FAQ

This is a list of common questions that people have regarding Flashcut CNC's products. It contains both support and pre-sales questions. If there is a question that you think should be on here, feel free to submit your question to support@flashcutcnc.com


How can I run a part multiple times without using the keyboard?

Customers who are looking to run a part multiple times without using a key board may choose to wire a switch into their Flashcut CNC Signal Generator’s Input Lines. This switch can be used to trigger the start of a program as long as the following occur:

  • The switch’s function must be defined as a ‘Start’ Input Line in the Configuration > I/O > Input Lines Configuration Panel.
  • The G-Code file of the part meant to be run repeatedly must be loaded.
  • An M30 command, which resets a G-Code file, must be added to the end of the G-Code file that is meant to be run repeatedly.

How can I make my system run smoother?

There are hardware changes that can be made to make a system run smoother:

  • If you are using a stepper system, check the amount of current being supplied to the drives modules inside the motor drive box (with the box powered off and unplugged). Turning down the current supplied to each drive could reduce machine vibration at resonant speeds.
  • A half stepping system can be replaced with a microstepping or a servo system, which can make finer machine movements, smoother motion, and a reduction in machining marks on a finished part.

There also software settings that can be changed to help give smoother machine motion:

  • If you see your machine ramping down between feedrate moves, you can increase the Continuous Contouring Feedrate Tolerance on the Configuration > Machine > Feedrate/Ramping Configuration Panel. For more information on the Continuous Contouring Feedrate Tolerance, please see the Flashcut CNC User’s Guide.
  • If you believe that the computer running your machine has poor graphics capabilities, you can increase your General and Jog Buffer times on the Configuration > System > Communications Configuration Panel to optimize machine performance For more information on the General and Jog Buffers, please see the Flashcut CNC User’s Guide.
  • If you see your machine stutter at higher speeds, you can increase the DRO and Viewport Display Update Periods (to 1.0 and 0.2 seconds, respectively) on the Configuration > System > Performance Configuration Panel. For more information on the DRO and Viewport Display Update Periods, please see the Flashcut CNC User’s Guide.
  • If you believe that your machine is cutting poorly during angled or contoured moves, you can increase the Timing Factor on the Configuration>>System>>Performance Configuration Panel. For more information on the Timing Factor, please see the Flashcut CNC User’s Guide.

What is the difference between 2D, 2 _D and 3D contouring?

Working in two dimensions (2D) means that you are cutting out a part with features that are all at the same depth. This is common for laser, hot-wire, water jet, and plasma cutting, along with engraving. The Flashcut CNC software’s DXF Import feature automates the creation of a tool path from a 2D DXF file.

Working in two and a half dimensions (2 ½ D) means you are cutting a part that has multiple flat features at varying depths. During a 2 ½ D cutting process, the Z axis positions itself to a depth where the X and Y axes interpolate to cut a feature. The Z axis then retracts so the X and Y axes can move to the start point of the next feature, which may be cut at a different Z depth than the last feature. Most simple CAM programs deal with 2 1/2 D parts.

Working in three dimensions (3D) means that you have the ability to control at least three axes simultaneously. 3D contouring can then be accomplished by creating curves that use all three axes at once, like in a helical cut. You will most often need a full CAM program to create g-code files capable of performing 3D contouring.

Customers also have the option of using more than three axes in 3D part creation. 4th Axis milling usually describes situations where a rotary table is involved in the cutting process in addition to the X, Y and Z axes. The 4th axis can be used for full contouring with other axes, indexing, or flipping a part over. You will most often need a CAM program equipped with 4th axis capabilities to create a tool path for any part you plan on cutting using a rotary table.


How can you do real time control in Windows?

By design, Windows is a multitasking operating system that constantly services multiple programs and peripherals in time slices on the millisecond level. Real time motion controllers like Flashcut CNC, however, require a dedicated clock that is accurate on the microsecond level. Windows is therefore not capable of outputting the timing necessary for real-time motion control by itself.

The Flashcut CNC architecture uses Windows for what it does well, i.e. a great user interface and graphic display of the tool path, but passes all of the real time information through a buffer to the signal generator. The signal generator has its own dedicated microprocessors that do nothing but orchestrate motor movement for multiple axes and control the I/O signals to and from multiple devices on the microsecond level.


What are the Tolerances of your Mills?

The tolerances of our machines vary depending on their application and use of backlash compensation, but listed below are some fairly accurate numbers for you:

  • Mill 2000 and 5400 +/- .001" to .003"
  • Mill 3000 +/- .001" to .002"
  • Mill 7300 and 8300 +/- .00075" to .0015"
  • Mill 9000 and 9100 +/- .0005" to .001"

Some customers have achieved even tighter tolerances by using our backlash compensation and by properly maintaining their machine.


What is Microstepping?

Microstepping is a motion control method that can help customers achieve very smooth cuts while still using stepper motor technology. The greatest advantages of microstepping include solving noise and resonance problems, and in some cases increasing step accuracy and tool positioning resolution. As a result, microstepping can even help minimize tool marks on the finished part.

Microstepping uses special drives in conjunction with standard stepper motors to produce these results. These drives are able to move the magnetic pulses of a stepper motor more smoothly than in full or half stepping drive modes. With the Flashcut CNC microstepping technology, the number of steps per motor revolution (typically 200 or 400 for full/half stepping drives), can be increased to 1000, 2000 and 12,800 steps per revolution.


What is the difference between stepper and servo?

Stepper motor control is the most cost-effective way to control a machine tool. The accuracy is exceptional, and the price is very reasonable. The only limitation is that the maximum speeds for rapid and cutting moves are not as high as for servo control.

Servo control uses feedback from an encoder to constantly monitor the machine tool’s exact position. Using the feedback signals, the control system can achieve very high speeds and exceptional accuracy, even under very strenuous conditions. A servo motor essentially has the ability to correct itself it is ever out of position.

The difference between stepper and servo control can be explained using the analogy of walking through your home in the dark. You know how to get from place to place, but you go move slowly because you don't want to lose your position and bump into a wall. This is like a stepper motor. If you instead turned the light on, you walk much faster because you are getting constant feedback from your eyes with respect to where you are. This is like a servo motor.


How do I switch the motors off so that I can easily turn them by hand for
manual use?

Turning off the motor drive box is the simplest and easiest way to enable you to run your motors manually, though at higher manual speeds you may experience a small amount of resistance from back EMF.

To eliminate EMF resistance during manual movement, you may disconnect the motors from the drive box while the drive box switched OFF. Please note that disconnecting motors from the drive box while it is switched ON may damage components inside the motor drive box.


How do I configure the Flashcut CNC software for a Rack and Pinion or other drive mechanism?

Use the equation below to find the Screw Thread equivalent for your Rack and Pinion drive mechanism:

Screw Thread = Rack teeth per unit length / Pinion Teeth

For example, if you have a 20 tooth pinion and a rack with 5 teeth per inch, you would find your mechanism’s “screw thread” to be 0.25 (screw rev/inch). In the Mechanics Settings portion of the Configuration Menu, enter the value that you found using the above equation for the Screw Thread field of that mechanism.

If you have a gear train or pulley between the pinion and your drive motor, put the pulley ratio of this mechanism into the Gear Ratio field. For example, if your motor has a 10 tooth pulley that drives a 20 tooth pulley using a belt, the Gear Ratio would be 2 (motor rev/screw rev).

For other types of drive mechanisms, enter the number of motor turns per unit length traveled by the axis.


How do I change my configuration’s units from inches to millimeters?

A setup file with English units (in) can be converted to metric units (mm) using the methodology described below:

  1. Open the Setup File that currently runs your machine properly by going to File > Open Setup on the Flashcut CNC Main Screen. This file may already be open if you have been running your machine recently.
  2. Go to the Configuration > System > General Configuration Panel and switch the System Units from English (inch) to Metric (mm). This will change the units throughout the Flashcut CNC software from inches to millimeters, but will not convert values.
  3. Using the tree on the left side of the Configuration Dialog Box, go to the Mechanics Configuration Panel. Divide each of the Screw Threads by 25.4. Multiply the Axis Lengths and Backlash by 25.4.
  4. Using the tree on the left side of the Configuration Dialog Box, navigate through each individual setting in the Configuration Panels and multiply each value with (mm) or (mm/min) as the unit by 24.5.
  5. Go to File > Save Setup As on the Flashcut CNC Main Screen in order to save your new configurations settings in a different Setup File. You may want to give this new Setup File a distinctive name like “METRIC Version.STP,” or something along those lines so that you do not confuse your new metric configuration with your original one.
  6. You can now easily switch between inches as millimeters as your units by opening the setup file that corresponds to the units that you would like to use.

How do I contact Support?

Flashcut CNC Support

Phone: (847)940-9305
Fax:(847)940-9315
Email: support@flashcutcnc.com