This board is ideal if you are mounting a 3D printer and you do not want to complicate your life.
It is the natural evolution of the Arduino Mega + RAMPS 1.4 SB. A solution with all the integrated components.
With this plate you’ll save having to buy the Arduino Mega 2560, plus 1.4 RAMPS, and having to connect a pair of drivers for step by step motors.
With OVM20 you have everything in one board.
For the Marlin firmware, the board is a RAMPS 1.4. The pins and connectors coincide precisely, and are 100% compatible
Download the Marlin, and select the plate
# define BOARD_RAMPS_14_EFB
It’s the setup that comes by default.
With this you can configure the Marlin as if it was a RAMPS 1.4 with an extruder, a layer fan, and a warm bed.
Static boards philosophy is to select the quality components. That’s why both the power connectors and the transistors are branded.
Selected to withstand hours of continuous printing, without having to worry that the connectors melt, burn, and have an accident.
This product will solve many problems if you are thinking of setting up a printer from scratch.
Or in case in which your old electronics have been burned, and you’re looking for a definitive solution.
- Design 100% compatible with Arduino Mega 2560 + RAMPS 1.4
- 100% compatible with Marlin firmware versions
- Based on the Atmega 2560 micro of 8-bit
- Compatible with all available LCD screens for 1.4 RAMPS
- Molex power connectors, designed to withstand the necessary current
- Support for 1 extruder
- Support for 1 hot bed
- STP200N3LL MOSFETs transistors rated for 120A
- Ultra-low resistance MOSFETs (barely heated after hours of use)
- Additional MOSFET for layer fan (controlled by Marlin)
- 2 additional connectors for extruder fan and for extra fan
- 4 DRV8825 integrated drivers for bipolar stepper motors
- Special design to improve the heat dissipation of the drivers in the plate
- Double connector for the Z-axis motor (not need to solder additional connectors)
- 1 single turn potentiometer (easier to calibrate)
- Manufactured in 4 copper layers
- Branded Linear Voltage Regulator
- General filtering capacitor with 820uF
- Connector for two thermistors, with additional 10uF capacitor filtering
- Includes the popular CH340g chip to connect the USB serial port
- Micro usb connector for easy access
- Side reset button (does not protrude from the board)
- Quartz clock (Best Precision at 16Mhz)
- Protection flyback diodes in hot bed, extruder and hood fan
- Supports maximum 12V input voltage
- It includes black anodized aluminum heat sinks
- Black design with blue LEDs
Dimensions for the OVm20 Lite
Frequently Asked Questions
Why is it called OVM20?
OVM20 comes from the Galician expression Otra vaca no millo, which translates as another cow in the cornfield.
The reason I put in the 20 comes from long time ago, I designed a similar plate, which has served as inspiration for this version.
Does it include heatsinks for the drivers?
Yes, the board has black anodized aluminum heat sinks
How many micro steps do the drivers have?
To simplify the design, the drivers are configured for 32 micro stepping.
I have a new version of Marlin. Will I work with the OVM2o?
Definitely. The OVM20 is the same as a RAMPS 1.4
Can I connect an additional fan?
The board has two 12V outputs for additional fans (or whatever you need).
What are auxiliary pins for?
There is a 6-pin block that is used to program the atmega2560 the first time. It is what is called ICSP, and if you are a hacker, you can use it for many things.
The other block has UART communication, which you can use to connect in remote (I do not know if it would work with a Bluetooth, you have to try it).
You also have an I2C output to connect a device such as colored LEDs.
Can I use the OVM20 to mount a CNC?
If possible. Marlin understands GCODE commands, and you can use the board to move engines and light a drill.
Can I use the OVM20 with 24V?
It’s not possible. The LDO controller does not withstand so much drop from 24V to 5V and overheats. In addition, the capacitors are 16V
What are the values to calibrate the drivers?
To calibrate the drivers, there is no exact value. It depends on many factors. If the printer is a Prusa, if you use bearings well lubricated, the weight of the extruder, and the speed of printing, etc.
The values of the OVM20 Lite are set so that the reference voltage of the potentiometer goes from 0 to 0.76V.
The formula is current = 4 * Reference voltage.
So if you put the potentiometer in half, the formula would be 0.76 / 2 * 4 = 1.52A, which is a normal value for a driver.
I leave here a table that can serve as reference (if for example, you set up many OVM20 lite at once).
If the engine gets very hot, turn the power off by turning the potentiometer.
And if you lose footsteps, then get on a little bit more. Simple.
The more you lower it, the better. The more you raise it, the more the driver will warm up.
And you do not want a hot driver. Driver life will be shorter, and you will have to change boards (or motors) sooner.
Check to see if you can better lubricate the bearings, or if you can lower the weight of the machine so that the motors do not have to push so much.
The computer asks me for drivers for the serial port CH340
In general, Windows should install it automatically, as soon as you connect the OVM20
But if you have problems, here is the link of the original drivers: http://www.wch.cn/download/CH341SER_ZIP.html