Topics

What an I Missing - Eagle Question? #eagle

John Ferguson
 

I now have a couple of years and dozens of successful boards cut on my 6040 router - and some bad ones too.

Boards are all cut from 2 1/2 x 4 inch single side pcb stock.  I made a jig for drilling holes in the corners to secure them to the fixture I made for the router with nylon 8-32 socket head cap screws. They're nylon so I won't ruin a bit if I screw up.

The fixture is a block of HDPE which has four recessed 10-32 socket head cap screws in the corners with Tee-nuts to hold it down against the router bed.  I've found that it is never really level as I put it down, and so I take a leveling pass with a fly cutter and then it is level.  I have a leveling G-Code snippet for the block which takes off .005.  I run all of this on LinuxCNC.

I started cutting with the 15 Degree etcher which came with the router. It worked very well after I got sharper on how to set it's height.  Then I bought additional bits, but none of them worked as well as the original until I bought a 15 degree 3 flute tapered stub EM3E8-0100-15V from Precise Bits. It does beautiful work requiring very little "adjusting"  It is wonderful.

I've had no problems with pcbgcode - worked out of the box.

My designs have all traces on bottom of card and so far no vias.

I export the Eagle design to DXF and use AutoCad to lay out the physical board, rounded (filleted) corners, mounting holes in corners, then run dxf of the board through SheetCAM to get G-code for the outline and corner hole milling.

Typically my projects have a microcontroller (Teensy 3.2) 28 pin DIL and a number of sensors, switches, maybe an OLED, a buck-type power supply and some Molex connectors for remote devices.

My problem is that Eagle doesn't seem to be able to autoroute traces among the pins on the devices without shorts - in other words it doesn't follow its clearance rules.  The result is that I have to go through the Board, find where traces are too close to each other or too close to pads and move them, often using the Alt key because they lock to a grid which seems to be part of problem.  This doesn't take long, but it seems to me that Eagle should get it right without any help.

I'm using only library components, trace width of 10 mill and clearance of 14 mill.  Since the bit is 10 mil, maybe I should be using 10 mill as the clearance rule?

If you guys aren't having to do all this editing, where do you think I'm messing up?

john ferguson

Chipteck
 

Have you checked your DRL file in Eagle?
I am using specific DRL files for establishing clearances/etc.

John Ferguson
 

yes, I think.  That is the file which tells Eagle I want 10 mil traces and 14 mil clearances isn't it?

On 11/17/18 8:52 AM, Chipteck wrote:
Have you checked your DRL file in Eagle?
I am using specific DRL files for establishing clearances/etc.

Fred Genius
 

I have the same problem, the autorouter seems to like running tracks between pads and I don’t like that, means a greater chance of a bad board.

 

Just for reference, I have a 3020 router, with a milling vice bolted to the bed. The vice has 80mm wide stepped jaws, and the pcb sits nicely on the step. I use Autoleveller  software, takes the output from pcbgcode and adds probing code so I don’t need to worry about the board being level.

 

I use carbide ‘V’ bits, typically 20°, they’re cheap enough so I use a fresh one for every board.

 

To make double-sided boards, I drill one hole all the way thought the board, usually the one nearest to the right-hand edge of the board. When I flip the board to etch the second side, I position the drill at the negative value of the original position, and push the board onto the drill bit, then lower the z until the board is sitting on the jaw step, then I can tighten the jaws knowing that it’s correctly located.

 

The router had one major problem when I first got it, there was a huge amount of backlash on all axes, and a huge number of failed boards. I replaced with ball screws and everything is good now.

 

Fred Ö¿Ö

 

From: pcbgcode@groups.io [mailto:pcbgcode@groups.io] On Behalf Of John Ferguson via Groups.Io
Sent: 17 November 2018 14:13
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle

 

yes, I think.  That is the file which tells Eagle I want 10 mil traces and 14 mil clearances isn't it?

On 11/17/18 8:52 AM, Chipteck wrote:

Have you checked your DRL file in Eagle?
I am using specific DRL files for establishing clearances/etc.

John Ferguson
 

HI Fred,

The autoleveler sounds like a good idea, although my typical work sequence is I set up the fixture, fly-cut it and then leave it on for a month or two - no more leveling needed.  I'm doing very small autonomous fixed wing aircraft design -by myself - and find that it's better to have two aspects of this going at once, electronics (pcb board) and coding work ok, but not pcb and airframe, because I cut airframe parts on the 6040 on a vacuum table which cannot co-exist with the pcb fixture. 

it's the traces between the pads on the microcontroller which cause most of my problems, but I have to have them or vias.  I could do two sides using scheme you suggest, but so far haven't.  I start my first run with a slight prick at 0,0 which I could drill through to index other side.  Itr is helpful if i have to re-index a card for another pass, although I couldn't do this the way I work if I've had some reason to take the card off the router.

I'm surprised your router didn't come with ball screws, mine did.  One of the highlights of the purchase was discovering the ballscrews were metris not imperial as advertised.  this didn't cause much of a problem with small stuff, but later on when I started to make 8 nch parts things didn't fit weel with parts made on my mill.

I love this stuff, though and really Eagle ought to be able to do better.  I have the lingering feeeling that I really have missed something.

john

On 11/17/18 9:37 AM, Fred Genius wrote:

I have the same problem, the autorouter seems to like running tracks between pads and I don’t like that, means a greater chance of a bad board.

 

Just for reference, I have a 3020 router, with a milling vice bolted to the bed. The vice has 80mm wide stepped jaws, and the pcb sits nicely on the step. I use Autoleveller  software, takes the output from pcbgcode and adds probing code so I don’t need to worry about the board being level.

 

I use carbide ‘V’ bits, typically 20°, they’re cheap enough so I use a fresh one for every board.

 

To make double-sided boards, I drill one hole all the way thought the board, usually the one nearest to the right-hand edge of the board. When I flip the board to etch the second side, I position the drill at the negative value of the original position, and push the board onto the drill bit, then lower the z until the board is sitting on the jaw step, then I can tighten the jaws knowing that it’s correctly located.

 

The router had one major problem when I first got it, there was a huge amount of backlash on all axes, and a huge number of failed boards. I replaced with ball screws and everything is good now.

 

Fred Ö¿Ö

 

From: pcbgcode@groups.io [mailto:pcbgcode@groups.io] On Behalf Of John Ferguson via Groups.Io
Sent: 17 November 2018 14:13
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle

 

yes, I think.  That is the file which tells Eagle I want 10 mil traces and 14 mil clearances isn't it?

On 11/17/18 8:52 AM, Chipteck wrote:

Have you checked your DRL file in Eagle?
I am using specific DRL files for establishing clearances/etc.

John Ferguson
 

DRL or DRU?

On 11/17/18 8:52 AM, Chipteck wrote:
Have you checked your DRL file in Eagle?
I am using specific DRL files for establishing clearances/etc.

Art Eckstein
 

Dumb question,
Are you doing a DRC check? 

"Tools">"DRC">"Check"

This should point out any errors you have in the design rules.




At 11/17/2018 09:12 AM, John Ferguson via Groups.Io wrote:

yes, I think.  That is the file which tells Eagle I want 10 mil traces and 14 mil clearances isn't it?
On 11/17/18 8:52 AM, Chipteck wrote:
Have you checked your DRL file in Eagle?
I am using specific DRL files for establishing clearances/etc.

Fred Genius
 

Here’s a link to Autolveller, it’s pretty easy to use, but always test your probe before you start. I use Mach3, have an indicator on my main screen the shows the probe status, guess you can do the same with your Linux cnc…

 

Btw, I use a big crocodile clip on the spindle to complete the probe circuit.

 

https://www.autoleveller.co.uk/

 

 

Fred Ö¿Ö

 

From: pcbgcode@groups.io [mailto:pcbgcode@groups.io] On Behalf Of John Ferguson via Groups.Io
Sent: 17 November 2018 15:21
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle

 

HI Fred,

The autoleveler sounds like a good idea, although my typical work sequence is I set up the fixture, fly-cut it and then leave it on for a month or two - no more leveling needed.  I'm doing very small autonomous fixed wing aircraft design -by myself - and find that it's better to have two aspects of this going at once, electronics (pcb board) and coding work ok, but not pcb and airframe, because I cut airframe parts on the 6040 on a vacuum table which cannot co-exist with the pcb fixture. 

it's the traces between the pads on the microcontroller which cause most of my problems, but I have to have them or vias.  I could do two sides using scheme you suggest, but so far haven't.  I start my first run with a slight prick at 0,0 which I could drill through to index other side.  Itr is helpful if i have to re-index a card for another pass, although I couldn't do this the way I work if I've had some reason to take the card off the router.

I'm surprised your router didn't come with ball screws, mine did.  One of the highlights of the purchase was discovering the ballscrews were metris not imperial as advertised.  this didn't cause much of a problem with small stuff, but later on when I started to make 8 nch parts things didn't fit weel with parts made on my mill.

I love this stuff, though and really Eagle ought to be able to do better.  I have the lingering feeeling that I really have missed something.

john

On 11/17/18 9:37 AM, Fred Genius wrote:

I have the same problem, the autorouter seems to like running tracks between pads and I don’t like that, means a greater chance of a bad board.

 

Just for reference, I have a 3020 router, with a milling vice bolted to the bed. The vice has 80mm wide stepped jaws, and the pcb sits nicely on the step. I use Autoleveller  software, takes the output from pcbgcode and adds probing code so I don’t need to worry about the board being level.

 

I use carbide ‘V’ bits, typically 20°, they’re cheap enough so I use a fresh one for every board.

 

To make double-sided boards, I drill one hole all the way thought the board, usually the one nearest to the right-hand edge of the board. When I flip the board to etch the second side, I position the drill at the negative value of the original position, and push the board onto the drill bit, then lower the z until the board is sitting on the jaw step, then I can tighten the jaws knowing that it’s correctly located.

 

The router had one major problem when I first got it, there was a huge amount of backlash on all axes, and a huge number of failed boards. I replaced with ball screws and everything is good now.

 

Fred Ö¿Ö

 

From: pcbgcode@groups.io [mailto:pcbgcode@groups.io] On Behalf Of John Ferguson via Groups.Io
Sent: 17 November 2018 14:13
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle

 

yes, I think.  That is the file which tells Eagle I want 10 mil traces and 14 mil clearances isn't it?

On 11/17/18 8:52 AM, Chipteck wrote:

Have you checked your DRL file in Eagle?
I am using specific DRL files for establishing clearances/etc.

John Ferguson
 

Yes, and I get no errors. but there are still shorts between pads and traces - and as I said before it's all library so it's their pads and their traces.

On 11/17/18 10:23 AM, Art Eckstein wrote:
Dumb question,
Are you doing a DRC check?�

"Tools">"DRC">"Check"

This should point out any errors you have in the design rules.




At 11/17/2018 09:12 AM, John Ferguson via Groups.Io wrote:

yes, I think.  That is the file which tells Eagle I want 10 mil traces and 14 mil clearances isn't it?
On 11/17/18 8:52 AM, Chipteck wrote:
Have you checked your DRL file in Eagle?
I am using specific DRL files for establishing clearances/etc.

Chipteck
 

I am sorry, I didn't have a lot of time and was too quick to respond.
In any case I am loading "20170624 -pcb-gcode.dru" file on my projects to setup my clearances and have been successfull to cut 0.2mm traces with 0.1mm clearances with the following:
pcb-gcode setup - Generation > Minimum = 0.03mm, Maximum=0.2mm, Step size=0.05mm - Machine > Tool Dia = 0.1mm
DRU:

Chipteck

Chipteck
 

Also let's not forget that an autoleveller like "AutolevellerAE-0.9.5u1.exe" will also help since these boards are not flat.

John Ferguson
 

This is very close to what I'm using in Imperial.  I need to check the pcb-gcode, but I don't think it is where my problem is. I can see the traces too close to pads in Eagle. Moving them manually does fix them. 

thanks much,

john

On 11/18/18 4:23 PM, Chipteck wrote:
I am sorry, I didn't have a lot of time and was too quick to respond.
In any case I am loading "20170624 -pcb-gcode.dru" file on my projects to setup my clearances and have been successfull to cut 0.2mm traces with 0.1mm clearances with the following:
pcb-gcode setup - Generation > Minimum = 0.03mm, Maximum=0.2mm, Step size=0.05mm - Machine > Tool Dia = 0.1mm
DRU:

Chipteck

Eric
 

That being the case, maybe switching off  Snap to Grid in Eagle will allow it do it properly for you.

 

Just a thought

 

73….Eric VK2VE

 

From: pcbgcode@groups.io <pcbgcode@groups.io> On Behalf Of John Ferguson via Groups.Io - jferg977=aol.com at groups.io
Sent: Monday, 19 November 2018 12:40
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle

 

This is very close to what I'm using in Imperial.  I need to check the pcb-gcode, but I don't think it is where my problem is. I can see the traces too close to pads in Eagle. Moving them manually does fix them. 

thanks much,

john

On 11/18/18 4:23 PM, Chipteck wrote:

I am sorry, I didn't have a lot of time and was too quick to respond.
In any case I am loading "20170624 -pcb-gcode.dru" file on my projects to setup my clearances and have been successfull to cut 0.2mm traces with 0.1mm clearances with the following:
pcb-gcode setup - Generation > Minimum = 0.03mm, Maximum=0.2mm, Step size=0.05mm - Machine > Tool Dia = 0.1mm
DRU:

Chipteck


Virus-free. www.avast.com

John Ferguson
 

I thought so too , but couldn't figure out how to do it. I'm running Eagle 9.2.2.  I've been away from it about a year.  seems to me that I was able to toggle snap to grid off in earlier version,l but cannot remember.

john

On 11/18/18 9:57 PM, Eric wrote:

That being the case, maybe switching off  Snap to Grid in Eagle will allow it do it properly for you.

 

Just a thought

 

73….Eric VK2VE

 

From: pcbgcode@groups.io <pcbgcode@groups.io> On Behalf Of John Ferguson via Groups.Io - jferg977=aol.com at groups.io
Sent: Monday, 19 November 2018 12:40
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle

 

This is very close to what I'm using in Imperial.  I need to check the pcb-gcode, but I don't think it is where my problem is. I can see the traces too close to pads in Eagle. Moving them manually does fix them. 

thanks much,

john

On 11/18/18 4:23 PM, Chipteck wrote:

I am sorry, I didn't have a lot of time and was too quick to respond.
In any case I am loading "20170624 -pcb-gcode.dru" file on my projects to setup my clearances and have been successfull to cut 0.2mm traces with 0.1mm clearances with the following:
pcb-gcode setup - Generation > Minimum = 0.03mm, Maximum=0.2mm, Step size=0.05mm - Machine > Tool Dia = 0.1mm
DRU:

Chipteck


Virus-free. www.avast.com

Harvey White
 

On Mon, 19 Nov 2018 13:57:48 +1100, you wrote:

If I remember this properly the following things could be happening:

1) if you manually set the grid size, then 0.025 may be small enough
for the primary grid, and 0.00625 (all inches) may be good enough for
the secondary grid. Tracks when manually routed follow the grid and
snap to it. Your job to manage pad size and trace width.

Now, Eagle's autorouter is set up for PC board houses, not for the
kind of routing either toner transfer or mechanical etching will need.

Trace size is generally set by net class according to the signal type,
however, the spacing between the trace and another trace, trace and
pad, pad and via, all of which the autorouter has to follow, that's
set by the Design Rules.

Check clearance to see what's going on.

As an experiment, set up three parallel pin headers, say about fifteen
or so long each. Connect corresponding pins on the two outer ones,
leaving the inner one disconnected. Set the clearances to 8 mils,
autoroute. ripup, set to 12, ripup, set to 16, then 24, then 32, then
40. Sooner or later, the autorouter will stop putting wires between
pins. Cobble together a board that has at least one surface mount
chip on either side, doesn't have to make sense. Do the same and I
think you'll start to see where the vias get placed.

Generally, when I routed boards that I was going to make (I used toner
transfer), I stuck to 10 mil trace, 10 mil spacing as the minimum
sizes.

Note that as long as the design rules are followed, the autorouter
doesn't care how close it gets to another trace and has no incentive
to spread them out.

Harvey



That being the case, maybe switching off Snap to Grid in Eagle will allow it do it properly for you.



Just a thought



73….Eric VK2VE



From: pcbgcode@groups.io <pcbgcode@groups.io> On Behalf Of John Ferguson via Groups.Io - jferg977=aol.com at groups.io
Sent: Monday, 19 November 2018 12:40
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle



This is very close to what I'm using in Imperial. I need to check the pcb-gcode, but I don't think it is where my problem is. I can see the traces too close to pads in Eagle. Moving them manually does fix them.

thanks much,

john

On 11/18/18 4:23 PM, Chipteck wrote:

I am sorry, I didn't have a lot of time and was too quick to respond.
In any case I am loading "20170624 -pcb-gcode.dru" file on my projects to setup my clearances and have been successfull to cut 0.2mm traces with 0.1mm clearances with the following:
pcb-gcode setup - Generation > Minimum = 0.03mm, Maximum=0.2mm, Step size=0.05mm - Machine > Tool Dia = 0.1mm
DRU:

Chipteck






Eric
 

Hi John,

 

Just been playing around a little and I also can’t find a way to turn off grid snap, however, you can manually move objects off the snap grid by holding down the ALT key whilst moving them so, for instance, you could click on a track and select move and then holding down the ALT key drag it away from the snap position and it will stay where you leave it.

 

Of course, you can also select the finest option for size and alternate grid sizes and that will give you much closer snap positions.

 

73….Eric VK2VE

 

From: pcbgcode@groups.io <pcbgcode@groups.io> On Behalf Of John Ferguson via Groups.Io - jferg977=aol.com at groups.io
Sent: Monday, 19 November 2018 14:29
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle

 

I thought so too , but couldn't figure out how to do it. I'm running Eagle 9.2.2.  I've been away from it about a year.  seems to me that I was able to toggle snap to grid off in earlier version,l but cannot remember.

john

On 11/18/18 9:57 PM, Eric wrote:

That being the case, maybe switching off  Snap to Grid in Eagle will allow it do it properly for you.

 

Just a thought

 

73….Eric VK2VE

 

From: pcbgcode@groups.io <pcbgcode@groups.io> On Behalf Of John Ferguson via Groups.Io - jferg977=aol.com at groups.io
Sent: Monday, 19 November 2018 12:40
To: pcbgcode@groups.io
Subject: Re: [pcbgcode] What an I Missing - Eagle Question? #eagle

 

This is very close to what I'm using in Imperial.  I need to check the pcb-gcode, but I don't think it is where my problem is. I can see the traces too close to pads in Eagle. Moving them manually does fix them. 

thanks much,

john

On 11/18/18 4:23 PM, Chipteck wrote:

I am sorry, I didn't have a lot of time and was too quick to respond.
In any case I am loading "20170624 -pcb-gcode.dru" file on my projects to setup my clearances and have been successfull to cut 0.2mm traces with 0.1mm clearances with the following:
pcb-gcode setup - Generation > Minimum = 0.03mm, Maximum=0.2mm, Step size=0.05mm - Machine > Tool Dia = 0.1mm
DRU:

Chipteck

 

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