Scara Setup
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David did you see my last post? I actually have most everything working !
Now I'm going to work on the Z homing and run some accuracy tests -
I missed your previous post. I'm glad to hear that it's all working.
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I have the limit switch at the bottom of the travel on the Z, so I'll be homing at the lowest point. The homing sequence works, but then Z should go up 200 mm to Z 0 to begin printing.
G91 ; use relative positioning
G1 S1 Z-100 F500 ; move all carriages up 300mm, stopping at the endstops
G1 S2 Z5 ; move all towers down 5mm
G1 S1 Z-8 F500 ; move towers slowly up 8mm, stopping at the endstops
G1 S2 Z5 F250 ; move carriages down 5mm
G90 ; back to absolute positioningI hope this doesn't sound confusing but Z0 will then be all the way at the top, and usable Z is 200 mm.
This is hard to describe but I will be printing on the top of the distal arm, there will be a plastic dish which I will be extruding clay onto. As the Z descendants the object will continue to print. The clay extruder is stationary above the
machine,
I know this sounds crazy but I've done it before with a Delta and it works fine.So if you can please help with the Z homing sequence and to get to Z0 at the top .
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So Z=200 is at the bottom, and Z=0 is at the top? Then your homing switch is a Z max switch. It sounds to me that you need to:
- Reverse your Z axis direction in M569 so that +Z is down;
- Change M574 to say that the Z switch is at the max position (Z2)
- Set Zmax = 200 (or whatever the exact value is) in the M208 command
- Reverse the movement directions in your Z homing file.
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David what command will stop the print when the Z Carriage hits the Z limit switch. Right now it's hitting the limit switch and then breaking the switch
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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.
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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 -
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
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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.
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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?
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You can use M581 commands to disable the trigger at the start of the homing files and re-enable it at the end.
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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] -
Thanks for your kind words!
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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?
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What type of output does the prox sensor have?
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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 -
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.
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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. -
I see what you mean. That isn't currently supported, but I will give i some thought.
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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.
