Tilting Trike video

[Morgen 3Eman]

Hi Folks,

This is a link to a video of my tilting trike prototype.  The power wheel will go on the left rear..

http://youtu.be/C7uuZab-1K8

TTFN,
Dennis

[sixty_cycle_hum]

Great work, Dennis.

Can we get some close up shots of the linkages on the rear?  Is it sprung or torsion biased to the center, or just free tilt?

-sixty

[Morgen 3Eman]

Hi Sixty,

Well, today it isn't even a trike!  To make a long story shorter, I made it into a tilting 4 wheeler.

I'll have to take some photos of the rear swing arm arrangement.  They are cross coupled with pull rods and levers, so the outer wheel in a turn lifts the chassis more than the inner wheel drops the chassis, so it is self righting when parked.  I have a small torsion bar between the swing arms to increase the self righting.  It is arranged like an anti-roll bar on a car suspension.  It was needed to keep the darn thing upright when I loaded  the cargo  basket with milk and cookies and had to go into the liquor store. 

It rides nice!  Or did...

TTFN,
Dennis

[Morgen 3Eman]

Hi Folks,

Since you were dumb enough to ask me to say more, here are some snapshots of the rear tilt mechanism.  Please ignore the ugly welds, this thing has been cut and folded a dozen times or so. 

If you look closely, you will see the linkage that makes one swing arm go up as the other goes down.  The angles of all the levers are selected to make the outer arm move up more than the inner arm moves downwhen tilting, which makes the seat raise up when tilting.  It also make a change in the wheelbase from inner to outer, but I'm not sure the effect is noticeable. 

TTFN,
Dennis

[Bikemad]

The angles of all the levers are selected to make the outer arm move up more than the inner arm moves down when tilting, which makes the seat raise up when tilting.  It also make a change in the wheelbase from inner to outer, but I'm not sure the effect is noticeable. 

Dennis, I think you meant to say that the the outer arm moves down more than the inner arm moves up when tilting, unless your trike/quad tilts away from the bend instead of leaning into it. 

Alan
 

[Morgen 3Eman]

Hi Alan,

Nope, It works just the way I said.  Since the wheel hub end of the swing arm stays at the same level above the ground, (about half the tire diameter)  the other end of the swing arm moves up. On the inside of the turn, the wheel hub stays at the same level above ground, and the other end of the swing arm drops down. 

Wanna see some pictures of a measuring stick next to the swing arm pivot?  The displacement difference is pretty amazing...

Sine/cosine effects can be very powerful when amplified by levers.

TTFN,
Dennis