Replacing A4988 Drivers with DRV8825 on Arduino Mega 2560 + Ramps

[Roxy]

PyramidDave: You might want to bring up the current RCBugFix located here: https://github.com/MarlinFirmware/Marlin/tree/RCBugFix

We have done a number of things to make printing from a USB cable better and more reliable. The version of Marlin that MakerFarm ships is very old.

[PyramidDave]

Last time I tried that, I could not get it to compile, but worked this time. Must have missed something before. Is there a standard Configuration.h file I should start with or should I do a compare using Notepad++ to see what I need to change for my i3v 10"?

[Roxy]

I think you should compare with NotePad++. The reason is, some of the #define names have changed. So you have to manually say "Yes, I want to keep that value..."

[usarmyaircav]

not to derail the topic, but is it worth going to RCBugFix from the standard Makerfarm version if you are not having any issues. Right now I am running a pretty vanilla 10" build.

[Roxy]

If you are happy with your printer, I don't think you need to move. But for sure... RCBugFix is a better platform.

[nissa23]

Some people are lucky and have never met this problem but someday it will bite them in the rear.

[PyramidDave]

I able to print a part that takes up to about an hour and a half before it stops, so am thinking this might be a heat related problem of some sort. I am trying to swap the A4988 drivers with DRV8825's on the Ramps board to see if my problem goes away & the printer is now printing the part what looks like half size. I tried keeping the default steps the same as the A4988's & also doubling them and either way the part prints what appears to be half size. I also noticed the Z axis has a little bit of vibration rattle to it while & X & Y axis movements seem smoother. I have Vref Voltages set to .4 to .42 on the DRV8825's. Is there something else I need to change in the firmware that I am missing or do I also need to change something in Pronterface or Slic3r 1.2.9? The nema 17 motors are type 42bhh48-151K-24B.

Here are the only settings I changed in the Marlin firmware.
//For A4988 drivers
#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,4000,865}
//For DRV8825 drivers
//#define DEFAULT_AXIS_STEPS_PER_UNIT {160,160,8000,1730}

[PyramidDave]

I updated the firmware to the RCBugFix & that seems to have fixed my scale problem. Should be able to tell in a couple of hours whether the DRV8825 drivers fixed my stopping problem.

[PyramidDave]

I tried just changing the stepper drivers to start with. When that failed, I changed all the whole arduino Mega+Ramps. I am at a loss as to what this problem is now. The print stopped about 40 minutes on this last print. I have replaced all the electronics & still have the same problem. I also replaced the P/S with the same Mean Well NES-350-12v. I have checked all the wires & connections, but maybe I have a bad connection somewhere that I missed. I am also using the Marlin RCBugFix firmware.

[PyramidDave]

I have finally resolved where the problem was coming from & just finished a 2hour 47 minute print. I had not gotten past 1 hour 30 minutes before. While doing a 40 minute print this morning I heard the relay switch kick in several time continuously. I then was wondering why that was even kicking in since I have stopped using the heat bed since discovering how well a glue stick on painters tape works. Thinking back on this, I recall hearing that relay kick every once in awhile, but hearing several clicks at one time made me stop & think why it was even kicking in. I had tested this before by disconnecting the relay from the arduino, but had not disconnected the 12volt lines from the P/S & the heat bed. This time I disconnected the relay entirely along with the heat bed connections & heat bed thermistor. I also redid the Marlin firmware turning off the heat bed with setting #define TEMP_SENSOR_BED 0

My LCD display did not go to garbage characters anytime during the print. That has been happening for awhile & I may not have mentioned that since it did not stop the print. I guess the problem could be either the relay switch, the heat bed wiring or the heat bed thermistor. If I need to use the heat bed again I will look at that further. My printer must have seen me order a DIY FolgerTech Kossel today & started giving a bigger clue to the problem. I was going to order another printer anyway. It will be nice to have 2 printers that work.