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Flywheel powered flipper
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Spockie-Tech
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Joined: 31 May 2004
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I had that thought when I first read that.

A CDI ignition might give you a nice whack and sudden pull-in on the coil, but its very short duration. so might not have enough time to move the mech bits.

Conventional ignitions work on magnetic decelerative techniques - they build the field up slow, then collapse them suddenly - its the rapid magnetic flux *change* that generates the spark.

In this case however, you want a constant sustained static field strength to hold your clutch in, the dump the field as quickly as possible.

Perhaps If you want to get really tricky, you could H-Bridge it and reverse the polarity into the coils, that should help push them apart and disengage quicker.

*edit* oops, sorry if I seem to be 3 messages behind. I started writing a reply, then wandered off, came back and finished it then saw that there had been intervening posts.
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Post Wed Nov 21, 2007 9:08 pm 
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Daniel
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http://www.wa4dsy.net/robot/flip-o-matic

Post Mon Mar 31, 2008 4:04 pm 
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assassin



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He makes some very neat stuff, I told you a dog clutch could work. Razz

I wonder what would happen if you kicked it with your foot! Laughing
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Post Mon Mar 31, 2008 4:33 pm 
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Spockie-Tech
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This would happen...
http://youtube.com/watch?v=brfrizTFWg8

I dont know about his 8 Horsepower (-friction) claim though.

If it only takes one horse to move your average 80kg person like that ^, I imagine that his flipper should have more of an effect on a 30lb robot than it seems to.

Ingenious mech and nice machining work - Be interesting to see how well it survives 50 flips and being pounded around in combat.. anyone can make a high power mechanism that works once or twice.. keeping it working the 50th time is the hard bit. Wink
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Post Mon Mar 31, 2008 5:07 pm 
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Knightrous
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quote:
I told you a dog clutch could work

A dog clutch 'could' work, but...


quote:
ingenious mech and nice machining work - Be interesting to see how well it survives 50 flips and being pounded around in combat.. anyone can make a high power mechanism that works once or twice.. keeping it working the 50th time is the hard bit.


Exactly why I reckon the dog clutch is not a solution Razz
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Post Mon Mar 31, 2008 8:43 pm 
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Nick
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I have to disagree in principle - it could work it the parts are properly engineered. The first failure it the screw linking the clutch to the flipper, no coincidence it looks to be the thinnest cross section part at the high impact part of the mechanism.

The solution is to make the entire dog clutch area beefier and to spread the load out over more material. Doubling the size of the final two gears would allow for a WAY bigger clutch. Its like most new ideas - revolutionary at the time and as they are refined, they become accepted and commonplace.
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Post Mon Mar 31, 2008 10:17 pm 
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Spockie-Tech
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I have no problem with new principles or ideas, nearly anything can be made to work reliably with enough experience..

Eventually you find all the weak points and engineer them out.. (provided some of the required engineering changes dont require fundamental changes in the design and bring a whole new swag of weak points along).

I was more referring to Trents "I told you it would work !" comment by reminding that it depends on what your definition of "work" is.

Hand Grenades only need to work once, Machine Guns have a totally different spec requirement Smile
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Post Mon Mar 31, 2008 11:03 pm 
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kkeerroo
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Well considering that gearbox was proof of concept model and not a finished product I think it looks very good. He does admit to a couple of problems including too much friction around the flywheel and that screw coming undone. I would like to see it in combat before saying it is a bad idea.

Strange that hand grenades last their full life expectancy while machine guns need constant work and their barrels changed every couple of hundred rounds. Different views of the same problem no doubt.
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Post Tue Apr 01, 2008 7:42 am 
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Knightrous
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The dog clutch just seems a bit violent to me, kinda like using a sledge hammer to press in bearings instead of using a press Smile It'll work, but you have a good chance of breaking it too.
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Post Tue Apr 01, 2008 10:31 am 
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Knightrous
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Dale has made a new version, but for combat this time.

http://video.google.com/videoplay?docid=4526774021146060709

Pretty good results considering the flywheel isn't too heavy.
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Post Mon Jul 21, 2008 11:15 pm 
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Nick
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He mentioned it stored 400J of energy - it gets a pretty efficient flip, considering some of our KE spinners have many times that and often throw the opponent less distance. its purpose built for an event without dangerous weapons though; that body work wouldn't last long at most events!

I'm waiting for someone to try scaling it up to superheavy size Razz

Post Mon Jul 21, 2008 11:21 pm 
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