Lowrider 2 with ramps controller

Thanks very much for huge and useful information to everybody here!

I’m a retired mechanical engineer from Istanbul, Turkey and planning to build a “portable cnc” to use even off grid places for my hobbies. Lowrider 2 CNC looks perfect for that, thanks for your efforts and studies for that Ryan!

BTW, making a CNC equipment is new for me and learning basics about that.

I have a question about electronics:

Planning to use Ramps 1.4+ Arduino Mega 2560 + Marlin configuration.

 

As I understand there are two possibility for step motors:

  1. Use three DRV8825 and serial cables for Y and Z axis
  2. Five DRV8825 and dedicate them one by one to 5 nema 17 step motors
What happens to firmware for these possibilities? Should we use different firmwares for these options or how firmware "knows" that how did we use drivers??

 

The second setup is called “dual endstop” and there isn’t preconfigured firmware for the low rider for it. If you wire your motors in serial (which you should), you’ll get plenty of torque for the low rider.

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As I understand:

for 3 drivers and serial connected step motors i should use this firmware (recommended) :

MPCNC_Ramps_T8_16T_LCD_32step

for 5 drivers i should use this:

MPCNC_Ramps_T8_16T_LCD_32step_DualEndstop

right?

First option is much better because you can use other outputs for others like extruder etc…

 

 

 

 

Correct, but the lowrider used dual Z and a single X, that’s why the series firmware works for both. To use dual, you have to edit the stepper settings in the firmware.

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So, both firmware is same except different stepper settings on MPCNC_Ramps_T8_16T_LCD_32step_DualEndstop?

Assuming you wanted dual endstops on the LR (which isn’t as helpful as it seems) and you are willing to home z to zmin, and not zmax, then it’s a few lines of change in the CONFIGURATION_adv.h file. I just pointed John to those changes in his thread:

IMO, dual endstops isn’t terribly useful on the the low rider. The two motors move in lock step when wired in series and it’s easy enough to start them against some hard stops to make sure they start square every time. The LR has a 5 foot gantry so it’s going to be easy to get it square with just a tape measure.

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Than as a novice, I should start with serial connected setup and make some practice first…

That’s what I’d do. It’s well documented from Ryan (the tutorials linked at the top).

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Noting after replying that this is an old topic, but maybe this will help someone in the same situation. I think more and more separately driving the X and Z motors will become the norm.

I have tried both approaches:

  • 3 stepper drivers driving 5 motors (series)
  • 5 stepper drivers driving 5 motors

I would say in terms of effort put into the wiring, they are about the same, so if you have 2 empty driver positions, why not?

The whole “dual-endstop” thing may seem complicated at first, but keep in mind that (a) You don’t need to use dual-endstops to use separate drivers, that is just how Ryan has packaged the firmware. You can still run that firmware without any endstops. (b) that said, separate drivers opens the possibilities with what you can do with independent control; and that includes using dual-endstops for automatic squaring of the x-axis.