Solved: Width for Height Conundrum

[AB Hammer]

Silvertiger

Never stop trying. I have had several wheels that showed promise that just taught me more of what I have to overcome.

[Tarsier79]

If you think it has promise, do a real world build. You can get very low friction bearings etc. Sims can be helpful, but will never give you the final answer.

[Fcdriver]

Low friction bearings? Why typical bearings of .07 are just fine! The battle is lift, not friction from bearings!

[Tarsier79]

Because ST is saying friction killed his design.

Silver, WM2D does some funny things with springs. They don't act like a spring actually does, although you can approximate it using a dampener.

You can minimise friction, and it is pointless to continue in sim if you have a suitable design.

Just build a real world test model.

[Silvertiger]

It doesn't have springs. I have a table of friction coefficients that I use and they average to around 0.001 for my pin joints. But yeah wm2d does use motors to simulate pin friction.

[Fcdriver]

Oh, sorry, then you still measured something wrong.
5 lbs can't lift 20 lbs. unless it falls farther than the 20 lbs is raised.

Yep you are right, but it is not suppose to move a equal distance! 5 lbs dropping 68 inches can lift 5 , 5 lb weights 1/6 the distance, fanned so that there is always one ready to fall!

[Tarsier79]

That isn't self sustainging though.

[Fcdriver]

Explain why?

[Fcdriver]

If you take count of everything in the universe how many are moving vs how many are sitting still?

[Tarsier79]

5 lbs dropping 68 inches can lift 5 , 5 lb weights 1/6 the distance, fanned so that there is always one ready to fall!

Is it just me? I thought it was obvious: 5,5,1/6. All your weights will end up on the bottom.

[Silvertiger]

I revisited an old friend of mine today: the lever. I have been working on this lever for some time. It's not the same as the one discussed here, but it is a potential solution to the height for width problem. The reason I have not posted about it is because there was a certain problem I could not solve, which is how to make it work when it is upside down. Today I solved for the mechanism that allows this to happen. I now have a lever that uses one pound to lift four. (Fletcher is familiar with this lever as he tried to help me solve the mechanism a while back, but to no avail to both of us). I'll post a video shortly. Stay tuned.

[Silvertiger]

https://youtu.be/PO_ro1ttQUE

[Silvertiger]

I'm of the opinion that it won't work mounted directly onto a rim. The shifting mechanism only works along the Y-axis. However, further scrutiny of this problem allows for at least one possible solution...mounting it to a gimbal. This would, hopefully, preserve the shifting function along the Y-axis relative to the plane of operation. In effect, the gimbal would allow the four-pounder to try to bottom out, which would flip the Y-axis of that plane about the X-axis, allowing a reset for the mechanism to shift the four-pounder back to the zenith. Thoughts? Fletcher?

[Fletcher]

Hi Jim .. I think anyone who has viewed your video https://youtu.be/PO_ro1ttQUE will be speculating on how a 1 lb weight equidistant from the pivot can lift a 4 lb weight, given the Law of Levers and gravity force. You have that part of the mechanism hidden from view for your own reasons.

However, they will follow some thought processes and make some deductions about how that might be achieved - that would very likely include extra forces in play from whatever source(s).

Then their next speculation down the trail would be about when the sim is stopped (preserving kinetic motion) and the gravity force is reversed. Why does it now flip its initial action to orientate to the new gravity direction (upwards) ?

They might not have any particular mechanical configuration in mind but reason will kick in at this point - all mechanical arrangements with degrees of freedom to move in a gravity field will find its position of least GPE, like water finds the lowest level. Unless other forces are in play that have Potential energy to call upon and which can be converted to GPE or KE.

So they will speculate about what the energy budget is for this mechanism. What was the initial sum of GPE at the start and what was the sum of GPE at the end of sim run ? And then what was the energy equivalent of any other force used in the mechanism that contributed to the Output observed ? What does the energy budget exercise show throughout the mechanism running ? Is there at any time a surplus of energy or potential, to indicate the possibility of a self sustaining, self resetting mechanism (either rotational or periodic) ?

The Milkovic Pendulum comes to mind here for me. Why can't the loop be closed for it ? Is this the case for your mechanism or have you found a real functional solution to close your own loop ? I can't comment on the gimbal approach because I can't imagine it closing the loop where the energy budget is never in surplus as far as I understand the problem to be.

[Silvertiger]

Fletcher, it isn't hidden from you. You should still have the 1-4 lever wm2d files I sent you a while back. I went with my original load shifter design; not the second. I made two changes to the shifter that allowed it to finally work both upright and upside down. Theses two changes removed the need for a latching mech while preserving the intended action to successfully shift it when flipped. But it must be flipped by rotating the system about the X-axis, not the z-axis, as the shifter only works if bound to the Y-axis of the plane of the wheel, hence the need for a gimbal mount, which will change the Y-axis to circular plane. I will attempt to test the gimbal approach this week.