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Vampire
Free Worlds League
Lieutenant Colonel
Joined: 05-Feb-2002 00:00
Posts: 912
Location: Spain
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 Posted: 30-Jan-2004 05:57 Post subject: A look at "bird leg" configuration 'Mechs |
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In another thread:
On 2004-01-29 18:08, Old Dog wrote:
Nah, Armless mechs can get up. The chicken-legged style have *no* problem,
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How come? It stands to reason that backward bending legs actually make it *harder* to stand up.
If a Locust falls another way that is not flat on its ass, it will have to call the tow truck.
The Locust is optimized for high speeds and for low cost, it walks on stilts, really.
However, it's not true that it can't get up if it falls over, as long as the claws on the feet can get a good grip on the ground, it can lift the body easily. Bear in mind that the 'Mech myomers are powerful, it has a very high power/weight ratio to achieve those speeds, and that those long legs act as lever, multiplying force by means of linear momentum, and all that. Put a pencil on the table, and push down the tip, see how the other end lifts up?
if you push down on the blunt end you can make the pencil go upright, (be careful of not sending it flying into your eye) do it slow motion and you can see that a Locust can indeed get up after falls. Of course it would involve a lot of tossing around using the rotating feet to get the 'Mech on its back if it fell on one side (given the design configuration, falling head first on its face would be rare), and it will scrape the paint, but it's not inmobilized like a tank that has thrown off a track.
However, best solution is to polish up the Piloting skill so you don't fall down at all 
It's no coincidence that the Jenner and the Cicada have conventional knee joints to make standing easier. The Cicada in particular has a double joint, backward in the hip, and forward in the knee, as does the Catapult and the Stalker
Makes a lot of sense. The Jenner is slower and can't do without the bird leg design, also it's Kuritan cheap, so no frills there.
The Cicada double joint makes easier to stand up, has both good speed and rough ground performance.
In the Cataput that same joint, aside from making easier to stand up in something that is a missile box with legs, serves two purposes. It allows to vary the 'Mech height to take advantage of cover (stand to full height to fire a volley of missiles over a obstacle and then hull down) it's also is a necessity on a 'Mech with Jump jets, to keep balance when you land.
And now that I mention it, this is the main reason why the Jenner uses the conventional knee joint, just recalled it jumps too.
The Stalker has a double joint too, for the same cover reasons as the Catapult and because it's hard enough to stand up with an 85 ton monster with no arms.
And there's the Marauder in this case the backward legs are just there to allow it to go hulk down and fire the autocannon turret without exposing the rest of the body, and get a better degree of protection from sloped surfaces. It doesn't need a second joint to stand up, as its weapons pods can be used as arms to push it back on its feet. The
Marauder would have a distinctive, "on stilts" gait.
You know, the more I study these things, the more I wonder at the cleverness of the original artist that drew them. That person knew about engineering, for sure.
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DarkAdder
Clan Star Adder
Star Commander
Joined: 10-Jan-2004 00:00
Posts: 604
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| Posted: 30-Jan-2004 08:22 Post subject: RE: A look at "bird leg" configuration 'Mechs |
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I just make the piloting roll and stand up the mech. 
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Steel-Scorpion
Steel Scorpion Mercs.
Mercenary General
Joined: 17-Nov-2003 00:00
Posts: 217
Location: United States
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| Posted: 30-Jan-2004 09:24 Post subject: RE: A look at "bird leg" configuration 'Mechs |
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well you do have a point there.
I have a point I'd like to make about Jump Jets, and all that...
The Jenner has ended up being a favorite, Heavily used recon and support mech of all kinds of people they are versitile. Any mech can Jump, the Reversed articulated (chicken-leg) mechs are great Weapon platforms, but Standard legs are also a good weapons platforms.
Yes, i can see a locust having some issues with getting up, but then again when you have Gyroscopes involved things become a little different, if a mech Gyro is hard mounted like some people think they are, it WILL make some actions on mech rather comical to watch.. a locust for example, could stand up on a lone leg... but the appearence would kinda look like the old film industries "Vampire raising out of the smoke with his arms streached infront of him" that rather artificial but comical, "physics-defying" manuver. But since i have played with gyroscopes extensively and have tried to duplicate the battlemech theory with models and gyroscopes, i know how the models behave... very unlike what we would commonly hink of them doing.
Yes walking and turning are un-hindered, but when the models fell over, and i would stand them back up, the toy gyro in the model made moving the model from laying down to standing up more difficult than you might think, a "resistance" to being moved off its "at rest" position. The same was true when the model fell over, it looked like some unseen force was "laying" it down gently. Mind you this was only a model, and it didn't have trouble on flat surfaces, but I couldn't just Stop on a dime either, i had to slow it to a stop or it would tip over. The model had stationary or fixed feet., but the hip and knee joints worked with servo's and pulleys. and yes i used a chicken leg design. It looked more like ED-209 off ROBO-COP than it did a battlemech, but it worked.
The faster a Gyro spins, the more resistant it becomes to being moved off axis... or tippingover. thats why you can spin one up really really fast and when you put in on a string it stays upright. Same principle applies when it become part of a devise. the devise becomes harder to tip over, an Artificial sence of ballence.
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"A 'Mech as powerful as possible, as impenetrable as possible, and as ugly and foreboding as conceivable, so that fear itself will be our ally."Aleksandr Kerensky — On the Atlas
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Vampire
Free Worlds League
Lieutenant Colonel
Joined: 05-Feb-2002 00:00
Posts: 912
Location: Spain
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| Posted: 30-Jan-2004 10:10 Post subject: RE: A look at "bird leg" configuration 'Mechs |
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Well, your point is that a gyro perversely would keep a fallen 'Mech on the ground right?
I don't see what's the problem here, just stop or slow down the gyro while you get up so the momentum of the gyro doesn't interfere with the operation.
I think that by being "hard mounted" you mean the gyro is set to a fixed number of revolutions, I don't think that's the case. In Battletech fiction gyros are described as whirring crazy to maintain the 'Mech upright (usually just moments before said 'Mech falls crashing to the ground)
For those that don't understand what we are talking about, basically the gyroscope is heavy piece of machinery that spins very fast to provide a counterweight to the 'Mech actions. If the 'Mech leans too much in one axis, the gyro tilts in the opposite and spins faster. The faster the gyro spins, the greater momentum it has and provides a greater counterbalance.
The neurohelmet provides the link between the 'Mechwarrior brain and sense of balance and the gyro. The neurohelmet also provides some finer motion control, but speed and direction in a 'Mech are done by throttle lever and pedals.
The gyro just keeps the whole contraption upright and stabilization for normal movements, but it cannot substitute piloting skill, the 'Mechwarrior still has to flail arms around and do footwork to keep balance, on the occasions the 'Mech is rocked hard enough the gyro cannot keep it steady by itself alone.
Back to the getting upright again, the gyro could help in recovery, slowing first and then speeding again to shift the 'Mech center of gravity.
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DarkAdder
Clan Star Adder
Star Commander
Joined: 10-Jan-2004 00:00
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| Posted: 30-Jan-2004 11:14 Post subject: RE: A look at "bird leg" configuration 'Mechs |
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Vamp, I think you hit the nail on the head with the neruohelmet. Think about it. When you take a fall, say you trip over something and land hard, you take a little longer to get up. Your inner ear 'gyro' doesnt quite want to get up, the same as with the mechanical gyro. I think that when a mechwarrior attempts to stand his mech, the neurohelmet transmits that 'slowness' to the gyro, slowing it enough that the mech can stand without too much trouble.
The neurohelmet also transmits that same fine control that the inner ear has. While the gyro used in Steels experiment was doing its job, it was inherintly to...perfect, I guess, for lack of a better term. Slowing the gyro, or maybe throwing it a bit off balance, would allow the mech to stand.
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Steel-Scorpion
Steel Scorpion Mercs.
Mercenary General
Joined: 17-Nov-2003 00:00
Posts: 217
Location: United States
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| Posted: 30-Jan-2004 11:19 Post subject: RE: A look at "bird leg" configuration 'Mechs (Dysecting yur post) |
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Quote:
| Well, your point is that a gyro perversely would keep a fallen 'Mech on the ground right? |
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no. only that moving it off axis is harder than normal. Buy a toy gyroscope... play around with it. you'll see what i am talking about.
Quote:
| I don't see what's the problem here, just stop or slow down the gyro while you get up so the momentum of the gyro doesn't interfere with the operation. |
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yes, thats also an idea to ponder on.
Quote:
| I think that by being "hard mounted" you mean the gyro is set to a fixed number of revolutions, I don't think that's the case. In Battletech fiction gyros are described as whirring crazy to maintain the 'Mech upright (usually just moments before said 'Mech falls crashing to the ground) |
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Yes. They assume a gyro is conastantly in motion, hence the piloting roll to stand is not as easy as one would think, the average greeny fights the gyro too.
Quote:
| For those that don't understand what we are talking about, basically the gyroscope is heavy piece of machinery that spins very fast to provide a counterweight to the 'Mech actions. If the 'Mech leans too much in one axis, the gyro tilts in the opposite and spins faster. The faster the gyro spins, the greater momentum it has and provides a greater counterbalance. |
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Both True and false. The Gyro does provide a centrifugal ballence, but the gyro itself does not correct the issue of being off center, it mearly provides the mech with mechanical sence of ballence, by which the operator [pilot] can correct by. This is also why gyro damage cause a mech to be ungainly... its tends to shake or wobble because the gyro is spinning badly, like riding a bike with a bent rim.
Quote:
| The neurohelmet provides the link between the 'Mechwarrior brain and sense of balance and the gyro. The neurohelmet also provides some finer motion control, but speed and direction in a 'Mech are done by throttle lever and pedals. |
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True. No further explaination needed.
Quote:
| The gyro just keeps the whole contraption upright and stabilization for normal movements, but it cannot substitute piloting skill, the 'Mechwarrior still has to flail arms around and do footwork to keep balance, on the occasions the 'Mech is rocked hard enough the gyro cannot keep it steady by itself alone. |
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uh, yes and no. A Battlemech's computer system will keep the mech upright with minor adjustments to the foot actuators, essentialy listening to the allmighty gyro. But it cannot move the move, if something knocks a mech around too much the computer just lets it fall over. This is why mechs dont fall over in high winds, or when other mechs walk by and shake the ground, and why mechs stay standing in soft earth, or mud.
Quote:
| Back to the getting upright again, the gyro could help in recovery, slowing first and then speeding again to shift the 'Mech center of gravity. |
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manipulation of gyro speed is something that could be done to help get up... neither good, nor bad, it just is.
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"A 'Mech as powerful as possible, as impenetrable as possible, and as ugly and foreboding as conceivable, so that fear itself will be our ally."Aleksandr Kerensky — On the Atlas
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Steel-Scorpion
Steel Scorpion Mercs.
Mercenary General
Joined: 17-Nov-2003 00:00
Posts: 217
Location: United States
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| Posted: 30-Jan-2004 11:25 Post subject: RE: A look at "bird leg" configuration 'Mechs (Dysecting yur post) |
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My statement on the Mech Computer control over the foot actuators, is meant to say the mech is standing in "stand-by" mode. to cleat that up before someone posts about it 
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"A 'Mech as powerful as possible, as impenetrable as possible, and as ugly and foreboding as conceivable, so that fear itself will be our ally."Aleksandr Kerensky — On the Atlas
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DarkAdder
Clan Star Adder
Star Commander
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| Posted: 30-Jan-2004 11:47 Post subject: RE: A look at "bird leg" configuration 'Mechs (Dysecting yur post) |
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Hey, Steel. When you did your experiments, did you find out if a too large, or too small gyro affected the things balance? It could be that the mech switches to a smaller gyro when it attempts to get up. One that doesnt 'lay down' quite so easily.
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Rarich
Federated Suns
Leftenant General
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| Posted: 30-Jan-2004 12:20 Post subject: RE: A look at "bird leg" configuration 'Mechs |
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My take on it would be that armless, bird leg mechs have no problem standing up if they fall on their back, or front. However if they fall on their side, they got to do torso twist and leg kick until they go back or front, then stand. Vestigal arms, would help a lot for sideway falls.
I alway took it that the gyro compensates for things like 5 mph winds, tremors from other mechs passing and inertia in turns, but still requires the mechwarrior to take care of big imbalances. The gyro can absorb, maybe, a 5-10 ton imbalance. More than that and the mechwarrior 's sense of balance causes the Myomers in the legs to "lean" to compensate. finally, at about 20 or so tons of imbalance, it becomes time to take a step, or put an arm out or take some other measure (hug a tree, maybe  )
That would indicate why a pilot roll needs to be made, a mech probably has the balance of a 3 to 5 year old. Kids make "pilot rolls" all the time when standing up. Adults are skilled enough at it that it is virtually automatic. A ten year old has no problem standing up, a ten year veteran mechwarrior is the same.
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Old Dog
Capellan Confederation
Sang-wei
Joined: 24-May-2002 00:00
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| Posted: 30-Jan-2004 14:55 Post subject: RE: A look at "bird leg" configuration 'Mechs |
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Well, for how easy it is for bird-style mechs to get up is easily shown...
Grab a big fat chicken. Turn said chicken on a side, or even on it's back. Put it on the ground. *whoosh* it's a-standin'. Blame my country roots. 
Shoot. I had something else to say but it just fell out of my ear.
Ack!
-- Old Dog, hates being sick. 
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Oafman
Draconis Combine
Tai-sho
Joined: 18-Nov-2003 00:00
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Location: United States
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| Posted: 30-Jan-2004 15:07 Post subject: RE: A look at "bird leg" configuration 'Mechs |
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And if you do not get away fast enough they sometimes try to peck your fingers when you do that.
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Steel-Scorpion
Steel Scorpion Mercs.
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| Posted: 31-Jan-2004 02:04 Post subject: RE: DarkAdder |
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since i could only use one size gyro, as only that smal one would fit, but yes, i experimented with larger and smaller gyros
larger = more stable, but more clumbsy
smaller is less effective... but good...
although engine size and rating sould not have anything to do with gyro's
IMHO
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"A 'Mech as powerful as possible, as impenetrable as possible, and as ugly and foreboding as conceivable, so that fear itself will be our ally."Aleksandr Kerensky — On the Atlas
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Rarich
Federated Suns
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| Posted: 31-Jan-2004 13:00 Post subject: RE: A look at "bird leg" configuration 'Mechs |
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Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!Wings!
Make the Whoosh!
Cheater!
'nough said
[ This Message was edited by: Rarich on 2004-01-31 13:02 ]
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Vampire
Free Worlds League
Lieutenant Colonel
Joined: 05-Feb-2002 00:00
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Location: Spain
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| Posted: 01-Feb-2004 06:02 Post subject: RE: DarkAdder |
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Quote:
| although engine size and rating sould not have anything to do with gyro's |
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Ah, you see but there's a relation.
Heavy 'Mech has a big heavy powerful engine to move it an average speed. Example: Rifleman 240 engine rating
Fast light 'Mech has a powerful engine to move it at high speed. Example: Hermes 240 engine rating
If your 'Mech is heavy, you need a larger gyro to compensate for the inertia, same for a very speedy 'Mech.
Rarich has spoken for me, so there's only one thing to add, about control.
The more I think about it, the more I'm convinced the gyro (nothwithstanding a separate gyro for control reference ) is a spinning mass to provide variable torque to serve as a stabilizing counterweight, the mass, likely spin rate, and location, high on the 'Mech structure confirm that hypothesis.
Steel Scorpion, I suck at math, but I can see that a 2 ton gyro spinning at 2000rpm would certainly have an effect on a 50 ton 'Mech, you can do the calculations yourself.
Otherwise, how are you going to stabilize such masses ? A 'Mech is a box on legs, it lacks all the twisting abilities of human muscles and tendons, and it hasn't an spine, either it can only maintain a balance by leg motion, though torso rotation or arms motion could help. On second thought, those things would complicate the balance equation, so it cancels each other effect.
Your statement about a 'Mech standing ... well, it's simpler than that. Just lock the legs in a balanced position, and no further adjustment if necessary, as long as there's electrical power keeping the myomer "muscles" in the leg tense and the leg locked in position. Indeed a 'Mech has les trouble standing at attention than a human. It doesn't wobble back and forth, it doesn't tire, it doesn't have to shift weight from one leg to another, it doesn't have to bend the knees every now and then to give some relief to aching muscles.
Of course, the problem with parking a 'Mech standing up is that the engine must be kept operating to keep the myomers tense. Maybe you could lock the legs joints so the 'Mech rests on its skeleton alone, but the wear and tear would be horrible, that's why 'Mechs have their engines shut down they are suspended in 'Mech bays or onboard dropships, to avoid the stress on the knee joint from all the weight of the 'Mech resting on the field. If no crane is available, then you just have to lay the 'Mech prone on the ground. All this is depicted in Battletech fiction.
One possible way to get around this if you really need to shut down the reactor would be hooking an auxiliary power unit to the 'Mechs to keep the myomers going.
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AWAD
Draconis Combine
Chu-sa
Joined: 06-Feb-2002 00:00
Posts: 766
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| Posted: 03-Feb-2004 21:15 Post subject: RE: DarkAdder |
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Quote:
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On 2004-02-01 06:02, Vampire wrote:
Quote:
| although engine size and rating sould not have anything to do with gyro's |
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Ah, you see but there's a relation.
Heavy 'Mech has a big heavy powerful engine to move it an average speed. Example: Rifleman 240 engine rating
Fast light 'Mech has a powerful engine to move it at high speed. Example: Hermes 240 engine rating
If your 'Mech is heavy, you need a larger gyro to compensate for the inertia, same for a very speedy 'Mech.
Of course, the problem with parking a 'Mech standing up is that the engine must be kept operating to keep the myomers tense. Maybe you could lock the legs joints so the 'Mech rests on its skeleton alone, but the wear and tear would be horrible, that's why 'Mechs have their engines shut down they are suspended in 'Mech bays or onboard dropships, to avoid the stress on the knee joint from all the weight of the 'Mech resting on the field. If no crane is available, then you just have to lay the 'Mech prone on the ground. All this is depicted in Battletech fiction.
One possible way to get around this if you really need to shut down the reactor would be hooking an auxiliary power unit to the 'Mechs to keep the myomers going.
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Item #1, hit the nail on the head. The Gyro is to compensate for the inertia of the Mech and imbalances it may cause, for a light Mech power means speed, for a heavy Mech it is force to move mass.
So on to the more interesting item #2. So why does most fiction and pictures portray them standing up? Also why do they ever power down? In books that was another issue, our Mechs are cold at it takes a minute to get going?
So with your idea it makes more sense to have Mechs lay down? Wouldn't that be great, go to a battalion Mech yard and see 36 lying prone!!???
But game mechanics take care of that idea, having to roll to get up or lay down, sorry 4 or less just shows up way to often.
But do you not think there are auxiliary battery systems in a Mech? In the stand down manner only minimal power would be needed to keep gyro and some myomer on line to maintain balance?
Or do you not think the skeleton was not designed to take the stress? Look at you? When standing at parade rest, you rely on skeleton to do all the work (muscles to prevent locking up and passing out but this is a steel machine). So a Mech skeleton has to keep the mass up operating or not, so being shut off is irrelevant.
As for powering off, maybe they do not want the wear and tear (yeah yeah it is fission but who knows) or they can do maintenance, or no signature to confuse surveillance, or even to reduce the use of fission material. Because do they ever mention if it is cold fusion and if so what materials are used?
AWAD- How about a regiment at Tharkad all prone outside the palace
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