Sunday, March 3, 2013

Tachometer Repair

When purchased, our tachometer didn't have a pointer/needle.  I found it later in a box with other gauges and parts.  The pointer was in horrible condition.  I purchased a new pointer but when I tried to install it there wasn't anything to attach it too.  The pin that the pointer attaches to was missing.  I found it in the old pointer.  That's it in the picture. 

This is the piece with the broken shaft.  After searching the Internet I couldn't find anyone that sells replacement parts.  It's too small to weld and glue won't work.  I decided to repair the piece by fabricating a new pin.  

Using my mini-lathe I made a new pin out of brass.

This shows the damaged shaft with broken end piece.  My fabricated brass piece is also shown.  

I decided later that the brass probably wouldn't hold up.  I made a new one out of a grade 5 bolt.  The exacto is pointing to the steel one.

I trimmed back the shaft then cut a brass tube to couple the two pieces.

5 minute epoxy was used to hold everything together.

It's hard to see but we now have a pin to attach the pointer.

It works great.

A couple days ago I posted about the windshield wiper motor.  If you missed it check it out.


  1. You are indeed a magician!!!!


  2. Thanks Lester. I think is was the best solution all things considered. It should work as new with no issues.

  3. Such nice information showing us how to repair a Tachometer. Tachometer are very useful devices.