I've often wondered how Johann Bessler built his wheel, by that I mean what order did assembly take place and what problems did he encounter in the process. I simply build onto a wooden disc but if I wanted to hide the interior I'd use a second disc to cover the open side. When all is assembled I mount it onto an axle and place it in the bearings which are fitted on a stand.
Bessler was dealing with a much larger wheel and considerably more, and heavier, weights. I think he would start by mounting the chosen axle onto a supporting structure, possibly one which he could move easily. But would he then mount a twelve foot disc for one side onto the axle? No, I think he would begin with a much smaller disc of about half size, say six feet diameter. giving him three feet depth to access the interior. He probably made the mechanisms, or at least as much of it as he could, before attaching it to the the cross bars. I assume that holes would be cut through both discs for the crossbars and fixed both inside and outside to each disc.
Having the wheel diameter much shorter would allow access for fitting the mechanisms to the cross bars. Without the second disc already in place there would be too little support for the mechanisms. Once the initial assembly had been completed in the smaller wheel he could add the rest and proceed to fit the remaining portions of the wheel. I have reason to think this method was used because of a piece of description of the wheel found in Bessler's Das Triumphirende. He describes the wheel as being in the form of a drum, twelve feet wide, with a thickness varying from fifteen to eighteen inches. Curiously nobody has ever recorded this variation in thickness, as far as I'm aware, but it seems safe to assume it was there.
I think 'sGravesande measured the thickness at the rim and got 18 inches, which suggest that the 15 inch thickness was further in towards the axle. If this is the case then the wheel was built in two sections as I described above, and the other part added once the mechanism was securely fixed inside. This later addition would have been attached to the outside of the first part thus giving and extra inch and a half to to each side of the wheel.
This is a copy of a drawing I included in my book about Johann Bessler, Perpetual motion; An Ancient Mystery Solved? It shows the two thicknesses I have described above :-
I suppose the canvas covering which would also have covered the positions of the cross-bars also disguised the varying thickness present.
I have considered other reasons for having varying thicknesses but this seems to me the most likely. It's possible that a section, or sections, of wheel might have been removable from under the canvas which could provide access to the weights to remove them when required. I can see how this might be achieved through several pieces being removable to allow access all the way around the wheel. Because that is another detail often overlooked; how did he access all the weights from around the whel through one aperture? He couldn't so there were either several, which would require several holes in the 'disc' under the canvas, or he simply removed sections from some area a certain distance from the axle, presumably near to the rim.
JC
10a2c5d26e15f6g7h10ik12l3m6n14o14r5s17tu6v5w4y4-3,’.
This comment has been removed by the author.
ReplyDeleteInteresting blog this. I too have pondered the method he might have used to construct, single handedly, a drum-like wheel 12 feet in diameter. That's certainly large, but not beyond what a single person could manage. Like you, I assume that he first fashioned the axle, then installed the steel end pivots. Next, he placed the vertical supports into position and made sure that the axle pivots fit securely into them and that the axle was horizontal. That basically leaves the drum. There are several ways to construct that and I think the simplest would have been to carefully lay out the pieces that formed the side faces onto a level floor. That makes aligning the parts easier. Then the parts would have been fastened together. When he had two of the rigid side pieces ready, he would have had to have lifted the axle off of its bearings in the upright supports (most likely using some sort of overhead hoist) and slid the two drum faces onto the ends of the axle. Once they were in position and aligned with each other, he would have secured them to the axle and installed the various cross pieces to make the full drum rigid. At this point the axle and its attached open drum were placed back on the uprights. From the illustrations he made, it looks like he had some sort of thin veneer of curved wooden pieces that were attached to the outer periphery of the drum. Next, he would have installed the various levers with their weights, the system of ropes to coordinate their motions, and the all important springs necessary to maintain the imbalance of their center of mass. The last step would have been to cover the sides of the drum with the oiled or waxed linen. This covering had various holes cut into it a strategic locations which allowed Bessler to make final adjustments to the tensions of the springs in the wheel. Obviously, this is a big job, but not beyond what a single very determined person might be capable of.
ReplyDeleteAs far as the variation in "thickness" of the drum is concerned, there is a simple explanation for that does not require us to assume he made each face in segments as you illustrate. Possibly, Bessler just gave the thickness of the drum on the outside, which was 18 inches, and the thickness on the inside which was 15 inches. The difference is 3 inches and that might mean that the thickness of the single piece radial parts of the drum face were each 1.5 inches thick. Not unreasonable considering the weight that the drum had to support.
IMHO, a disc is actually not required at all...levers carrying weights can be hung from the circumference of the drum...the levers need to be free to swing...like pendulums..and this is what is all about the game...the sides of the drum-like structure can be any screen to conceal the inner mechanism...axle design, diagonal crossbar support to hold the drum circumference and a two/four legged stand to carry the entire assembly need to be basically built...later, eight levers with weights have to be fixed to the circumference....not to forget the eight divisions or segments inside...
ReplyDeleteJohn,
ReplyDeletedid Bessler have to make every screw, nut, bolt, nail etc. himself, or was some available "off the shelf" ?
Did he fell his own trees, and cut, plane and finish every piece of wood, or would he have bought it ready sawn into planks ?
The thickness of the rim suggests two back to back wheel with four segments each... each lever with weight requires sufficient area to swing...
ReplyDeleteBessler didn't have to manufacture each and every nut & bolt, in my opinion...but yes, most components had to be custom made....maximum wood work was involved...when you go to make a unique design sometimes it is even necessary to start from scratch i.e., buy raw materials and work on it....the weights bessler used were not available readily...it required casting if I am not wrong...the levers also had to be designed anew...
Bessler probably had the same problems modern inventors have. There are always certain parts you need that you can not easily fabricate yourself and you must then purchase them from those who specialize in making those parts. Bessler probably purchased stock wooden pieces and then cut them down to the dimensions he needed to make the vertical supports, axle, and drum framing pieces. Parts made of steel such as nails, screws, lever pivots, and springs were probably purchased from carpentry and clock repair suppliers. Perhaps he cast his own lead weights, perhaps not. I think there is a quote in which he complains that his wheel "ate while he starved". In other words, he occasionally had to make a choice between eating and buying parts for his inventions. That takes real dedication.
ReplyDelete