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Subject: 
Rack and Pinion Steering
Newsgroups: 
lugnet.robotics
Date: 
Wed, 3 Nov 1999 16:56:06 GMT
Original-From: 
The WordMeister <dwilcox@wordsmithdigital./spamcake/com>
Viewed: 
572 times
  
Here's where I really miss not having a digital camera.

I'm working on a wheel-based 'bot that has rack-and-pinion steering, and
I've run into a snag. (I realize that dual-motor steering and a caster-type
rear wheel makes more sense, but I wanted a challenge.)

My assembly uses an 8t gear that drives the rack. The gear is connected to a
motor via a rubber-band "belt" drive. This, in theory, allows the motor to
move the wheels left or right to their fullest range, and lets the pulleys
slip to avoid ripping the assembly apart. More rubber bands act as springs
to pull the steering assembly back to center. I use the NQC Float command to
allow this [theoretically] to happen. Also, I don't own the coveted clutch
gear yet.

The goal is to get this assembly to steer the robot, without requiring use
of a touch sensor or rotation sensor (the latter which I also do not have)
by activating the steering motor during turning and letting the steering
assembly automatically recenter (or recenter with a small push in the
opposite direction from the motor) when the turn is finished.

I'm having some problems getting this to work effectively (if the pulleys
are strong enough to always move the steering section to the full left or
right, they are too strong to allow the recentering to work well--if they
are not as strong, it always seems to work much better in one direction than
the other), and would welcome any suggestions the group might have.

--The WordMeister

Doug Wilcox

WordSmith Digital Document Services
403 VFW Drive
Rockland, MA 02370

781-871-6162
fax 781-871-6264
http://www.wordsmithdigital.com
ICQ# 24868783

• Web design (including e-commerce)
• Searchable Digital Documents on CD
• Desktop Publishing • Design • Scanning
• Computer/Software Consulting (Technical Wizardry)
• Computer Demons Exorcised
• Officially Registered in Dogbert's New Ruling Class



Message has 1 Reply:
  Re: Rack and Pinion Steering
 
(...) I think you should look at a design in which each steering wheel's pivot axis is NOT in the same plane as the steering wheel's axle. Specifically, each wheel's axle should be behind its pivot axis, where "behind" is referenced in terms of the (...) (25 years ago, 3-Nov-99, to lugnet.robotics)

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