Actuating tools solve unique machining challenges

By adding an actuating tool to your machine, you're adding another axis that it normally wouldn’t have. CERATIZIT

If you’ve ever gotten bogged down by a unique and challenging part feature, you essentially go through the five stages of grief (denial, anger, bargaining, depression, and acceptance) while figuring out how to machine it.

Cylinder bores, stator bores, and the even more difficult-to-machine piston bores are three examples just from boring operations. Tapering medical parts, complex contours, and every imaginable unique, difficult shape—the ones that keep programmers and machinists up at night—require a unique tooling option.

Enter actuating tools.

An actuating tool gives your machining centre some turning capability, either with its factory-installed U-axis (a spindle with a drawbar) or by a retrofitted kit. With an actuating tool, internal machining of a bore can be performed in the machining centre, removing the need to move the part to another machine.

The entire process is performed in a single clamping setup. This process also has other benefits, maybe not related to cycle time, but definitely to surface finish. In some cases, the tolerance of large bores can reach IT6 quality. And any increase in cycle time is offset by the fact that parts no longer need to be shuffled from machine to machine.

While special inserts may be needed for very unique machining tasks, typical ISO inserts are used in the majority of applications.

Canadian Metalworking (CM) asked actuating tooling experts Mark Blosser, executive director of technology and solutions/sales and applications at CERATIZIT, and Larry Cameron, national MTB group manager at MAPAL, for their advice in deploying these tools correctly. Here’s what they had to say.

Cameron: Any tool where you can control movement of the inserts is an actuating tool. Commonly, this is done by using a simple drawbar or pushrod; a machine’s U axis, if it’s fitted with one; a contact stop socket; coolant pressure; or a retrofitted drive module, like our TOOLTRONIC.

Drawbars and pushrods actuate the slides that position the inserts. This often is the easiest method to deploy these types of tools because it requires the least amount of work in the machine itself. A simple push/pull rod actuates the thrust face tool portion of the tool.

Retrofit kits add electronic capability into the spindle and control actuation that way. For this to work, first of all, you need room in your machine for it, and you also need room for an access card in your controller.

It’s important to know that actuated tools are not for roughing operations. They're more of a semi-finish and finishing operation tool. MAPAL

Blosser: Electronic tools have their own programmable servo drive inside the head itself that you program.

Basically, by adding an actuating tool to your machine, you're adding another axis that it normally wouldn’t have. There are many different types of mechanisms that make the actuating movement happen.

For example, in large-scale applications, especially if you have a non-symmetrical part that requires profile turning that you can't effectively do on a lathe, you have to do it on a machining centre. These tools give you the ability to create these profiles on that machining centre.

In other large-part applications, you can use these tools on a bridge mill and use the quill to actuate them. This is the type of actuating mechanism that you see quite often in the valve industry, oil and gas, and sometimes in aerospace work.

Other actuating tools use a compression disk. In this method, you make contact with the fixture or the workpiece, which presses the tool adapter into the tool, which actuates the slide.

Cameron: But no matter how it is powered, as soon as you actuate, or as soon as you activate U-axis capabilities of the machine, then you need to start thinking of it more in terms of a lathe, because there is some axis swapping going on in the controller.

The programming is pretty simple, because you use standard lathe programming cycles.

It’s also important to know that actuated tools are not for roughing operations. They're more of a semi-finish and finishing operation tool. You can rough with them, but you have to use lighter depths of cut.

Cameron: Typically, these tools are used for very specific to jobs. Whether it's for creating a cylinder bore or making something like a fluid end for a fracking pump, these are unique tools made for a specific type of job.

In fact, you can create shapes that are almost impossible to make with a plunging-style tool.

Blosser: Let’s take the example of a landing gear part. In the past, they usually have one insert on a boring bar that gets bolted to the head and then just uses the entire slide to create the bore.

We've actually designed tools that have multiple slides, so you have two or even four effective cutting teeth. You can create the part feature with a much quicker cycle time than you could potentially with just a single-point tool.

And we can add sensors to the slides for micron-level positioning and accuracy.

Let’s say you’re making a bearing shoulder and you have to do a bore. You can actually control the bearing diameter very well. And then when you get to the bottom across the floor, you can create perfect perpendicularity on the floor for the bearing surface. It really is the best way to do something like this.

The reason we talk about bores so much is if you have to make a series of parts that have 10 different bore sizes, and you've got a facing head that's got 20 or 50 mm of radial stroke, you can pretty much set up one tool to do every bore without having dedicated tools for every single one.

Cameron: This is when we are talking about machines that have U axis, that is what goes through the spindle and drives it. Also, machines can have line bars that have actuating capabilities, which is just a simple push/pull rod where you can actuate the thrust face tool portion of the tool.

The way we do it is by adding a unit that adds electronic capability into the into the spindle.

You might have to invest $50,000 to $80,000 to install an actuated tool on your machining centre, but you've now eliminated the need to put the part on a lathe. You’ve eliminated the need for a lathe, you've opened up floor space, eliminated handling, and eliminated work-in-process.

Blosser: This depends on what type of actuating tool you have. If it’s a mechanical head, then you need to make sure to lubricate it. That’s pretty much all you have to worry about.

If it’s an electronic tool, it’s a little more effort. There is an area on the back end of the spindle that transfers the power through inductive energy and gets back data. You have to take care not to damage the coil on the back. For example, you don’t want to submerge it all the time.

Cameron: These tools can be stored in the tool magazine along with all the other tools. That means you can access them easily for service.

Generally speaking, if this tool is being used every day, we like to see it hand-oiled. There's oil spigots on the side of these tools, and you need to oil them daily.

We think it’s also important to use a good presetter. This means you can actually guarantee that it's going to achieve the diameters that you want.

CERATIZIT, www.ceratizit.com

MAPAL, www.mapal.com