CNC Lathe Tool Turret – How to Properly Distribute Your Tools

I love the fact that as a former CNC service tech I am now able to pass my experiences in machine repair onto others through the use of our BLOG. I have seen a lot in my many years in the field and I feel that I have some valuable tips and tricks to pass on to others … and love to do it. ( PS … If you haven’t subscribed to our BLOG NEWSLETTER you can do so in the left toolbar. This way you can keep on top of our valuable tips and tricks. )

In this post I would like to touch on the proper way to load your tooling onto your CNC lathe turret. Seems like a pretty simple thing but actually doing it improperly can cause turret misalignment and even fatigue over time and lead to damage to the turret indexing mechanism. So hopefully a few quick pointers will help your CNC lathe enjoy many years of worry free service.

If you have a mill … vice and fixture placement carries the same type of consideration. See this blog post for more on that ;


The first and main consideration is to evenly distribute the weight around the turret. Keep in mind that ID tool holders weigh considerably more than OD turning tool holders. In the process of loading tools and seeking clearance for indexing and cutting … you might be tempted to load all the longer tools (usually the ID drills and boring bars) on one side … and all the shorter tools (OD turning and grooving tools) on the other … and there is the problem as the pic below illustrates.

This type of configuration put all the weight with the ID holders and makes the turret unbalanced.  It works for cutting as it keeps the tool interference issue off the table … but should be avoided as much as possible. The pic below illustrates  a more balanced and healthy approach to tool distribution.


The reason balanced weight distribution matters you ask? As the turret rotates to index tools … and new machine index speed is pretty fast … even weight distribution insures that the turret stops … and clamps … in an efficient and let’s say less stressful manner. With unequal weight distribution … the turret may overshoot during indexing and be unable to clamp … causing a lock up … or it can cause uneven wear on the curvic coupling over time … the mechanism used for the accurate turret face to turret body clamping. You can watch the turret index, stop and lock and if the movement seems clunky … you might try to readjust the weight distribution.


Sometimes it’s just impossible to keep the tools and weight evenly distributed … tool interference  usually being the main culprit. So what can you do? One of the best tricks is to use “dummy” holders to help distribute some weight. 

As the pic above illustrates … loading some heavier ID holders opposite the needed ID holders can help balance the weight and allow you to place tools where required to avoid tool interference during cutting.  Being creative can surely help.

Using a little common sense and taking the time to watch closely the movement and indexing of your turret to insure it’s smooth can mean longer life and accurate cutting for your CNC lathe.

Kenney Skonieczny – President
Kentech Inc.