Home Forums Hunting & Shooting Gunsmithing Eliminating Grizzly Lathe Vibration With Before and After Videos

A few years ago, I bought a Grizzly G0709 14x40" lathe for gunsmithing work. I build guns for my own use, not as a profession. My main reason for choosing the Grizzly was that a) I could have it delivered to my door relatively easily and b) it wouldn't require any restoration work the way an old American lathe might-- I wanted to build rifles, not a lathe.

As I began to use the lathe, it became apparent that it vibrated excessively-- this thing acted like it wanted to walk itself out the door when I ran it. Needless to say, this made it very tricky to use. I finally narrowed down the source of the vibration to the drive belts, which had "bumps" in them, probably from sitting in storage for an extended period of time. I replaced them with link-style belts that Grizzly provided under warranty and the vibration decreased significantly. Nonetheless, there was still too much vibration for doing real precision work which made fitting and chambering a chore. I turned out some real shooters but I was fighting the machine constantly. I tried re-leveling the machine, trading-out the "feet", you name it: nothing worked.

Here is an example of the vibration/runout at the spindle with a .0001" test indicator to quantify what was happening:

https://youtu.be/CHGHrr320vE

The vibration appeared to be the result of the poor quality single-phase motor as well as the mounting system. I decided that I had to do something about it.

I bought an appropriately-sized three-phase motor along with aVFD to convert my single-phase power to run the motor. I also bought some vibration-dampening mounts to eliminate the hard mount between the motor and the machine. I'm not much of an electrician so I hired a friend to wire it all up.

The result is a machine that runs far smoother and I also have the ability to control the motor's speed using a potentiometer.

Here is the "after" video:

https://youtu.be/FkXgtSkR8H4

Hope this helps for anyone fighting the same battle. And yes, I learned my lesson-- I should have sucked it up and bought an American machine or at least a better import (Nardini, etc.).

Interesting to learn that the Chinese motor was the source of your problem. That is the reason that I will not even consider purchasing a Chinese sourced machine. During the time I was working I had the opportunity to set up a shop for two of my employers, I chose an Austrian made Emco Meier ( NOT the same as Enco) and was well pleased with the machine and its performance. We had a Nardini in the toolroom at the company I retired from and it too was an excellent machine.