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Author Topic: Picking things back up  (Read 33117 times)

webby2

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Re: Picking things back up
« Reply #105 on: April 25, 2023, 11:34:34 am »
Not a bind,,

I made an error in design and the system is setup so loose that things kind of move the wrong way.

I made a "fix" for most of that and now I am getting the force differences but they are not as much as I thought they would be, so at its peak difference right now it is only 1.5 :1,, I also need to check on the string pull distance to make sure that that is not also 1.5 :1 which means I will need to build a rig of some sort to check that.

webby2

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Re: Picking things back up
« Reply #106 on: April 25, 2023, 11:52:30 am »
I just had a funny thought,, what if I took out the path locking part and used my open path part again,,  well I did and the pull force went back to being the same.

Interesting.  Some minor differences could be had but it is back to depending on which spring scale I pulled on harder first.

webby2

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Re: Picking things back up
« Reply #107 on: April 26, 2023, 07:29:45 pm »
So I was wrong on the closed and open path, still figuring that one out.  The 4 day print job was somewhat not needed but it did show that I either made that part wrong or that removing that pathway is problematic for my desired end goal.

I printed another part so I could actually check the push side and it works the same as the pull side.  I made that with some slop but unfortunately that part would require zero clearance.

I am getting a max, at this point, fairly reliably of 1:1.5, that is my input is going from a 1:1 and ramps up to a 1:1.5 and then it goes back down to a 1:1.  This is happening while the input and the output are rotating in sync at a 1:1.

Now to ponder if I want to build a full system and close up the slop as tight as I can,, or if what I have is enough to satisfy my curiosity.

webby2

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Re: Picking things back up
« Reply #108 on: April 27, 2023, 03:59:21 am »
So I thought about stuff, and well I got sidetracked :)
I took my locked path part and tried to lock the path with the zero clearance I need and that worked nice a few times but as I was using it that way and then trying to look at the scale readings the force transfer was getting to be less and less of a gain, that had me puzzled until I noticed that my lock piece was actually moving and allowing the clearance to grow larger and larger, move things back to a "tight" fit and run it back and forth a few times and the lock piece moved.  It takes a fair amount of effort for me to move that lock piece and yet the system is moving it which means of course that I must then lock that lock piece,, or maybe don't bother and do something else.

The first time I was able to watch the scale readings they did get up closer to like 1:1.8 I was seeing around 650g on the input and around 1200g on the output peak difference which is better than the 800g to 1200g I was seeing before adjusting the lock piece.


webby2

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Re: Picking things back up
« Reply #109 on: April 27, 2023, 08:39:21 am »
I took the lock piece and screwed it onto the lock hub so it does not move, then I used a screw to set the distance to get rid of the clearance but I am only stopping that in one direction, so there is a push against the set screw but it does not pull on it.

What is interesting is that this changed things, so I can pull harder on the output while moving the input or I can pull harder on the input while moving the output and this little subtlety is a little problematic, if I do not allow the same motion between the input and output spring scale the readings appear to change which makes no sense, worse is when I use the push side I can pull on the input scale a huge amount with little to no change on the output scale.

The only other thing I changed was to add more tension on one of the shaft bearing sets, to reduce the shaft deflection or run-out.

I need to get better at moving the spring scales and then I might be able to figure out how, when the system is in the same basic position, I can get very different readings that seem to be dependent on how the scales are moving.

If the system is as it should be, that is just a 1:1 transfer since the distance is the same then the force should also be the same,, then how am I getting readings that do not show that for every reading??  How can I show say 1200g on the output and then move the input up to 2000g with no change in the output scale,, I actually had that down to 800g on the output and over 2000 on the input.

The thing is I can not feel anything that is sticking, even under load, and yet I can bounce the force on these spring scales a lot without that reflecting on the other scale,, makes no sense really.

webby2

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Re: Picking things back up
« Reply #110 on: April 29, 2023, 05:57:33 am »
I built a string guide plate so that Mr. Hand has little to do with things and I turned all forces into vertical forces.
I placed an approx 500g mass on the input string to get rid of that spring scale.
I used the spring scale on the output side and tested for different spots.

For just about all static conditions the scale read approx. 500g, the scale weighs 50g.
While moving the scale could read more but I would need to keep accelerating the scale,, f=ma after all.

The arm lengths are a little interesting, the output is fixed at 125mm the input changes from 85mm down to 65mm.
Both strings are on the same 55mm radius for the pulleys.
Both strings move the same distance as each other, in sync but reverse directions.

I think I have everything adjusted fairly close to where it should be by the design,, as it is now.

At this time and this setup then this system is doing what it should and only giving a 1:1 transfer of work.

I tried playing with the push side,, things need to be adjusted for that side before I can play much with it but the little range I did have did not seem to be that much different than the pull side, things just popped much faster past the end of range.

webby2

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Re: Picking things back up
« Reply #111 on: April 30, 2023, 03:39:14 am »
In a nutshell,
I have observed that when Mr. Hand is supplying the input force that the systems I have built CAN have a different work in than out, the question is how.

When using Mr. Hand the force is only constrained to a tension in the string which is wrapped around a pulley as such that the tension creates a tangential force which is converted into a rotary motion.

I built a pull string guide system so that the forces on\from the strings were fully constrained and in that condition the input work equaled the output work, as is predicted by standard practices.

The guide system is attached to the base system, as such the system is then closed upon itself.

The task now is to find out which of those closed constraints I need to open and in what fashion so that the system reliably shows a change in the work performed between the input and output.

webby2

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Re: Picking things back up
« Reply #112 on: May 02, 2023, 04:36:35 am »
I think I am identifying the causality,, not so sure on how the system translates the forces and motions and stuff but the area I am looking into does seem to create a secondary feedback that can either add, subtract or stay neutral depending on the angles of interaction and directions of forces.

I have one possible condition that is interesting.  This condition is where with one direction of change of force creates a condition where the system seems to want to find balance after it has lifted a weight, reverse the direction of change and for the same change for the system the weight would be dropped twice the distance,, so I am thinking that if I designed that stage of operation so that the lift condition is converted into a force of rotation as such that the change in potential rotates the system to maintain the relative height of the mass instead of lifting it that this might provide for a reset condition where I would need to disconnect the mass from the pull string, move the system back to the start position and then reconnect the mass to the pull string and allow the system to move, with force, back to the end position.

webby2

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Re: Picking things back up
« Reply #113 on: May 09, 2023, 04:53:38 am »
I printed off a few parts to start testing using the test-bed this way.
One thing I have noticed is that the system responds differently when using what I have labeled the pull side and the push side.
It looks like, not tested yet, like my input force and distance are not the same as the output force and distance.
I will need to print off a few more parts to make testing more straight forward.

webby2

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Re: Picking things back up
« Reply #114 on: May 12, 2023, 07:04:46 am »
These are just some crude measurements of force and distance
I have an average force of 77.5g moving a straight line distance of 95mm on one side
The average is between the relax to move backwards being 60g and the increase to 95g to start the pull forward

I have a force of 185g moving a straight line distance of 28mm on the other side

webby2

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Re: Picking things back up
« Reply #115 on: May 18, 2023, 06:51:26 pm »
I printed off another part so that the 2 distance values I am looking at for this setup are the same.
With that, one force moving the same distance of change as the other force,, those are 185g and 200g.

With consideration for friction and stuff I would say that they are very close if not close enough to call them a 1:1
I have another "out" method I can use and when I use that method my input force is 185g but my distance of change is still needing to have some parts created for,, I can see the distance Mr. Hand moves but I need to measure it correctly, that distance is less than the output distance of change and when I have those parts I can then measure the output force and distance of change.

webby2

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Re: Picking things back up
« Reply #116 on: May 19, 2023, 03:45:02 am »
That does not make much sense.
I am walking down a dark hallway of the unknown and I am trying to place lampposts along my path and using the light to try and see what the next step should be,, or could be.

Mr. Hand with the present test-bed setup is supplying a few things, 2 forces and 1 distance.
I can replace the forces with a mechanical system for each one that would not cost me anything leaving Mr. Hand only supplying a change in distance,, and a catch and release mechanism.
Think of it sort of like this,, a pulley with a string over it and equal masses on each end of the string, Mr. Hand is holding up the pulley, this can easily be replaced.  When the system is active there is another force 90 degrees to Mr. Hand that does not move that Mr. Hand is resisting, this to can be easily replaced.
Now Mr. Hand needs to move one of the masses up and down and since there is an equal mass on the other side of the string Mr. Hand is only supplying the change in distance.

My end goal is to hopefully make an NRL, Non Rotating Lever.
I have a system that can supply an infinite distance of change, I am building a system that should be able to supply an infinite force.  These 2 components are the WTF that is customarily trapped as an internal exchange of potentials but with the systems I am trying to put together this internal exchange is being allowed outside so if I place a potential of 1N and a change distance potential of 1m then the system should respond and externalize that exchange as work performed from the supplied potentials.

webby2

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Re: Picking things back up
« Reply #117 on: May 20, 2023, 05:29:15 am »
I have been using what I have and testing.

Right now I have the approx. 185g mass dropping approx. 65mm.  When I raise the mass and set the system so that that is the start point and then release the mass the system will rotate CW, the system then, with how it is setup, will create an approx force equal to 300g moving approx. 38mm.

This is close enough to say that this is a 1:1, the work I put in to raise the mass is equal to the work I can recover by letting it drop the same distance.

When I break the internal path and externalize the WTF the system responds by rotating CCW with some force value, not measured yet, and the mass drops some value, not measured yet.

If the system were designed so that there would be no prop in the mass then takes care of that reset part.

So then what it looks like I can do is put in the work to lift the mass by itself with the system in the end position, then externalize the WTF and have the system move with force into the start position, internalize the WTF and release the mass and let it drop 65mm moving the system with force into the end position and recover that work into something so that I can then lift the mass.

Just for more confusion, I need to lift the mass and then move it into the horizontal position where the system would be when I am going to release the mass and let it drop, a horizontal movement has no work needed for the mass.

I will be making more little changes and testing trying to get the externalized distance so that the mass does not drop.

webby2

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Re: Picking things back up
« Reply #118 on: May 20, 2023, 05:55:14 am »
I did a quicky,, and I am able to stop the drop by design.

The interesting part is where this force is favorable and where it is not.

I have a partial range of motion where without the mass dropping the system moves with force one way, I go past that point further and the system moves back the other way with force to the balanced area,, apparently.

The drop condition is still the same but now it drops further.

webby2

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Re: Picking things back up
« Reply #119 on: May 21, 2023, 04:37:24 am »
What I am finding is that these setups are trending into a 1:1 so with the one funny setup I am expecting that there is going to be some change in height that I am not able to measure yet and that that will account for the perceived work out.

Using all the same parts I can get different force relationships, right now I can use the same 185g to create a counter force needed of 600g,, just by changing a path

 

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