Welcome to HobbyMilling.com. This site will eventually become a useful site with information regarding the construction and purchasing of CNC milling equipment that is suitable for hobby projects. Please check back soon, since this site is just getting started.
CNC machines consist of one of more axis, on which a mechanical piece of hardware is allowed to move. Choosing the number of axis to have for your CNC router or mill is the first, and potentially most important design choice you will need to make.
The next step towards building your router or milling machine is to decide what fundamental type of machine you want to build. This website will primarily focus on 3 axis milling machines which are the most common types of machines for hobbyists. There are two fundamental types of machines; mobile bed and mobile gantry designs.
After you determine the fundamental type and size of the CNC machine you want to build, your next step is to choose linear bearings. Your choice of linear bearings is one of the most important decisions you’ll need to make. Linear bearings are the mechanical devices that allow parts of the CNC machine to slide with little friction, and little backlash. Bearings can be as simple and cheap as simple drawer slides from a hardware store, or bearings can be complex and expensive pillow blocks gliding on stainless steel rods.
Threaded rods vs. ACME rods
There are many methods of accomplishing linear power transmission, otherwise known as linear movement. Anything from a simple wheel, to a gear on a rack, to rubber belts will work. However, for hobby CNC machines, the most common method to accomplish movement is using threaded rods, or ACME rods.
After selecting the threaded rod or ACME screw you intend to use for linear motion, you need a way to effectively connect this rod to a stepper motor such that there is zero slip when the motor is rotating. I’ve found a number of articles about this subject, but I’ve found many of them give inadequate solutions to this simple problem.
Choosing an appropriate stepper motor can be difficult and time consuming. This webpage is intended to help you easily and quickly select a good stepper motor for your project. There is a lot to cover, so consider this the first part in the series
There is a lot of discussion on whether to use bipolar or unipolar stepper motors for your CNC project. Each type of motor has different characteristics, but when all is said and done, the best choice is usually bipolar stepper motors. This article is a short explanation why bipolar stepper motors are usually the better choice.
Choosing an appropriate stepper motor for your CNC project is important. If you choose a motor that is too small, you may experience very slow maximum speeds and torques, and even missed pulses. On the other hand, if you choose a motor which is too big, it may require a powerful and expensive power supply and driver.