3 Steps You Need to Know to Cut MDF by CNC Router Machines

MDF is a usual wood material used during woodworking. To learn how to work with is very easy, just follow those steps, you will become more confident during your work.

Step One: learning MDF
Medium-density fibreboard (MDF) is an engineered wood product made by breaking down hardwood or softwood residuals into wood fibers, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure.
MDF is generally denser than plywood. It is made up of separated fibres, but can be used as a building material similar in application to plywood. It is stronger and much denser than particle board.
FYI: Comparing to solid wood and MDF, cutting and engraving on engineered woods like particle board and plywood are more complex. Because wood fibres used during synthetic wood manufacture may not be the same type of woods, and maybe combine other materials, so each part’s hardness are not same.

So I don’t recommend PCD cutters for engineered wood working if you are not sure about the material used in the board, some particle boards and plywood with bad qualities may contain small rocks, wood knots or other very hard stuff which can easily damage the blade of router bits.

Solid carbide double flutes spiral up-cut bits are good choice for MDF cutting. Two large grooves can easily remove chips and keep bits in balance during rotation. They are also high temperature resistant, and tungsten solid carbide can guarantee a long use life. (See the suggested size table in actual use below)

Step Two: Understand the feed rate, RPM and Chip load (with actual data)
Learning working material and choosing suitable MDF cutting router bits are the first step to handle MDF working.
Another important step, is to fully understand the best cutting speed (feed rete), router RPM (revolutions per minute) and how bit’s chip load affect those two.
Cutting speed is the speed difference (relative velocity) between the cutting tool and the surface of the work piece it is operating on.
RPM (revolutions per minute) is the number of turns in one minute.
Chip load refers to the size of the chips produced during cutting. The main purpose is to get the maximum chip load possible, so you can increase productivity, reduce heats of MDF and cutter, and also prevent premature dulling. The chip load is to small means bits will become too hot and dull quicker; chip load is too high means cutters will cause a bad surface finish, and in worse situation, the bits break.
Chip load = Feed Rate / [RPM x number of flutes], this formula shows the relationship between chip load, RMP and feed rate, which can give an estimate figure as your reference.
Each kind of cnc router bits have different chip load, and also cutting different material have different chip load.
For cutting 1.8-1.5cm MDF, N2LX622 with 6mm CED is good enough. N2LX415 is for cutting 1.2-0.7cm MDF, and thickness below 0.7, you can use N2LX3.12.
Here is the suggested figure to cut different thickness of MDF:

Attachment 26934

Normally, we use 18000RPM to cut MDF, but need to adjust feed rate, for example:
Recommended parameter to cut 1.8-1.2cm MDF:
RPM: 18000RPM
Feed Rate: 10-11m/min

Recommended parameter to cut 1-0.7cm MDF:
18000rpm
Feed Rate: 7-8m/min
For other model, please leave a common, I will respond you as soon as possible.

Step Three: Testing
Below is the strategy you might need when testing unfamiliar bits. This works particularly well for routers. Optimizing feed rates and speeds:
Start off using an RPM derived for the chip load for the material being cut.
(18000RPM to cut MDF)
2. To increase the cutting speed (feed rate) by 1m/s a time, until the part’s edge starts to be rough or hold downs is starting to lose control. Then decrease speed by 10%.
3. To decrease when the edge of part starts to be rough, and then bring RPM back up until finish is acceptable.
4. This optimizes RPM and speed to remove the largest possible chips. To reduce the amount of work needed, a range of feeds and speeds is provided to start at (step 1 above). To increase performance, optimize feeds and speeds as detailed above. If there are any surface finish problems, adjust until performance is acceptable. If there are a lot of work holding issues, it may be necessary to revisit the hold down method to ensure it is adequate.