SP6 CNC Shield V4 Modification
This is my first time working on CNC Shield and related eletronics. I want to make sure I am doing the modfication (4 edits) correctly. Do you think you can share a picture of the backside of the CNC board after the modification? For example, I am not sure how to do Edit 2, Do i just short the four nodes on the right side, and connect the Vcc on the left to the top node on the right using a wire?
Thanks a lot,
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You are getting closer. The RTC tracking is a good sign.
The board is configured for 16X microstepping, so a 200 step motor needs 16 * 200 = 3200 steps per revolution. The SP6 clock has a 15 tooth pinion driving a 54 tooth gear_2 for a ratio of 3.6:1, so the controller needs to receive 3200 * 3.6 = 11520 steps per minute, or 192 steps per second.
The stepper driver should receive pulses with a high time of 2604uS and a low time of 2604uS to equal 192 full steps per second. Your clock should be running properly with 200 step per revolution motors. I am fairly certain that you have 400 step motors.
One quick fix is to change the algorithm to produce twice as many pulses per second, each with half the duration. Open the sketch in the IDE and scroll down to around line 340 and change one of the cases. I recommend changing case 0 so case 3 is left untouched.
Here is the code to replace the original case 0 section:
case 0: // 3.6 RPM for SP6 with 400 step motors
motor_steps = 384; // 3200 * 2 / 60 * 54 / 15 = 384
extra_steps = 0; // no extra steps needed
min_motor_delay = 1245;
max_motor_delay = 1312;
break;
Hope this makes sense