Hello, I'll be building my first printer based on coreXY, the arduino uno 328p and teacup firmware. Here's my connections that I planned:
0 Rx serial
1 Tx serial
2 X Axis Stepper Direction
3 ~ Y Axis Stepper Direction
4 Z Axis Direction
5 ~ X Axis Stepper Step
6 ~ Y Axis Stepper Step
7 Z Axis Stepper Step
8 Extruder Stepper Step
9 ~ Extruder Heater
10 ~ Heat Bed
11 ~ X Axis Min End stop
12 Y Axis Min End stop
13 Z Axis Min End stop
A0 Heat Bed Thermistor
A1 Extruder Thermistor
A2 X Axis Stepper Enable
A3 Y Axis Stepper Enable
A4 Z Axis Stepper Enable
A5 Extruder Stepper Enable
As some of you may have already noticed, I omitted the direction control for the extruder stepper as I feel it's unnecessary to retract the filament and as I read recently that it's no longer supported by the firmware I guess, do I really need to connect it to the arduino or can I hardwire it to the "extruding" direction ? I also need to know if I omitt it, how do I adapt that to the code ?
Next is the Z axis, stepper motors are expensive here in Egypt, so I decided to use a single NEMA17 2Kg.cm motor for the Z axis with a pully system or a threaded rod. Lead and ball screws are expensive too, I'll manage the backlash with two nuts with a spring in between. Also two smooth rods to move on. Is that sufficient ?
For the CoreXY system, I would like to know how to configure the code for it, I know it's possible with logic gates but that would be too troublesome. I'll use aluminum extrusion bars for the CoreXY frame, 4 smooth rods (2 per axis), 4 linear bearings (2 per axis), 2 idler pullies, 2 GT2 drive pullies, 6 toothed idler pullies, GT2 belt, 2 NEMA17 2Kg.cm motors.
I'll use an adjustable opto endstop for the Z axis and mechanical endstops for the X and Y.
Any further suggestions are highly appreciated.
