Recent Posts

11

General stuff / Re: Picking things back up

« Last post by webby2 on April 21, 2024, 05:00:33 am »

if you have 2 levers and you use a spring to connect them together and you want to compress or stretch that spring you need to supply a force on each lever.  While the spring is potentialized then it does not matter which way the levers move, that is one side moving up while the other moves down or vice-versa, the needed forces on the ends of the levers remains the same.

My system has 2 reactionary levers, the input side and the output side, the input is 90mm and the output is 120mm.  These are locked into a 1:1 rotational value.  I supply the input side with some force and that force is transferred via a belt across the system to the output side at a 1:1 so the output side sees the same force.  All things, except for the reactionary lever arms, are 1:1.

It is my go-between parts that allows this to happen.  What I thought was the only reactionary force I needed to counter was easy enough.

I was expecting that if I supplied the input side with a force potential so that the belt was transferring 10N of force that the reactionary arm of 90mm would create the appropriate work potential and that with the 10N of force being provided to the output side it would produce its appropriate work potential that was 1\3 more than the input side, being the arm is 1\3 longer.

What I got was close enough to a 1:1 pass through when the input side also supplied the motion to call it a 1:1.

When I measured the system when the output side was providing the motion things were different, I had to supply more force than I was getting from the input side.  This is what I have been looking into.

I am slowly making parts to see if I am correct and to see if I can make a gain out of this, right now it does appear to be a sink, or a loss of work.

12

General stuff / Re: Picking things back up

« Last post by webby2 on April 19, 2024, 07:38:39 am »

strange,
The shift is not always the same, it is as if the tension in the belt is interacting with everything.

13

General stuff / Re: Picking things back up

« Last post by webby2 on April 19, 2024, 07:09:09 am »

Found an issue with the build.

2 pulleys printed from the same printer and the same file gave me 2 slightly different diameters.  These are then walking around one another so that is what I think is showing the results I have been getting.

14

General stuff / Re: Picking things back up

« Last post by webby2 on April 13, 2024, 06:05:52 am »

trying all sorts of little changes and at this point the one thing I have noticed is that when using the 190g weights the system behaves a little differently than when I use more or less.

I add 30g to the output side and the nudge the system and it will slowly fall down a little bit, put it on the input side and I do not have to nudge the system at all.  I have tried with my sync point moved, using CW and CCW rotation, switching the weights, so it seems that there is a preferred force direction of change, how much and why, not sure.

15

General stuff / Re: Picking things back up

« Last post by webby2 on April 13, 2024, 04:25:47 am »

I upped the weight to 270g and things appeared to become more "normal".

Then I thought about the limiter, so I shifted the system one way and not much change then I shifted it the other way and now the output side having the extra 30g goes up, very slowly and I need to nudge things so I am thinking that what I thought was "synced" may be in the wrong place.

16

General stuff / Re: Picking things back up

« Last post by webby2 on April 13, 2024, 04:07:49 am »

My setup needs some structural parts added but the functional parts are in place well enough for a few basic tests.

My spring scales are problematic in that I need to overload the system to get smooth readings and that drives the system out of sync so that a limiter I have in place comes into play and locks things.  While it is in this condition if I pull on the output with 1200g I only need to supply 900g to the input, however if I pull on the input with 900g I only need to supply 1000g to 1050g on the output.

I changed up to dropping weights, each are 90g.  When I reset so that the input and output are synced back up the input side has a very slight tendency to fall.  I add another 30g to the output side and it has a small tendency to fall.  If I give the system a spin it moves further one way more than the other, that is to say that the heavier side will continue to move down further than lifting it up.  If I put the 30g on the input side it falls without needing to spin.

I increased the drop mass to 190g and the system seems to be balanced, no tendency to move either way.  I add 30g to the output side and it drops fairly quickly, when I move the same 30g to the input side it drops very slowly and will stop moving until I give the system a little push.

Not the results I was hoping for, but not the results I was expecting.  I was expecting the system to stay balanced and behave in a normal fashion.

17

General stuff / Re: Skinner

« Last post by webby2 on April 12, 2024, 02:40:11 am »

I watched another attempted replication of the Skinner device and was disappointed at the test-bed.

First, it was not the device that was tested and yet it was concluded that the device claims were debunked.

If I have a mass sitting on that lower arm that is in a downward position and I activate the system by spinning it up that mass is going to lift upwards via whatever you wish to label the force, gyroscopic, CP, CF or whatever.  That direction of force transfer is going to take the lower shaft and force it away from vertical, it is going to PUSH that shaft away and that is the wrong direction of force.  This test setup has been tried many times and while the system is moving slowly the mass being lifted by an external means applied to the lower shaft will want to fall and cause rotation,, while moving slowly.

If you use a smaller mass and mount it on its own shaft on the end of the lever you can still do this, so a small mass on a post attached to the end of the lower arm raised up some distance from the lever.  Activate the system by spinning it up and this time the ???force is going to try and force the small mass away from the center of rotation which then applies a force down on the lower lever it is mounted on, and that tries then to PULL the shaft away from vertical.  You now have 2 forces acting on the mass with both of them trying to make the mass move down and PULL the shaft away from vertical.

Why would someone want to use a bent driveshaft to connect things together?  Worse yet why would they also use ball joints on the driveshaft?  There is no way that shaft can pass a torque, you can try and stop that shaft from spinning or try to spin it up and no torque is transferred.

If then for a moment you consider a deconstructed swash plate, more precisely a 3 plate swash plate.
https://en.wikipedia.org/wiki/Swashplate
If you think this through you might start to think that the lower system and upper system combined together has a feedback mechanism that forces the upper arm to rotate.

The middle plate is not in alignment and that mass on that middle arm\plate is going to do what when it is spun up, which way is that force flowing?

My test-bed had all of these relationships being a rather sensitive balance of forces, interactions and reactions.  I could for a moment achieve an interesting result but it was very easy to loose the sync and over spin the system or take to much out or not enough,, it was very temperamental and I did not have the patience to try and work it all through.

I concluded that the system would not be practical as it was shown and that as it was shown it was not setup to actually function as described.

This is just my opinion of course.

18

General stuff / Re: Picking things back up

« Last post by webby2 on April 09, 2024, 04:07:19 am »

I think I might of found the pathway that I need to interact with, it is not really the way I thought it would be.
I am printing off more slightly changed parts, I keep getting the slop and printer error and stuff a little off so I get into either a miss or a bind and keep making small changes to get each part to fit and work together, it was in going over all this so many times that I saw what might stop the system from doing what I wanted it to do, that is provide me with a 1:1.314 gain in work.

Now to print more parts and see what I see, then print more parts from there.

19

General stuff / Re: Picking things back up

« Last post by webby2 on April 05, 2024, 06:05:00 am »

the systems are not equidistant from the shaft so I am thinking that it is the difference that is providing for this interaction, however to counter the one side adds a force into the whole system so I would need to counter each system relative to the central shaft.

20

General stuff / Re: Picking things back up

« Last post by webby2 on April 05, 2024, 05:38:55 am »

just double checking things.
the lighter weight is 70g, the lighter weight is 50mm from the central shaft
the heavier weight is 90g, the heavier weight is 55mm from the central shaft