filament change

[DarrylPortelli 0]

Hi, 

recently I used the pause at height function to embed a nut into a project and it worked flawlessly first try. 

 

today I tried the filament change function to try a dual color print. 

I had 2 problems : 

 

1. the print stopped at the correct layer, went to home position and retracted the filament well and then after loading the filament it purged the nozzle well --- the problem is that it went to the home position meaning that the nozzle was like 0.1mm from the bed with no space to extrude and purge the nozzle well ... it made a bit of a mess but no harm done ... How can I make the print head move up a bit in the Z direction so that it has some space to purge the nozzle? 

 

2. just as it finished the print for the filament change and it was about to go to home position, it left a bit of a blob on the print ... I think it may be that the stock retraction setting was 30mm on cura, it might need to be -30mm maybe ? 

 

thanks 

[gr5 2,170]

What kind of printer is this?  I think you are going to need to probe this further yourself.  You need to learn to read gcodes.  They are pretty simple.  "G0" and "G1" mean to move the steppers.  F is the speed in mm/minute (60X more than mm/sec). X Y Z E are the 4 steppers.  E5 means move filament 5mm.  E6 means move one more mm (absolute mode which is most common - relative mode would mean move another 6mm - I don't think cura uses relative mode much).

 

It turns out the gecode is quite easy to read.   You will probably need the M codes for getting in and out of relative extruder mode.  And read up on M82.  That's it - that should be the only gcodes you need but they are all here:

https://reprap.org/wiki/G-code

[DarrylPortelli 0]

ok, I understand ... I'll read a bit about the g-codes ... 

 

The printer is a CR10V3 

 

so All I would need to do is locate the g-code that cura inserted where it goes to home, and add another g-code to raise the Z axis by a few centimeters right ? 

 

Thanks !!! 

[gr5 2,170]

Okay so instead of learning only about 5 gcodes you might have to learn one more: G28.  That's the homing command.  Just go for it - just start looking through the gcode.  Also "M1" or "M0" - one of those I think does a "pause".  90% of the codes are in the first 20 lines and you can ignore most of them - they do things like fan, bed temp, nozzle temp.

[GregValiant 1,250]

A word of caution.  When using Pause at Height or Filament change - be careful using G28.  Better to send the print head to X0 Y0.  When you use G28 the print head goes back to the switches and the switches aren't very accurate (meaning they aren't very repeatable).  One homing move might be .5mm different than the next homing move.  That doesn't matter when starting a print, but in the middle of a print it could cause a layer shift.  Remember also that G28 sends the Z to 0 and if there is a print in the way when the head drops there will be a crash.