Talk:RAMPS 1.4
In the Power Supply With/without diode sections, you mean D1 right? — Weasel 05:22, 4 December 2011 (UTC)
Contents
power terminal
The leads of the power terminal push against MEGA's power supply socket. You can't really fit the boards together
And did it really have to be SMT? -- Soleld 12:13, 13 March 2012 (UTC)
D1 D2 Diode
The information entered is confusing, please add a picture representing all three configurations I.E. D1 with D2 / NO D1 with D2 / D1 with no D2 / NO D1 with NO D@
(a better design for this should be made to prevent damage to electronics)
Wiring BlueTooth
I think there is a mistake in the picture : http://www.reprap.org/wiki/File:BT_Connection_RAMPS1.4.png The two resistor should be connected between GND and +5V and not with RxD.
would you like to add this link http://www.reprap.org/wiki/Jy-mcu to the bt discussion on page?
would you like to add this link http://www.reprap.org/wiki/Jy-mcu to the bt discussion on page?
http://www.reprap.org/wiki/Jy-mcu
it allows the arduino to directly setup the bt device in most cases.
The Picture of a fully loaded Ramps 1.4 is missing
The Picture is missing of the Ramps 1.4 board with all of the stepper drivers fitted unless I missed seeing it..?
There are text warnings on the cct diagram about plugging the step-stick/Pololu drivers in the right way round but not one single picture showing "Them plugged in the right way round"
The jumper selector section is wrong
The jumper section for drivers is wrong - it can vary for drivers, like DRV8825. Section should mention this.
Small heatsink suggested for Q3 (heatbed MOSFET)
I strongly recommend using a small heatsink for Q3, the MOSFET used for the heatbed. This is because it carries heavy current when On i.e. up to 10A. From the data sheet, we have the resistance of the junction when the transistor is On = 0.015 Ohm. This gives us the power dissipation: P = i^2 * R or 100 * 0.015 = 1.5W and we can calculate the temperature rise of the transistor using the thermal resistance of the TO-220 case to ambient air again from the datasheet:
This leads us to the conclusion that the Q3 transistor without a heatsink will reach temperatures above 100C while the heatbed is heating up. With even a small heatsink, the transistor's temperature will remain in a safe zone below 65C.
In other words, it's a good idea to add a $0.10 heatsink to Q3 on the RAMPS 1.4 board for your RepRap.
