William F. Skinner - 1939 Gravity Power

[mksboysal]

mksboysal, that is quite a construct.
Artoj has extensive plans for a replication. Until I have a good working model, I don't want to multiply problems by 4. I plan to build a single device. I'm going to build a copy, not a replication. I’ll do as you did and just use an off the shelf reduction motor. The advantage of building a quad device is that you should be able to cancel out some of the huge momentum swings.
Armandino bolted his device to the wall.
At 1:02, this device has a very cute 4-gear system; https://www.youtube.com/watch?v=Bp4t...ature=youtu.be
IF I find the time to work on this and IF I am successful, then, I will look at making the much larger quad machine. Good luck on your project.

Danny, it was said that: Great things are done more through courage than through wisdom. Applies to building this machine, some errors may show up but easily solvable. Building a copy and not a replica it's good thing. For the reason that you may have a resource for building materials and parts that might be free to get it or salvage it. Your comment on building a " quad device is that you should be able to cancel out some of the huge momentum swings" Great idea, William Skinner must have thought of that too, that's why his 5th generation machine the 1 min. clip that is available today works so smooth.
"Armandino bolted his device to the wall" excellent idea, if you have a place to make it permanent installation, you can resolve a lot's challenges by doing it so.

[Danny B]

Mehmet, I'm pretty sure that Skinner made a lot of attempts before, he got his final design. He probably noticed the shaking very early. I'm finalizing design ideas,, in my head for the moment.
Plan "A" is it now stands is; build a 100 gallon water tank with an open top. From there, attach 4 uprights of box steel tubing. Then, 2 parallel steel plates to hold the 2 lower bearings.
The weight of the water will keep it from scooting around the shop. I'll use a variable speed motor for the drive. The output shaft, under the lower plate, will be connected to a water-wheel. I have a General Radio strobotach so, I can check rpm. I can use a dummy load to check adjustments.
I'm lining up constant-velocity U-joints,,, a must https://upload.wikimedia.org/wikiped...nimated%29.gif

Tracta joint; https://upload.wikimedia.org/wikiped...city_Joint.jpg
Tripot joint; http://mechanicaldesign.asmedigitalc...55504jmd1.jpeg
I'm leaning towards the tripot joint because I believe that it will take more weight than the Rzeppa joint. The Rzeppa joint is what you see on the front axle of your car. I'll slowly work my way up to the top. I don't have a very clear picture of the top yet.

[Danny B]

dimensions,,, again

Artoj, I have your dimensions on the links that you kindly sent. You give a weight / size of ; 5 3/4 X 7 for the upper weight and 4 X 33 for the lower weight. If you look at :32 in the vid, Skinner has his hand on the upper weight, https://www.youtube.com/watch?v=ObdM7VzE18A
He isn’t a midget so, the weight is larger than 5 3/4 X 7
The lower weight also seems bigger than 4 X 33.
Can I safely assume that your plans are for a scaled down device? I'm probably going to start buying materials next week.

I might have to postpone for a bit, though.
For some unknown reason, Flight 33 Productions wants to use my wood gas truck for a feature that they are getting ready to shoot.
http://i8.photobucket.com/albums/a28...psy4bz31ux.jpg
Flight 33 Productions
No rest for the wicked.
EDIT, the photobucket picture for my woodgas truck is now listed as an attack page. WTF

[artoj]

No Midget

Danny, Skinner is 66.36" in height, I drew a 3D/perspective computer projection to a resolution of about 1/8". All materials, bolts, pulleys, motors, shaft etc conform to the dimensions as presented. I was replicating all period materials as available in 1925-1939. I am an Artist and this was a way of clearing the speculation as to any mystery, as I see it, there is no more hidden aspects. Regards Arto.

[Danny B]

A few quotes

There seems to be some difference of opinion as to whether the shafts/weights move in a circle or in an ellipse..

"The "gravity power machine" stricKen about two weeks ago consists of a steel framework containing four shafts controlled by on the eccentrics. "
"controlled by on the eccentrics. On each shaft is an off-balanced weight which Skinner said was "about the secret of the whole thing." He explained that the shafts, turning in the eccentrics, "
"The one-eighth horsepower electric motor. Skinner said, was used only for power to turn the eccentrics and the "gravity power machine 'provided the power"
"He explained that the shafts turning in the eccentrics, moved the weights in a circular motion at 60 revolutions"
" of the weights to new centers of gravity caused by the changing positions of the shafts. The weights do not actually fall. The one-eighth horsepower electric motor, Skinner said, was used only for power to turn the eccentrics"

If you look at the bias on the gimbals, you can see that they are much longer than they are wide. This would suggest an eccentric rather than a circle. There is no reason to use his style gimbal. The new stuff is much better. Though the gimbal does carry the whole weight of the upper counter weight.

My lower weight is 4" X 42" steel bar stock. I'm still working out the ratio of upper to lower weight.

[3758]

My latest / updated / revised / amended "Replication Investigation" video

https://www.youtube.com/watch?v=mEat-8zOjlE

[Aaron]

Skinner Machine Elliptical Input

Elliptical input:

https://youtu.be/JolNozy8UEY?t=34m52s

https://www.youtube.com/watch?v=lA9wHJsFzm4

[BroMikey]

Thanks for the Video work.


[VIDEO]https://www.youtube.com/watch?v=mEat-8zOjlE[/VIDEO]



[VIDEO]https://www.youtube.com/watch?v=rxIRaJlTD4Y[/VIDEO]



[VIDEO]https://www.youtube.com/watch?v=lA9wHJsFzm4[/VIDEO]

[Danny B]

Thanks guys for the excellent video work. Huge improvement. It definitely looks like the upper shafts move in an elliptic. BUT, I'm somewhat at a loss. Starting at 7:45 in this vid, you can clearly see the 4 shafts. https://www.youtube.com/watch?v=mEat-8zOjlE
3 are moving and one appears to be stationary. I'm not trying to start an argument. I am in the process of building the full size machine with the full size weights.
Duh, the 4th shaft is hiding behind the closest shaft. What i thought to be a stationary, immobile shaft is a highlighted reflection off the corner upright member.

EDIT, at :50 you can clearly see that all 4 are moving; https://www.youtube.com/watch?v=mEat-8zOjlE
At 9:01 to 9:17 you get a good view of the bottom side of the weight. It kinda looks like the bottom has holes in it. At 9:11, it appears that there is some sort of cross plate on the bottom of the upper weight. Is the upper weight solid?
The upper weight has a much smaller support bar than the lower weight? I'm at the point of fabricating the "translation plate" Does anybody have a good guess at dimensions?

[Danny B]

hollow weights?

I'm playing around with my piece of solid round bar stock. It's 4" X 42". I'm convinced that the weights are NOT solid bar. There is only a bottom mount for a piece of steel weighing 175 lbs. The bottom mount is just too flimsy to stand up to the rotation that he uses. The top of the tall weight has a small rounded, raised lip and some kind of small protrusion in the center. I believe that the center protrusion is an attaching point for lifting.

In the vid, he moves the upper weight with his fingertips. I just don't believe that it is solid bar. Also, it swings back on it's own in a manner that tells me that the mass isn't all that high. At 9:01 to 9:17, it looks like the base of the upper weight is perforated with big holes.
So ???

[Danny B]

Concrete weights

Here is part 1 of a very interesting replication. He uses concrete weights and by part 4, he has to put a tether at the top of the weight. He works his way up to a system that goes from a circle to an ellipse. Part 5 wouldn't load for me so, I don't know the final step of his progress.
https://www.youtube.com/watch?v=00xIxEQqRsk

[armandino]

2^ step replica Gravity Power Assisted

Hello, I see that the interest in such a complex machine like the one designed and built by Skinner, has not decreased. The tests and simulations of many of you encouraged me to continue my experience. According to video I posted previously, I started building my machine with one element evaluating the multiple mechanical reactions caused by the movement of a rotating weight and, believe me, they are very strong. For this reason I do not approve the experiments in a closet for clothes where mechanical support is appreciable but I think it dangerous for the operator. I continued the construction of my machine with the addition of three other rotating modules to the first existing. I thought much the pressures that are generated for which I have synchronized the rotation of the top as opposed to coppia.- in this way get a counterbalancing of the rotation of the axes, and so will be well for lower weights. Each sistemma turns 120Kg !!, you've got it right, in total will be 480 kg, offset. I think I have played well the thought of Skinner who showed us a mechanical system that is standing alone. Head a mechanical bypass throttle system I inserted after the first transmission that inprime the boards a boost of 120 ° that, I ricoldarlo to those who have not considered in their implementation, are the Archimedean levers that instead of traditionally move with a vertical movement, in this case carrying out a rotation that allows to multiply its power output without reducing the revolutions. then I show you the 3rd stage where even the lower weights will run synchronized oscillations hopefully contained.
Cordial greetings and ....... do not be evil, this BITES machinery.

[armandino]

Video replica Skinner Machine

sorry I forgot to enter the video link.
good vision and let's hear

https://www.youtube.com/watch?v=HJMXDB5bF7o

[soundiceuk]

That's an impressive replication!

You must be the first to go for all 4 sections.

Is it a full size replication?

[armandino]

machinery characteristics

That's an impressive replication!

You must be the first to go for all 4 sections.

Is it a full size replication?

Hello,
thanks to you I appreciate your compliments. It is a full size. The dimensions of the machinery? height of 3.20 meters x 2.50 x 2.50. I'm making some size different from W. Skinner machinery. I avoided that the lower weights during rotation are detected by the protection of the frame. The distance of the weights from its axis is of 50cm. That's why I got this width. I wanted to avoid an unwanted blow to the legs that would have crushed. The material I used is C45 steel, the dimensions vary depending on the specific use in the machinery. But ...... how much effort to assemble everything !!