|
|
|
 When you build a practice robot, you're literally buying time. - sanddrag [more] |
 |
|
|||||||
|
||||||||
One idea for the 2013 Ultimate Ascent. We figuired that we would make even more of an ascent this year than the other teams! All the electronics and motors are mounted under the sheet below the rotors.
Discussion
view entire thread
09-01-2013 22:58
z_beeblebrox
Re: pic: The Cow that Jumped over the moon!
1st: Really?
2nd Why?
If legal (which I doubt) and works (same issue), why is this better than a more normal robot? However, if you really build it, I'd love to see pictures and video.
09-01-2013 23:21
CalTran
Re: pic: The Cow that Jumped over the moon!
Bumper rules, specifically robot height?
09-01-2013 23:28
nikeairmancurry
Re: pic: The Cow that Jumped over the moon!
We had a kid on the team keep pushing this type of idea. Printing the OP's picture and showing him he wasn't alone after all.
09-01-2013 23:39
valeriemoore
Re: pic: The Cow that Jumped over the moon!
This is legal, but only if the bumpers stay within the bumper zone (2-10 inches).
10-01-2013 06:42
GaryVoshol
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by valeriemoore
This is legal, but only if the bumpers stay within the bumper zone (2-10 inches).
|
To the OP, beware the Grapple rule.
10-01-2013 07:06
JesseK
Re: pic: The Cow that Jumped over the moon!
There's a fundamental design flaw with this, if you continue to use the sheet.
http://dsc.discovery.com/tv-shows/my...p-lift-off.htm
|
Originally Posted by Mythbusters
Tossing another bee in the myth's bonnet, physics principles wouldn't permit the buzzing army to fly away with the laptop because the airflow beneath their wings would push down on the laptop.
|
10-01-2013 09:37
Toa Circuit
Re: pic: The Cow that Jumped over the moon!
Okay, so here's the rundown of things:
Why do this design?
1. Unable to be interfered from other robots.
2. Directly dump disks into the high and pyramid goals with ease.
3. Able to block disks from opponent robots by bypassing the height limitations.
4. Sit on the pyramid at the end of the game for maximum bonus points.
5. Put other game players in a state of awe and anger and render them incapable of playing the game well.
Is it legal?
Im fairly sure. That sheet/wall is a rolled up thing of cloth that would fall down after match start, so it would at least begin satisfying the bumper rules there. Maybe the mechanism would be removed.
To JesseK:
Hmm... okay. We might have folding propellers or cut out that plate in the top to allow airflow then.
To GaryVoshol: What is the grapple rule? (I don't know any rule by that name.)
10-01-2013 09:54
MARS_James
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by Toa Circuit
What is the grapple rule? (I don't know any rule by that name.)
|
The following actions are prohibited with regards to interaction with FIELD elements:
grabbing,
grasping
grappling
attaching to,
damaging,
becoming entangled
Actions A-D do not apply to ROBOT interactions with the PYRAMID.
10-01-2013 10:16
JesseK
Re: pic: The Cow that Jumped over the moon!
Oh! I didn't realize the sheet was vertical. In that case, there isn't a design flaw so long as the plate is cut to allow air flow. There's a strategy flaw with point # 5 though:
|
Originally Posted by R08
4.1.2 Safety & Damage Prevention
R08 ROBOT parts shall not be made from hazardous materials, be unsafe, cause an unsafe condition, or interfere with the operation of other ROBOTS. <blue box> Examples of items that will violate R08 include (but are not limited to): A. Shields, curtains, or any other devices or materials designed or used to obstruct or limit the vision of any drivers and/or coaches and/or interfere with their ability to safely control their ROBOT |
10-01-2013 10:21
nighterfighter
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by JesseK
Oh! I didn't realize the sheet was vertical. In that case, there isn't a design flaw so long as the plate is cut to allow air flow. There's a strategy flaw with point # 5 though:
|
10-01-2013 10:25
JesseK
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by nighterfighter
It would be safe as long as they put some sort of shroud over the blades.
|
10-01-2013 10:30
nighterfighter
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by JesseK
The safety issue isn't in the spinning propellors. The safety issue is the vertical sheet (shown as cow print in their CAD picture) preventing the opposing drivers from controlling their robot -- as called out in the blue box beneath R08. I emboldened the appropriate wording above.
|
That vertical sheet could be made out of a mesh or something instead. It would still serve the purpose of blocking shots, but not interfere with vision.
On another note: Do you think that the FRC battery will be able to provide enough power to keep the robot flying at acceptable altitudes? If you've ever flown one of those remote control helicopters, you'll notice that as the battery gets drained the helicopter's maximum altitude dramatically falls, and as the battery gets even lower you can no longer gain altitude.
But I think it would be awesome to see a flying FRC robot!
10-01-2013 10:33
MARS_James
Re: pic: The Cow that Jumped over the moon!
I am more interested in which motors you will use for the propellers
10-01-2013 10:33
JamesCH95
Re: pic: The Cow that Jumped over the moon!
Do the power calculations required to fly and/or hover the minimum required equipment in a robot given the available motors and battery. It will soon become obvious why there has never been a flying FRC robot before.
10-01-2013 10:36
dondanvm
Re: pic: The Cow that Jumped over the moon!
This idea is legal. The lower hanging "shield" that is in a crazy cow print would not be needed. If you have flown or been on a helicopter, you need the open bottom or the robot to get air flow. With the open bottom, the prop wash would create a disturbance and affect the flying ability of all frisbee's that fly underneath it, providing great "D".
This being said, it ruins the spirit of the game.
Using the battery and CIM motor's, it is possible to lift that much weight with a helicopter style blade
10-01-2013 10:40
JamesCH95
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by dondanvm
This idea is legal. The lower hanging "shield" that is in a crazy cow print would not be needed. If you have flown or been on a helicopter, you need the open bottom or the robot to get air flow. With the open bottom, the prop wash would create a disturbance and affect the flying ability of all frisbee's that fly underneath it, providing great "D".
This being said, it ruins the spirit of the game. Using the battery and CIM motor's, it is possible to lift that much weight with a helicopter style blade |
10-01-2013 11:10
dondanvm
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by JamesCH95
Care to throw some numbers at this?
|
http://www.heli-chair.com/aerodynamics_101.html
Still, not in the spirit of the game
10-01-2013 11:17
MARS_James
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by dondanvm
I used the calculation method from this website assuming that each CIM is just under 1/2hp and weight roughly 3 lbs. You could use all 6 cims or just 1. The math is complicated, but it walks your through pretty well. You certainly would not have a lot of weight room left but it is possible from my calculations.
http://www.heli-chair.com/aerodynamics_101.html Still, not in the spirit of the game |
Cause I can't imagine this happening but I would love to be suprised
10-01-2013 11:27
dondanvm
Re: pic: The Cow that Jumped over the moon!
Yes. Light light light everything. How bout some carbon fiber!!! The battery is the biggest weight. The rest of the electronics are fairly light compared. Build the frame small and start with the props vertical so you do not need much in the way of metal/carbon fiber or bumpers. This is all conceptual, not anything you can or should try. It would get shut down for ruining the spirit of the game as well as safety (carbon fiber explodes).
10-01-2013 11:29
alicen
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by Toa Circuit
Okay, so here's the rundown of things:
4. Sit on the pyramid at the end of the game for maximum bonus points. |
Also, what happens if you're not hanging onto the tower at the end of the match and your power gets cut? I'm guessing it wouldn't be well-liked to watch a 100 lb robot falling 10 ft to the ground
10-01-2013 11:30
nighterfighter
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by MARS_James
Did you factor in the weight of bumpers, metal, crio, motor controllers, etc.?
Cause I can't imagine this happening but I would love to be suprised |
10-01-2013 11:37
Nuttyman54
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by dondanvm
I used the calculation method from this website assuming that each CIM is just under 1/2hp and weight roughly 3 lbs. You could use all 6 cims or just 1. The math is complicated, but it walks your through pretty well. You certainly would not have a lot of weight room left but it is possible from my calculations.
http://www.heli-chair.com/aerodynamics_101.html Still, not in the spirit of the game |
That being said, if you run 6 CIMs at full power continuous a) your battery will probably drop to at least half-voltage within a minute and b) the motors will likely overheat and start losing power.
All of this ignores the safety aspect, which is that FIRST probably wouldn't allow a flying robot onto their field on safety grounds. The nets are designed to contain frisbees, not runaway helicopter bots.
10-01-2013 11:44
Jim Wilks
Re: pic: The Cow that Jumped over the moon!
6 CIM's all working near full power? You'd trip the main 120A breaker in a few seconds.
10-01-2013 11:49
nighterfighter
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by Jim Wilks
6 CIM's all working near full power? You'd trip the main 120A breaker in a few seconds.
|
While they wouldn't be at free current, they wouldn't be drawing massive amounts of current if they are powering a light-weight rotor, would they?
10-01-2013 11:51
dondanvm
Re: pic: The Cow that Jumped over the moon!
The point of this conversation being... Someday it will be possible. Try it outside of the competition for fun!!!
10-01-2013 11:52
John
Re: pic: The Cow that Jumped over the moon!
Using the method from that website:
Area = #rotors * diameter^2 * pi/4
Area = 4 * 14in^2 * pi/4 = 616 in^2 = 4.28 ft^2
Power will be limited by the battery and main breaker, with a maximum continuous power of:
Power = voltage* current = 12 V * 120 A = 1440 W = 1.93 HP
PL = Power/Area = .452 HP/ft^2
TL = 8.6859 * PL^(-.3107) = 11.12 lb/HP
Thrust = Power * TL = 11.12 lb/HP * 1.93 HP = 21.5 lb
The battery alone is 12 lb. Each CIM is 2.8 lb. If I did the math correctly, I don't think you can fly.
10-01-2013 12:37
JamesCH95
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by Jim Wilks
6 CIM's all working near full power? You'd trip the main 120A breaker in a few seconds.
|
|
Originally Posted by nighterfighter
Each CIM wouldn't be experiencing very heavy loads though. The stall current is 133 Amps, and the free current is 2.7 Amps.
While they wouldn't be at free current, they wouldn't be drawing massive amounts of current if they are powering a light-weight rotor, would they? |
|
Originally Posted by John
Using the method from that website:
Area = #rotors * diameter^2 * pi/4 Area = 4 * 14in^2 * pi/4 = 616 in^2 = 4.28 ft^2 Power will be limited by the battery and main breaker, with a maximum continuous power of: Power = voltage* current = 12 V * 120 A = 1440 W = 1.93 HP PL = Power/Area = .452 HP/ft^2 TL = 8.6859 * PL^(-.3107) = 11.12 lb/HP Thrust = Power * TL = 11.12 lb/HP * 1.93 HP = 21.5 lb The battery alone is 12 lb. Each CIM is 2.8 lb. If I did the math correctly, I don't think you can fly. |
10-01-2013 12:37
artdutra04
Re: pic: The Cow that Jumped over the moon!
|
Originally Posted by JesseK
There's a fundamental design flaw with this, if you continue to use the sheet.
http://dsc.discovery.com/tv-shows/my...p-lift-off.htm They demonstrated this with miniature helicopters -- the helos could lift themselves in unison when all connected to the same wooden lattice. Yet once they mounted a sheet underneath the lattice, the helos couldn't get off the ground. |
|
Originally Posted by nighterfighter
Each CIM wouldn't be experiencing very heavy loads though. The stall current is 133 Amps, and the free current is 2.7 Amps.
While they wouldn't be at free current, they wouldn't be drawing massive amounts of current if they are powering a light-weight rotor, would they? |
12-01-2013 09:38
Camren
Re: pic: The Cow that Jumped over the moon!
I am fairly sure this is illegal because you blocking the sight of a drivers station and it is not safe at all. plus with disks flying and hitting the wall you better hope that is a stable system or everyone would get to see a cliche ladder tipping scene.
view entire thread
Tags
loading ...