Spindles can be split into 2 categories.
These are the typical type of router used by hobbiests for home wood working.
They usually have some sort of speed control and are generally considered powerful enough for wood work.
| Pros | Cons |
|---|---|
| Inexpensive | Noisy |
| Easily available | Poor Maximum life |
| Powerful enough for wood | Not designed for extended use (hours) |
| Low Precision | |
| Low torque at low speeds | |
| Poor speed control |
The speed control on the router can be addressed to allow more fine grained control using a SuperPID but this is expensive.
There are two brands which are usually chosen if going down this route.
These are available in many sizes but generally, only 4 sizes are considered for the home built CNC routers due to the power requirements.
These are:
| Rating | Torque | Collet Size | 120v Current | 240v Current |
|---|---|---|---|---|
| 0.5kW | 0.5Nm | ER11 | 4.5A | 2.25A |
| 0.8kW | 0.3Nm | ER11/16 | 7.2A | 3.6A |
| 1.5kW | 0.6Nm | ER11/16 | 13.6A | 6.8A |
| 2.2kW | 0.875Nm | ER20 | 20A | 10A |
In countries that use 120v, if 240v can be made available, this is a much better route to go down.
The 1.5kW and higher spindles have VFD (variable frequency drive) controllers. These allow for a lot more accurate speed control. They also allow for speed control through gcode. In some cases an adapter such as this one will be required to allow this.
The 120v spindles in the Aliexpress kit come with VFDs that output 3-phase 120v power. This power output is very unique and seems to only be available in the Huanyang and Ylang VFDs. If there is an issue with the 120v kit VFD it can only be replaced with another Huanyang or Ylang VFD.
As of Feb. 4, 2022 there are no name-brand (Teco, WEG, Hitachi etc.) VFDs that output 110v 3-phase power.
The 240v spindles come with VFDs that take 240v input and output 240v 3-phase. If the 250v kit VFD has an issue it can be easily replaced with a name-brand VFD.
Only having 120v power available does not limit you to a 120v spindle and the Huanyang or Ylang VFD.
VFDs are readily available that accept 120v input and produce 240v 3-phase power.
To future-proof your build, it is recommended to select a 240v spindle for the kit, omit the VFD and source a 120v to 240v 3-phase VFD elsewhere.
The collet size is important as it denotes the size of cutter that can be used on the machine.
| Collet Size | Length | Diameter |
|---|---|---|
| ER11 | 18 mm | 11.5 mm |
| ER16 | 27.5 mm | 17 mm |
| ER20 | 31.5 mm | 21 mm |
Pros and cons of spindles
| Pros | Cons |
|---|---|
| Run for longer | more expensive |
| Higher precision | water cooled require a pump |
| more power |
The water cooled spindles run a lot quieter than the air cooled spindles.
Typically, the 0.5kW and 0.8kW spindles come with controllers that only allow for speed control by rotating a control knob. This makes judging the current speed difficult.
As with the routers, controllers such as the SuperPID can be employed but again, it would be worth while spending that money on a higher powered spindle.
https://openbuildspartstore.com/router11/
This style is the most widely used one. And is also part of the standard printnc kit.
Please be advised that any spindle from Vevor is high recommended AGAINST due to the spindles containing incorrect bearings for PrintNC application
The most popular one is: G-penny “metal cutting” 80mm spindle