by ‍‍Olavi Meriläinen, Jergens guest blog

In the late 1970’s, Finnish inventor and entrepreneur Mr. Olli Kytölä developed a new clamping method for workholding. The simplicity of the idea is mind-blowing even today: instead of moving large machine vise jaws against each other, a small wedge-operated jaw is pressing the workpiece against fixed stoppers. The clamp has two jaws, so possibility to clamp one or two workpieces with one clamp is built-in.

During last 40 years, this wedge operated workholding clamp has become famous with the name OK-VISE Low-Profile Clamp. The core application has always been in CNC milling, an in early days do-it-yourself people used to build their own workholding fixtures using OK-VISE clamps and milling the remaining parts of the milling fixture themselves. ​

When we are talking about clamping the workpiece securely and safely for machining, it is important to look at various clamp models and their strengths.

The features of the machining process and the workpiece typically determine the requirements for the clamp. In most fixtures, so called force-closure is being used.

This means that typically 3 sides of the workpiece have free access to milling tool, and holding force opposing the machining forces is created by friction.
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When dealing with high forces during machining in force-closure fixtures more friction is needed between the jaw and the workpiece. This can be achieved by selecting a larger clamp, for bigger forces, or a model with enhanced grip for better friction compared to a smooth-jaw clamp.
Luckily, you can find a range of clamp options from us to securely attach even the most challenging workpieces.

In mostly used the jaw slides along the fixture base. These are called hold-down models, because the wedge design holds the jaw down and prevents the jaw from lifting up while clamping.

One way to build a workholding fixture is form-closure, where the geometry of the layout prevents the workpieces from moving.
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Another and more typical application is force-closure, where the friction between the workholding clamp and stopper jaws create a holding force that prevents the workpieces from moving. In most typical application there are 2 workholding clamps and 2 stoppers, each with the same force clamping the workpiece. When this force is multiplied by friction coefficiency µ, then we can calculate the holding force, in the abovementioned example.

H = 4 µ F
 where F is the clamping force, and friction coefficient varies. Example values when workpiece from steel is in use.
 µ = 0,15            smooth jaws
 µ = 0,28            tungsten carbide coated jaws
 µ = 0,8              serrated jaws

All in all, using a wedge operated clamp is one of the easiest and best ways to build workholding fixtures. Its operation allows you to use it for clamping multiple workpieces simultaneously or when you need a high clamping force in limited space. For more details about our low-profile clamp, we have gathered product information in our instructions.
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Stay tuned for more updates from OK-VISE as the company continues to innovate and deliver cutting-edge solutions to its customers.

Looking for the perfect 5-Axis Self-Centering vise to the test against a leading competitor's vise. We've rigorously evaluated both vises across four critical performance categories to help you make an informed choice for your workholding solution.

Test Categories: 

• Jaw Lift: We examine the vise's ability to securely grip your workpiece, ensuring it won't budge during the most demanding tasks. 
• Jaw Repeatability: How consistent is the vise in holding and releasing your materials? Precision and reliability are key. 
• Jaw Changeover: Time is money in any shop. Find out which vise allows for swift jaw changes, optimizing your workflow! 
• Jaw Recentering: We test the vise's capability to reposition and recenter your workpiece quickly and accurately, saving you valuable time. 

Discover the results and decide which vise is your ideal companion for all your projects.

At Jergens, we're committed to providing top-quality manufacturing solutions, and we believe in transparency. Our goal is to help you make an informed decision when it comes to your tools, and this video is just one example of that commitment.

Don't forget to like, share, and subscribe for more informative content about our products and manufacturing innovations. Have questions or suggestions for future comparisons?

When it comes to broad capability, there are a few clear machine tool choices that production units and shops consider most – Five-axis, Vertical and Horizontal Machining Centers. The criterion for choosing looks different depending on what seat you sit in – from ownership to management to purchasing and finance – but from the shop floor perspective it’s all about making chips.

Getting the most out of these highly sophisticated machines involves a combination of processes, programming, tooling, workholding and human creativity. Set up between them is very different, too. Workholding on a 5-axis and Vertical Machining Centers is very straight forward – literally – since the spindle points directly to the table.

Setting up a Horizontal Machining Center (HMC) requires quite a bit more thought because the spindle points to . . . well nothing, just into the open space within the machining envelope. So, what’s the call for it?

Over the years, HMCs have evolved from single station to double, with the use of pallet changers, to pool pallets for multiple setups, and now to even include hydraulics within the pallet to load and clamp on the machine. And the evolution continues.

Today’s HMCs have great productivity characteristics including the ability to continue machining in one location while part change can take place in another. Many feature automatic tool changers and automatic pallet changers making them well-suited for uninterrupted, unmanned and continuous machining.

Configurations with multi-axis spindles also permit true five axis machining. And thanks to gravity, the chips naturally fall away from the parts.

​To meet this great potential, requires a review of several workholding issues at the outset.

1.  Angle Plate or Tombstone
First, let’s get back to the open-air orientation. All machining on an HMC starts with a workholding solution. That’s either going to be an angle plate or tombstone (column) that mounts to the HMC indexing table to provide the position and orientation of the workpiece to the spindle. The choice of this fundamental base is dependent upon the answers to remaining things to consider.

2. The Four Basics
As with all machining, all fundamental requirements must be met. Workpieces must be held securely. They must be positioned to allow access to machine all sides (ideally without having to change). Operations have to be repeatable (within tolerance). And the setup has to be designed to be easy for the operator. That includes the ability to clear chips, load, move and other ergonomic factors with the safety of that individual always being priority one.

3. What is your current need?
If you’re gearing up for the next run of parts, it’s best to begin with an SOW (Scope Of Work) including everything from what you’re looking to accomplish now, to opportunities for greater productivity, and how to best support operator skill level.

4. What is down the road?
On the heels of that, savvy engineers are mindful of future needs. Plan for it now and be ready when the demand arises. This past-the-horizon approach saves time for further utilizing technology such as incorporating robotics and other automation.

5. Opportunities for increased productivity
There are two additional productivity boosters available depending on the application. The first is the move from an angle plate to a tooling column for the ability to load a greater number of workpieces for any given setup. This is just a matter of math – a two-sided column essentially doubles that number, three-sided triples, and four-sided quadruples.

For every incremental increase, there is a corresponding decrease in overall setup time (or downtime), and conversely an increase in productivity (or uptime).

​Connections are standard T-slots or grid patterns. The second opportunity is the addition of a quick-change system that allows the entire column to be removed, changed and the next one connected, fully loaded and all in a matter of minutes or even seconds. This quick on and off works when repeatability is high and avoids having to again find zero for every changeover.

Finding the sweet spot for your shop’s productivity is very much a human effort, and a matter of choosing the best combination of man and machine. In the case of high producers like HMCs, the goal continues to be loading and changing parts faster than the machine can make them.

Jergens has introduced its new Washdown Tool, which provides 360° of spray using coolant flow to wash away chips from exposed surfaces.

The in-between-processes tool is programmed inline after a predetermined number of machining cycles. The Washdown Tool provides thorough chip removal from the many exposed surfaces inside the machining area. In turn, this saves time for operators by reducing the time spent cleaning chips from a machine interior, workpiece or workholding setup.
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The unit uses multiple spray nozzles on its circumference, providing a steady and pressurized stream. Each nozzle can be plugged or opened to create customized spray patterns. Added spindle rotation is said to ensure that coolant reaches virtually everywhere inside the machine.

​Residing in the tool changer, the Jergens Washdown Tool is deployed periodically at scheduled intervals. This automation shortens cleaning time and supports long machining cycles, even lights out manufacturing periods when no operator is present.

The user selects which outlets to open, which controls the pressure and direction of the jets. Moving and rotating the spindle under a constant flow of coolant achieves an excellent and systematic cleaning of the machine interior.

​Through the optional installation of a pressure gauge, the status of the pump, filter, and entire supply line can be checked.

 Product Specifications:

• Outlets: 14
• Working Medium: Machine Coolant
• Repeatable, systematic, & thorough cleaning of a machine's interior
• No aerosol pollution harmful to the health of the machine operator
• Reduction of cleaning time
• Wash away chips and clean the machine at scheduled intervals during long machining cycles or "lights out" machining periods when no operator is present

​Jack Rushlander, Jergens Technical Sales Manager discusses layout and planning techniques for 5-axis machining centers.

Jack talks about how advancements in 5 Axis CNC machining technology has changed dramatically in the past 20 years. Dynamic Work Offsets and other capabilities have made workholding easier but also given shops even more opportunities to to improve process and reduce cycle time.

Check out the video below and see how Galactic Widget Company tackles the workholding of a Thingamajig.

• 00:00 - 01:35 Introduction
• 01:35 - 03:50 The Pros of 5-Axis
• 03:50 - 06:20 The Cons of 5-Axis
• 06:30 - 09:36 Process Essentials
• 09:39 - 11:53 The Machine
• 11:55 - 15:40 Part Drawing & Raw Material
• 15:50 - 19:45 When to Use a Dovetail
• 19:46 - 21:35 Start to Finish Operation in Drawings
• 21:36 - 30:38 Work Envelope in Solidworks
• 31:24 - 33:58 Analyze With Your Machinists
• 35:30 - 37:08 Troubleshooting
• 37:18 - 37:56 Getting Other Eyes on Your Project
• 38:00 - 39:40 The Process of Sending Project to Your Programmer
• 39:45 - 49:36 Questions

The ER Collet Fixtures provide a simple and low profile solution for clamping cylindrical workpieces using the same technology you are already familiar with in your rotary toolholders.