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

Encoding position of item on conveyor with idler belt

Encoding position of item on conveyor with idler belt

Encoding position of item on conveyor with idler belt

I'm working on a system where we are laser-marking an item as it goes by on a conveyor.  To better control the velocity, we are locally driving one side of the item with a urethane round belt. Normally I would use a skid plate backer, with a friction wheel and encoder on the other side to tell the laser when to fire, but the print length is longer than the area a friction wheel can hit. I started with another urethane belt with an encoder on the trailing pulley for the back side, but it was too stretchy, and took a set which provided uneven torque to move it, which meant some slipping.  So I am using a timing belt for the back side, which has an encoder on the trailing pulley. There may be more than one item between the belts at one time.

Here are my questions:
-Has anyone done anything like this before (a friction belt for encoding), and is there a better way?
-if not, would you recommend lots of toothed idlers to support the timing belt with low tension, or just end pulleys and very high tension?


RE: Encoding position of item on conveyor with idler belt

Maybe a photo or drawing would help.

Mike Halloran
Pembroke Pines, FL, USA

RE: Encoding position of item on conveyor with idler belt

I think you'll be happier with the idlers, or a polished stainless shoe, applying pressure to the toothed side of the timing belt to keep it in contact with the 'item'.  The shoe can work at modest speeds because the belt teeth are usually faced with nylon.  Not so much for molded urethane belts.

Super high belt tension won't bother the timing belt much, but it will bother the bearings on the encoder and idler pulleys, and make the passively driven belt susceptible to jamming from the odd piece of paper or other detritus falling on the belt teeth.

I think you can order timing belts with high friction backs, too.


Mike Halloran
Pembroke Pines, FL, USA

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! Already a Member? Login


Research Report - How Engineers are Using Remote Access
Remote access enables engineers to work from anywhere provided they have an internet connection. We surveyed our audience of engineers, designers and product managers to learn how they use remote access within their organizations. We wanted to know which industries have adopted remote access, which software they are using, and what features matter most. Download Now
eBook - Managing the Context of Product Complexity Using the Digital Twin
Keeping track of changes to complex products is difficult—think Aerospace & Defense equipment, new generations of commercial aircraft, and software-based automobiles. A new way to managing the digital context of the physical product is required and the answer is the Digital Twin. This ebook explores the opportunity available for Operations and Maintenance for the Digital Twin. Download Now
White Paper - Trends in Industrial Filtration
Substantial progress has been made in filtration technologies in recent years. New filter media materials, designs and processes have led to filters that are more efficient, reliable, compact and longer lasting. This white paper will discuss the various trends that are impacting operational responsibilities of MROs today and the resources that are available for staying up-to-date on the latest filtration solutions. Download Now

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:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close