Use the MKS Gen L Boards for CNC Foam Cutting
The MKS Gen L board is an Arduino Mega 2560 and RAMPS integrated into one unit, which in itself isn’t a big deal. However, a few features on the board make it an attractive alternative.
The latest firmware works on both versions of the MKS Gen L boards, the V 1.0 and V2.0, as well as the Arduino Mega 2560 with a RAMPS board. I consolidated the firmware in March 2024, so all boards use the same limit pins for the A-axis.
Why use the MKS Gen L Boards?
The two main reasons I believe it may be a good choice for foam cutting are that it can run at 24 Volts and uses external drivers with bigger stepper motors.
24 Volts
A few builders have built machines with carriages over 1 meter or 39 inches apart. Some have struggled to get the wire hot enough. The D8 connector on the RAMPS board works from a 12-volt power supply only.
The MKS board can operate at 12 or 24 volts. Using 24 volts solves the problem of the long wire not heating up enough. I use 24 volts even though my wire is 800mm but I did get good results on the RAMPS board at 12 volts at this length with 0.4mm nichrome wire.
External Drivers
You can use external drivers as the board provides connectors to take the step and direction signals to external drivers. This would allow you to use much bigger stepper motors like the NEMA23.
If you use onboard drivers like the A4988 or the DRV8825, these can only support at most 2 Amps in a burst. Generally, they run best at 1.5 Amps or less with NEMA17 stepper motors
If you build the foam cutter on this site, it doesn’t need NEMA23 or bigger stepper motors. But if you have some available, you can connect them with suitable external drivers. I also used the MKS Gen L V1.0 to convert my CNC Router from a parallel port connection to USB. I’m upgrading the CNC Router again to a bigger size and using the MKS Tinybee 32-bit controller for some extra features. This is physically the same size as the MKS Gen L boards.
Detailed electronics build guide for the MKS Gen L V1 and V2
Follow this link Electronics Build Guide MKS Gen L V1 and V2 for a step-by-step guide to the electronics build
Using external stepper drivers
This is one of the advantages of the MKS board. You can do this with the RAMPS board by not fitting the onboard drivers and inserting wires into the sockets, but it’s a bit messy, and you will need 2 power supplies. The RAMPS board requires 12 Volts, and most external stepper drives work on 24 Volts or higher.
| Qty | Image | Description |
| 1 |  | 4 x Drivers Modules such as TB6560 or TB6600. Similar drivers can be used as well. See the section on External Drivers |
| 1 |  | MKS Gen L V1.0 Board |
| 4 |  | 57BYGH56-401A or similar. |
 | Self-Adjustable Ratchet Wire Crimping Tool with 1900 Wire Terminal Crimp Connectors |
Which external stepper drivers should I use?
There are quite a few to choose from, but like the onboard drivers, you need to make sure the driver can supply the current for stepper motors. Popular choices are the TB6560, TB6600, DM542 and the Gecko drivers. The main differences are current capacity and price. If you search the Internet, you’ll find good and bad user experiences with the cheaper drivers. I ran my old foam cutter using the TB6560 all-in-one controller was 100% reliable. So my advice to you is to buy the best you can afford with a good returns policy.
Connecting the drivers to the MKS board
I ordered some NEMA17 4 to 6 ping cables to connect to the external connectors to take the enable, step, direction and ground pin to the TB6560 drivers. I cut off and discarded the 6-pin connector and then used some ferrules and a crimping tool to make the 4 connections. I connected each one as the wiring diagram below.
Before you connect any power, we need to set the current to match the stepper motor. On most external drivers, DIP switches are used. My NEMA23 stepper motors are rated a 2.8 Amps, so I’ve set the DIP switches to 2.6 Amps and 1/8 micro-stepping.
The EN-, CW- and CLK- pins on the TB6560 need to be bridged and connected to GND on the drivers to make them work.
On the TB6600 and the DM542, you will probably need to leave the EN- and EN+ disconnected. I don’t have these drivers but a couple of builders have confirmed this.
Connecting the Stepper Motors
Most stepper motors used for hobbyist projects are usually 4-wire bipolar. Connecting is quite simple, just find the pairs and connect them into A-A+ and B-B+. It doesn’t matter which pairs go to A or B but keep them all the same. The only effect it has is the direction of rotation. We can change this in settings on the Windows controller program later if needed.
You can find the pairs very simply. Just hold two wires together so they are connected, and turn the motor. If you feel resistance, then that is a pair. If it turns very freely, then try another wire. Then make a note of the colours of each pair. Quite often, the manufacturer will give the colour codes for each pair.
A common colour code for pairs is GREEN/BLACK and RED/BLUE. But check as above to make sure they are pairs.
Power Supply
If you are using internal drivers and want to use 24 volts for the hot wire, then you don’t need a big current power supply. Using the DRV8825 or the A4988 if you can use up to 2A for each, the MKS will take around 1A, and the hotwire will at most need 3-4A then we have a total of 13A. So a 15A power supply will be fine. Remember, the drivers won’t be drawing maximum current, and if your build is very smooth in operation with no binding, it will probably never hit 2A.
For external drivers, it’s the same procedure. My motors are 2.8A so that’s a total of 16.2A with 1A for the MKS board and 3-4A for the hot wire. So a 20A power supply will be fine for this.
If you are unsure, going for a bigger 24 Volt power supply won’t hurt; it will just cost a little more.
Summary
Hopefully, following this post and the e-book, you have your MKS Gen L board working now. Check the videos as well, where I go through it all, calibration and homing in Part 2.
If you have any issues, please double-check all your connections and software settings. If that doesn’t help, then drop me a line via the contact page and I’ll do my best to help you out. I always respond to emails and YouTube comments.
