wont give my secrets away however

[Jackpietrzak1]

so if i build a flipper & i wanted to have blades space apart on the flipper arm or scoop, would any items like springs be ideal to keep the flipper blades or scoop down so it brushing with the floor of the arena?

[Revsmin]

It's a good plan, springs help the likes of DTK, Ripper and of course Titan be the lowest robots out there. They don't work too well for flippers, mind you, and they don't half chew up the floor!
Oh, and Gareth, Titan and Dystopia may have had similar ground clearances when they last properly fought, back at Gloucester 2012 when it was still Ripper, but since then she's had springs added, and recently 2kg of lead in the tips. No flipper can put as much pressure on the ground as that.
Bearing that in mind, is the extra hassle of springs worth it, knowing you can't win the ground clearance battle?

[Garfie489]

We have discussed this at length Jarvis XD. I still await some slow motion footage for us to analyse before i come to a conclusion :P

For a flipper i prefer Dystopias solution - It has a lower wedge angle, keeps flipper weight as low as possible, and also i have slightly modified it to increase its effectiveness in non direct attack (not giving away secrets XD) but this modification would not be possible on either Ripper or Titan

[adz600]

I also have been pondering this issue, as building ceros being able to get under robots head on is key but my design is difficult as most of the robot weight is at the back, thats wy I am going to use a large hardox front snow plough for the weight and blade width but as discussed a wide blade doesnt stay flat on a floor, but adds area to the arm

[Garfie489]

Just looking at your design. What i would say is to try and either make the base more stable, or make the Flipper and base act independently whilst accelerating. Dystopia is an example of this, as the flipper does not actually touch the base at any point. This allows it to accelerate with the body doing a wheelie, whilst the flipper remains flat on the ground. Its only on full acceleration where the locking bar mounts hit the body, that the body actually starts to lift the flipper off the ground.

You say you want a scoop aswell. Unfortunitly with a true scoop (Behemoth, Dystopia), its hard to get inventive with your blade. Because to be effective it needs to lead onto the scoop effectively aswell, whereas with flippers you only need to think about the leading edge. Scoops also tend to have less area to work with, if Behemoth had a more extended tip its body would tip forwards when it flips rather than turn the other robot over. So i would advise to make the scoop as a flat blade, then add bits onto it later. This is how both Ripper and Dystopia work, Dystopia has some flappy panels held on to the origional scoop by screws for example.

[geeza]

It's a good plan, springs help the likes of DTK, Ripper and of course Titan be the lowest robots out there. They don't work too well for flippers, mind you, and they don't half chew up the floor!
Oh, and Gareth, Titan and Dystopia may have had similar ground clearances when they last properly fought, back at Gloucester 2012 when it was still Ripper, but since then she's had springs added, and recently 2kg of lead in the tips. No flipper can put as much pressure on the ground as that.
Bearing that in mind, is the extra hassle of springs worth it, knowing you can't win the ground clearance battle?

It depends on your spring rating, but I can put 1.7kN of force on the ram to force the flipper into the ground!

[Garfie489]

It depends on your spring rating, but I can put 1.7kN of force on the ram to force the flipper into the ground!

So thats why the things so bloody low XD

I remember charging at it at a uk champs whiteboard, its futile to try and get under it head on, same with Eruption.

[Revsmin]

Speak for yourself . My problem with Turb is the pneumatic tyres, can't push the damn thing.

[geeza]

And that's with a 9 year old flipper arm that is a bit knackered. Building a new one for next year should be straighter and a bit lighter, the current one is nearly 19kgs!

[geeza]

Also getting new tyres for next year. The good thing about having pneumatic tyres is that you can adjust the ride height to get the flipper tip parallel to the floor.

[Revsmin]

We have discussed this at length Jarvis XD. I still await some slow motion footage for us to analyse before i come to a conclusion :P

In which case I suggest we fight 1v1 at the next event in order to obtain said footage.

[Garfie489]

Speak for yourself

Who else would I speak for?

Also im perfectly up for a 1v1 jarvis

[Revsmin]

You're on!