search

DerAndere1 / Marlin

Optimized firmware for RepRap 3D printers based on the Arduino platform. The branch Marlin2ForPipetBot is optimized firmware for cartesian robots (lab robots, also known as liquid handling robots or pipetting robots)
https://derandere.gitlab.io/pipetbot-a8
GNU General Public License v3.0
53 stars 20 forks source link

5-Axis really required on Foam Cutter?[FR] (feature summary) #67

Closed ABLomas closed 3 months ago

ABLomas commented 1 year ago

Is your feature request related to a problem? Please describe.

No response

Are you looking for hardware support?

No response

Describe the feature you want

There are many 4-axis boards (at least on definition - creality 1.x series (AVR), MKS E3 and so on, so on) - on paper they look like perfect candidate for foam cutter. But in reality code requires 5 axis, one of them is unused. I tried to add fake definitions for mks robin e3 - a bit too many checks, can't even select the same pins for "fake axis".

There is another issue with endstops - foam cutters work perfectly without any homing endstops. Still, code requires some axis min/max definitions (this one needs more testing, may be related to my (poor) 5-axis hack).

While second one is related to safety - first one is clearly artificial. Can we get rid of this requirement?

Additional context

No response

DerAndere1 commented 1 year ago

It would be great if someone could prepare a pull request targeting upstream Marlin to compile without Y or Z axis. But it is a tedious task. For now much easier is to define a fake Z axis. You can have a look at my FOAMCUTTER_XYUV pull request to see how it can be done: https://github.com/MarlinFirmware/Marlin/commit/b06e378703d9046b01c24d73bfb647b08517a91f

DerAndere1 commented 1 year ago

My last answer was a bit incomplete. The default foamcutter example config for RAMPS relies on Marlins implicit pin-redifinitions. If I remember correctly, current Marlin redefines unused extruder pins as I axis STEP/DIR/ENAABLE pins. The following is a more general approach for a fake Z axis:

  1. identify one or more free pin(s) that can be configured as an output pin, e.g. pin 36 in the case of the RAMPS - based foamcutter by rcKeith.
  2. In your motherboard's pins_YOUR_MOTHERBOARD.h file, change the Z_ENABLE_PIN, Z_STEP_PIN, Z_DIR_PIN to that free pin:
#define Z_ENABLE_PIN 36
#define Z_STEP_PIN 36
#define Z_DIR_PIN 36
  1. Change the Z stop pins to -1: 
    #define Z_MAX_PIN -1
#define Z_MIN_PIN -1
ABLomas commented 1 year ago

Yes, i did all this (on 32b board, too), this is simply additional job which is required to fool some checks, which are not required in first place ;-) (btw, working good so far)