1 Topic by agentsmith (edited by agentsmith 2013-09-17 23:31:50)

  • agentsmith
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  • From: Dublin, Ireland
  • Registered: 2013-06-14
  • Posts: 94

Topic: Protecting the printer through limit switches

Hi guys,
Unfortunately when calibrating the heated bed with the paper method it is almost too easy to input a wrong manual command and crash the extruder into the bed. It seems that the limit switches are there just to allow XYZ calibration and nothing more. They are not limiting the movements past the axis ends.
Sometimes the "cold extrusion prevented" message appears when attempting to go over the axis end and the limit switches is tripped but it is not 100% woking.
I'm running Marlin 1.0.0  Last Updated: Jul  8 2013 16:47:04 | Author: Lawsy/Rincewind/Tealvince/Adrian Compiled: Jul  8 2013

I see there is a software function in Marlin firmware that is disabled by default. 

#define min_software_endstops false //{SD Patch} //If true, axis won't move to coordinates less than HOME_POS.
#define max_software_endstops false //{SD Patch} //If true, axis won't move to coordinates greater than the defined lengths below.

In order to enforce limit switches to stop movements past axis end shall I turn it on, compile and flash?
Is it possible to add additional three switches, so to have two switches per axis, to the Sanguinololu board?
Which part of the Marlin firmware configuration should get enabled/ modified?

IMHO Solidoodle should ship the machine with 6 limit switches and protection enabled...

Thanks!
Nick