Creality Upgrades for CTC A10s Electronics Enclosure V2 (Stand Alone)

Having a new appreciation for silent 3D printers, I've decided to replace the Anet v1.5 mainboard that came with my CTC A10s with a Creality 32-bit board with silent stepper motor drivers (V4.2.7).

My first inclination was to add standoffs to the base model for the Creality board, leaving the corner standoffs for the Anet board so that the lengthy base print could be avoided for those who are upgrading their CTC with a Creality board.  After contemplating potential interference by including both sets of mounting points, I decided to keep the Creality version a separate model completely and post it here as a remix.  I'm still using the design for the lid, fan mount, foot extenders, enclosure brackets and PSU brackets from the CTC design, but have included them here as well.

Aside from the altered mainboard mounting locations and face plate, I also changed the hole size for the mounting standoffs from just under 4mm to 3mm to allow for alignment adjustment and to share fasteners with the external mosfet mount.

Notes:  Upgrading the CTC A10s with a Creality Ender 3 32 bit mainboard isn't 100% straight forward, although the task was not nearly as time consuming as I'd expected.

For starters, the CTC uses 3 pin JST connectors for all three end stop switches and both thermisters, while the Ender 3 board uses 2 pin connectors.  None of the three pin connectors for those switches and thermisters use all three pins, so connecting everything up is not a problem so long as you have five 2 pin JST connectors to replace the 3 pin connectors.

The CTC board has two fan headers, one that's always on for the mainboard fan and heatbrake, and the other is controlled via firmware for part cooling.  The Creality board has two wire terminals intended for always on fans, and two firmware controllable headers for parts cooling.  You'll want to connect both the mainboard fan and heatbrake fan to the screw terminals, and parts cooling fan to either of the two PWM headers which, as far as I can tell from probing, are the same signal on either connector.  Be advised that the polarity, for whatever reason, is reversed on the two PWM headers, so you'll have to swap the two wires that plug into that header if you want part cooling to work.

Two problems I fully expected to see and didn't are:

1.  All of the stepper motors worked, and in the correct direction.  There's no standard that everyone uses for wiring NEMA stepper motors.  Nearly every time I've had to add or replace a stepper motor, I've had to rewire it because it's either running in reverse, or it's trying to drive and brake at the same time.

2.  I expected that I'd have to swap out all three end stop switches.  When I bought my CTC in 2019, the Y axis end stop switch came broken, so I ordered a lot of 6 switches for the CR-10 as CTC is not even a real company and getting stock parts… good luck.  Long story short, the little circuit board the switches are on for the CTC is just a pass through with no circuitry and the CTC is just looking for the normally open side to close.  The CR-10 switches have a diode and some kind of resistor network, making use of both the normally open and normally closed contacts I suppose as some sort of failsafe.  Even though the two switches appeared quite similar, they are not interchangeable.  I ended up desoldering the switch from the Creality endstop board and soldering it the CTC board for the Y axis.  I still have those remaining 5 Creality switches but surprisingly didn't have to use them.

Another note:  I was nervous because the 32 bit board clearly says “24VDC” right on it for input voltage.  Looking at the information on Creality's site, they specify 24volts in and 12volts out.  I'm assuming they're referring stepper motor voltage when they say 12volts out because as far as I know, the Ender 3 uses 24volt fans and heating elements.  I was tempted to order a 24volt power supply, but I thought I'd see if it would even boot up with the 12 volt supply I currently have on the machine.  Even though Creality doesn't specify that the (V4.2.7) board will work from 12volts, I'll tell you it does work perfectly.

Yet another note:  When I ordered the Creality board on Amazon I also ordered an Ender 3 display so I'd be able to connect it with one ribbon cable and immediately start testing it with the Ender 3 firmware on the CTC A10s.  I know Marlin supports the old CTC display because I saw it in the generic configuration files, but my old display was in really rough shape and the new display was only 20 bucks.  I made a new display case for the Ender 3 display to go along with this upgrade.  It's available at:  https://www.printables.com/model/551280-ender-3-display-housing-for-cr-10-a10s-etc