A very good demonstration of Reaction Wheel System

[sidew]

[AngelLestat]

Heh, what a concidence, I found and see the same video 5 min ago

Yeah is a really good demo.

I would show this to my brother that he was exceptic when I told him that a vessel can rotate or move (no delta V) like it wants with a gyroscope.

[Tommygun]

I'm wondering how hard it would be to turn that into a guidance system?

[Nibb31]

I'm wondering how hard it would be to turn that into a guidance system?

Quite easy. It's basically what the Von Braun's V2 used for guidance.

[MC.STEEL]

this should be made into a toy so that whe can teach kids how awesome science is

just think what else sends a clearer message than toys to a 5 year old...

[Tommygun]

Quite easy. It's basically what the Von Braun's V2 used for guidance.

That's exactly what I was thinking, but some digital electronics use complicated multilayer PC boards and hybrid computer chips that make re-purposing very challenging.

I guess it depends on how off the shelf the parts are.

[Nuke]

this was on hack a day two or three days ago. its pretty cool.

[nhnifong]

It's interesting how fast the device can spin up it's wheels after a maneuver. To accelerate those wheels without moving, counter torque must be applied. It can only do this because it can use gravity and the normal force of the surface it lies on, giving it significant new abilities that a spacecraft would not have.

[Tommygun]

It's interesting how fast the device can spin up it's wheels after a maneuver. To accelerate those wheels without moving, counter torque must be applied. It can only do this because it can use gravity and the normal force of the surface it lies on, giving it significant new abilities that a spacecraft would not have.

I was thinking about that too.

Perhaps if you could give each reaction wheel a small counter rotating flywheel to eliminate unwanted movement.

Maybe even a finely controlled step motor that accelerates non-linearly.

[DannySwish]

I want one. :L

[tntristan12]

this should be made into a toy so that whe can teach kids how awesome science is

just think what else sends a clearer message than toys to a 5 year old...

While I agree with you in principle, I do not want to be on that company's PR team when a 5 year old manages to break the case apart and get his hand mangled in the reaction wheels.

[lajoswinkler]

While I agree with you in principle, I do not want to be on that company's PR team when a 5 year old manages to break the case apart and get his hand mangled in the reaction wheels.

Screw him. If we used such logic, kids would have no toys to play with because everything can be turned into a weapon.

I want one, too.

[mrfox]

https://www.youtube.com/watch?v=Qf1uafBCaYw

[nhnifong]

Screw him. If we used such logic, kids would have no toys to play with because everything can be turned into a weapon.

I want one, too.

They do use that logic, at least in court. If it were up to me, I would make it the law that people who hurt themselves using things they bought have only themselves to blame.

Of course, this logic is a bit weak.... there have been cases where the company should have done a much better job at making a safe product. But in those cases, It would be ideal if the company were then forced to either do their job and make the product better or to forfeit their capital and intellectual property to a company that can. that's real consumer protection in my opinion.

[lajoswinkler]

They do use that logic, at least in court. If it were up to me, I would make it the law that people who hurt themselves using things they bought have only themselves to blame.

Of course, this logic is a bit weak.... there have been cases where the company should have done a much better job at making a safe product. But in those cases, It would be ideal if the company were then forced to either do their job and make the product better or to forfeit their capital and intellectual property to a company that can. that's real consumer protection in my opinion.

They use that logic in some courts and it goes so far that even toys which are labelled as "not for 3 year olds" can be a problem if a careless parent gives them to a 3 year old.

Really, any toy can cause problems. Cuts, suffocation, you name it. If such cube is well protected so that only a skilled person can open it, I see no problem if it is given to a small kid.

[Camacha]

They do use that logic, at least in court. If it were up to me, I would make it the law that people who hurt themselves using things they bought have only themselves to blame.

Of course, this logic is a bit weak.... there have been cases where the company should have done a much better job at making a safe product. But in those cases, It would be ideal if the company were then forced to either do their job and make the product better or to forfeit their capital and intellectual property to a company that can. that's real consumer protection in my opinion.

Luckily courts in other countries are a bit more sensible when it comes to these things. If you mess up there yourself, you get to deal with it. Take it to court and at best the judge will be annoyed as you are wasting his or her time. Toys should be safe, but not fool proof. You can not let the world be run by idiots who order coffee and complain when they find out it is hot.

Anyway, probably the best way for kids to learn is to experience something themselves. You should prevent them getting permanently scarred or damaged otherwise, but overprotecting is just as harmful as not protecting enough. Let a kid that has been warned a couple of times stick his finger in the candle, that will probably be the last time he ever does that. When it comes to something like a fireplace it is a different story

[lajoswinkler]

Kids used to have extremely cool chemistry sets. Nowdays you can buy sets that "contain no chemicals!".

The stupidity meter runs off the scale.

I'm against such idiotic warnings.

[Camacha]

I'm against such idiotic warnings.

You would say that it is pretty much something Darwin wrote about. It is not good for the species to preserve specimen that iron their shirts while they are wearing them

I think my sister had a proper chemistry set. She never hurt herself and, more importantly, is a succesful Real Lifeâ„¢ scientist nowadays. You have to grow those, they do not magically turn into great scientists when they turn 20 years old.

Edited December 25, 2013 by Camacha

[S4qFBxkFFg]

If that chemistry set didn't contain any chemicals it would be far too dangerous to give a child.

Either it's a box of perfect vacuum - imagine what would happen if your finger was near the resultant hole in the box when it was opened.

Even worse, it might be a mixture of free protons/neutrons/electrons, somehow prevented from combining into chemicals - I wonder how exothermic that reaction would be when it finally happened.

[Savage117]

Kids used to have extremely cool chemistry sets. Nowdays you can buy sets that "contain no chemicals!".

http://a.yfrog.com/img737/5272/hj7umk.jpg

http://makezineblog.files.wordpress.com/2011/04/fun-activities-with-no-chemicals.jpg?w=500&h=379

The stupidity meter runs off the scale.

http://grahamten.files.wordpress.com/2009/07/warning9.jpg

http://legacy-cdn.smosh.com/smosh-pit/062011/warning-fails-5.jpg

I'm against such idiotic warnings.

You know what sends me even further over the edge when it comes to these kind of warnings. In most cases those warnings didn't exist until someone actually did what the warning is warning about and then complained or sued, or someone complained that it did not have the warning.

On that no chemical chemistry set, I wonder if we could sue for false advertising, unless everything is contained in a complete vacuum it still contains air and other chemicals that are just floating around when its boxed up, hell the box itself contains more chemicals than I have under my sink.

On subject though, this thing is pretty cool, but it wouldn't work properly in space, as another forum goer already said it uses gravity to anchor itself, so no gravity, no anchor. I would like to see how it would react in a zero G situation though, would it just freak out and start spinning every which way as fast as it could? Would it jerk around as it tried to compensate for the reactions from its actions? Or would it do nothing and just sit there and spout errors to whatever would be listening at the time?

[lajoswinkler]

If you sue them for false advertising, they might say that their definition of a chemical is different and includes artificial compounds only.

Regarding Cubli, yes, it would be very interesting. It has sensors that feel gravitational force, so without it, they send random data or no data at all to the CPU.

I think it would jerk around, at least for a while, because the sensors would feel acceleration from every move it makes using its reaction wheels. Whether this would be in a fashion of a positive or negative feedback loop, I can't tell. It depends on the system interior. It might behave like a bad SAS.