Building A Monowheel!

[akumabito]

I never stated he should instead build a diwheel.

Look back at my original post. I made two points there: first being that diwheels are easier. Second being that there are some elementary difficulties with designing and building a workable monowheel.

For some reason, Gearworks took offense at both comments.

As for the simplicity of the diwheel, he could have simply stated something along hte lines of "I know, but I like monowheels better." simple, effective, and would have taken the point across without further drama. Instead however, he decides to go off on a rant, insulting me in the process.

As for the second point I made; again, he took offense to that for no apparent reason whatsoever, wrongfully claiming that it somehow offended him. He asks for opinions, and when they are given, he acts all insulted. Does not compute. I in turn, take offense to that as it is an unsubstantiated claim.

This whole discussion is ridiculous, and nothing more but the fruits of his overreacting. Here's what though, if he is so incredibly offended, let him take it up with Tinkergirl or Copper Sulphate.

[Flynn MacCallister]

Indeed, that is probably fair to say, but why press the point when it is clear that, however illogically it may appear to you, the person you are talking to is taking offense?

And surely we are mature enough here to settle our arguments without needing to run to the moderators? I like to imagine that we are not moody thirteen-year-olds who require such supervision.

[Gearworks]

I have noted an apology, may the great work continue uninterrupted.

[CapnHarlock]

Gentleman,

It is late on a Saturday night/Sunday morning, let us not allow things to get out of hand . I want to see a usable vehicle.

I propose the soon-to-be-infamous Y-Prize  challenge:

Whoever presents motion-pictures of a new working scale (or full-size) model of a usable mono-/di-wheel (the film "Steamboy" shall be used as a minimal example of function) vehicle shall receive:

• $1US - the fabulous Y-Prize (to be provided by CapnHarlock)

[li(if, and only if, agreed) a xerox-copy of other competitors'  handshake.[/li]
[/list]

Let the Game begin.

[Gearworks]

Here is a more color correct updated version of the monowheel rough sketch.  Not quite to scale.



It occurred to me that one could rig the rear wheel to the handle bars, and thusly use it as a rudder, but it might be beyond my ability to build.

Also, the approximate diameter of the primary wheel should be about 4'6".

[Gearworks]

On that note of steering:



The looking top down version isn't technically correct, but you get the idea.

[Flynn MacCallister]

I have to say, I'm not confident that rear-wheel steering would work, or at least work terribly well... Could you explain your logic?

[Clym Angus]

So if I'm reading the plans correctly. We're talking about front gear pedal drive linking 1:1 ratio via a chain and back wheel stearing with the pilot in a reclining position?
I take it that the front "wheel" isn't a wheel but a pedal?

What were your thoughts on maintaining the integety of the monowheel itself?

[Gearworks]

I have to say, I'm not confident that rear-wheel steering would work, or at least work terribly well... Could you explain your logic?

I've had some experience boating, and that's where I took the idea from.  It's blessing is that it would be easy to rig.

So if I'm reading the plans correctly. We're talking about front gear pedal drive linking 1:1 ratio via a chain and back wheel stearing with the pilot in a reclining position?
I take it that the front "wheel" isn't a wheel but a pedal?

What were your thoughts on maintaining the integety of the monowheel itself?

You are reading the plans correctly.

I was hoping someone would ask about the pedal system.  I'm actually not sure what to do with the front wheel.  I know I want a forward stabilizer and I want to keep the diameter of the primary wheel as small as I can get it for reasons of cost and simplicity.  What I came up with on the rough draft is my compromise of the two ideas.  I was thinking that the gear on the roller under the seat could be at a higher ratio than on the forward wheel, keeping the primary wheel as the main source of locomotion. 

I believe that my placement of the rollers will be adequate if a strong enough material is used for the frame of the primary wheel.  However, I have not decided on what materials I will be using for most of the parts.  In a perfect world the primary wheel should be able to hold its own with little help.

[Mr. Fish]

Ahem,
this is a request for clarification, not in any way a criticism you understand.
The design as presented, does it have one, two or three wheels in it's final form? A the moment the design looks like a linear Tri-wheel not a monowheel.

Don't get mad Gearworks, it still looks like a sweet little machine. But is it what you really want?

Mr. Fish

*leaves little note on desk and moves rapidly from the lab with hat clamped firmly to head*

[Clym Angus]

And the higher ration would give you more torque to use against the higher mass of the main wheel. Yes I see. I can see how some stability is very important (after all it would be deeply imarrassing to power the pilot round the wheel instead of the wheel along the ground). Having your legs effectively straddling the monowheel is something I haven't seen before. Interesting.

I would say that you might want to look into under seat steering I may be reading this wrong but the handle mechanism may restrict your range of movement some what. I'll see if I can look up some of the specs......

http://www.ihpva.org/people/tstrike/tas/richard.htm
http://www.atomiczombie.com/product-wildkat.htm

In fact you may be able to steal a fair few tricks from atomic zombie, hell take a look at their book section they have one or two nice books on electric power which might be worth you while.

Looking into the wheel issue again this is a bit of a long shot but

wire wheels hold their own integrety, I'll take a look around see if I can find any scymatics.

http://www.erdc.usace.army.mil/pls/erdcpub/WWW_WELCOME.NAVIGATION_PAGE?tmp_next_page=3003804

It's a pain in the ass this, every solution I think of has major problems dealing with the encompasing nature of the spinning monowheel. It's a right pisser from an engineering point of view can't use spokes or a hub in any traditional sence. Off centre spars don't work as the'd chop the driver to ribbons. I need to give this some more thought.

[Flynn MacCallister]

I have to say, I'm not confident that rear-wheel steering would work, or at least work terribly well... Could you explain your logic?

I've had some experience boating, and that's where I took the idea from.  It's blessing is that it would be easy to rig.

^__^ Cool, I sail too... but I still have my doubts about how well a rudder-style rear-wheel-steering system would work here.

[Gearworks]

Ahem,
this is a request for clarification, not in any way a criticism you understand.
The design as presented, does it have one, two or three wheels in it's final form? A the moment the design looks like a linear Tri-wheel not a monowheel.

Don't get mad Gearworks, it still looks like a sweet little machine. But is it what you really want?

Mr. Fish

*leaves little note on desk and moves rapidly from the lab with hat clamped firmly to head*

My Dear Mr. Fish,

This is a sound statement and I will quote the wikipedia article on the subject "Small wheels used for steering, either one to each side or a single unit either in front of or behind the vehicle. It is a matter of debate as to whether such a vehicle would still properly be called a monowheel."  The vehicle by my own personal definition is a monowheel, in that I will be sitting inside the primary wheel.  If I could safely go about with only the primary wheel I would, but common sense prevails as I do not wish to land on my head because of gerbling, hence the forward stabilizer.  The back rudder wheel was originally planned because I needed a place to put my things, so at one point is was merely an attachment.  In the end, a traditional monowheel is quite dangerous.  Perhaps you could call it a monowheel on training wheels?

And the higher ration would give you more torque to use against the higher mass of the main wheel. Yes I see. I can see how some stability is very important (after all it would be deeply imarrassing to power the pilot round the wheel instead of the wheel along the ground). Having your legs effectively straddling the monowheel is something I haven't seen before. Interesting.

I would say that you might want to look into under seat steering I may be reading this wrong but the handle mechanism may restrict your range of movement some what. I'll see if I can look up some of the specs......

http://www.ihpva.org/people/tstrike/tas/richard.htm
http://www.atomiczombie.com/product-wildkat.htm

In fact you may be able to steal a fair few tricks from atomic zombie, hell take a look at their book section they have one or two nice books on electric power which might be worth you while.

Looking into the wheel issue again this is a bit of a long shot but 
wire wheels hold their own integrety, I'll take a look around see if I can find any scymatics.

Yes, that is very interesting stuff.  It might be worth while to look into that under seat steering.  I would like to point out that if the steering bar was brought away from the primary wheel far enough and then bought back to a position slightly higher than the rider's body, a person could theoretically turn up to 45 degrees.  And yes, it would be a bit awkward.

[heavyporker]

 If I am thinking rightly...

 If wire wheels hold their integrity, and you can acquire a non-rubberized tractor or dump-truck wheel skeleton...

 Then why not just have a sled-like base that could ride the wheel's rims, with a fairly hefty (lead or depleted uranium ingot) on the bottom of that base for counterweighting?

 That could greatly simplify the seat's construction. Oh, and if the wheel's rim curves inward, you could even do a crimping thing on the sled-base so it can't ever fall off the wheel, thereby increasing safety.

 Also, however cumbersome, why not do away with that rear wheel, and just steer by leaning to the right or left? That would be ever so much more bad ass.

 This would mean you would have to throw out the idea of straddling the wheel to pedal. But these types of wire wheels are wide and deep, which means you could actually do your paddling inside the wheel's well, right? Which means in any accident, your legs are a lot less likely to be chopped off because you straddled the wheel, exposing them to the dangers of physics.

[Smaggers]

The front sprocket,  Is that not going to hit the ground under braking?  Or is it an You could have an actual wheel with the sprocket mounted alongside?

[Gearworks]

If I am thinking rightly...

 If wire wheels hold their integrity, and you can acquire a non-rubberized tractor or dump-truck wheel skeleton...

 Then why not just have a sled-like base that could ride the wheel's rims, with a fairly hefty (lead or depleted uranium ingot) on the bottom of that base for counterweighting?

 That could greatly simplify the seat's construction. Oh, and if the wheel's rim curves inward, you could even do a crimping thing on the sled-base so it can't ever fall off the wheel, thereby increasing safety.

 Also, however cumbersome, why not do away with that rear wheel, and just steer by leaning to the right or left? That would be ever so much more bad ass.

 This would mean you would have to throw out the idea of straddling the wheel to pedal. But these types of wire wheels are wide and deep, which means you could actually do your paddling inside the wheel's well, right? Which means in any accident, your legs are a lot less likely to be chopped off because you straddled the wheel, exposing them to the dangers of physics.

tractor or dump-truck wheel and a sled like base: Well, I'm going for a certain aesthetic, which is hard for my to vocalize, but suffice to say I'm pretty happy with the design as it stands right now. 

Removing the rear wheel: 1) I want a place to store things while traveling and 2) Gerbling.

Getting my legs copped off: I probably wont have too much to worry about if I keep to a decent and safe speed and I don't get run over by any larger motorized vehicles.  Remember, this is pedal powered and just for future notice: I am not a daredevil; my favorite speed is sauntering.

The front sprocket,  Is that not going to hit the ground under braking?  Or is it an You could have an actual wheel with the sprocket mounted alongside?

Not to worry, its a wheel with a sprocket.

[Smaggers]

In which case it'll probably need to steer a bit otherwise the physics will have you faceplanting off the first bump.   

Not sure about the rear wheel steering either,  current wisdom has it that rear wheel steering a single track vehicle is a bad idea from a self-steering point of view, though there has been one example of a two wheel steer /two wheel drive motorcycle built by an aussie.

Probably the best thing to do is try it out, perhaps lock the freewheel on a conventional bike and try riding it the wrong way round.  The physics should be similar enought to make it a valuable test.

[sidecar_jon]

I'm no expert on transport contraptions but the mono wheels ive seen on the net are steered (i think) just by leaning. jockey wheels are usually to stop "Gerbling" (Sp? as in the pet rodents).

[Smaggers]

Yup.   The problem is that single track vehicles don't move in straight lines,  but in a series of slight self-correcting curves.   Monowheels lack castor so the self correction is a bit more flakey.   Once a mono starts to fishtail you have a problem.     A drag wheel might help to self-correct keep the big one in a straight line,  but round corners it may possibly have undesireable effects.

[Gearworks]

In which case it'll probably need to steer a bit otherwise the physics will have you faceplanting off the first bump.   

Not sure about the rear wheel steering either,  current wisdom has it that rear wheel steering a single track vehicle is a bad idea from a self-steering point of view, though there has been one example of a two wheel steer /two wheel drive motorcycle built by an aussie.

Probably the best thing to do is try it out, perhaps lock the freewheel on a conventional bike and try riding it the wrong way round.  The physics should be similar enought to make it a valuable test.

I don't think that test would work very well, as the center of gravity is different, however I was thinking that it would be advantageous to have a holder for the steering bar which would make control a bit easier.

I'm no expert on transport contraptions but the mono wheels ive seen on the net are steered (i think) just by leaning. jockey wheels are usually to stop "Gerbling" (Sp? as in the pet rodents).

Yes, but I would like greater turn control.

Yup.   The problem is that single track vehicles don't move in straight lines,  but in a series of slight self-correcting curves.   Monowheels lack castor so the self correction is a bit more flakey.   Once a mono starts to fishtail you have a problem.     A drag wheel might help to self-correct keep the big one in a straight line,  but round corners it may possibly have undesireable effects.

I think I can negotiate those problems, but we'll see when the scale prototype is complete.

[Gearworks]

Here is a go at another rear steering design.

[Smaggers]

You could compensate for the lack of a forward steering axis by having weight forward of the centreline, on a 20" wheel this is offset typically 3"-4", I guess it scales up, though wheel weight also plays a part.  It might also leave your rear wheel off the ground except under acceleration.     The rear wheel also should probably steer from somewhere just forward of the centre axis.  I would advise making this adjustable since a small amount of trail adjustment would probably have a significant effect on handling and how prone the rig is to weave.

It would also be worth making the steering adjustable as well. So n1 degrees of input can be geared to n2 degrees of wheel turn. Knowing what I know about two wheelers my gut feel is that you really would need very little steering,  indeed a lot of steering could slew the front wheel causing it to flip out.     

Any way you can lower that CoG any more?   

[Gearworks]

To steal from an earlier idea, what if I throw out the rear steering and just put on two wheels that are above the ground a fair distance on either side and use those as turning aids?

[Johnny Payphone]

Do not be swayed by any design that varies from the original:  Rim, seat, pedals.  This is very possible and very rideable.  I have additional information but very little access to the internet.  I will try to post more as time allows.

[Gearworks]

Thank you for your support, I've had to tell myself several times the story of the miller, his son and their donkey.