6 Easy Ways to Optimize CNC Program

Optimize CNC Program with tips and directions provided by DATRON Applications Engineer Dann Demazure in this blog.

“Optimize CNC Program” – it’s the instruction you hear in your head when you’ve finished a machining program. And it can be an arduous process that, if you’re like me, you slave over. Typically a bit too much, wasting a lot of time on changes that don’t add up to a substantial improvement. As we all know, time is money, so, I’ll try to relieve you of some of the labor of revamping your program. Here’s a list of quick, easy, and effective tweaks for your DATRON programs.

Optimize CNC program tips and detailed instructions in this blog by Dann Demazure from DATRON Dynamics.
Blog Author and DATRON Applications Engineer, Dann Demazure, optimizing a CNC milling program.

 

Optimize CNC Program Tip 1 –  Leave the coolant on

It may not sound like much, but this gain can really add up. If you’re using coolant in your program, consider switching it from the Positioning/Cutting feed setting from Cutting <0>, to Travers<1>. You may not easily perceive it, but there is a very brief dwell programmed into the software so that the coolant has time to begin spraying. This change in the command will leave your coolant spraying between positioning movements, thus avoiding the initial dwell. Now, each dwell may only last 1/10th of a second, but if you have 200 retracts in your program, you just shaved 20 seconds of your program, and that’s not nothing.

Optimize CNC program by leaving the coolant running during positioning movements to avoid the initial dwell.
Optimize CNC program by leaving the coolant spraying during positioning movements.

 

Optimize CNC Program Tip 2 – Ramp

If you’re cutting along a contour, consider changing your method. If you are currently doing depth cuts, try a ramp instead. A ramp keeps the tool engaged in your desired amount of material throughout (except for the very beginning and the very end), and has no retracts. Let’s say again that your part has 200 retracts cutting contours on 20 different features (10 retracts per feature). By ramping, you’d bring that number down from 200 to 20 (final retract), and if each retract takes half a second, you just saved 90 seconds.

Optimize CNC Program Tip 3 – Be smooth

If the devil is in the details, then small contours are your devil. If you’re doing intricate engraving or 3D contouring, then you’ve probably noticed that the machine will slow down to follow all contours tightly. It’s just following orders, but if you have a little leniency in your adhesion to contours, Smoothing can make a huge difference.

Optimize CNC program with smoothing functions to clean up jagged geometry for a tighter milling path.
Optimize CNC programs using Smoothing functions like PerfectCut to smooth jagged geometry. See the results in red above.

 

Smoothing will take jagged geometry, like what is pictured above (purple), and apply arcs to the contour to create a smooth, more continuous motion (red). Not only does this have benefits for surface finish, but since the machine doesn’t need to slow down nearly as much in an arc as compared to a vector, time savings can be abundant. And utilizing it is as easy as writing the code in your macro, editing the preset values (which work well for most things), and pressing the “Go” button.

Optimize CNC Program Tip 4 – Be dynamic

I’ve talked about dynamics at length before and all the benefits from using them to fine tune a process for speed optimization and ideal surface finish, so why am I mentioning them again? Easy, besides the fact the dynamics settings are one of the easiest ways to reel in cycle time, adjusting them in conjunction with smoothing yields even better results. A high dynamics setting combined with a smoothing filter means that a very minimal amount of deceleration is needed to turn a corner quickly, thus cutting your cycle time even further.

Optimize CNC Program Tip 5 – Get low

This is usually a gimme, but it takes about 10 seconds of your time to change your retract heights from 0.5”, to 0.050” (or lower). Minimizing your retract height won’t save you much time per retract, but think of the big picture. Even if you only saved 5 seconds per part, if you’re making 20,000 parts per year, you just saved over a day of machine time. Every second counts.

Optimize CNC Program Tip 6 – Keep your tools in order

It seems obvious, but try to keep your operations organized so that when a particular tool is done, it never gets used again in the program. Sometimes this is unavoidable, but each tool change will cost you somewhere around 15 seconds of time. Consider using combination tools to cut down on tool changes. Most importantly, if you have parts nested, use tools sequentially rather than by part. If you have to cut 24 parts, and each part uses 4 tools, you’ll either spend 24 minutes changing tools again and again, or 1 minute changing all the tools once.

If you’d like more information on the PerfectCut Smoothing mentioned in Tip 3, Download the Data Sheet by filling out the form below:

Download Optimizing CNC Program Smoothing Tip #3 Data Sheet

How to Save Time and Money with Combination Cutting Tools

Combination cutting tools from DATRON save time through their ability to perform multiple functions with one milling tool.

So, you’re cranking out parts on your machine at a steady rate. The orders are being filled and the boss is happy. Life is good.

But, if you’re like me, you’re still agonizing over the seconds that could be saved. I’ve talked before about the benefits of Dynamic settings to decrease cycle time and increase surface finish quality, but then what? One surefire way to save some time in your process is to decrease tool changes. After you’ve organized the order of your operations to minimize tool changes, things have improved, but what if we could exchange two tools in place of one? Well, luckily, DATRON has the same thing in mind.

Combination Cutting Tool – DATRON Milling Thread Mill

Combination cutting tool that combines milling of holes with threading those holes in a single action with not tool change required.
Combination cutting tool for milling and threading holes.

Meet the Milling Thread Mill. The name may sound redundant, but there is a big reason why. Before the outer flutes take care of the task of cutting the threads, the three flutes at the tip remove all the material in your way. By comparison to standard thread milling, this not only saves you the time of changing the tool from a drill/mill to a thread milling tool, but also the time spent removing that material in the first place.

A combination cutting tool made by DATRON mills holes and threads them in one pass, thereby eliminating a tool change and time associated with drilling holes with one tool and threading them with another.
A combination cutting tool from DATRON cut the hole and thread it in a single pass.

Consider this: This piece above, for example, has ten M6x1.00 threaded holes. Using a 3 mm single flute end mill and a M5-10 thread mill, it is taken care of in 3 minutes and 20 seconds. However, the same part done with the Milling Thread Mill blasts through in just 1 minute and 11 seconds. That’s 20 seconds a hole versus 7 seconds a hole, a 65% improvement! Apply that to your thread-heavy application and you’re looking at a considerable benefit in the long term (especially if you’re hand threading after the fact!).

Not to mention that since you’re not using two tools to accomplish one task you’re saving on tooling cost as well as adding useable life onto other tools. It’s a win-win. Now watch it in action:

Combination Cutting Tool Video (Milling and Threading Holes)

Combination Cutting Tool – DATRON Milling Countersink Tool

Combination cutting tool for producing holes and countersinks at the same time without a tool change.
Combination cutting tool for milling and countersinking in one process … without a tool change!

This combination tool is well suited to front panel applications, but is also handy elsewhere. When many holes need a countersink, this tool combines both operations into one quick operation. With a single flute end mill at the tip and a single angled flute at the shoulder, both operations can be taken care of quickly. It is not limited to just countersinking however, as you can also use it as a chamfer tool to de-burr edges or mill appealing bevels.

Combination cutting tool for milling holes and a countersink in one action to eliminate the need for a tool change which saves time and money.
These holes and the countersinks were made with a single combination cutting tool.

For example; This simple part has 5 countersunk holes and a chamfered perimeter. When cut the typical way, a 3mm single flute end mill clears out the holes, while a 45 degree countersink takes care of the rest. This is accomplished in 1 minute 22 seconds.

When using the combination mill though, the holes and countersink are created at the same time, and the perimeter is beveled without the need for a tool change. Thanks to this small change the cycle time improves the 45 seconds, which is about 45% quicker than before.

So next time you find yourself chasing down seconds, take a look at DATRON tooling, and you might end up saving minutes.

Learn More: Download the DATRON Cutting Tool Catalog:

Cycle Time vs. Surface Finish

Cycle Time vs Surface Finish in CNC milling is a never-ending consideration for machinists and this blog sheds light on dynamics as the means of balancing the two.
Cycle Time Vs. Surface Finish is a deliberation encountered by machinists every time they use a milling machine or machining center to produce a new part. This blog discusses dynamics as a means of balancing the two when using a DATRON high speed CNC milling machine.
The never-ending deliberation … Cycle Time Vs. Surface Finish

For most machinists, it’s a constant quandary, cycle time vs. surface finish? Do I optimize for a perfect surface finish or a minimized cycle time? I know I’ve personally spent hours of programming time in order to shave off precious seconds of cycle time. The reality is that in this day and age, you probably can’t completely sacrifice one for the other (cycle time vs. surface finish) because demand will always be high for both. So, if you’re like me, you’ll ramp up the feed rate, organize the tool changes, minimize retract height and optimize the cut path … and that’s gotten you close … but not close enough. So now what?

Well, good news … dynamics is here!

Ok that may sound a bit boisterous, but there’s good reason for the excitement. To understand why, you have to understand dynamics and we feel that our good friends over at CNCCookbook do a great job of explaining when they say:

“The ability to control the machine’s contour dynamics is a bit like the ride control on a modern high performance car’s suspension: do you want a comfortable ride, sporty, or full race?”

I like to think of it switching from a jackhammer to an exacto-knife, but you get the idea. There’s three main parameters at play in a dynamics adjustment:

Circle resolution: The fineness of movements in an arc.

Acceleration: The change of velocity over time.

Jerk: The rate of change of acceleration.

So using a DATRON high speed milling machine as an example – dialing down these values in Dynamic 1 within the control software, we get the most precise movements with the most gentle acceleration ramp, which leads to the best surface finish possible. First, however, you need to rough out that part and this is where Dynamic 5 shines. At over 4 times greater values than in Dynamic 1, the time advantage you can gain is significant.

I’ll illustrate the range between Dynamic 1 and Dynamic 5 by milling the part below.

Cycle Time vs Surface Finish balanced using dynamics settings in the CNC machine program to achieve optimal results.
Aluminum part programmed to illustrate the difference between dynamics settings.

On Dynamic 1 you can mill one of these parts every 8 minutes 40 seconds Not bad, but on Dynamic 5, each part is milled in 6 minutes 3 seconds. In both instances, the spindle speed is 40,000 RPM and the feed rates are 4 m/min. with a 6mm single flute end mill and 3 m/min. with a 3mm single flute end mill. So the only variable is the Dynamic setting.

What is really great is that unlike the more time consuming portions of program optimization, adjusting these settings is as simple as typing “dynamics” in your editor and selecting 1-5.

So, if you’re perplexed by the cycle time vs. surface finish dilemma it’s time to consider Dynamics. Dial it in and enjoy the best possible of both worlds.