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Trouble changing the thermal relief spoke width in Ultiboard

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I am trying to change the thermal relief spoke width of various pads on an existing Ultiboard layout made with a previous version, and they are not changing. I can change the "type" to x or +, etc. but not the spoke width.  Is there some global setting preventing this? What does "Use Polygon Settings" mean when setting the type, and how does this affect the thermal relief spoke width? I find nothing in the Help file. I also searched Help and the user manual for what happens if I select Automatic for the width, but I find no instructions about what this means. 

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Message 1 of 5

Hi dalyl,


I'm unable to reproduce the behaviour you mentioned. Could you attach your design so we can take a closer look?


The "Use polygon settings" option for the type and spoke width refer to the settings for the copper area the pad is connecting to:







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Message 2 of 5

Hi Jeff,


In working with my layout I find that the copper rectangles that I am using for the top and bottom ground planes have a Measurements Width setting on the General tab of the Copper Rectangle Properties window. By experimentation I find that this width value seems to limit how small the thermal relief spoke width can be. In my layout the top layer ground plane rectangle had a value of 25 mils and the lower ground plane rectangle had a value of 20 mils. I do not remember chosing these values. I could not get the spoke widths to be smaller than these values on the respective planes.  When I reduce the Measurement Width to 5 mils for each copper rectangle that I am using for top and bottom ground planes, I can then reduce the spoke width to 5 mils. But when I change this Measurement value, the copper rectangles disappear and I have to replace them. I finally got the layout to do what I want. 


It would be great if the help files and the manual could describe details like this. I tried to find answers there but came up empty. I would never have thought the thermal relief spoke width was related to this Measuremens Width.


I am guessing that the settings for Measurements Width did not carry over from my computer in the file that I sent, so that the copper rectangle properties on your computer have a smaller Measurement Width, and this is why you could not duplicate the problem. 


Please feel free to correct me if I have stated the Ultiboard operation incorrectly, or if there should be some clarification.

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Message 3 of 5
Accepted by topic author dalyl

I was able to confirm the behaviour you're seeing where the spoke width is limited by the measurement width of the coppe area / power plane. This is definitely not intentional and I have filed a defect report for R&D to look into. I'm very sorry for the inconvenience this has caused you.


There were no files attached on your post so I can't confirm with your actual designs. Please let me know if the workaround (of adjusting the measurement width) will allow you to get the results you are looking for, despite the incorrect behaviour.



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Message 4 of 5

Hi Jeff,


Thanks a lot for your quick response.  I had sent my Ultiboard file to Wendy Reyes to check out and I assumed you might have also seen that to evaluate the problem.  My mistake. 


Now that I know this behavior exists I can easily deal with it even though it was not intended.  I thought it might have been based on some other layout requirement and that I was ignorant about something in Ultiboard.


When unintended behaviors like this (bugs?) are discovered, would it be possible for users to get email notification and a workaround? I imagine that other people might encounter this issue and it would be nice (and time saving) to have a list of things to watch out for and how to deal with them until the next version fixes it.  Maybe this list exists somewhere on an NI webpage.

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Message 5 of 5