Contact US

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!

*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

Visual inspection for open gear guide

Visual inspection for open gear guide

Visual inspection for open gear guide

Hello all,

I am trying to find a guide for visual inspection on wear for open gears (girth gear and pinion). Specifically for ballmills or kilns. I saw the AGMA 1010 E95, but I am trying to find measurement points and how to take them.

In my country we do these measurements (backlash, contact and alignment), but I want to know if there is a better way. I have seen on youtube videos that sometimes the use lead wire to measure contact on open gear. However there are various questions, like how thick should the wire be? can I use lead/tin wire for soldering (pure lead is not very common) or does it have to be specifically for this application (because of precision measurements of some sort)?

Anyway if somebody has a guide I could follow or a book I can buy I would greatly appreciate it


RE: Visual inspection for open gear guide

It seems like that is a way to measure backlash - any soft lead that won't damage the tooth surface should be OK to try. You are measuring the thickness at the minimum point. Pure gold wire should also work, but lead is less expensive. If you've ever put a copper coin on a railroad track you know that if the material isn't fully soft it can still register a thickness even if there is no nominal gap - much less likely in lead on a gear mesh. Obviously the wire needs to be thicker than the expected backlash; I would not go farther than 3X but up to 5X should be problem free.

Watch your fingers. If the input gear can be hand-cranked, that would be great.

What may be more critical is the tooth form, but I don't know any cheap ways to do that. My experience is the most wear in a mesh will be on either side of the pitchline due to the sliding contact for the typical involute gear. On the pitch line you may see pitting from contact loads creating a fatigue failure.

RE: Visual inspection for open gear guide

We use lead to measure the rod bearing wear on EMD engines, it gets smashed between the piston and head. It's plenty malleable.

RE: Visual inspection for open gear guide


I did not reply immediately because I had to keep an open mind. but I have come to the conclusion that this will not be a satisfactory method of inspection. the gear teeth mesh back lash would have to be rocked.
I believe the best test would be a contact pattern test. and a review how contact pattern looks.

RE: Visual inspection for open gear guide

Thanks for your responses,

3DDave, What do you mean by tooth form and how do you measure it? Is it the same as contact pattern test? How do you measure this last one?


RE: Visual inspection for open gear guide

Google is your friend for supplying more information about that than I can.

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


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