The Beginner’s Guide to Flat Table CNC Machines Or, What to Expect When You’re Expecting a New CNC

Christine Bergeron & Christopher Manclière, Planit Canada

Congratulations on your new CNC! Much like the arrival of a new baby, the delivery of your first Flat Table CNC means you have to become an expert at a whole lot of things very quickly. You may find yourself awake in the middle of the night, frantically Googling what is a controller?”, vacuum optimization,” or what does a CNC operator do?


The first step in knowing how youre going to operate your new baby is to understand how to communicate with it. Rather than adorable baby-talk, your control software will be in charge of reading pre-programmed commands that tell your machine how to execute actions to make a part.


G-Code is a common CNC language, which looks just like a text file that the machine can read and then execute. (Awww! So cute!) Some machines will use proprietary language. The device will only accept the format defined by its controller, and if it doesnt understand a command, it will stop the programs execution and spit up an error message. Less cute.


Creating programs for your CNC, or CNC programming, is done using one of three methods: with a code editor, with CAM software, or with a CAD/CAM software.


The code editor is probably the most tedious way to create a CNC program. It requires you to write the G-code from scratch. While it could be a decent solution for making parts with simple operations, it would involve writing thousands of lines of code to execute complex functions.


To speed things up, you can use CAM software. This method allows you to import or draw a CAD file, and the software will automatically generate the CNC program for you. Youll have a graphic interface allowing you to see your part and verify the machining is correct. Your CNC programmer may need to manually modify operations for each piece before generating the files for the machine.


The third option is the CAD/CAM software which is a fully integrated solution. The same software you use to create your drawing will also generate your CNC program. It will take you from design to manufacturing without requiring the use of 2 or 3 other solutions to create a program for your CNC. Your workflow is simplified, and you wont need complex programming skills.


Now that you can talk to your baby, youll need to set up your spoilboard. You want to be thinking about maximizing the vacuum on your CNC to hold parts and make sure they dont move. Before mounting the LDF or MDF board onto your CNCs permanent table, youll want to ensure youve got flat, even surfaces with four sealed edges. We recommend using two coats of paint to seal the edges and prevent bleeding airflow or losing vacuum at the top of the board.


Your CNC machine will have a surfacing program for flattening the spoilboard, and every member of your team must be familiar with how to use it. Youll need to have the right tool – a spoilboard surfacing cutter with a wide diameter. Remember to enter the new board thickness into the controller after running the program. Once in a while, youll want to flip the spoilboard to prevent warping and to ensure your pump can keep the spoilboard in place.


Understanding how to optimize your CNC vacuum is critical when cutting parts that are smaller than the table. To ensure the vacuum holds your sheet down properly, youll want to use scrap material to cover the space on the table to block airflow.


The decision to screw or not to screw the spoilboard to the permanent table is entirely up to you. If you prefer not to screw the board to the table, make sure that you keep your vacuum rubber seal in good condition and that you clean away the dust between the table and the spoilboard regularly.


Youre now becoming a fantastic CNC parent but will still need to have some essential parts on hand for quick replacement and to avoid the stress of waiting for rush delivery from your provider. Maintenance emergencies for your baby come with a high price tag when you consider lost production, rescheduling technicians, and rushed parts delivery.


Depending on the type of production you have, youll want to consider having: a flycutter to resurface your spoilboard, a compression bit for the outline cut (typically ½” or 3/8″ compression bit), 3mm, 5mm, 8mm, 10mm drills depending on the type of hardware you use, down cut tools with various diameter to create the dados or any other cuts that do not cut through, and mitre bits of various angles. If you are machining MDF doors, youll have a longer list. Make sure you have tool holders with the proper shank diameter for all the tools youll need.


Also, make sure you get the specs from your tool provider to know their speeds and feed rates. You dont want to break them or burn your table if theyre not running fast enough. As you know all too well friction, wood, and vacuum are a terrible mix.


Now, who will care for your new baby while youre doing other things? Your CNC Operator will be up to the task once theyve mastered these essential skills: keeping the machine clean, resurfacing the spoilboard, loading tools, setting the tool length offset and diameters so you can use cutter radius compensation, loading programs onto the device, and of course, doing the daily and weekly maintenance according to your schedule.


Ultimately, you are responsible for maintaining your baby. We strongly suggest having a preventive maintenance plan with tasks your operators can easily do themselves with daily or weekly maintenance to control dust, check hydraulic pressure and fluids, lubricant levels, seals, filters, and keeping tools in good shape. For monthly, quarterly, and yearly maintenance, you may want to hire a mechanic or a CNC technician.


They grow up so fast, dont they?

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