Merseburg wheel part

[ovyyus]

But could someone have stopped the wheel by grabbing the rim? It doesn't seem any more likely than grabbing the handle.

I expect they could if Bessler allowed it. As Jim says, the covering was described as an oiled canvas, which would be pretty strong. However, the potential hazards (to limb and machine) of grabbing hold of the 17+ miles per hour rim might be a good argument for installing an axle handle on the Merseburg wheel. It seems the Draschwitz wheel, being less powerful, was apparently stopped by grabbing hold of the axle directly. The Draschwitz wheel was covered with thin planking which might have given some nasty splinters if grabbed at the rim.

[rasselasss]

The reason i mentioned "where's the bearings",to me an important factor is because...if we ARE to believe the etching the small iron/steel shaft poking through the support would suggest as has been stated elsewhere,the shaft having wooden slats to build it up to 6 inches dia.....the questions that then arise are........the wooden stop handle ,how could it go through the centre of this....is the steel/iron shaft not continuous throughout the length of the axle ....why...is it concerning the mech.inside the wheel also the whole weight of the axle and wheel could be a lot lighter than we estimate .

[jim_mich]

Of course we do not know exactly, but it is assumed that the iron axle pin extended only a short distance into the end of the wooden portion of the axle. The wood axle was built like the axles of old wagon or coach wheels, which were build much like wooden barrels, with wood slats held together by iron rings, with wooden end blocks to close up the open end of the hollow axle.

[daxwc]

The axle, which passes through the centre of the
wheel, is 6 feet long and 8 inches in diameter, and in its
movement is supported at each end by an almost one-inch thick
steel bearing. The bearings taper somewhat, and the
arrangement has been designed in such a way that the
rotational movement of the entire vertically suspended wheel
can be slightly modified by the application on each side of small
weights, as the appended plans at the end of the treatise clearly
demonstrate.DT pg 191

[rasselasss]

Jim Mich,i can "go"with that detail of the small iron axle,and I DO appreciate your knowledge and input....Daxwc,does that 8 inch axle refer to the wheel at Kassel,which i believe they had to remove the bearing caps to lift the wheel to another location....in the Merseburg engraving the bearing have to be of the"bush"variety.....i can't understand tapered bearings being used ....my intention is to try and give a better understanding of these devices and using our intelligence to cut through the smoke and mirrors by civilised debate(i'm dyslexic so forgive any sentences disjointed)

[jim_mich]

rasselasss,

You can use the forum advanced search feature to search the forum using different key words or phrases enclosed in quotes.

This topic of the axle has been discussed extensively, and there is a wealth of information of all kinds waiting for you to discover buried in old postings going back ten years of more.

Alternately, you can use the Google search at the bottom of each page, but Google does not see the Community Buzz portion of the forum, so it will miss a lot of content.

Just trying to be helpful.

[jim_mich]

I might add that a well seasoned solid white oak wood axle, eight inches diameter by six feet long would weigh slightly over 100 lbs.

[rasselasss]

Thanks for that Jim,would you agree that this wheel and axle is a lot lighter than we think..if so what weight would you reckon. just to add posted this at same time as Jiim's axle weight est.

[eccentrically1]

23. Wooden lever to bring machine to rest.

The lever is 5 times smaller than the diameter of the wheel.
Third wheel – Merseburg

Diameter = was 12 feet or 144�
Lever was 28.8� /2 = 14.4� leverage from center of axle.
So two handles of 11� at a speed of 40 rpm.

The force necessary at the end of the handle to stop the wheel wouldn't have been 70 lbs. even if there was no block and tackle.

If the handle was about a foot long then the force at that distance was between 4 and 70 lbs. To balance 70 lbs. at that distance would take about 8 lbs., in other words, to hold the box of bricks in place, the man would have to apply 8 lbs of force to the end of the handle. I don't know how much more it would take to accelerate 70 lbs. to 40-50 rpm. Even if it was twice as much, 16 lbs. doesn't seem like too much to ask a man to stop. Am I way off here?
And besides the total weight of the wheel, I'm curious about how the rpm's were measured. Were all measured by pocket watch? The rpm difference from M (40-50) to K (26) is strange considering everything. It makes me think something's not right there too.

I might add that a well seasoned solid white oak wood axle, eight inches diameter by six feet long would weigh slightly over 100 lbs.

I thought the axle was hollow?

[jim_mich]

Yes, most agree the axle was most likely hollow, but we really don't know.

There are so many variable associated with the wheel, that it might have weighed anywhere from maybe 150 lbs with weights removed, or up to maybe 800 lbs or more with its weights.

[jim_mich]

Imagine how you might construct a wheel. Calculate the cubic inches of wood needed. Spruce is light weight and strong, but you need thicker pieces to have the same strength as oak. White oak is very strong and so you can use thinner boards. White oak is common in Europe.

Bamboo weighs about 0.013 lbs per cubic inch.
Spruce weighs about 0.016 lbs per cubic inch.
Red oak weighs about 0.027 lbs per cubic inch.
White oak weighs about 0.029 lbs per cubic inch.
Live oak weighs about 0.042 lbs per cubic inch.

[eccentrically1]

I imagine I would make it as light as I could if I had to move it around. A light wheel would be easier to accelerate up to speed too. It would be easier to repair.

[Tarsier79]

Unless you want the wheel to have the added advantage of acting like a flywheel.

[eccentrically1]

Well, if you built it so the most mass was concentrated at the rim, it would have that advantage no matter how much it weighed. If his big wheels only used 4 lb. weights, then it couldn't have weighed very much in total to have a flywheel advantage, if you think that was part of it.
If they weighed up to 800 lbs as has been suggested, then 32 lbs. isn't going to give you much of a flywheel effect. The first wheel was portable, I think he used it as a blueprint to build the bigger wheels as light as he could. The spokes in all of them could have used the same size boards, as small as 1 X 1. The axle was most likely hollow, there isn't a good reason to make it one solid piece. He probably built the axle around the spokes, which went from one side of the wheel to the other as 8 continuous lengths, rather than butting them into the axle and having those unnecessary connections.

[murilo]

Unless you want the wheel to have the added advantage of acting like a flywheel.

Great note! Absolutely!
Go for it!
Fantastic! Clap, clap, clap...
(if you were any other I was going to be against so intelligent and smart guessing! 8[