A Real Flipper

peterwaller · Post by **peterwaller** » Fri Jun 01, 2007 6:35 pm

I have spent the last couple of weeks trying to build a real flipper that can toss an ant into the air without the use of pneumatics and it is proving somewhat difficult. I am now up to version ten drawing and version three prototype and it is still not looking to good. Back in the early days there was little nipper that used a mouse trap but that was a one shot system. I have tried leadscrews to reload and and have now moved on to a worm drive but it is not that good. It has only about 500gms lift at the end of the lifting tynes and take the best part of twenty seconds to reload. I have had a system working before with a large servo and a carbon fibre leaf spring but that was much to bulky to fit into the new version of variant which I am trying to design it into. Has anyone else come up with any good systems or got any good ideas.

Post by **BeligerAnt** » Fri Jun 01, 2007 8:33 pm

Peter, I suspect you are the person most likely to solve this problem!

I tried springs and camming-type recovery mechanisms on the very first RONNY, but my mechanical fabrication let me down. Also I thinks it's very difficult to keep everything properly aligned in the rough & tumble of the AWS arena.
The recovery mech is necessarily very slow which is a big disadvantage in battle.

I think the most impressive non-pneumatic flipper I have seen is Entrant. I suspect they "tweaked" the servo a bit...

Maybe that is a route forward? Take a reasonably high-powered motor, add a suitable gearbox and build your own "bang-bang" high-speed servo.
If using a standard servo control circuit, you will need to make sure the bandwidth is sufficient to keep up with the feedback signal, but since you're only interested in 2 positions it should be possible.

Hope this helps to invigorate the grey cells...
Gary

(For general info)
If using a servo-based sysem, it is important to control it via a switch on the Tx. If you control it from a stick, you just can't move the stick fast enough and the servo just tends to follow. This effect is visible even using standard servos which is why we have a switched channel on our Txs for RONNY and Antipathy.

Marco Roberts · Post by **Marco Roberts** » Sat Jun 02, 2007 2:11 pm

after seeing a lot of heavys over the past months I realise that a few ant mech flipers have as good a flip as heavy pneumatics for there size. If you watch AWS 20, you can see that chrono trigger can flip some one out of the arena from a fair distance away. But for something like pressing a button and launching an oponent a mile away with an electric system will be hard.
The way I was thinking about improving my fliper with current methods of using a motor.
Get a over powered motor and gear it down to a good speed. The servo I use is a park servo and goes to 60 degrees in 0.07 of a second and thats before I overvolt it.
Set up the system properly. Make sure that the fliper is properly tensioned and none of the power is wasted on a flexing fliper.

To be honest I dont thing you can get much further past chrono trigger with electric servo flippers. Possibly get something a lot better with a powerful micro motor with a gear box. Or maybe with those solar bots motors.

I think compressed energy flipper that can be reset would be the best option for what you are trying to achieve.
I remember that axe system that you made. Maybe try something like that but turn it upside down?

peterwaller · Post by **peterwaller** » Sat Jun 02, 2007 4:47 pm

The main problem is that I am trying to design this into the new variant which has really limited the size and shape I can use. The large servo flipper I mentioned was the old axe system turned upside down but that is just to bulky. Variant has had to be redesigned to get the 2.4Ghz receiver in but I am trying to improve the modular approach at the same time. Instead of having to remove the screws they now only need to be losened and the module slides in on slots see below.
http://i109.photobucket.com/albums/n66/ ... CF0469.jpg
Also the electrical connections to the module automatically plug in as the module is slotted in.
http://i109.photobucket.com/albums/n66/ ... CF0470.jpg
The spinner module is finished and operational.
http://i109.photobucket.com/albums/n66/ ... CF0467.jpg
The flipper is designed to eventually fit under a titanium wedge front and the flipper tynes will come through slots as per the original variant.
Here is the flipper so far in up and down positions and placed under the variant chassis to give an idea of the final thing if I get it working better.
http://i109.photobucket.com/albums/n66/ ... CF0462.jpg
http://i109.photobucket.com/albums/n66/ ... CF0465.jpg
http://i109.photobucket.com/albums/n66/ ... CF0472.jpg

peterwaller · Post by **peterwaller** » Tue Jun 05, 2007 6:30 pm

Right thats the flipper scrapped. With the armour on it went from a nice flip over to can't even self right so it now has a two servo lifter. I recon I can probably get a flipper to work in a robot design specifically for it where I can use a much bigger and more powerful motor but not in variants modular unit.

Remote-Controlled Dave · Wed Jun 06, 2007 7:33 am

Nice to see someone trying something new...and slightly crazy of course.

peterwaller · Post by **peterwaller** » Wed Jun 06, 2007 1:37 pm

Here is the lifter.
http://i109.photobucket.com/albums/n66/ ... CF0475.jpg
http://i109.photobucket.com/albums/n66/ ... CF0476.jpg

EpicentrE · Post by **EpicentrE** » Thu Jun 14, 2007 12:33 pm

I had an idea concerning a big flipper without pneumatics a while back, I did some CAD designs but it never saw the light of day, mainly because It was too complicated for me to build at the time, although I might give it a go someday.

The basic idea was to have a flywheel (powered by a brushless motor), which spins up inside the robot. once it reaches full momentum, some kind of clutch engages onto the flywheel (difficult to achieve considering how fast it would be going), which in turn throws the flipper up. There are a lot of complications, for example, the clutch mechanism would have to automaticaly disengage when the flipper reaches the top of its travel, so as not to stall the motor and/or break the robot, and then the flipper would need to be pulled back down (by elastic bands or something) once the clutch was retracted.

Theoretically, this would allow you to build a flipper that was as powerful as the throws you see from vertical spinners.

P.S. I am returning soonish! Be afraid. MWUAHAHAHAHAHA

leo-rcc · Post by **leo-rcc** » Thu Jun 14, 2007 1:33 pm

before I started reading the explanation i thought Warrior SKF.

peterwaller · Post by **peterwaller** » Thu Jun 14, 2007 6:24 pm

Funny you should say about that Scott I had a simlar idea. It didn't use a clutch but the some kind of rubber tyre around the outrunner which could be brought into contact with another tyred drum on the flipper. The mechanics would need to be very strong to withstand the sudden impacts but it should give one hell of a flip. Maybe one day but you can see from my sketch so far I havn't exactly worked it all out yet.
http://i109.photobucket.com/albums/n66/ ... 6/flip.jpg