×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Turning model ?

Turning model ?

Turning model ?

(OP)
Not quite sure where to post this.

If one has a scooter (two wheels) with a known overall length, wheel base and width, how do one calculate / plot the path it takes during a sharp 90 degree turn?

Or in other words:
Can I roll it into this holding area without having to lift it to get around that corner ?

Is there a simple math model for this ?

A link would be welcome, but so far I have found none. Maybe because I asked Google the wrong questions smile

RE: Turning model ?

Sounds a little like half of an Ackermann construction.  Assume that the front and rear wheels are purely rolling along the circumference of the same circle and that you aren't leaning the thing over at all.  Then plot the inner and outer "tracks" of scooter width about the center of the circle to determine the required path width.

Norm

RE: Turning model ?

(OP)
But the thing is, that the front wheel (turned 45 degrees) will follow a much wider turn, than the rear.

I have tried to simulate it in exel but my result was an ever increasing spiral. (Which I do not believe to be correct!)

We are more into the (fun ?) math here, as I do not think I can roll the thing in there without lifting it around one specifically tight corner.

Oops. Just came to think about one thing.
The two circles must be linked, and the difference in radius must be 0.707 times the wheel base at 45 degrees.
Now I only have to find one radius, then I can start plotting. But how to find it?

RE: Turning model ?

Make that two circles with the same center.  Front wheel circle radius is the hypotenuse of a right triangle whose opposite side is the wheelbase and angle is the same as the steer angle.  Rear wheel circle radius is the adjacent side.

Or you could lean, steer, and stomp on the rear brake only as you approach the storage area and skid the back end around a bit (remembering my coaster-brake bicycle days).

Norm

RE: Turning model ?

(OP)
That is exaecly what I just found out myself smile

Things are at times so simple, if you only get the right idea to begin with!

RE: Turning model ?

(OP)
Now the sad part is, that my turning radius will be way too wide, as I expected.

But we will see, when the time comes. Now I know, what to expect.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources