Picking things back up

[webby2]

Not sure what this means.
While I am just playing and printing more parts for testing stuff.

I set things up in a strange almost backwards way, then I use Mr. Hand to hold the output still and then use the other Mr. Hand to apply force against the input arm.  I then shift things so that it is close to where I think a force gain situation should be,,, now the funny thing happens.  I move the arm and of course the output moves then I take Mr. Hand on the output and I increase the resistive force he is applying.  Well, Mr. Hand on the arm does not feel that increase in force but several of the parts bend and flex more, as I would expect from the increase in force from the output.

[webby2]

Still just playing around.

I have been looking at what kind of exchanges I can have and what makes sense and what does not,,
I thought of something last night and then after thinking about it it seemed like it would have to end up being a net zero, well I printed a few parts off overnight and thought I would just go ahead and play with them, then I found that I made one hole to big for the screws I am using, anyway I just used a nut and bole and locked those parts together instead of allowing them to move on a bearing.

So my gears haves a 24mm radius boss, so a pulley if you will, I used the teeth to hold onto 8 rubber bands and held the other side to a non moving part, then I used 1 rubber band on a part that has a 100mm radius, the 1 rubber band would stretch and then it would move everything and stretch out the 8 rubber bands.

Not sure if it means anything but I thought this usage would not do anything.

[webby2]

I got curious so I measured the force on the 8 rubber bands when pulled to the "starting" position length, that force was 7N
The hub piece has a 24mm radius.

I have 2 positions I can measure for an output.
The lock pin has a radius of 80mm and has a force at the "starting" position of 4N
The other pull point has a radius of 94mm and has a pull force at the "starting" position of 2.4N

My spring scale has 0.4N marks

Edit to add:
The "output" points and the input hub rotate at a 1:1 ratio

[webby2]

I am running with only 1 set of 2 arms in this system and with what I have played with my expectations, if I were able to run a full cycle test, would be that the system would start at a net zero condition, ramp up to a maximum gain then down to a net zero then down to a maximum loss and back up to a net zero.  I would expect that the maximum gain would match the maximum loss and show a complete cycle as a net zero.

If I were to add another set of 2 arms to the system then I would expect to be able to use the new set of arms as the transfer component instead of the loss cycle from the first set of arms, add more sets and I could be higher on the gain section.  The more sets the higher on the gain slope the system could be maintained.

[webby2]

I can only run a static test, with that I setup where I thought the system should show a loss and it does show a loss but not as much as I thought it would be, so maybe the max loss part of the cycle is not where I think it should be.

[webby2]

I was just thinking to myself that what if the net zero to max gain and back to net zero is for less than 180 degrees and the net zero to max loss and back to net zero is for more than 180 degrees.  This would allow for the loss to be not as much force but over a longer rotational moment.

If that is the case I can still add in enough systems to stay on the gain side.

[webby2]

Funny thing,, I thought I would print some purposefully made parts to improve on the ones I kind of just scabbed together.

Well now I know that my measurements are not so bad, with the "new and improved" parts it looks like it changed the functionality to a net zero,, that is tongue in cheek there, when I go back so do the readings.

[webby2]

Trying to figure out the actual transfer modality is frustrating.

With that, I thought to myself that if what I think might be able to happen within the system does I could then use a low force, aka 2 rubber bands, to check to see if the same force applied on the same radius at a 1:1 turn ratio can in fact manifest 2 different forces.

My sprockets can be setup for this simple test within the test-part.  I set it up that way and used 1 rubber band on 1 sprocket and then used another rubber band on another sprocket in opposition to the first sprocket and each seeing a non-moving attachment point to the test-part.

My assumption was that if indeed the interaction with the system manifested 2 different reactionary forces that one of the rubber bands would stretch the other one out until the forces were balanced throughout the system.

I have ended up with one longer rubber band and one shorter rubber band and the system has a desire to rest in one position leaving the rubber bands in the long to short condition every time I move the system out of this resting position.

[webby2]

I tried the same thing on 2 sprockets next to each other, they are not as good I think but I tried it anyway.
So I still get the shift to a preferred position even tho it is not as strongly attracted to that position but here is the funny part, I thought to myself why not just hook the rubber bands directly to the sprockets with no fixed point of observation?  Well when I do that and stretch out the rubber bands they do in fact move the system but they will move the system backwards compared to the fixed point direction and dependent on the system orientation.

[webby2]

right now as I am playing with this it is looking like it might be the slop that may be creating the motive values.

It might be that if I use the correct set of sprockets with there systems interacting and the slop is just right the system moves with some force.  I have been trying the same relationship with other parts and other sprockets and I am finding that the shift is not all the same but that when there is one that the tendency is in the same direction.

[webby2]

I am focusing on the test I can do that has little to no involvement of Mr. Hand.
That test is setting the system in a particular spot, applying the rubber bands hooked on the teeth of the sprocket and a fixed point on the frame and setting the stretched length of the rubber bands the same.

[webby2]

I was getting inconstant tests with different sprockets, some showed no change others some change.

My frame is 2 pieces bolted together, there are many points that line up with these 2 parts BUT when I loosened the bolts and tweaked the alignment most of the "indexed" went away, unfortunately so did the reaction I was seeing from the one setup.
Conclusion: There was an internal storage and exchange that I did not understand and would most likely lead to a net zero condition.

Next step is to get back on the path I was heading, which I did and am again frustrated with issues.

What I see via a spreadsheet is that there is a potential to have a 1:1.5 relationship for work, however things load up, if you will, when trying to pass enough force to not worry about the frictional losses .  So far the only thing I can say is that on one side it takes me approx. 1N to make the unloaded system move and it takes approx. 0.75N with the other side to make the system move.  Same movement by the way since the sides are 1:1 that way.

[webby2]

made a few more parts.

I use the spring scale on one side with no load and the scale shows next to nothing to rotate, on the other it shows up to approx 0.25N to rotate so setup of things is closer.

I am using an arm for input and output and 2 spring scales.
I have used each scale on each arm.
The input measures approx. 1.5N and the output 1.75N.

I have run this a few times but since this is not a full rotation not much can be said other than this is less than what I thought I might see.

[webby2]

I am using a lot of bearings in this system. All those bearings are still packed with grease so they have some drag on them.  I thought that I could just increase my input force and not worry about those losses so much.

I made a poor design choice\compromise in that my input interacts with a large group of levers and uses a bearing for that interaction, the bearing is supposed to run square with the lever face but my poor choice has a very small angle to the interaction and as I increase the force that angle forces the bearing to run across the face of the levers and it "pops" off of them.  I increased the strength of the arm in an attempt to stop that but it still does it anyway.

Now I get to re-design all of those parts.

One interesting part to all of this is finding what WTF I need to break and redirect.  I did not see where that was and am hoping that I have found the correct path to interact with.  With that, I can see several ways of making that interaction if I am correct.

[webby2]

I am testing out a design change and have an interesting thing.

I have reduced the input\output radius, with that I can now apply approx. 15N of force on each side and nothing moves.  If I want the system to rotate with this consideration in place I need to increase the force up to approx. 20N on whichever side I wish to be the driving side to move the other side at approx. 15N.

This could just be me not applying and moving things correctly but the same relationship appears to happen with more or less force being used.

I tried another one but the part was rather flexible and under force it would flex changing the rate of angular change side to side and showed a growth in force when I used the input side but the input side, due to the flex, moved a larger angle than the output side.