Tag Archives: cnc turning

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 ;  http://kentechinc.biz/move-that-vise/

WEIGHT

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.

WHY WEIGHT MATTERS

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.

DISTRIBUTION TRICKS

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.

Shop Efficiency Series Part 3 : Re-Thinking Your Lathe Tooling

We’ve always been a big fan of Sandvik Coromant and their tooling … not just because they are a member of the Kipware® family … but we have always found their tooling, inserts, support and design to be cutting edge and of the best quality. On the shop floor … they were our tooling manufacturer of choice and never let us down whether in standard type production or when we were looking for that new and innovative tool to get us through the toughest job or materials.

One of my personal best purchases was in converting our CNC lathe tool turret from standard lathe tooling to the Sandvik CAPTO system. I can compare this transformation to the points I outlined in Part #1 of this Shop Efficiency series … click here to read that article … and the transformation that takes place when you bring your VMC table into the 21st century. A CAPTO system will bring your CNC lathe turret into the 21st century.

First – What is CAPTO?

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The CAPTO system is basically a quick-change, modular tooling system for CNC lathes and turning centers. Instead of mounting tooling directly into the turret … tools are mounted to quick-change clamping units that are mounted onto the turret. Tools are then easily interchanged by simply changing the “head” mounted onto the clamping unit. Need to change from an 80 degree turning tool to a 55 degree … just simple swap the “head”. Need to change from a .750 insert drill to a 1.250 … simply change the “head”. For live tool turning centers … need to change from a 1″ drill to a face mill … simply change the “head”.

Second – Why Use CAPTO?

This type of modular tooling system comes with tons of advantages. Here are just a few of the more important ones pertaining to the Shop Efficiency factors which are the main focus of this series.

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  • Quick tool change which keeps the spindle running and the machine making chips / money. Not only in changing the complete tool type … but insert changes can take place off-line while the head is replaced at the turret involving less time than an insert change.
  • Greatly reduced set-up and changeover times because of the cutting edge repeatability when re-mounted in the clamping unit.
  • Greater tool stability leads to improved cutting and cycletimes.
  • Greater flexibility in tool selection and tool type.
  • Same tooling can be used throughout the shop … reduced tooling costs and inventory.
  • Greater options for through-tool coolant delivery … again, improved cutting and cycletimes.
  • Turning Centers with Live Tools can see the biggest impact. By simply swapping heads that tool station can go from a face mill to a drill to an end mill in seconds. With greater repeatability meaning less set-up / touch off times. In addition … turning that face mill station into a turning tool station can also be accomplished … quickly and easily.

I could go on and on … but I’m sure you’re machinist mind sees the point.

Third – Cost vs Features

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Like anything in life … the system does require an initial investment. How much can be spread out over time as you integrate the system into the machine and the shop over time. I will say from experience that the long term savings are there … in quicker change overs, increased cycletimes and reduced tooling inventory … especially if you integrate the system into multiple machines. The beauty part here is that once you have the clamping units on all your machines … all machine will now utilize the same tooling. That is a huge advantage including reduced tooling costs and inventory all around.

Conversational

RESULT – Increased Shop Efficiency

As you can see from the points outlined here … there are a ton of features that can lead your CNC turning department to increased shop floor efficiency with the transformation through a CAPTO system. By integrating the system into your shop bit by bit you can defer the initial investment a bit and still reap the long term advantages and savings as you build the system into your shop floor. From faster insert changes … to faster tool change-overs … to faster set-up … to improved cutting and cycletimes … your shop floor can certainly reap improved shop efficiency with a CAPTO system.

LINKS for ADDITIONAL INFORMATION 

  1. For a more in-depth look … take a peek at the Sandvik Coromant video by CLICKING HERE.
  2. For more information on CAPTO in general … download the informational PDF by CLICKING HERE

Please come back for our next installment in our series on Shop Efficiency. Until next time … Happy Chip Making !!

Kenney Skonieczny – President
Kentech Inc.