Change track width mid net?

On 26/01/16 19:06, Martin Rowe wrote:

Hi,

 

I would like to change a track width mid-net. Is this possible?

For example in the snippet below, I want 30mil tracks for the high

current devices (relays & diode)

but the indicator LED only needs a 10mil track.

Yes, I know I can change the track width after routing. But it is one of

those jobs that gets forgotten

after one has been round the design loop n times! Safer to assign the

track to a net class?

As you say, you can always change the track width while routing (and

stuff you do after the autorouter has run is still "while routing", not

"after"). Unfortunately the net class hint to the autorouter is too

blunt a tool for avoiding that manual step. It applies, after all, to

the net, which is everything that's electrically connected together.

If it actually matters that the LED path is a different net, which in

this case it doesn't but for "star earthing" type techniques it does,

then most people show that on the schematic by inserting a "star point"

or a "link" - a component that looks like a slightly special wire on the

schematic and consists of two overlapping SMD pads on the board. Then

the signals either side of this are different nets even though they're

electrically connected.

Thank you for the advice. One supplementary question:

Are these "links" and/or "star points" library components?

Or are they techniques or functions within the schematic editor?

Regards, Martin

On 26/01/16 21:34, Martin Rowe wrote:

Thank you for the advice. One supplementary question:

 

Are these "links" and/or "star points" library components?

Or are they techniques or functions within the schematic editor?

 

Library components, although not in a standard library. They're really

easy to create, or you could hunt back in the archives for the several

times somebody's posted (a link to) their version.

I'm really sorry to keep pestering all you experts, but ....

They're really easy to create

Hmmm.... I have been trying. No luck, but I'm thick!. I keep hitting "Can't place pan on pad".

... or you could hunt back in the archives for the several

times somebody's posted (a link to) their version.

Tried that as well - hunted for hours. But yet again, I'm probably looking in the wrong place?

Regards, Martin

On 27/01/16 09:02, Martin Rowe wrote:

I'm really sorry to keep pestering all you experts, but ....

They're really easy to create

Hmmm.... I have been trying. No luck, but I'm thick!. I keep hitting

"Can't place pan on pad".

 

... or you could hunt back in the archives for the several

times somebody's posted (a link to) their version.

Tried that as well - hunted for hours. But yet again, I'm probably

looking in the wrong place?

 

OK, here's an example of the sort of thing I use. It's a V5 library so

should be OK but may have upgrade issues if it violates the new, more

rigorous checks.

Has the attachment fallen off?

Or, yet again, am I doing something really stupid?

Martin

On 27/01/16 19:25, Martin Rowe wrote:

Has the attachment fallen off?

 

Or, yet again, am I doing something really stupid?

 

Martin

 

Well, I don't know about "really stupid" but you are using the Element14 web portal, which is very poor. I'm posting directly to the underlying NNTP news server.

Try "Eagle Central"

http://www.eaglecentral.ca/index.php/mv/msg/52193/164945/88991f4efc2173e672d738d3a42278e9/#msg_164945

Well, I don't know about "really stupid" but you are using the Element14 web portal....

 

Hi Rob,

Sorry it is taking me so long to say "Thank You" for the attached Eagle 2-STAR library file.

I am waiting for the Eagle Central registration email. Once my registration has been approved, I would like to seek your help in trying to figure out why it is not working. However, that can wait until I can avoid going through the Element14 site.

Best regards, Martin

Hi Rob,

I have been working with the 2-STAR library that you kindly offered.

As you suggested, after I had made a non-significant change (moved a pad

and then back again), it invited me to save in a later format, which I have

done.

Next, as an exercise, I created a new project and added two 2-STAR and two

resistor components.

I then linked the two 2-STAR and the two resistors with two nets. Like

so...

2-STAR N$1- 2-STAR

R1-----N$2----- R2

In the board, I ran the auto-router. The two resistors routed but the

airwire between the two 2-STARs did not.

They will manually route. But the auto-router just ignores N$1. Any

suggestions on what I may be doing wrong? 

Best regards, Martin

--

Web access to CadSoft support forums at www.eaglecentral.ca.  Where the CadSoft EAGLE community meets.

On 31/01/2016 7:55 a.m., Martin Rowe wrote:

Hi Rob,

 

I have been working with the 2-STAR library that you kindly offered.

As you suggested, after I had made a non-significant change (moved a pad

and then back again), it invited me to save in a later format, which I have

done.

 

Next, as an exercise, I created a new project and added two 2-STAR and two

resistor components.

I then linked the two 2-STAR and the two resistors with two nets. Like

so...

 

2-STAR N$1- 2-STAR

R1-----N$2----- R2

 

In the board, I ran the auto-router. The two resistors routed but the

airwire between the two 2-STARs did not.

They will manually route. But the auto-router just ignores N$1. Any

suggestions on what I may be doing wrong?

 

Best regards, Martin

 

The auto-router won't route if it would break a rule.

Eagle lets you can manually route, breaking a rule, and it will be

identified when you run a Design Rule Check.

So to get that Star component to be included with the auto router you

need to manually route way from it so the auto router can approach it

without breaking rules.

Thus you still need to remember to make the stubs before auto-routing.

HTH

Warren