- Thread starter Prajna
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Prajna
Fixing things for the love of it
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So here is Mk-7. I'm waiting for a couple of SKF 635 bearings. Meanwhile I'm printing bits to do fit testing. The chain links have come out nice and with a bit of cleaning up I have a nice slinky chain. I hope it will work ok in a horizontal orientation. I've modified the links today to allow space for HDPE washers, which make great bearing surfaces for PLA. Gotta find some punches to make washers or fix my friend's laser engraver to cut them out.
Prajna
Fixing things for the love of it
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Chains are actually quite efficient. Whether that is true in this orientation is another matter. In any case it will be better than the lock up with badly printed gears (think my X and y axis are calibrated slightly differently!
Guineafowl
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That’s elaborate.
I was expecting you to build a much simpler proof-of-principle machine first. Maybe one fixed magnet, one attached to a pivot so it can lift an adjustable weight up and down as the gate is moved in and out of the field.
Is it too late to say that? Yes, much too late. Sorry.
I was expecting you to build a much simpler proof-of-principle machine first. Maybe one fixed magnet, one attached to a pivot so it can lift an adjustable weight up and down as the gate is moved in and out of the field.
Is it too late to say that? Yes, much too late. Sorry.
But every iteration has more shafts and bearings. It's not so much the chain I was referring to. I know nothing so its just my ignorant viewpoint.
Dev
8th generation, Weyland type
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Is that what you’ve made or a render?
Prajna
Fixing things for the love of it
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No, you're right, @Guineafowl, it would be much more practical to do a simple proof-of--concept but the project has kinda evolved over time and the initial experiments I did convinced me that the principle is sound. Realising it in practice with 3D printed parts (especially given the printer I'm using, though for today's test prints I've upped the quality by dropping the layer height from 0.3 to 0.2mm and it looks like the quality has improved immensely, though print time has consequently expanded considerably).That’s elaborate.
I was expecting you to build a much simpler proof-of-principle machine first. Maybe one fixed magnet, one attached to a pivot so it can lift an adjustable weight up and down as the gate is moved in and out of the field.
Is it too late to say that? Yes, much too late. Sorry.
Prajna
Fixing things for the love of it
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Development continues but now I am looking at something quite different. In trying to improve the SFT I have come up with an idea that employs the same principle I have been using in the SFT designs but it operates (if it operates at all) in a different way.
Here's a model to examine:
That is looking from one side of the device and only shows one pair of carriages. The following image displays two pairs and labels the parts:
What you're looking at is a cylinder with two opposed sinusoidal cam tracks running around the sides and slider rods that support carriages carrying a magnet and a bearing each. The carriages can slide up and down the slider rods and the bearings constrain the carriages to follow the cam tracks. The magnets are fitted in the carriages so that like poles are opposed on each pair of carriages. There are ferromagnetic tabs (soft iron or transformer laminations) arranged around the centre of the cylinder at each point where the opposite cam tracks are converging and gaps between the tabs wherever the tracks are diverging.
When the cylinder is rotated such that the magnets on one side are closest there is no iron in the gap between them, so the magnets repel, imposing a vector force on the cam tracks that causes the cylinder to rotate to the left. The magnets on the opposite side will be at their maximum separation but they also then encounter a tab in the gap and will be attracted to the tab rather than their fields opposing, thus imposing a vector force on the cam track that also causes the cylinder to rotate to the left (because there the tracks are converging.)
A further two sets of carriages should be arranged on the adjacent axes for smoother rotation, to increase power and to provide some assistive thrust when the vectors of the adjacent magnets are aligned to the cylinder axis at the peaks and troughs of the sinewave, (i.e. one set facing you and the other set at the back of the cylinder.)
There are five peaks in the sinewave of the cam tracks, so on either side of this image the magnets will be at opposite extremes of their travel, one set pushing and the other pulling. The front and rear sets of carriages will be in an intermediate position, still with one set pushing and the other pulling. The closest magnet pairs will exert the most force (due to the inverse square law) and there will always be one pair of magnets exerting a strong repulsion (or strong attraction.)
Hopefully that is enough info to describe the device.
Here's a model to examine:
That is looking from one side of the device and only shows one pair of carriages. The following image displays two pairs and labels the parts:
What you're looking at is a cylinder with two opposed sinusoidal cam tracks running around the sides and slider rods that support carriages carrying a magnet and a bearing each. The carriages can slide up and down the slider rods and the bearings constrain the carriages to follow the cam tracks. The magnets are fitted in the carriages so that like poles are opposed on each pair of carriages. There are ferromagnetic tabs (soft iron or transformer laminations) arranged around the centre of the cylinder at each point where the opposite cam tracks are converging and gaps between the tabs wherever the tracks are diverging.
When the cylinder is rotated such that the magnets on one side are closest there is no iron in the gap between them, so the magnets repel, imposing a vector force on the cam tracks that causes the cylinder to rotate to the left. The magnets on the opposite side will be at their maximum separation but they also then encounter a tab in the gap and will be attracted to the tab rather than their fields opposing, thus imposing a vector force on the cam track that also causes the cylinder to rotate to the left (because there the tracks are converging.)
A further two sets of carriages should be arranged on the adjacent axes for smoother rotation, to increase power and to provide some assistive thrust when the vectors of the adjacent magnets are aligned to the cylinder axis at the peaks and troughs of the sinewave, (i.e. one set facing you and the other set at the back of the cylinder.)
There are five peaks in the sinewave of the cam tracks, so on either side of this image the magnets will be at opposite extremes of their travel, one set pushing and the other pulling. The front and rear sets of carriages will be in an intermediate position, still with one set pushing and the other pulling. The closest magnet pairs will exert the most force (due to the inverse square law) and there will always be one pair of magnets exerting a strong repulsion (or strong attraction.)
Hopefully that is enough info to describe the device.
hotponyshoes
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Interesting observation,
A runaway diesel has a source of fuel. It will normally destroy itself before the full runs out but it will stop once its run out of fuel if not.
Where do you see the power for the acceleration coming from in this device?
Prajna
Fixing things for the love of it
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Yeah, there may still be a few minor wrinkles to iron out.
Onoff
In the land of the unfinished project I am King!
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