How to Install the Gulfcoast Robotics Heated Bed (Ender 3 / 5)

Creality 3D Printers are notorious for having a warped heated bed. The Ender 3 and 5 series have it the worst, with seemingly zero quality control on what reaches the customers. Purchasing a glass plate has become almost a necessity, a band-aid fix to cover up underlying surface problems. With flatness tolerances ranging anywhere from +/- 0.3mm to an upwards of 1.0mm, it’s no surprise that many of these beds are practically unusable.

To address this, we’ll look at how to install the Gulfcoast Robotics Heated Bed Kit. It’s equipped with a precision CNC milled aluminum build plate, powerful 24V silicone heater, and all the conveniences to make it a simple drop-in upgrade.

Disclaimer: I work at Gulfcoast Robotics and have provided feedback in the design of this product. As this is my personal website however, the thoughts and opinions shared here are entirely my own.

Purchased Parts

235x235mm Heated Bed Upgrade - $59.99

Checking Build Plate Flatness

Most of us don’t have the tools needed to measure flatness tolerances, they are expensive. The good news is, there are a couple DIY methods to figure out if your heated bed is warped.

However, testing while it’s installed on the 3D Printer won’t give us accurate results. Tension on the corners from the bed leveling screws can heavily skew the shape. As such, make sure to remove it from the machine before trying these out.

These aren’t perfect tests by any means, but they are quick and dirty checks that anyone can do. For the most part, they will give us a reasonably good idea if the build plate is anything less than flat.

Heated Bed Installation

To get started, we first need to remove the original heated bed. Loosen the thumb wheels until they fall off, then set these and the leveling springs aside. Carefully lift the bed up from the Y axis and place it behind the 3D Printer for now.

Next we need to disconnect the bed from the board. Open the electronics case by removing the (3) hex screws on top, two in the front corners and one in the middle rear. With these out, you can lift the lid and set it aside, taking care not to stress the cooling fan wires.

The bed’s (2) power cables are secured in a clamping terminal block. Using a small flat head screwdriver, loosen both set screws on top until the cables can freely slide out. While we’re in here, we also need to unplug the thermistor, the white 2-pin JST connector (circled below).

Pull the power cables and thermistor wiring out from the back of the Ender 3 to detach the heated bed.

With the original heated bed removed, we can start preparing our replacement for installation.

Flip the build plate over with the bottom side facing up (countersunk holes facing down). At this point, it’s a good idea to clean the surface with isopropyl alcohol, just to remove any greasy fingerprint oils before we attach the heater.

Now position the silicone heater so that the holes match up with the build plate. There is only one correct orientation due to the additional hole for optional 3-point leveling support. Once it’s aligned, peel back the protective 3M adhesive backing and start applying the silicone heater with firm pressure.

After the silicone heater has been mounted, we’re just about ready to install it on our Ender 3 / Ender 5 3D Printer. Before doing so however, we’ll take a quick look at the wiring.

The (2) white cables are for powering the heater. One comes pre-stripped while the other does not. Using wire strippers or a pair of scissors, strip off 1/2 inch of the insulation to match, exposing the wire strands for a solid connection.

At this point, we’re ready to go ahead and start installing the new heated bed. For the sake of clarity, the connections are shown below on an empty board. Run the silicone heater’s power cables and thermistor wiring into the electronics case, routing them through the back of the lower frame.

The (2) white power cables are inserted into the HOTBED terminal block, then clamped down by tightening the set screws on top. In contrast to the original heated bed, there is no polarity with the silicone heater, meaning the cables have no +/- and are interchangeable. Give them a gentle tug to make sure they are properly seated.

The 2-pin JST thermistor connector plugs into the 2nd port from the right labeled THB.

With the silicone heater now wired up, the last step is mounting the heated bed.

As this kit does not come with additional hardware, we’ll reuse the M4x35mm bolts from the original build plate. Depending on the type of print surface it has, you may need to peel this up at the corners to reach them. At this point, everything goes back together the same way it came apart.

In my case, I am also using the Gulfcoast Robotics Y Carriage with a 3-Point leveling configuration. For those with the stock Y Carriage, ignore the center right hole and place a bolt, spring and thumb wheel at each of the 4 corners instead.

After we’ve wrapped up the installation, it’s time to test. Power on the Ender 3 and preheat the bed from the LCD menu. If everything is connected properly, it should start warming up.

Firmware Update

Flashing a firmware update is not necessary to use this product. However, adjusting the TEMP_SENSOR_BED value may offer slight improvements to the temperature readings.

Ender 3 firmware is configured to use a value of “1” (EPCOS) whereas this silicone heater works best with a value of “11” (NTC3950). As these are both 100K thermistors with 4.7K pull-up resistors, they have similar results, but the temperatures reported may be a few degrees off.

In the Marlin firmware Configuration.h file, locate the line “#define TEMP_SENSOR_BED” under the “Thermal Settings”. After this value is changed from “1” to “11”, recompile the firmware and flash it to the board.

//===========================================================================
//============================= Thermal Settings ============================
//===========================================================================
// @section temperature

/**
* --NORMAL IS 4.7kohm PULLUP!-- 1kohm pullup can be used on hotend sensor, using correct resistor and table
*
* Temperature sensors available:
*
*     0 : not used
*     1 : 100k thermistor - best choice for EPCOS 100k (4.7k pullup)
*     2 : 200k thermistor - ATC Semitec 204GT-2 (4.7k pullup)
*     3 : Mendel-parts thermistor (4.7k pullup)
*     4 : 10k thermistor !! do not use it for a hotend. It gives bad resolution at high temp. !!
*     5 : 100K thermistor - ATC Semitec 104GT-2/104NT-4-R025H42G (Used in ParCan, J-Head, and E3D) (4.7k pullup)
*     6 : 100k EPCOS - Not as accurate as table 1 (created using a fluke thermocouple) (4.7k pullup)
*     7 : 100k Honeywell thermistor 135-104LAG-J01 (4.7k pullup)
*     8 : 100k 0603 SMD Vishay NTCS0603E3104FXT (4.7k pullup)
*     9 : 100k GE Sensing AL03006-58.2K-97-G1 (4.7k pullup)
*    10 : 100k RS thermistor 198-961 (4.7k pullup)
*    11 : 100k beta 3950 1% thermistor (Used in Keenovo AC silicone mats and most Wanhao i3 machines) (4.7k pullup)
*    12 : 100k 0603 SMD Vishay NTCS0603E3104FXT (4.7k pullup) (calibrated for Makibox hot bed)
*    13 : 100k Hisens 3950  1% up to 300°C for hotend "Simple ONE " & "Hotend "All In ONE"
*/
#define TEMP_SENSOR_0 1
#define TEMP_SENSOR_BED 1

Further Improvements

For most owners, a precision milled CNC plate with tight flatness tolerances will be more than enough. This solves the biggest problem with Ender 3 and Ender 5 3D Printers, a bowed print surface. We can however take this a step further with other heated bed upgrades.

3-Point Leveling

You might have noticed the Gulfcoast Robotics Heated Bed supports 3-Point bed leveling. This is an entirely optional feature, but one that improves the leveling process as a whole.

Back in grade school, geometry class taught us that a plane is defined by 3 points. So why does almost every 3D Printer come with 4 point leveling? Manufacturers like Creality know their beds are warped, but adding an extra leveling point can force it into a semi-flat, somewhat usable shape.

3-Point Leveling won’t fare well with a warped bed for obvious reasons, but that’s not a problem with this ultra flat build plate. We do however need a compatible Y Carriage plate to take advantage of this feature.

Heated Bed Insulation

The silicone heater preheats faster than the original circuit board heater (PCB), but what if we could speed that up even more, cutting it down to a fraction of the time?

Since heat rises, most of the warmth gets transferred into the build plate, but we can still lose a lot of it from the bottom. By insulating the underside, we can trap the heat and force it to rise as well. This will decrease the duration it takes to reach and maintain temperature.

Corkboard

Cork is a tried and true material for insulating heated beds. It’s cheap, environmentally friendly and withstands temperatures up to 140C. Corkboard tiles average around $1 each and can be mounted using a variety of adhesives.

Foam Foil

A more recent addition to the market, Foam Foil is a decent alternative that’s ready made for 3D Printers. It’s lightweight and heat resistant, plus it comes with a pre-applied adhesive backing. You still have to cut holes for the bed leveling screws, but it’s otherwise ready to use.