Coupler Upgrade

by Ivan Hamilton 3/31/2009 7:49:00 PM

I was keen to attach my home brew servo motors and see the mill move. The shaft on the mill's screws is 17mm, whilst the motor's 12mm shafts are designed for a small chain gear (small section of keyed  shaft and a left hand thread), and I needed to grasp below this.

Since I'm coupling the motor directly to the shaft, a figured a coupler with a little flex was in order. My immediate solution was some vinyl hose and a pair of hose clamps. Affixing and tightening the coupler was tricky. The uneven shaft sizes (17mm & 12mm) made it difficult, and I destroyed several hose clamps trying to get it tight enough. That would work for a little while, but it wasn't able to handle the torque and would eventually twist in the middle. I added some support in the middle with a section of hard plastic tube to help prevent this.

But the length of the vinyl tube was too great, and its twisting added extra backlash to the system. Not only that, the backlash amount was unpredictable, increasing during use as the vinyl warmed up. It was always meant to be an interim solution, and the purchase of a 1m length of Ø40mm acetal rod ($55AUD) was the start of something better.

Technically, this was my first CNC machining experience. It was only 2 axes, and involved numerous manual interventions, but to see it moving automatically to perform the desired machining operation was very rewarding.

I've already made two couplers (X & Y), and shortly will make a third to automate the quill (Z). With that, I'll have full 3 axis control and should only need to stop for tool/fixture changes.

Currently rated 1.5 by 150 people

  • Currently 1.476735/5 Stars.
  • 1
  • 2
  • 3
  • 4
  • 5


CNC | Mechanics

Powered by BlogEngine.NET
Original theme by Mads Kristensen

About the author

Name of author Ivan Hamilton
"My inner nerd can beat up your inner nerd."

E-mail me Send mail



<<  October 2021  >>

View posts in large calendar

Recent comments





    The opinions expressed herein are my own personal opinions and do not represent my employer's view in anyway.

    © Copyright 2021

    Sign in