scara dual estruder

tony73

hello does the kinematic scara support the offset for the second extruder? can you help me Thanks in advance

list item

timcurtis67

Can you use a G10 with the tool offset? I would think the duet would just calculate the offset with each move as it does with all other printer formats.

See https://duet3d.dozuki.com/Wiki/Gcode#Section_G10_Tool_Offset_and_Temperature_Setting

Veti

@tony73
if it doesn't i would consider that a bug.

as far as i understand the kinematics code is modular in such a way that it is abstracted away from the rest of the code, i.e. tool selection

dc42

On a SCARA, for each nozzle it would be necessary to specify a separate distal arm length and an angular offset from the head reference point (HRP). Similarly for the Z probe. This hasn't been coded in the firmware.

However, you can probably accomplish it in the tool change files, by resetting the M669 parameters when you select a tool. The snag is that using M669 normally flags the axes as not homed. I guess this could be changed for SCARA.

Danal

@dc42 said in scara dual estruder:

The snag is that using M669 normally flags the axes as not homed. I guess this could be changed for SCARA.

And/or, redefine the endstop to be the opposite of what it really is (NO v NC) and G28 that axis. It will "home" without moving.

tony73

@Danal
merry christmas everyone! and thanks for the answers, danal can you better explain the G28 home without moving? and dc42 the problem of the M669?

Danal

If an endstop is defined in the configuration as Normally Closed, and it is physically Closed, the axis will move during a home until the switch opens.

But...

If the real printer is as above, and we momentarily re-define that switch to be Normally Open, then when the homing starts... the switch will ALREADY be "triggered". So no movement will occur (assuming the home.whatever files are written with no backoff).

Then put the definition back its proper way.

Very much a "hack", but might work as a bypass until DC42 decides the best way to properly implement something.

And... Merry Christmas to all!

tony73

This post is deleted!

tony73

@dc42
happy Holidays!! could you give me an example to use a second nozzle? I have in config.g
M669 k4 P200 D200 A-125: 125 B-176: 176 C0: 0: 0 X0 Y0 I didn't understand if possible to do this. And the G28 distal home without moving from danal how can you do it?