How to Design a new CNC RouterBy Youssef Edward
February 25, 2019
Designing a CNC router is not a difficult task if some basics are well understood. those are defined as follow:
1. determine the exact working area of the CNC router. determining the working area is the first step to proceed. this step must be worked correctly and with caution. if the dimensions of the gantry are not correct, the working area ma be as not desired.
2. choose the right CAD software for you. designing the CNC must be on computer and not by hand of course. you must select the most favorite software to choose based on the skills to use it.
3. choose the right sliding and bearing components to use. the bearing blocks and guide rails are the base for building the machine. the chassis and the gantry drills and dimensions depend on those you choose. so be aware of them too much before doing anything. to be aware, you must view the datasheet and dimensions carefully, know how to install them, know how they work internally, and study the parameters such as static load rating to avoid choosing wrong ones.
The slides and bearing components include:
- the rail guide
- the rail bearing
- the ball screw
- the ball screw nut
- the nut support
- the end support
- the couplings
- the gears ( if used).
- the motors.
each of the above must be studied before doing anything. moreover, it must be carefully selected between several choices. for instance, the rail guide have width dimensions of 16,20, and 25 mm. deciding to choose 20 or 25 mm depends upon the loads and the speed of the machine.
4. design the building blocks of the router in 3D manner. designing the blocks in 3D is a major advantage if you want to succeed. this helps avoid errors and see the whole machine as will be produced in reality. this step include two phases:
- Chassis design : this is the base for the machine and the most important one. if properly designed, the whole machine will be stable, and rigid. this is because the machine is prone to vibrations due to tool friction with the workpiece.
- Gantyy Design : this is the moving part of the machine. this is less difficult than the chassis . the most important factor to consider is to avoid large moments to occur while the gantry is moving. this is because some parts tend to rotate due to load from the workpiece. the moment is a function of force and distance. for instance, if the distance between slides on the X axis is too large, momentum generates that tend to rotate the Z axis block. this affect the quality of machining and may reduce the lifetime of the bearing