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Default PTP speed too fast
#1
Hi Jeremy,

I am running a Kuka robot directly with RoboDk. The first PTP move of every program is moving the robot dangerously fast!

I also need to limit the LIN speed and CIRC speed in the default.

I am aware that the speeds can be changed at the "Set Speed" Instruction in the programs. However, I need it to be changed in the default speed. I have noticed 4 x  speed settings in the Robot parameters screen:

1. Speed
2. Accelaration
3. Joint Speed
4. Joint Accelaration

Which of the above speed settings will affect the PTP move speed in a program automatically created by DXF2gcode?

Also, if I reduce the Speed (mm/s) setting, I assume it will also automatically reduce the Joint Speed (deg/sec)? 
Also, if changing the Speed or Joint speed, should I also adjust acceleration? 

Curt

Hi Jeremy,

I have reduced all the speeds below by 50% in the parameters but notice no change in the program generated by RoboDk?

The speed to the start position remains at 1000mm/s in the program after I have changed it to 500mm/s in the robot parameters.

Please advise what I am missing here?

Curt

By speeds below I meant:
1. Speed
2. Accelaration
3. Joint Speed
4. Joint Accelaration
#2
Hi Jeremy,

Note that all my programs are created from DXF drawings through DXF2Gcode. I have noticed set in the generated program that the default speeds just before the PTP move (Program Start) and the next move (Path Start) are "$VEL.CP = 1.00000"
#3
Hi Curt, 

To modify the speed of the first PTP motion, you need to "Right-click" the generated program -> "Show instruction" -> Find the first "SetSpeed" (it should be before the first MoveJ) -> "Right-click" -> "Edit" -> check "set joint speed" and enter a value. 

   

Then the speed of the approach and retract movement are set by the "Fast move speed" you can find under "Program events" of the settings window. 

The speed of the program itself is baked into the code by DXF2Gcode. 
Therefore you need to modify the DXF2Gcode parameters to set that up. 

Jeremy
Find useful information about RoboDK and its features by visiting our Online Documentation and by watching tutorials on our Youtube Channel


#4
(11-30-2020, 08:26 PM)Jeremy Wrote: Hi Curt, 

To modify the speed of the first PTP motion, you need to "Right-click" the generated program -> "Show instruction" -> Find the first "SetSpeed" (it should be before the first MoveJ) -> "Right-click" -> "Edit" -> check "set joint speed" and enter a value. 



Then the speed of the approach and retract movement are set by the "Fast move speed" you can find under "Program events" of the settings window. 

The speed of the program itself is baked into the code by DXF2Gcode. 
Therefore you need to modify the DXF2Gcode parameters to set that up. 

Jeremy

Hi Jeremy,

Thank you for your well received response. 

Just to confirm, the move which is the biggest concern is the move to PATH START. This is the move when the tool moves to the first cutting position. Is this the move which will be affected when setting "Fast move speed" under Program Events? in other words, is this move called the "approach" move? I was under the impression that the Approach move is the move after the tool reached the first cutting position and then starts to move into the workpiece? We have noticed that when the cutting position is reached the speeds entered on DXF2Gcode takes over, which is perfect.

However, even though it is possible to change the speeds at set-speed when right-clicking the program and also the "Fast Move Speed" for approach and retract at program events it will not be convenient for us. The reason is that we have up to 10 or more different programs which are then run by a "Main" program which means that we have to right all 10 right-click all 10 sub-programs to change "setspeed" and we also have to change the approach speed at programs events for each of the 10 sub-programs. We have 8-12 such Main programs to run per day to cut 8-12 different slabs of granite per day.

This is very time consuming and very easy to miss something and make a mistake. Is there not a place where we could set the DEFAULT "Fast Move Speed" and DEFAULT "Set joint speed" in RoboDk? These 2 speeds will be the same for all our programs.

Curt

Hi Jeremy

Under Tools => Options there are tickboxes for :

- Fast approach/retract
- Include a normal approach/retract by default

Both of these are ticked for my station. How does this affect my speed issues?

sorry, the path is Tools => Options => CAM

There is also "Default Operation Speed (mm/s)" set to 30 in my station. What speed does this affect? I assume that DXF2Gcode speed settings override this sepped setting?
#5
Hi Curt,

Ok, right.

I see what you mean.
I will push for us to add an option to set the first PTP speed.

In the meantime, I think you can simply add a set seed as the first command of your Main to set the "Joint speed".
"Right-click" -> "Add instruction" -> "Set Speed" -> "Right-click" - > "Edit"

As soon as you have one of those set properly, you can simply "copy and paste" it to another program.

DXF2Gcode does indeed override the default speed.

Jeremy
Find useful information about RoboDK and its features by visiting our Online Documentation and by watching tutorials on our Youtube Channel


#6
Hi Curt, 

I now have a solution for you. 
The PTP speed is actually hardcoded in the post-processor. 
We modified the post-processor to expose the porting controlling this. 

You will therefore be able to decide the PTP speed and acceleration by modifying these two lines of code in the post-processor. 

   


I added the new post-processor. 
You can place it here: C:/RoboDK/Posts

Follow this link for more info related to post-processor.
https://robodk.com/doc/en/Post-Processor...tProcessor


Have a great day. 
Jeremy


Attached Files
.py   KUKA_KRC4_Slow.py (Size: 6.24 KB / Downloads: 42)
Find useful information about RoboDK and its features by visiting our Online Documentation and by watching tutorials on our Youtube Channel


#7
(12-03-2020, 04:11 AM)Jeremy Wrote: Hi Curt, 

I now have a solution for you. 
The PTP speed is actually hardcoded in the post-processor. 
We modified the post-processor to expose the porting controlling this. 

You will therefore be able to decide the PTP speed and acceleration by modifying these two lines of code in the post-processor. 




I added the new post-processor. 
You can place it here: C:/RoboDK/Posts

Follow this link for more info related to post-processor.
https://robodk.com/doc/en/Post-Processor...tProcessor


Have a great day. 
Jeremy

Hello Jeremy,

Thank you for the attached post processor. However, I have a KRC-2 and the attached post is a KRC-4. Will the post processor work KRC-2?

Kind regards
Curt
#8
Hi Curt,

Look at line 93 and 94, you can select the controller version you want.
Just uncomment line 93 and comment line 94 and it should work just fine.

Jeremy
Find useful information about RoboDK and its features by visiting our Online Documentation and by watching tutorials on our Youtube Channel


#9
Hello Jeremy,

Thanks for the Post file attached. However, I feel a bit foolish - please bear with me! When I click on the file which you have attached to download it, a link is opened as per the attached screen clip. Please let me know what I am doing wrong?

On another note, I notice that you have PNG screenshots inside of you messages. Please let me know how to do it. The previous time I tried on another post, it brought up a lot of strange incomprehensible letters.

Regards
Curt

otherwise, please email the post to curt@graniteobjects.co.za
#10
Hi Curt, 


You should be able to "right-click" the attachment and select "Save link as". 
Save in it "C:/RoboDK/Posts"


For the image, follow these steps. 
1- Choose files
2- Add attachment
3- click where you want to image
4- Insert into post 



   
Find useful information about RoboDK and its features by visiting our Online Documentation and by watching tutorials on our Youtube Channel


  




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