Start of a new project, the Swift Flyer

[Lykle]

Hi all, first post here so be kind please?

I am in the process of designing my second vehicle, this one is going to be a tilting electrical trike, with 2 front wheels and one powered rear wheel.
The overall height is going to be approx 1 meter to the top of my head.

It is the steering and tilting mechanism that is going to be interesting. It will use feet to tilt and steer. Push with the right foot and the whole thing tilts counter clockwise. Push the toes forward and the front wheels steer more to the left.
While the main body holding the driver and the rear wheel tilts, the front wheels tilt a small amount as well, in proportion.

As for the electrics, I am thinking of using the Leaf motor and to keep it simple, I will use all the stuff they have as controller, throttle, battery pack etc.
I will go for the 48V 1KW motor and the 20Ah battery pack. I like the fact that it should be all plug and play. Remember, it will be my first electric bike and also, I think I will have to focus a lot more on the control mechanisms for the tilt and steering then on the propulsion.
With the 1Kw motor it will not be legal as a bicycle, so I am still debating if I should start with a smaller motor and progress from there. Don't really want to spend money on two motors.

Any initial comments? Any suggestions as to why I can't go this way? Anybody have a problem with the Leaf controllers etc? I did read a lot about the new motor that was good, so I am hoping I can simply buy the whole pack and be done with it.
Looking forward to your comments and suggestions.

 

[Nobuo]

Awesome mechanics. Would be much for you to make an animation of the mechanism??

No pedal? In my opinion you should stick on 1000W or more. That low build will shine on >20mph speeds.

I'm assuming the battery will rotate on the dynamic main platform, so where is the place saved for the battery?

Very interesting project! 8)

 

[Lykle]

Thanks,
Animation? I looked at it, but it involves too much work. I would need to define all the constraints completely. Just not happening. Sorry

1000W, yeah I feel I should go that way. It would make it illegal here, so I will build a limit switch in there somewhere. But it is not the way I want to go. Unfortunately, the rules here are such that I can't go another way. So I have to make a decision, staying completely legal, or stretching it and make it fun.

Here is an overview of the main components.

 

[made_in_the_alps_legacy]

niiice - subscribed

 

[Lykle]

Here is the first stress related image.

It is clear that I will need to do some more work on stiffening the frame. OK, the displacement is magnified, it is only 2 cm or so, but still too much. The stresses in the frame are not too bad and I think will be fine by the time I stiffen up the frame. Only way to go is probably increasing the diameter of the long tubes. I do not want to change the geometry too much as it is already a tight fit for everything.

The rear suspension box is more than stiff enough. The main tubes in the front are also fine, predictably. It is the empty space in the middle, where I have to sit, that is the problem. I do not want to just add more and more pipes, I do not want to make another "Birdcage" (even though it was a fine racecar)

Ah well, that is what the design phase is for, right?

 

[Lebowski]

In the tilting picture of the first post, isn't part of the vehicle touching the ground ? How about when the front springs compress due to the weight ?

Awesome project, hope you will keep us up to date !

 

[Nobuo]

Now is all very much clear.

When you mention "48V pack space for two" what chemistry and capacities are you thinking of?

So are You going to build the whole thing? What materials are included in the whole build?

 

[Lykle]

For now I have decided to buy everything form Leaf.
So this is the battery pack I am going for:
http://www.leafbike.com/products/li...the-newest-48v-20ah-lithium-battery-1007.html

Also, I will be using their controller, controls etc.

As to touching the ground, correct, in that picture it will. But the chassis has been changed quite a lot since that image. It is now more rounded and tucked in at the back. The cross beam that you see touching the ground is just that, a cross beam and I can shorten it all the way back to the chassis. That will give me a lot more tilting clearance. But I want the cross beam to make it easier to get in and out. I am thinking of enclosing the thing completely, but am beginning to doubt that now. It ain't easy.

It is not completely clear in this picture, but there is more ground clearance at the front and the back. I will see if I can generate a better image.
In bump? I will have to see how far I can push it, but I have a little flexibility. I can raise the back easily and at the front I can play with wheel diameters, shock spacers etc.

OK, did a quick render. This is the ground clearance with a little bit of bump at the full tilt angle of 45 deg. In real life, I don't think I will manage that tilt angle, my current max is defined by the mechanism and is 41 deg.

The ground clearance is about 2 cm. That is not much I agree. But this is one of the reasons I want the cross beam there. It is to protect me whan I dip too low. I want steel to be scraping the tarmac, not heel.

 

[Lykle]

First idea of the bodywork.

This is not going to be it, I am just getting my mind around the various parts that I would like to have covered.
Maybe I will go the other way and only do the sidepods and maybe a simple cover over the top and nothing else.

 

[Lebowski]

Afaik in a velomobile the rear of the fairing is very important for low drag figures. They even sell a short and a long faired velomobiel, with the comment that the long one is much faster...

 

[Lykle]

Currently I am not that interested in low drag or perfect aerodynamics.
It is all about the steering and tilting mechanism for me.

The only reason I am thinking of bodywork is to protect my legs from stones as there are a lot of loose stones and such on the roads here.

This is what I call the ribbon body. Bodywork reduced to the minimum. I like it, but I am not done yet. It is clear that aerodynamically this is not a good solution, ah well.

 

[Lykle]

OK, I have been quiet lately, but I have some real issues. Need a job and can't find one.

I have been working on some things tho. The chassis is designed and strong enough. I have modified it a little and have space for 2 battery packs, if I want to go there.

Really can't wrap my head around the bodywork, I just can't seem to get a shape that works for me. Ah well, maybe when I have the bare steel there, it will form itself.

Now, the interesting part for today. The controls. As I steer with my feet, the hand controls are throttle and brake only. Shape first. I had originally designed normal bike controls, right with a twist throttle and brake levers. But I think I am going to go for joy stick like control. Push forward, throttle, pull back, brake. My first idea was to have left and right do the same thing. This would allow me to alternate hands.
But now I am thinking of doing it differently.

Right hand, throttle and rear wheel brake. Push forward, increase power, pull back, first increase regenerative braking, then add braking force with the hydraulic brake.

Left hand, front wheel braking, but here it gets tricky.
I am considering to be able to modify left and right wheel brake pressure. So pull back, both front wheels brake with the same force. Pull back and left, the left front wheel brakes harder than the right and visa versa. Jam all the way to the left, left front wheel locks up, apply full throttle and the Flyer will spin around the left wheel.

Still working on how to do this, hah! Still working on IF I want to do this. The idea really appeals to me. I want more control, this will give it to me. I am sure there are all sorts of laws that will prohibit me from doing it, but in this case? I don't care.
Current thinking is to use two angled master brake cylinders. Pull back straight, both get pressure. Pull back at an angle, one cyl gets more pressure than the other. Playing with the angle between the two cyl will allow me to tune it to a workable feel. I think.

Any comments? Ideas? Gotchas? Curses? Trips to the asylum?

 

[ErnestoA]

Looks really neat! I like the idea of using legs to make the tilt action. Less likely to lose control and get thrown about due to insufficient arm strength.

 

[voyager6]

Hi all, first post here so be kind please?
I am in the process of designing my second vehicle, this one is going to be a tilting electrical trike, with 2 front wheels and one powered rear wheel.
Looking forward to your comments and suggestions.

This is all interesting stuff. Here's my maiden posting, and it's an intriguing one...
I was wondering if there are any vehicles out there that combine in-phase steering of the rear-wheels and tilt...
Why am I asking? Well, tilt works wonders on narrow vehicles (like the Toyota i-Road, see picture). The trade-off however is tandem seating, where the passenger sits claustrophobically tucked away behind the driver. Co-steering (or in-phase steering) rear-wheels, as opposed to counter-steering rear-wheels, may help to keep body roll in control of the let's say not so narrow vehicles, like the one way below (seen from above).

 

[macribs]

From the top of my head I know the Japanese car makers did a lot of 4 wheel steering in the late 80's and early 90's. Usually on sporty or luxury saloons.
There was the co work of Dodge and Mitshubishi resulting in Stealth and GTO(?) that was 4 ws among others. For productions cars I guess the added costs in construction and parts didn't really pay off, as 4 ws was more prone to needing steering adjustments and service then regular cars. 4ws added weight, cost, service intervals and didn't really give that much advantages. Some even rebuild the rear end of the dodge stealth to avoid 4ws.
I think for the most part the focus was on counter steering rear wheels.

Are you thinking of making a narrow vehicle like the Toyota you posted or more of a car like vehicle, or maybe a trike/quad?

 

[Willow]

I love the cincept.... BUT....

The tilting mechanism doesn't work like it should. Forget about trying to let the rider 'sway' and have the back wheel in trail steer - will be a nightmare. Check out the designs from Harley and SWAY tilting trikes for a reasonably well done tilting front end. The front wheels need to move in the vertical plane - equal and opposite to each other, whilst turning in the direction of the steering/lean....


like this...

 

[macribs]

And you might wanna look at Wesll.com
They made a leaning quad, trikes and even a leaning snowmobile.

 

[voyager6]

From the top of my head I know the Japanese car makers did a lot of 4 wheel steering in the late 80's and early 90's. Usually on sporty or luxury saloons.
There was the co work of Dodge and Mitshubishi resulting in Stealth and GTO(?) that was 4 ws among others. For productions cars I guess the added costs in construction and parts didn't really pay off, as 4 ws was more prone to needing steering adjustments and service then regular cars. 4ws added weight, cost, service intervals and didn't really give that much advantages. Some even rebuild the rear end of the dodge stealth to avoid 4ws.
I think for the most part the focus was on counter steering rear wheels.

Are you thinking of making a narrow vehicle like the Toyota you posted or more of a car like vehicle, or maybe a trike/quad?

Thanks all you guys for your comments. Actually I should have posted my comment some place else on this forum. But this was the only one that brought up the subject of tilting vehicles. We shouldn't forget that it took a long time to perfect a car's four wheel suspension: from rigid axles on leaf springs to the very sophisticated 4WS and torque vectoring of (for instance) the latest Porsche 911. Perhaps I start a new thread.

IMO, three-wheeler or semi three-wheeler narrow vehicles have a future. https://endless-sphere.com/forums/viewtopic.php?f=7&t=81294

However car makers, except for maybe Toyota, don't venture in that direction. In a four-wheeler the steering front-wheels always need to overcome the tendency of the rear-wheels to plow on in a straight line. Here is a picture of how vehicles deal with lateral forces during cornering. A car dips the outside and lifts the inside, a motorcyclist leans into the corner. IMO, a (semi) three-wheeler that uses a bit of tilt and slightly co-steering rear-wheels, to deal with the weigh shift, deserves looking into.

You might even think that there ought to be a computer program on vehicle dynamics, that is able to feed variables into some sort of equation - steer input, speed, center of gravity (CG), load, degree of tilt, degree of co-steer of the rear-wheels, Ackermann, front- and rear-track, wheelbase, even wheel size, stance and tire width - and sort out the effects.

 

[tahustvedt]

Awesome project. Looks very tail heavy though.