19 replies to this topic

[AUSSIETROOPER4]

Has anybody calculated the force a 100 tonne mech would have just walking on the human body?
I know they have something called a mech couch, but how exacty does that absorb the force?

[Katus]

By the lore an average Mech has about 26 "bones". Then they have Actuators that connect to the Myomer bundles that are the Mech's "muscles". Internal to the legs are also a series of shock absorbers that assist in the absorption of the Mech's movement.

Again according to the lore, some Mechs offer a smother ride then others. Also speed is a factor. But for the most part the ride is smoother then you would get in a tracked vehicle on rough terrain. One of the massive advantages that a Mech has over a conventional vehicle is its ability to traverse terrain that would bog any other machine.

Here is the opening to Mechwarrior 4, its a mix of CG and live action and I kinda think it would be a fairly good representation of what it looks like inside the cockpit while the Mech is underway. I don't know if the game is cannon in the Battletech universe but the video seems to fit with the descriptions in the novels.

[mikelovskij]

116th NorskaFresh, on 28 March 2014 - 09:43 PM, said:

Has anybody calculated the force a 100 tonne mech would have just walking on the human body?
I know they have something called a mech couch, but how exacty does that absorb the force?

The weight of the mech does not have any impact on the pilot. The only fators that matter are the weight of the pilot and the accelerations applied by the mech on the pilot.
Probably a lighter mech which has much higher accelerations than a heavier one exerts on the pilot a bigger force.

You can do a similar reasoning comparing the shocks you are subject to on a motorbike vs the shocks you are subject to in a car or in a train. Since the car and the train have a bigger inertia, they transfer less acceleration to the pilot and therefore force.

[Alaskan Nobody]

mikelovskij, on 29 March 2014 - 01:46 AM, said:

The weight of the mech does not have any impact on the pilot. The only fators that matter are the weight of the pilot and the accelerations applied by the mech on the pilot.
Probably a lighter mech which has much higher accelerations than a heavier one exerts on the pilot a bigger force.

I could be very wrong, but I seem to remember in one of the stories, an comment about how the slow stomps from an poor condition (IE was in poor repair) Atlas jarred the pilot some.... (but that could be waved by the "poor condition" bit)

[Undercover Brother]

I drive a 40 ton vehicle for a living (I'm a truck driver)...

We have seats that ride on airbags, and sway forward and backward. You'd be amazed by how much of a difference that simple addition to a standard bucket seat can make in a big rig. I would assume a similar seat would be in a mech. That, coupled with the gyroscopic stabilizers, shock absorbers in the joints, etc..., I would assume the ride would be about as smooth as a wooden roller coaster. LOL!

I DO believe that the "chicken-walker" mechs would be quite a bit bumpier than the more humanoid mechs, but are a more stable firing platform. Humanoid mechs would, in theory, be capable of higher speeds and better maneuverability.

I WILL say this though: It takes a hell of a lot to start or stop a truck, and you surely notice it when you're driving one. It's by no means a smooth ride. I also own a small, rather sporty, car... And it isn't very smooth of a ride either. Taking volume, acceleration, and mass into account, I would surmise that mechs in the 45 to 65 ton weight classes, maxing out between 65kph and 75kph (35-45mph) would be the "smoothest" rides. Anything smaller and faster would cause you to risk chipping your teeth (jogging is harder on your joints from feet to the base of the neck), and riding in anything large and slower would be mind-numbingly slow and ponderous.

Edited by T Decker, 29 March 2014 - 05:08 PM.

[mikelovskij]

Shar Wolf, on 29 March 2014 - 02:32 PM, said:

I could be very wrong, but I seem to remember in one of the stories, an comment about how the slow stomps from an poor condition (IE was in poor repair) Atlas jarred the pilot some.... (but that could be waved by the "poor condition" bit)

Well, the weight can be important in an indirect way: a heavier mech has probably much stronger actuators, and if someting wrong happens with those actuators... welp

[CyclonerM]

mikelovskij, on 30 March 2014 - 01:23 AM, said:

Well, the weight can be important in an indirect way: a heavier mech has probably much stronger actuators, and if someting wrong happens with those actuators... welp

I think only the number of actuators changes and this is obviouvsly needed to make a hevier machine walk and move.

[Strum Wealh]

Katus, on 28 March 2014 - 10:33 PM, said:

Here is the opening to Mechwarrior 4, its a mix of CG and live action and I kinda think it would be a fairly good representation of what it looks like inside the cockpit while the Mech is underway. I don't know if the game is cannon in the Battletech universe but the video seems to fit with the descriptions in the novels.

Marack Drock, on 30 March 2014 - 04:20 AM, said:

MW4 was officially canonized (at least the story and mech designs were) in 2005.

None of the MW video games (up to & including MWO) are, themselves, canonical.

Some elements of the video games have been adopted as canon (for example, the storyline for MW3 was canonized as the short story "Trial Under Fire", and the canonization of the Deimos (which started as a MekTek MW4 'Mech)), but the games themselves are never canon.

[9erRed]

Greetings all,

Mech's like the Catapult, given a large engine, and designed to stride similar to an ostrich, should have a gait similar. As the stride is extended out, at speed, the ride becomes smoother. But what we do not see "in Game" is the leaning into the turns with speedy Mech's. (although I think the Cicada is the only Mech modeled to lean when turning.)
~ Now given that land speed on two legs translates from down force + stride = speed
~ The Mech's that can extend there stride will be the faster, "the chicken walkers" probably being the speediest.

Without having an actual real machine or vehicle modeled on the BattleTech Lore or Tech spec's, we can only use the stated elements within the design (as a starting point) to calculate the (theoretical) transmitted forces through the frame from foot pad through the leg, crossing into the torso then main body where the cockpit would be located. Each component within the leg designed specifically to transfer energy into movement, down force into acceleration or stopping power.

Still using the Ostrich as reference, if you have ever watch them being raced, (actual people on there backs) there gait moves through three phases.
- The walk (smooth side to side movement during the progression.)
- The trot (stride extended but quite bouncy side to side)
- The run (Gait smooth's out, feet move to center under frame, large leans during turns.)
[very similar to progression of a horses movement to full gallop, not withstanding the additional legs.]

This all translates into the legs taking most if not all the force of the movement shock during any activity. With the foot pads, feet and the lower leg (thigh area) being designed to absorb the majority of this force, before transferring anything to the upper leg sections. The knees would rotate through each phase to act as additional absorbers for any impact force, with the final hip socket, connection point having the ability to move through 3 planes. All combining elements should be able to eliminate the final shock or force movement before it transfers to the torso let alone cockpit.

Now this does not eliminate all side to side movement, and the Mech chassis would still need to be transitioned for balance of each step, on turning, climbing, descending, impacts. And there should still be some lateral movement while the legs rotate from their forward positions to rear extended. (Somewhat theoretical at this point, but could be computer modeled, given enough spec's.) - see video at end.
- The shock, impact of actually moving should be eliminated with all these elements, and for within the BattleTech universe, the Mech's Di computer calculating the force, distance, position required for the selected move. (combined with the Pilots balance inputs)

For some Real world dynamics of what early prototypes actually do with this leg design see here:
- Known as the HRP3L JSK (High Power Leg)

http://youtu.be/9WthsRHLU4M

Actually a bit scary to see this size of a machine react so quickly, and then translate that to the sizes we are talking about in MWO, with a much more robust design. From within that video, notice how the "body" actually doesn't move up/down and the legs take up all that movement. This video shows the beginnings of level walk transition and balance keys.
(PS: That video is from 2011, so quite a bit of technology changes have happened since then.)

9erRed

Edited by 9erRed, 30 March 2014 - 04:26 PM.

[B0oN]

Fiction ?
Not for much longer I guess ma´friends ...

[ThatBum42]

I had a stupid thought the other day when mulling about BattleTech. These artificial muscles, do they have an equivalent of getting sore? Would that mean that part of the maintenance of a BattleMech would involve giving it a massage?

[CyclonerM]

ThatBum42, on 03 April 2014 - 01:19 AM, said:

I had a stupid thought the other day when mulling about BattleTech. These artificial muscles, do they have an equivalent of getting sore? Would that mean that part of the maintenance of a BattleMech would involve giving it a massage?

Unlikely. They are polymer fibers that behave like muscles when electricity flows trought it: control circuits make some fibers contract to create movement, be it walking, punching or grabbing.

[Strum Wealh]

ThatBum42, on 03 April 2014 - 01:19 AM, said:

I had a stupid thought the other day when mulling about BattleTech. These artificial muscles, do they have an equivalent of getting sore? Would that mean that part of the maintenance of a BattleMech would involve giving it a massage?

CyclonerM, on 03 April 2014 - 05:06 AM, said:

Unlikely. They are polymer fibers that behave like muscles when electricity flows trought it: control circuits make some fibers contract to create movement, be it walking, punching or grabbing.

Indeed; BattleTech's concept of myomers are an application of electroactive polymers (which is not to be confused with metallic shape memory alloys, aka "muscle wire"), which don't experience any of the situations that would cause muscle fatigue or soreness in living tissue (such as build-up of lactic acid & other end products, or tissue edema, or other causes).

[Pht]

Katus, on 28 March 2014 - 10:33 PM, said:

Internal to the legs are also a series of shock absorbers that assist in the absorption of the Mech's movement.

Do you have a source for this? If it's legit I'd like to look into the source and add it to the BMT:E thread in off topic.

I have not heard of this anywhere else.

Quote

Again according to the lore, some Mechs offer a smother ride then others. Also speed is a factor. But for the most part the ride is smoother then you would get in a tracked vehicle on rough terrain. One of the massive advantages that a Mech has over a conventional vehicle is its ability to traverse terrain that would bog any other machine.

How rough a 'Mech's ride is really depends on the geometry of it's stride and how much force it has to absorb, which can be a pretty complex thing to sort out.

The Main thing I *have* heard of for absorbing this shock is the way the command couches (pilot's seats) and restraints are built - they have shock absorbing equipment built into them, and I imagine some pretty heavy duty stuff at that, as being in a 'mech that's fallen and hit the ground or run smack into an obstacle is pretty darn rough. Sometimes rough enough to make pieces of cockpit consoles rip off and go flying, I suspect.

Marack Drock, on 30 March 2014 - 04:20 AM, said:

MW4 was officially canonized (at least the story and mech designs were) in 2005.

Sturm is right MD.

The video games are considered derivative, even if they perfectly follow the canon and/or many of the 'mech designs unique to said games make it into the canonized sources.

Edited by Pht, 03 April 2014 - 01:42 PM.

[9erRed]

Greetings all,

Reference the "Shock Absorbers" in the legs of Mech's:

I submit a few images showing the mechanical absorbers, reference only. The Myomer bundles are not shown as these would completely cover any internal components, similar to how our muscles cover all internal items.

These are Clan Mech's but the structures of Mechs for the Inner Sphere was similar, although no indication of "endosteel" is displayed in the images, it existed on many of the Clan designs.











All for now,
9erRed

[Strum Wealh]

TechManual mentions, on page 31, that "shock pads" are used in the feet of BattleMechs.

Moreover, it stands to reason that:

• the motive systems of BattleMechs, being modeled on those of humans, would be programmed to emulate the natural spring-like behavior of human legs, and
  
• The leg structure would include shock-absorbing pylons ("SAPs") or equivalent components, similar to those used in prostheses.

Either or both of those would very likely be needed just to allow a 'Mech to be able to walk or run (and, where applicable, jump/land) without shaking itself to pieces in the process.

[Pht]

9erRed, on 04 April 2014 - 01:49 PM, said:

Greetings all,

Reference the "Shock Absorbers" in the legs of Mech's:

I submit a few images showing the mechanical absorbers, reference only. The Myomer bundles are not shown as these would completely cover any internal components, similar to how our muscles cover all internal items.

The art is really neat. But it's not to be construed as "the rules of the universe" - and no, this isn't just my opinion... it's actually the official line on the topic. I'll go find the link later.

Beyond that, Cray (author of THE definitional source for 'mech workings in the lore) has related that the blueprints are quite wrong.

ATM the techmanual article on battlemech technology and the information that it hasn't supersceded are the official and main sources on how BattleMechs work.

[TheKatzMan]

XD

XD

[Undercover Brother]

Something else to consider: The "pads" in a mech's foot are likely VERY similar to the ultra-sensitive pads on an Elephant's foot... Only in the rarest instance do Elephants ever see their own feet, yet they can walk backward on an 8-inch wide "beam" using touch alone. Its been said that an Elephant can sense when the step on a dime under their back feet... And they CAN run up to 30mph (approx. 48kph) for short distances.

[Corwin Vickers]