Printable View
Had this idea in my head for a while...
What if you used a spinning flywheel to store energy in a robot and then via a clutch dumped all the energy in to some kind of flipping device? It has probably been done or looked at and then discarded but the only issue I can see is building a strong enough clutch.
It could be as fast and as as strong as a pneumatic flipper but not have the issues of running out of gas. The same could go for an axe weapon.
Thoughts?
Has been done more than once with quite a lot of success. There is an american builder who I believe has 2 automatically-triggering flippers on his FW (for DragonCon). It works well, it seems. Then again, full machine shop tools help a little!
And I think it was Ewan experimented with this in a BW-scale axe. Again, had good results, lots of power.
Edit: the American machine is called Overthruster. I'll let you do the YouTubing. ;)
Team whyachi built a very nice machine. Full bodied spinner with an eccentric ring on top. The mechanism engaged and transferred all the energy into the flipper. Would be a bugger to machine though!
That Overthruster thing is cool! How on earth does it work though? Its got some serious kick to!
Edit: Didn't take long... http://www.wa4dsy.com/robot/overthruster-robot
SKF WarriorQuote:
Originally Posted by typhoon_driver
http://www.youtube.com/watch?v=zs36Lv8P_1o
What a crazy but awesome idea!!
The over thruster guy has loads of info on his site and several different ke flipper designs. The best of which seems to work on a dog clutch.
He has a new one based on an exponential threaded screw which seems to work very well and is much less complex... its just manufacturing an exponential screw that is the problem.
I like the idea of innovation in robots but it seems alot of work to get something which to be honest is worst than a simple 1 burket FP co2 system
Hi,
please excuse my bad English. It is not easy to build a kinetic flipper. I have built one 6kg bot ala team whyachi. See the image. Without a lathe and milling machine it won't work. My bot / the mechanic was to sensitive in a real fight . So.... whopper Mark IV no longer exists. Perhaps, however, you could do it as a featherweight.
If you need, I have a few pictures of team wyhachis robot
Any vids of your robot (just out of curiosity?)
I'd be interested in seeing more picks of Team Wyachi's machine.
Images and Vids would be brilliant! We may have more luck at 13.6kg too.
Here is a video with whopper
http://www.youtube.com/watch?v=7H1H6L7bXxc
and the pics of skf warrior
pic 2
pic 3
pic 4
pic 5
the last
That has to be one of the most complicated robot I have ever seen... How on earth does it work? I understand spinning up the outer disc to store energy but now does it transfer the power?
probably through gearing and a clutch
Not even close.
You can see from the pictures. The ring is spun up by the motor which engages with the teeth in the ring to transfer power. The ring has an off center circle machined into it. The flipper mechanism engages in the off center circle and transfers all the energy into the flipper.
Rather then all this fancy machining with custom clutches could you use a mountain bike brake disc and calipers to transfer the energy?
Doubtful as you wouldn't get a sudden impulsive transfer of energy which you need for a flipper
I don't know. I've gone arse over tit a few times on a bike from hitting the brakes too hard. Mabye gearing the the rpm's down between the fly wheel and clutch would be smart since you don't need a flipper spinning at 10000 rpm
Yes but you have a large radial momentum based on where your body is in relation to the brakes. Feel free to try but I can't see it working
I've thought about the bike break thing before too.
I'm pretty sure the amount of force you can apply with your hand on the brake lever is going to exceed any Servo.
I would have a go. :shock:
Do a mock up and test how practical it would be, the more variations on weapons the better.
In competitions I think you should get points for being different :mrgreen:
You would have to use a linear actuator or a small pneumatic cylinder to give you enough force. Either that or use hydraulic brakes. Of course, the issue then becomes transferring the energy from one moving object to another. A heck of a lot of design required.
I think you miss the point of the servo PJ-
Im pretty sure the servo only moves a linkage to engage a clutch... i.e. moves a lever which gets put into the spinning disc to lock it solid, the force then gets translated into the flipper....
Kind of the like the principal of ramming a metal bar through the spokes of a bike wheel while someone is on it...when the bar locks against the front forks of the bike, the energy is put into throwing the unlucky person of there bike....
I'm saying making the caliper grip with enough power would be unlikely with a servo.Quote:
Originally Posted by Daniel
Yeh you could use a pneumatic cylinder, but doesn't that kind of defeat the object? Just use that to power the flipper.
the cylinder required would be tiny in comparison to a flipper cylinder
Uh, I think this is actually getting worse confusion-wise!
I believe he meant you could use a hydraulic disc-brake caliper, the cylinder of which you would power with a strong servo or similar instead of with your hand. So imagine the brake handle on a bike powered by a servo, and the flywheel is the bike wheel.
I don't think it would work. It would slip, which would sap up power. It would have the grip at full compression of the caliper to do the job, perhaps, but in getting there it'll slip, causing all sorts of problems. It would have to be a locking pin like system.
Three different viable methods of kinetic energy storage device tried to date seem to be:
1) Pin/cam engaged flywheel as on the Whyachi machine and one of 'Dale's robots' creations
2) Screw thread/momentum based 'dog clutch' trigger, as a builder called Glen in the US has tried and me at beetleweight scale
3) Continually rotating 'flipper' with spring-steel or similar contact surface and and high-speed flywheel maintaining momentum through an impact, as on this machine
Never come across a conventional brake based flipper, not that I can remember anyway
Actually I'm looking forward to having some spare time to finish that beetle.. one day
On the dog clutch mechanism what stops the flywheel climbing up the screw when the motor is running?
Nothing. You want it to climb or move along the thread to move away from the engagement point. Stop spinning the thread and watch the flywheel engage
Well what stops it unscrewing most of the time is the acceleration of the flywheel - this force (F=ma..) will make it screw down onto the pulley/driving surface until the shaft/thread is braked and then it will unscrew itself with its own momentum
Sorry to be anal but with rotational dynamics it's not F=ma as it would be for an object travelling in a straight line. It would instead be Torque = moment of inertia x angular momentum. As the screwed thread is helical it is a component of the torque which acts to keep the flywheel in position before the thread rod shaft is stopped.
The nuts and bolts of the problem however is that a flywheel and threaded rod arrangement would provide a very effective means of transferring the energy to a flipper if you could engineer the individual components to survive the engagement of the flywheel.
Don't worry Gary, I know as much, F=ma is just a convenient abbreviation for the force due to change in momentum
Good good :)
I couldn't quite wrap my head around this but I just stuck a bolt into the chuck of a drill with a nut on it and spun it up and I was able to see how when you stop the nut moves up a bit even with such little inertia. This is a really cool concept