Picking things back up

[webby2]

Just throwing this out there.

Using this design setup to cause the system to move, on the output side I need to apply approx. 1.5N of pull then to use the input side to move the system I need to apply approx. 1N of pull.

[webby2]

I have checked the mass and force on the drop weight, 2.5N.  I have that connected to a string and am running that string over a pulley so it applies its force horizontal into the system.  I have taken that pulley and used the other spring scale on the other side and it shows the same 2.5N even when I am raising and lowering the drop weight.

Moving slowly I have to apply from 3.2N to 3.6N of force to raise the drop weight, this is when the drop weight is on the output side.  It is almost the same for the other side, but there are some spots where the force required jumps up to almost 7N when a part transitions its orientation.

[webby2]

I have made some parts strong enough so that I can actually see what the parts look like as they are interacting, those are the input arm and the interactive drive unit.  This allows me to see what the lever system is doing as the forces are being applied and transferred from one area to another.

I have a pivot shaft that is supposed to be rigid but even with a small amount of force being transferred those rigid pivots are bending.

I am aware of these forces but I did not appreciate the reality of how large they become so I need to constrain that reactionary force issue before I can proceed.

[webby2]

simple solutions are good.

I am however having significant issues with the plastic parts deforming and not providing for a smooth interaction, when I use force the parts are almost grating by each other instead of sliding and rolling smoothly.  I have one small spot where the input force to start things moving is less than 2.4N but then things get sticky and it takes over 4N to move but then the system kind of shoots forward and stops again until I pull further on the input.

It would seem that I need to use hard surfaces instead of plastic ones.

[webby2]

so my chain and sprockets are adding more losses than I thought.  If I only use them to transfer between 2 sprockets I have an increase from about 0.5N up to about 3.5N.  To take up all the slack and just start the motion of transfer is close to the drop weight value but to get the system to move more than that takes initially a lot more and then it drops down while motion is maintained,, somewhat due to Mr. Hand not being really good for this.

I took all that off and used one of my alignment jigs instead of the chain and things were interesting.  I increased the drop weight to 4.5N and, depending on where in the rotation I measure, the input force goes from about 3.2N up to over 6N.

Watching the test-part bend and twist with all this is a bit of an eye opener as to how much constraint is going to be required.

[webby2]

sidetrack:
I have my multi-systems interacting with the input, so named because that is the way I have been viewing it to distinguish direction of throughput not as the ONLY way of using it.

My input and the multi are connected as such that one rotation of one drives one rotation of the other, they are a 1:1 rotation.
In looking for alternative methods of adding a constraint to stop the massive deflection of shafts and stuff I can up with a way but it has an interesting issue.  The direction of rotation of the multi can go either CW or CCW but the input always rotates in the same direction CCW.

In one view then they are a 1:1 but in the other they are a 2:1, that is I can rotate the multi in the opposite direction of the input and one rotation is still one rotation which means that between them there are 2 revolutions.
This is not all new stuff, at least to me and I am guessing that it will end up leading to nowhere, but it is kind of fun.

[webby2]

I have drawn up something that is a little confusing.

I have a fixed input distance of 120mm
I have an angle of change at a constant 3.65 degrees for the input.  I think this means my input work is going to be the same amount for any of the transfer system lengths.


the output is 45 degrees of rotation on a 10mm arm.
the longer I make the transfer system components the interactive angle between the input and output changes, ie: at one set of length values (468mm) the range goes from 106.01 to 74.83, many times longer (12m) the range goes from 115.8 to 71.37.  This is in consideration that a 90 degree interaction angle would be the best force transfer.

I think that this could be a kind of non-rotating lever (NRL) in that my input distance is always the same.

[webby2]

not really useful for much but an interesting method.

[webby2]

I have rebuilt my test-part, I have made it smaller and with only 4 subsystems.

They all are mounted in bearings on a frame and they are all connected to each other with a single common part.  They are all connected so that there rotational change is the same and in the same direction as each other.

I have test pulleys that are 31mm radius and are mounted on each subsystem shaft.  I am using these to test input and output stuff so that I can identify and follow what the feedback systems are within the whole system.

On one pulley I have wrapped a string with a 180g mass hanging on it, well I can not find my other 180g mass right now so on another pulley that is opposite the first one I have wrapped a string with a 250g mass hanging on it.

The drop and lift distances are the same due to the pulley radius being the same and the angle change being the same.

There are force changes within the systems and in one point of view that can be viewed as a 3:1 and this is where the feedback part is that I am looking into, it should cancel that advantage.

So,, I start the first test with the 180g mass low and the 250g mass high, let the system slip through my fingers and the 250g goes down and the 180g goes up nicely for a 180 degree rotation.  Now I reset my system for the other 180 degrees of rotation but I set the 180g mass high and the 250g mass low.

I use Mr. Finger to help the 180g mass to move down, a small amount of rotation and the 250g mass will drop back down, go past that value and the 250g mass no longer can lift the 180g mass, Mr. Finger is noticing a "heavy sluggish" feel but it is the same for either direction of rotation, keep rotating and Mr. Finger notices this "feeling" is reducing until there is a point where it is very easy to rotate the system in either direction a little bit, 10-20 degrees.

I tried to add 70g to the 180g mass to see if it would lift the 250g mass, well it did not work so well and the sluggish feeling got much worse.

I have to improve a few parts and then make sure that I have not created an artificial force potential with the setup, nothing like loading a spring without realizing it to mess with things.

[webby2]

making parts and playing with things,, fun stuff.

So I have made this one setup that actually has a few rough spots but for the most part moves OK, a little resistance but it rotates.
I found 2 electric motors that weigh 80g and am using those for my drop weights.

In the setup I am playing with right now I have 4 pulleys that go round and round but do not rotate Roberval anyone.

I have my 2 drop weights on opposite pulleys so the system should be balanced but it is not, both weights move the same distance, one down the other up and it is always the same weight, within this range of rotation, that will fall with extra force raising the other weight.

I actually was expecting either nothing, or the opposite of what I have so this is getting interesting.

[webby2]

just as a note; I am using gravity as a source, BUT, I have to supply both the motive force and the force of opposition, both of these are courtesy of gravity.

[webby2]

another note; a belt and pulley or a chain and sprocket are one-way force transfer devices.  You can not transfer any force on the slack side of the belt\chain.  You can MAKE and external constraint system to allow you to transfer a push for either but by themselves they can only transfer a pull.

[webby2]

I can add any number of sources to the slack side so long as the added force into the belt\chain is in the same direction, it would not be a source if it were not in the same direction.

To make or impart any FORCE there must be a force of opposition, an output if you will, or a sink.  This point of opposition then determines the tension side and slack side and if the system were closed upon itself, like a belt or chain usually is, then I can instantly change where the slack and tension sides are, source and sink.

I can also have any number of outputs ,and as it should be the output(s) must equal the input(s).  Any force potential that is not used by one of the outputs is passed through to another output that may be at any point along the path of the belt\chain.

Since force does not have a velocity or a distance then the modality of how the force is manifested does not matter.  In the real world you just can not have your sources run through, physically, any other part.

So the belt\chain then, in a sense, becomes a storage medium for potential similar to momentum  and how that potential is depleted is how the work is performed.

[webby2]

This is a little petty maybe but I want my test-part to use a different storage potential than the test-bed.  The test-bed uses CP as the storage medium for work transfer and it looks like I can do something similar with the test-part but I want it to do things differently.

If I look at the "how" that may work and then look at what I thought the test-bed was doing,, well I might of over-thought the "how" for the test-bed.

[webby2]

On a 30mm arm I have hanging a 185g mass, on a 60mm arm I have hanging a 90g mass through a certain area of rotation the 90g mass picks up the 185g mass with ease, I need to add 30g to the 185g to balance things out.  I changed my applied points so that they are 180 degrees across the same axle and on the same lever arm.

The complete lever arm weighs 30g and enough of the arm and parts are on the 90g side that when I weigh that side it is 20g.  So this should then be close enough to being balanced.  30@210 60@110 roughly speaking is very close.

I have a range where this seems to hold and a range where it does not.
The whole system is very stiff to move but the weights on the arms move the whole system easy, so that is the internal moving parts are very stiff but the whole system is very free to rotate and move with no masses.

I am looking into a funny thing with this part of rotation relative to the direction of gravity and the relative positions of my system.