Helicopter propulsion

FIRST General Forum
1

Posted by John Nicholson at 1/15/2001 4:27 PM EST

Student on team #481, D.A.R.T., from Central California High and None.

hi,
My team and i was wondering if it was legal to design a robot that could take off and land like a helicopter, doing away with a drive system and not having to worry about the ramp at all. With this design, we can do a number of things easily…like pick up the strecher and fly it accros to the other side, or pick up the ball and put it on top of the goal or put the goal on the bridge to balance. I think this would be a great idea if it is allowed in the rules.

Check out our blueprints that our team designed.

Comments?

thanks

2

Posted by Tom S. at 1/15/2001 6:04 PM EST

Student on team #177, The Bobcats, from South Windsor High School and International Fuel Cells & ONSI.

In Reply to: Helicopter propulsion
Posted by John Nicholson on 1/15/2001 4:27 PM EST:

i’m not sure about the rules on ‘flying’ bots… but its gonna have to be one strong helicopter… we weighed out the goals as being about 65 pounds empty… People have also said that the stretcher is quite hefty… to lift that plus the weight of the bot is gonna be difficult. Also, when your on the ground and something breaks, it usually doesn’t damage anything but the thing that broke, falling from the sky onto the playing field could do some serious damage to your bot.

Just my thoughts.

Tom S.
Team 177

: hi,
: My team and i was wondering if it was legal to design a robot that could take off and land like a helicopter, doing away with a drive system and not having to worry about the ramp at all. With this design, we can do a number of things easily…like pick up the strecher and fly it accros to the other side, or pick up the ball and put it on top of the goal or put the goal on the bridge to balance. I think this would be a great idea if it is allowed in the rules.

: Check out our blueprints that our team designed.

: Comments?

: thanks

3

Posted by Michael Betts at 1/15/2001 9:29 PM EST

Engineer on team #177, Bobcat Robotics, from South Windsor High School and International Fuel Cells.

In Reply to: Re: Helicopter propulsion
Posted by Tom S. on 1/15/2001 6:04 PM EST:

John,

Tom is correct, but this needs further discussion.

First of all, I note that you list your team as a high school with no corporate backing. I assume that this means you have no professional engineers, machinists or mentors on your team.

As mentors, one of our primary jobs is to make sure our students leave the competition with the same number of eyes, fingers and toes as they had at the beginning.

Imagination is wonderful. Think outside of the box and revel in your creativity. BUT, do a reality check before you build!

That said, let’s consider your problem.

IF YOU COULD design a helicopter which fits the 30x36x60 package, is made from kit materials and can lift a good payload, a few things need to be true.

  1. The blades are hinged and unfold at the beginning.
  2. The RPM required would be truly astronomical.

With the possible exception of some frightfully expensive titanium, you lack the space age composite materials to make a strong enough straight blade, much less a hinged one, and when the blades rip loose from your bot, it’s not the bot I worry about. It’s the hundreds of spectators who will be ripped to shreds.

Regardless of what else might be said, FIRST would never allow anything resembling a helicopter to be used on stage. They would site Rule S6 and never give you the chance to compete.

The reality is that you have less than 2 horsepower of motors available in the kit. You don’t have enough power in your motors to airlift your “minimal system” (battery, control, light, et cetera) much less a payload. BUT YOU DO have enough power to cause some major damage to yourself and your friends!

Trust me, if you try and build something on this scale, you, or someone on your team, could be seriously injured.

Mike

4

Posted by Justin Stiltner at 1/17/2001 12:31 AM EST

Student on team #388, Epsilon, from Grundy High School and NASA, American Electric Power, Town of Grundy.

In Reply to: Re: Helicopter propulsion
Posted by Michael Betts on 1/15/2001 9:29 PM EST:

: John,

: Tom is correct, but this needs further discussion.

: First of all, I note that you list your team as a high school with no corporate backing. I assume that this means you have no professional engineers, machinists or mentors on your team.

: As mentors, one of our primary jobs is to make sure our students leave the competition with the same number of eyes, fingers and toes as they had at the beginning.

: Imagination is wonderful. Think outside of the box and revel in your creativity. BUT, do a reality check before you build!

: That said, let’s consider your problem.

: IF YOU COULD design a helicopter which fits the 30x36x60 package, is made from kit materials and can lift a good payload, a few things need to be true.

: 1. The blades are hinged and unfold at the beginning.
: 2. The RPM required would be truly astronomical.

: With the possible exception of some frightfully expensive titanium, you lack the space age composite materials to make a strong enough straight blade, much less a hinged one, and when the blades rip loose from your bot, it’s not the bot I worry about. It’s the hundreds of spectators who will be ripped to shreds.

: Regardless of what else might be said, FIRST would never allow anything resembling a helicopter to be used on stage. They would site Rule S6 and never give you the chance to compete.

: The reality is that you have less than 2 horsepower of motors available in the kit. You don’t have enough power in your motors to airlift your “minimal system” (battery, control, light, et cetera) much less a payload. BUT YOU DO have enough power to cause some major damage to yourself and your friends!

: Trust me, if you try and build something on this scale, you, or someone on your team, could be seriously injured.

: Mike

Well Said!!

Justin Stiltner
Team #388
Grundy VA,
(still rembers the time he was picking himself up out of the ditch after seeing a model helecoptor crash and flop around like a dieing bird)

5

Posted by Dave Lavery at 1/19/2001 12:47 PM EST

Engineer on team #116, Epsilon Delta, from Herndon High School and NASA Headquarters.

In Reply to: Re: Helicopter propulsion
Posted by Justin Stiltner on 1/17/2001 12:31 AM EST:

I hate to disagree with all those who are saying “no way” regarding this topic, but if John and his team can figure out a way to do it, then they should be encouraged to go for it! If nothing else, it would be a wonderful demonstration of the power of divergent thinking!

To show that this idea is not completely outside the realm of possibilities, think back to the 1997 FIRST competition (those that have been participating that long). That year, a team of undergrads from MIT built a hovercraft from the kit of parts. They set out to build a machine that would not necessarily do well in the competition, but would demonstrate what was possible with the robot kits. Their hovercraft was constructed entirely of legal parts, successfully passed inspection, and was used in the competition as a “placebo” player during matches (that year you had to have three robots competing at a time). There were even occasional matches that it (entirely by accident) won!

Admittedly, a ground-effect vehicle is a long way from free flight, but it took a pretty significant step in that direction.

As for materials selections, early helicopters used simple aluminum blades. So, space-age composites are not necessarily a requirement. Folding blades may not be the only solution (although the navy and DARPA have done a lot of work in this area, including entire aircraft that fold up inside artillery shells and are fired at battle locations). Other possibilities include ideas like vertical ducted fans (e.g. the “Aerocar” and early experimental single-seat craft from the '50s and '60s), which could address both the performance and safety concerns.

Am I sure that this could work? No, not without sitting down with an aerodynamicist and running through some of the numbers. You almost certainly could not make a machine with enough performance to allow you to manipulate a goal full of balls and/or a loaded stretcher. But it may be possible to build one that could just get from one side of the field to the other and get ten points for reaching the end zone. That alone would be very impressive. And at this point in time, I don’t think anyone can say definitively that it would not be possible (whether or not it is sensible is an entirely different question).

Just count me as one of those people who see the phrase “it can’t be done” as a challenge…

  • dave lavery
    Team 116
6

Posted by Scott Strickland at 1/19/2001 1:23 PM EST

Engineer on team #21, ComBBAT, from Astronaut & Titusville High School and Boeing/NASA.

In Reply to: Re: Helicopter propulsion
Posted by Dave Lavery on 1/19/2001 12:47 PM EST:

Let me be the first to say…

Hope someone can do it… BUT, I’ll be watching from the safety of the pits.

I can see it now… FIRST Cage matches for flying robots.

7

Posted by Michael Betts at 1/19/2001 1:58 PM EST

Engineer on team #177, Bobcat Robotics, from South Windsor High School and International Fuel Cells.

In Reply to: Re: Helicopter propulsion
Posted by Dave Lavery on 1/19/2001 12:47 PM EST:

Mr. Lavery,

Of course, you are right. But you are also wrong. I guess I did not get my points across in my earlier post.

  1. It sounds like this is a team without a corporate sponsor. This type of a project needs specialized expertise. Without that technical help, structural failures are not only possible, but likely.

  2. Regardless what was published in the updates (Q49/A49), FIRST would NEVER allow a helicopter in the competition. The risk of injury to the spectators would be too great to risk it.

I love inspiration and imagination. I would not have invested rather large portions of my so-called life, over the last 7 years, to this institution if I did not. This is true of every adult who participates in FIRST. However, we also have an obligation to focus and channel these talents toward safe and attainable goals.

What will you say to these students when they invest 6 sleepless weeks on a flying 'bot just to be denied and sit in the stands?

Can you imagine how you will feel when you find out that one of these students had been seriously injured while attempting this?

Bottom line: Would you advise YOUR team to build a helicopter? Would you urge YOUR family to sit in the front row of the audience if a helicopter were in this competition?

Mike Betts
Corporate Team Leader
Team 177, Bobcat Robotics

8

Posted by Joe Johnson at 1/19/2001 10:33 PM EST

Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.

In Reply to: Re: Helicopter propulsion
Posted by Michael Betts on 1/19/2001 1:58 PM EST:

Johnson votes with Betts on this one.

AND…

Should some team actualy try this and FIRST allows it
to compete, I can tell you that the Chief Delphi Team
will be voting with its feet.

The idea of watching such a machine without a serious
barrier between me and it scares me. Really.

We’ll take a zero for the match and go home entire.

Joe J.

9

Posted by ChrisH at 1/22/2001 3:10 PM EST

Engineer on team #330, Beach 'Bots, from Hope Chapel Academy and NASA JPL, J & F Machine, Raytheon, et al.

In Reply to: Re: Helicopter propulsion
Posted by Justin Stiltner on 1/17/2001 12:31 AM EST:

Back in Ladder Logic there was a question posted about a helicopter robot. FIRST replied with a list of concerns that the judges would want answers on. Some of the non obvious ones were blade containment and stability, also keeping it in the field. It ws pretty clear that while they didn’t want to say NO, they would look very closely at all such attempts from a safety perspective.

What was really fun was all the people running around the National trying to find the “helicpter robot”

Personally I think the battery is the biggest obstacle. While remote controlled electric helicopters have been built, they never weighed anything near what the kit battery does, let alone the rest of the hardware you would need to use from the kit just to control it. I’m not sure a full up R/C helicopter with a gas engine could lift that battery.

I won’t say it can’t happen, but I don’t think the power density is there with the current kit. Though I admit I haven’t done any calculations to verify.

Just my $0.02

Chris Husmann,PE
Team 330 the Beach 'Bots

10

Posted by Alan Partington at 1/15/2001 7:46 PM EST

Engineer from Crescent School.

In Reply to: Helicopter propulsion
Posted by John Nicholson on 1/15/2001 4:27 PM EST:

: hi,
: My team and i was wondering if it was legal to design a robot that could take off and land like a helicopter, doing away with a drive system and not having to worry about the ramp at all. With this design, we can do a number of things easily…like pick up the strecher and fly it accros to the other side, or pick up the ball and put it on top of the goal or put the goal on the bridge to balance. I think this would be a great idea if it is allowed in the rules.

As well as the weight issue, there are many strategical disadvantages to a helicopter. First, any system that allows you to pick up balls and put them in the hopper will be very slow. Also The fine contol needed unless you can somehow scoop the balls will be VERY difficult. I have worked with remote helicopters before and they are very difficult to stop quickly or accurately. From over 24 feet away, you also have a problem of seein gexacly what is going on.
Picking up an 80 lbs. hopper is out of the question, and the large balsl would also be difficult. If you could pull off the eingineering to make a working helicopter robot, you would be able to design a much better robot by puttign you energies in other places.

11

Posted by Matt Leese at 1/15/2001 9:09 PM EST

Other on team #73, Tigerbolt, from Edison Technical HS and Alstom & Rochester Institute of Technology.

In Reply to: Helicopter propulsion
Posted by John Nicholson on 1/15/2001 4:27 PM EST:

Well, given I don’t see any blue prints, I won’t comment on them. There are several problems you will most likely have. The big one is getting enough thrust to get off the ground. I don’t think that the power output provided by the motors (any of them) is enough to lift the robot off the ground (minimum 30 lbs for all the mandatory stuff on there). The other problems include stabilizing while in flight (the tail rotor on a helicopter). And then of course there’s the problem of controlling during momentum. Helicopters tend to tilt forward and that’d be difficult to control. I doubt the aerodynamics of a helicopter would be well suited to actually accomplishing anything (moving goals, picking up balls, etc.). I still am hoping to make a zero-bouyancy blimp some day…

Matt

12

Posted by Joe Johnson at 1/15/2001 9:17 PM EST

Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.

In Reply to: Re: Helicopter propulsion
Posted by Matt Leese on 1/15/2001 9:09 PM EST:

Any team that can have the FIRST battery and control
system AND stay aloft for anything like a two minute
match will have my undying respect!

Honestly, I don’t think that the energy density of that
battery is sufficient to allow it.

I’ll be impressed if anyone can pull it off.

Joe J.

13

Posted by Matt Leese at 1/15/2001 10:02 PM EST

Other on team #73, Tigerbolt, from Edison Technical HS and Alstom & Rochester Institute of Technology.

In Reply to: May only break the laws of physics!
Posted by Joe Johnson on 1/15/2001 9:17 PM EST:

That just reminds me of Andy Baker (I think it was him, please claim the comment as your’s if it is) comment that in meetings between Electrical Engineers and Mechanical Engineers, an Electrical Engineer will suggest something that breaks the laws of physics. Hrm…methinks we might have a winner. :wink: It also reminds me of the joke: Gravity, it’s not just a good idea, it’s the Law. Ok, I’m done now. If anyone actually pulls off a flying robot, I’ll .

Matt – it’s been a long day…

14

Posted by Andy Baker at 1/16/2001 6:42 AM EST

Engineer on team #45, TechnoKats, from Kokomo High School and Delphi Automotive Systems.

In Reply to: Re: May only break the laws of physics!
Posted by Matt Leese on 1/15/2001 10:02 PM EST:

: That just reminds me of Andy Baker (I think it was him, please claim the comment as your’s if it is) comment that in meetings between Electrical Engineers and Mechanical Engineers, an Electrical Engineer will suggest something that breaks the laws of physics.

Yeah, it was something like that, back when the “Careers” forum opened up.

Usually, during such a meeting, you can tell which engineers are mechanical… they’re the ones on the floor, laughing!

Andy B.

15

Posted by Matt Leese at 1/16/2001 12:23 PM EST

Other on team #73, Tigerbolt, from Edison Technical HS and Alstom & Rochester Institute of Technology.

In Reply to: You’re right
Posted by Andy Baker on 1/16/2001 6:42 AM EST:

: Usually, during such a meeting, you can tell which engineers are mechanical… they’re the ones on the floor, laughing!

: Andy B.

And I’m just waiting for a blimp… realizes he’s a CE major and that’s real close to EE

Matt

16

Posted by Ken Leung at 1/16/2001 1:48 PM EST

Student on team #192, Gunn Robotics Team, from Henry M. Gunn Senior High School.

In Reply to: You’re right
Posted by Andy Baker on 1/16/2001 6:42 AM EST:

After reading this… I am having doubts about my original decision of becomming a Mechanical Engineer…

17

Posted by Matt Leese at 1/16/2001 9:26 PM EST

Other on team #73, Tigerbolt, from Edison Technical HS and Alstom & Rochester Institute of Technology.

In Reply to: Re: You’re right
Posted by Ken Leung on 1/16/2001 1:48 PM EST:

So you want to be one of those who comes up with impossible ideas?

Matt realizing yet again he’s a CE…

18

Posted by Jason Iannuzzi at 1/17/2001 3:33 PM EST

Engineer on team #11, Marauders, from Mt. Olive HS. and BASF, Rame Hart, CCM.

In Reply to: Re: May only break the laws of physics!
Posted by Matt Leese on 1/15/2001 10:02 PM EST:

actually, that quote was mine, in an unusual spurt of funoucityness compounded by a serious fight with boredom at work.

a little digging, and i was able to turn up the original post…

http://www.chiefdelphi.com/wwwboard-2000/messages/6260.html

19

Posted by Anton Abaya at 1/15/2001 10:12 PM EST

Coach on team #419, Rambots, from UMass Boston / BC High and NASA, Mathsoft, Solidworks.

In Reply to: Helicopter propulsion
Posted by John Nicholson on 1/15/2001 4:27 PM EST:

i know i read it once…hmm… anyone find it?

i swear i thought i saw it… hmm, maybe i can make one using some velcro…

-anton

20

Posted by Josh Vetter at 1/16/2001 3:39 PM EST

Student on team #548, Robostangs, from Northville High School and BOSCH.

In Reply to: Helicopter propulsion
Posted by John Nicholson on 1/15/2001 4:27 PM EST:

According to update 4, flying is allowed, so I say you should do it. It may not be powerfull enough to get anything done, but it sure will look cool.