×
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

# Alternate method to determine position in two axis besides using linear encoders?

 Forum Search FAQs Links MVPs

## Alternate method to determine position in two axis besides using linear encoders?

(OP)
Hello,

I'm working on a project where I will need to determine and record the XY position of a stylus over an 18" x 36" table. The stylus will be mounted on a gantry to move freely in the Y axis, and will also be mounted on a slide on the gantry beam to move freely in the X axis. I want the user to be able to hand move the stylus and have the program record it's XY coordinates every 1/10th of a second.

I've looked into using linear encoders for this but the cost is far too expensive. Is there any other cheap and simple method that I can use that can (somewhat) accurately determine the XY position of the stylus without using linear encoders? I've thought about using a stepper motor and counting steps but the resistance will be to great to move the stylus easily.

Any ideas would be greatly appreciated!
Thanks,
-M

### RE: Alternate method to determine position in two axis besides using linear encoders?

I don't understand. We make small linear motion demo units. We use quadrature encoders that cost about \$75. I don't know if they have a z pulse. For a small system like you describe you can just run the stylus into to end stop and set the position.

Peter Nachtwey
Delta Computer Systems
http://www.deltamotion.com
http://forum.deltamotion.com/

### RE: Alternate method to determine position in two axis besides using linear encoders?

Use really small stepper motors and gear them so they don't affect the motion.

Or.

Use touch circuits with linear tapers to allow reading the positions of the two axis. Use a micro with a charge peripheral like most Microchip processors to pole the "touch" point. Tiz very fast and cheap.

Alternatively use variable inductance coils where the axises run a core into coils changing their inductance. Measure the position by measuring the inductance.

Or use a Kinect and just look at the hand.

Keith Cress
kcress - http://www.flaminsystems.com

### RE: Alternate method to determine position in two axis besides using linear encoders?

And what's about mouse including internal image processing with XY pixels outputs?

### RE: Alternate method to determine position in two axis besides using linear encoders?

define cheap?
define accurately?

String pots?
Ultrasonic? https://www.sparkfun.com/products/13959

#### 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!

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!

Already a member? Close this window and log in.