Advice on teeth/flaps to get under opponents?

Hi guys

I've been contemplating a few ideas on additions to my four bar lifter to enable it to get under the other robots. I've drawn up a few designs based on existing robots but not sure about the effectiveness/technicalities/drawbacks of each design.

Design 1 is just a flat 'tongue' like Explosion

http://i1298.photobucket.com/albums/...ps246b3f7d.png

What material and thickness would this need to be to not bend on impacts? And what would be the best way to attach it? To have the wedge and tongue as one piece of bent sheet or to bolt it on from underneath/on top?

Design 2 is based on Ripper and Little Hitter, 3 small flat 'teeth'

http://i1298.photobucket.com/albums/...ps7b6ac228.png

Again material and thickness? And is having gaps rather than one continuous lip better for getting under opponents? Also methods of attachment?

Lastly, design 3 based on New Ripper

http://i1298.photobucket.com/albums/...ps1004867a.png

Three thick teeth. Are these better than the flat teeth (I read that John said that New Ripper gets under opponents easier than the old Ripper). Material and thickness? I would worry that they may be spinner fodder.

Sorry for all the questions, but any advice/feedback would be greatly appreciated.

Thanks

Personally, I'd go for design 3. Whilst I've never built a lifter or anything similar, the other two will get buckled too easily I feel (dependent on the material of course, but under most circumstances...) , and once they're buckled too much they're as good as useless. 3 looks a far sturdier design by far - as for materials, I'm not sure what to suggest, however.

I'd go for design 3 made from solid blocks of steel- about 15mm wide then whatever dimensions you want for the triangle shape but I imagine about 50mm high and 50mm long.
from my experience with my flipper I managed to mangle a piece of 5mm aluminium like in design 1.
Also make sure the construction of the lifter arm is strong around the bends- mine kept bending made form 5mm aluminium with alu triangle welded on the inside of each bend as triangulation and it still bent! make sure when making the arm it was some material in a vertical orientation and some horizontal to resist bending- for example use steel angle.
Basically imagine what you would need in a worst case scenario and then triple it!

Thanks for your thoughts guys, appreciated.

I'd go for design 1 (no surprises there!) and I think we've proven on Explosion (as many others have) that design works. The whole arm on Explosion is made out of bent 3mm Hardox, so the only welding is on brackets and supports underneath. This is what makes the lip pretty strong. We've never had any trouble with it getting buckled at normal events, but it did happen once at RoboChallenge, which is why we use a spinner flipper arm with no lip for fights with spinners.

The robot which I currently reckon to be the hardest to get under, Kronic, also uses this design.

I like the idea of interchangeable scoops.

Has the flipper gone pretty much undamaged for the life of the robot Michael?

If you are going for option 3 then only go for two teeth. Getting 3 to all remain touching the ground is a nightmare

I'd say design 0 myself. It doesn't matter. Either you get under someone or you don't, regardless of what the flipper edge is. Aiming it is a much bigger variable than this.

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Originally Posted by ChrisKazoo

I like the idea of interchangeable scoops.

Has the flipper gone pretty much undamaged for the life of the robot Michael?

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At the normal events, yes. At RoboChallenge events, no. The only time the lip has been buckled was against Inertia XL, but the rest of the flipper has been pretty badly damaged by NST (twice) and 360. Having said that it'd probably be impractical to make an arm that can stand up to the spinners as it'd be too heavy (it's 2kg as it is).

I agree with Ceri to a certain extent. There's never going to be one design that gets under everything else. As much as "flappy bits" and lips can help, there are plenty of other robots, such as Beauty and Little Flipper, that get under things very well with just a plain front edge to the flipper, but that's something I've never managed to master with Explosion.

Forks in theory should get underneath more easily, but in practice I think it matters little. The important thing is that the scoop or forky bits stay flat to the floor. Any of these shapes are deemed fairly useless for frontal attacks on other machines if they get bent up just 1-2mm. To an extent it depends on drive power and speed of impact but I'd go for whatever you feel you can build the strongest.

Generally the word "strongest" is in the same sentence as "Hardox" for scoops, it seems. Tormenta 2 had 3mm (might have been 4mm even) steel and against Inertia XL (and any ground-scraping vertical) it was mangled easily.

For Tormenta 3 I am set on 4mm Hardox for the scoop, 5mm if it can be done.