Scara Setup

dc42

A G1 S1 Zxxx command will stop when it hits the Z limit switch, if the switch is correctly connected and configured. Use either M119 or the Machine Properties page of Duet Web Control to check that the limit switch is working and recognised by the Duet.

DannyDefe

I'm not sure if we're talking about the same thing, but this is the command that I'm familiar with in smoothieware
(gamma_limit_enable)

the scara is working fine ,all of the end switches are perfect but during printing if the carriage goes too far it hits the limit switch .
This should stop the machine

DannyDefe

One more question ,how do I eliminate the necessity to have thermistors. I'm extruding clay and I have no need for these so is there a way to bypass without physically hooking them on the board

dc42

You can set up a trigger to stop the machine if the limit switch is hit, see https://duet3d.com/wiki/G-code#M581:_Configure_external_trigger.

You don't need to connect thermistors if you don't use them. Define your tool to have no heaters in the M563 command, and use M140 H-1 to tell the firmware there is no bed heater.

DannyDefe

Okay this command works (M581 TO Z1 S1 C1 ) and the switch when triggered stops the machine. However it stops the machine when it's first homing, so the print doesn't start. How can we delay this till after the first homing sequence?

dc42

You can use M581 commands to disable the trigger at the start of the homing files and re-enable it at the end.

DannyDefe

I thought the group would like to know my experience setting up my Duet wifi board with my scara. I've previously had a smoothieware and decided to try the Duet and there is no comparison.
The Duet has fantastic GUI interface, and the help and setup files that David (dc42 ) has created is extremely helpful. Talking about David, he gives excellent support and helped me work through my small issues. If anyone was considering trying this board I would give it a super thumbs up.
I haven't had much time to fine tune the machine and it's going to be used for ceramics only.

scara ceramic printer
[[url]https://www.dropbox.com/s/vsklk2lhr2dk4qy/20180205_111555.jpg?dl=0]

dc42

Thanks for your kind words!

DannyDefe

David
I would like the ability to do 360 degree continuous prints. This means I'm printing continuously Non-Stop around the perimeter of the Scara.

Because of this request, I also have proximity sensor on the prox arm. This sensor requires 5v, so what's the best way to wire this?
thanks

dc42

What type of output does the prox sensor have?

DannyDefe

So what's the answer can we run 360 continuous?

LJ8A3-2-Z BX
Voltage: DC 5V
Theory: Inductance Sensor
Detection distance: 4mm
Output current: 200mA
Polarity: NPN
Ouput Status: Normally Open
Detect Object : Iron 15151mm
Response frequency: DC:0.5kHz AC:25Hz
Wire type: 3 wire type (Brown, Blue, Black

dc42

You can connect that sensor directly to the Gnd and Stp pins of the endstop input, and power it from 5V.

I can't think if any reason why you can't configure the proximal arm to have a range of -180 to +180 degrees.

DannyDefe

David I don't think you understand my request.
I have a big scara , and I'm printing a large object with the machine in the center. Therefore I need to have the ability to go continuously in rotation as I built the object around the machine.

dc42

I see what you mean. That isn't currently supported, but I will give i some thought.

DannyDefe

David I'm currently running smoothie with working continuous revolving future and in order for me to switch over this is necessary. I would appreciate if you could stick this into the firmware code.

dc42

I'll add it to the list, but I have a deadline for the 1.21 release and I may not have time it implement it by then.

How do you propose to home the proximal arm? Or do you not bother?

Do you have some sort of slip ring arrangement to allow the proximal arm to rotate continuously without the hot end wires getting twisted?

DannyDefe

I have a standard homing sequence for the prox, and after homing this switch is ignored.
And yes I have continuous slip ring .
What's the deadline to finish 1.21?

DannyDefe

Prox switch

[[url]https://www.dropbox.com/s/pd58x96vdv9nci7/20180213_101118.jpg?dl=0]

dc42

The deadline for the 1.21 release it the end of this month. I will try to include provisional support in the next RC, but I will need you to test it because I don't have a continuous-rotation SCARA arm.

DannyDefe

No problem with testing, we just installed Duets on the large scara.