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Void

Member

Registered: 2011-12-29

Posts: 7,818

Modified gym equipment to partially simulate low gravity.

I previously in other topics mentioned a rickshaw and/or handler robot to be used to simulate low gravity on Earth.

I want to add to that the possibility of using a modification of some gym equipment.  For instance a lat pulldown machine.

Example:
https://www.bodybuilding.com/exercises/ … t-pulldown

This machine is an example.  Another would be an assisted pull-up machine.

The point is these have counterweights on cables that basically lift up part of your body weight.

How I would modify these would be to make a harness(s) for the body, instead of engaging the machine with your arms.  I would also make the frame mobile and with a low center of gravity so that the test subject could move about on a flat floor.

An additional preference would be that the frame be motorized and capable of working with the test subject to move about on the floor.

With that and people willing to endure this for months, you may test legs and perhaps back, maybe more for reactions to simulated low g.  Of course the simulation is an approximation.  You would not have the potential of blood pooling in the upper body, or the potential of eye damage, the reaction of the blood and immune system, etc.

However you could examine for bone loss and mussel atrophy.

You could simulate the Moon and Mars I should suppose.

The subject(s) would not have to be in the harness all the time.  Perhaps they could sit in chairs, and that would be ok.  They certainly should be able to sleep in a bed in a very normal fashion.

This could be helpful to gather such information.  Even if we get humans on the Moon and Mars, it could be helpful to know the difference between how this simulation causes the body to react, and how the body reacts on the Moon and/or Mars.

Space Medicine may get a better definition of what is going on with this information.

Done.

Last edited by Void (2018-03-05 13:02:06)

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Antius

Member

From: Cumbria, UK

Registered: 2007-05-22

Posts: 1,003

Re: Modified gym equipment to partially simulate low gravity.

Not sure how gym equipment can simulate micro g.  A better bet might be a bungee rope.  Maybe skydiving - you get 5 minutes of zero g before leaving a lasting impression on the Earth.

Void

Member

Registered: 2011-12-29

Posts: 7,818

Re: Modified gym equipment to partially simulate low gravity.

I appreciate your interest, this will take a bit of time, but I will "Walk" you though it. 
https://www.bing.com/images/search?q=ba … IGREWeight Balance Beams.  I worked sort of thing with this quite a lot for a long time.

Now Antius, suppose you are in a harness perhaps about your chest, and instead of a pan on that hook, you are on the hook.
Void slides the weight on the beam so that .62% of your weight is compensated for.  Now your legs only have to hold up .38% of the weight of your body.

It is possible that we could modify this so that your spine could be tested as well, but for now lets just say we want to only test legs.

......

Now the rickshaw
https://en.wikipedia.org/wiki/Rickshaw

You should see two rickshaws, and each of them is a balance beam.  If you were pulling either one.  By adjusting the distance forward or backward of your passenger you can adjust the force up or down that is imposed on you.  Probably in this case they have balanced it so that if you have a tiny or big person it will not matter because perhaps 1/2 of their weight will push down on you and 1/2 will try to make the front end of the balance lift upward.  More or less.

The weight is centered over the pivot of the balance beam.  In this case the axel of the wheels.

But I could put a really heavy person on the seat, and move the seat backwards, and you then would be lifted off the ground if the person was heavy enough, and we moved the seat back far enough.  So, for you, I could arrange a situation where you the rickshaw puller ended up with your feet dangling in the air, or for your legs, zero gee, sort of.  Gravity would actually in that case be pulling on your legs.  So, not a prefect simulation of zero gee.

Butt if I found a person of the correct weight and put that person on a seat of the right distance backwards, I could cause this thing to reduce the force on your legs down to .38% of Earth Gravity.  Again not a perfect simulation for your whole body, but for some body parts such as legs, and maybe even the back a ~simulation is possible.

......

Handle the robot in some ways resembles an insane robotic rickshaw.

https://www.youtube.com/watch?v=-7xvqQeoA8c

If you look carefully you will see a balance beam and a rickshaw.

......

OK, back to the gym.
https://www.bodybuilding.com/exercises/ … t-pulldown

OK this dude is not me.  I think I could BS that I have 1/2 those mussels.  Actually!   Looking again actually 2/3rds.  Ha Ha.

There are three important items to note in this picture. 

1) The thing above his upper legs that keeps him from floating off of the bench he is sitting on.  I pull so much weight that I actually come close to floating off of the seat.

2) the black colored weights in front of him inside the frame.  You select how much weight you want to pull down with your lat muscles.

3) And of course he is suspending part of his body weight from his arms to exercise his lat muscles.

......

We would not particularly care to bother with that.  Instead we would alter this picture with the following notions:

1) A harness, perhaps around the chest or under the armpits.  Actually we might want quite a few different alternate harness situations.  We don't want the subject to develop abrasions, sores from continual contact.  So alternate types of harness.  The subject is in a standing position, with some of its weight compensated for to simulate a partial Earth gravitation, most particularly on the legs of the subject.  This could be extremely boring though, even if you had television.  And you should want the subject to flex their legs anyway to exercise the leg mussels under a sort of simulated 1/6 g or .38 g.

*Note: So, you are incorporated into a stationary frame with a harness of some kind, and the force on your legs is possibly 1/6 g, or .38 g.  You are getting bored looking at the wall and you tell Void so.

So we decide the machine should have wheels on it so you can walk it about.  This will make the simulation better anyway.  But actually inertial would be incorrect in such a simulation, so you need to motorize the frame and give it AI so that it knows how to work with you and simulate normal inertial for you.

And that is pretty much it.

I'm done.

Really respect your capabilities Antius, but really could we not work for a greater purpose?  Not be enemies?

Last edited by Void (2018-03-05 16:11:32)

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louis

Member

From: UK

Registered: 2008-03-24

Posts: 7,208

Re: Modified gym equipment to partially simulate low gravity.

You'd still need some suspension in your chair I think to simulate micro G...a gentle uplift. Could be provided by air jets I guess...?

What if you had a centrifuge with an isolated chamber in it and you balanced a 1G with air pressure, or maybe magnets,  pushing in the other direction against the isolated chamber at a force of 0.62G  - would that simulate Mars G?

Last edited by louis (2018-03-05 16:34:52)

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Void

Member

Registered: 2011-12-29

Posts: 7,818

Re: Modified gym equipment to partially simulate low gravity.

No Louis.  Wait until I finish please.

And I don't want to simulate micro gee.  That has been done on the international space station.  No need.

I am done now.

Last edited by Void (2018-03-05 16:11:57)

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Antius

Member

From: Cumbria, UK

Registered: 2007-05-22

Posts: 1,003

Re: Modified gym equipment to partially simulate low gravity.

Ok.  Interesting ideas.

Void

Member

Registered: 2011-12-29

Posts: 7,818

Re: Modified gym equipment to partially simulate low gravity.

Nice, and thankyou.

Well Spacenut has been messing with me in the thread:
Index
» Interplanetary transportation
» Alternate BFR (Big Falcon Rocket)

So, I bring the question here as well:
The Question:
"And that leads to a really thrilling question (For me):
Do bones each decide how much they should accumulate mass individually or do they make that decision in collaboration?  This is one way to test the question. "

#146 post.  I am really interested because on Earth leg only or leg and back only simulations might give some important information for this question.

Very pleased to arrive at a useful question that could be tested here on Earth.

Leave me alone, I am going back to bed, need my sleep.

Last edited by Void (2018-03-05 20:51:51)

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SpaceNut

Administrator

From: New Hampshire

Registered: 2004-07-22

Posts: 29,431

Re: Modified gym equipment to partially simulate low gravity.

One could make like the pilsbury, michellen man, stay puff suit that could be inflated with helium for free movement of all extremities but I get the cradle harness lift is much in the same way weighlessness is done in pools of water for the space travel.

Have a good nights sleep, mine is usually broken up every couple of hours

Void

Member

Registered: 2011-12-29

Posts: 7,818

Re: Modified gym equipment to partially simulate low gravity.

There are mechanical possibilities on Earth.

Of interest to me beyond that would be a tumble method for a BFR type rocket in LEO.

Then it might be possible to get direct correspondence of data from that for a small number of test subjects vs a larger number of test subjects on the surface of Earth, to estimate just how worth while your Earth based simulations are as to measure reality.

The process previously mentioned for Earth simulations primarily of legs and perhaps portions of the back, could be improved if you did cable attached counterweights for the legs themselves.  While the machines I have proposed may give approximate simulations, there is the issue of what happens when you lift your leg in 1 g.  Without counterweighted method then your leg lifting is in 1 g, not the 1/6 or .38 g you might prefer to test.

Still, K.I.S.S. first, and if you can afford it later, make it more complexly accurate.  It will never be a completely accurate simulation.  You can only hope to achieve an approximate simulation.

Then you might want to compare to data from a small number of test subjects in orbit in a tumbling BFR.

End.

Last edited by Void (2018-03-06 12:06:42)

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vemsemigma

Banned

From: USA

Registered: 2018-03-28

Posts: 10

Re: Modified gym equipment to partially simulate low gravity.

Like astronaut training with the large airplane doing loops to simulate loss of gravity for a few minutes?

Rob

Void

Member

Registered: 2011-12-29

Posts: 7,818

Re: Modified gym equipment to partially simulate low gravity.

Sure, sorry I missed your post for this while.

Whatever it takes to get smidgens of information.

For instance Jeff Bezos wants to launch an Amazon type delivery service to the Moon, "Blue Moon".
https://www.geekwire.com/2017/jeff-bezo … igin-moon/

Perhaps SpaceX will provide service to the Moon earlier.

In either case, I have to suppose that some test data can be generated by placing living things on the Moon (In containers of course).

As for the BFS tumble I previously mentioned, I have updated that.

I think that 2 ea. BFR's joined at the tail by several tethers could form a baton type synthetic gravity machine.
Perhaps first trying for a 1/6 g force in the nose of each ship where perhaps a small gym could be put.

Then after that I would dream of .38 g for to simulate "You know where".

These simulations might last for quite a time, after all the BFS devices are expected to travel from Earth to Mars, which has to take months.

Based on the data for 1/6 g and .38 g, and existing 1 g (Earth) and microgravity data, it should be possible to make a guess for what is a g force sufficient to delay deterioration of human beings sufficiently in space flight.

Then test that to confirm it.

Then you are all set to have some amount of health benefits by baton mode to and from Mars.  Lets just suppose it would be .5 g.  (Not saying it is).

......

But of course even just now on the surface of the Earth it should be possible to test leg bones in living humans by using gym equipment based machines to simulate a lower stress gravity field.

So, then you would already be suspicious of what the minimum amount of bone stress needed would be.
Should give you some idea of the muscle loss as well, I would think.

Last edited by Void (2018-04-29 09:57:32)

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