Topics

Eagle-polygons-rectangles

Roy Emeny
 

Hi
Sorry if there is an answer elsewhere - found lots of references but nothing helpful.
Having a great time making PCBs thanks to Eagle and pcb-gcode.
Problem using Eagle conventionally is it produces nice looking boards but often tiny areas of copper are left between tracks and around components. These can give rise splinters and shorts.
My mill isn't the most accurate - so simple functional, non-artistic boards are fine by me. The best method I have found so far is create ground planes on both sides using polygons with thermals off - (thanks for previous help in this respect). Then routing the board with thin tracks so I can see how everything connects on both sides. Then filling the board with rectangles over these thin tracks on either top or bottom layer - rectangles are so quick with only two defined points (using alt and finest grid setting).
Milled results are good and tend to contain only half as many gcode instructions, thus quicker.  By ensuring that the gap between adjacent rectangles is only say 0.2 mm the mill effectively goes in almost the same path twice clearing any splinters.
But there is an issue, because you can't name a rectangle as you can a polygon, Eagle doesn't recognise them as part of your nets so they can't be speedily ripped up. There is also a danger of nudging them out of place when moving component names etc when tidying up an eagle file to pass on to others. I wonder what others are doing? Is there a way of naming rectangles or creating a polygons as quickly? - I find the latter very fiddly and slow to use for creating in large quantities.  Have attached a jpg - as you will see the quality of my soldering doesn't warrant an artistic board - really must get a new poker ....

Roy

mlmcnc
 

Hi Roy,
I noticed that nobody has given you a response so I thought I would chip in.
I would normally try to directly answer the question you asked to help solve your problem but in this case I find myself puzzled by your solution to what seems to be the trivial problem of copper slivers.
As you say about Eagle "it produces nice looking boards". PCB-Gcode can then do an excellent job of reproducing these nice boards.
Why then would you want to make them less nice.

If the slivers are the only problem then there are a couple of things you can do.
1) Buy yourself one of those small wire brushes with copper bristles. The type used for cleaning suede shoes. A few strokes with one of these will soon clear away the slivers and also clean the board ready for soldering.
2) Use the "Isolation" feature in PCB-Gcode which was designed specifically for this purpose. Appropriate settings will clear away for your chosen distance around the tracks.

I think you are causing yourself unnecessary problems (and extra work) with the "solution" you have chosen.

Regards
Martin Marriott
mlmSolutions

--- In pcb-gcode@..., Roy Emeny <forjacdf@...> wrote:

Hi
Sorry if there is an answer elsewhere - found lots of references but nothing helpful.
Having a great time making PCBs thanks to Eagle and pcb-gcode.
Problem using Eagle conventionally is it produces nice looking boards but often tiny areas of copper are left between tracks and around components. These can give rise splinters and shorts.
My mill isn't the most accurate - so simple functional, non-artistic boards are fine by me. The best method I have found so far is create ground planes on both sides using polygons with thermals off - (thanks for previous help in this respect). Then routing the board with thin tracks so I can see how everything connects on both sides. Then filling the board with rectangles over these thin tracks on either top or bottom layer - rectangles are so quick with only two defined points (using alt and finest grid setting).
Milled results are good and tend to contain only half as many gcode instructions, thus quicker.  By ensuring that the gap between adjacent rectangles is only say 0.2 mm the mill effectively goes in almost the same path twice clearing any splinters.
But there is an issue, because you can't name a rectangle as you can a polygon, Eagle doesn't recognise them as part of your nets so they can't be speedily ripped up. There is also a danger of nudging them out of place when moving component names etc when tidying up an eagle file to pass on to others. I wonder what others are doing? Is there a way of naming rectangles or creating a polygons as quickly? - I find the latter very fiddly and slow to use for creating in large quantities.  Have attached a jpg - as you will see the quality of my soldering doesn't warrant an artistic board - really must get a new poker ....

Roy

Roy Emeny
 

Hello Martin,
Many thanks for taking the time to reply.
I must admit I haven’t paid much attention to the isolation feature so perhaps I need to study that carefully.
Perhaps a little more detail will help you understand why I took this route:
The original milling motor supplied was quite big but created huge amount of vibration and noise. I was afraid it would wear the movement screws rapidly apart from being extremely annoying.
I replaced it with a tiny proxon unit (50E).  Really quiet and smooth in comparison but of course has to mill quite slowly. Boards were taking around 3 hours per side to mill at this speed with anything fancy.
Using the rectangle approach means that there are virtually no areas of unconnected copper everything either carries a signal or is ground plane. The only milling done separates these areas and is mainly straight lines.  No little triangular bits left near circular bits. Previously I would have had two tracks separated by thin strip not connected to anything. With rectangles and no gaps (just a cutter bit width) times and mill wear are thus almost halved.  
 
In total I have only a couple of months active experience being new to everything – Eagle, PCB-GCODE and Mach 3.  When I use the system I always have a job to do and a time limit so I am not as well read as I should be.
 
If you can suggest what I need to read / do to improve my technique I would be most grateful.
 
Roy


On Tuesday, 4 February 2014, 19:16, mlmcnc wrote:
 
Hi Roy,
I noticed that nobody has given you a response so I thought I would chip in.
I would normally try to directly answer the question you asked to help solve your problem but in this case I find myself puzzled by your solution to what seems to be the trivial problem of copper slivers.
As you say about Eagle "it produces nice looking boards". PCB-Gcode can then do an excellent job of reproducing these nice boards.
Why then would you want to make them less nice.

If the slivers are the only problem then there are a couple of things you can do.
1) Buy yourself one of those small wire brushes with copper bristles. The type used for cleaning suede shoes. A few strokes with one of these will soon clear away the slivers and also clean the board ready for soldering.
2) Use the "Isolation" feature in PCB-Gcode which was designed specifically for this purpose. Appropriate settings will clear away for your chosen distance around the tracks.

I think you are causing yourself unnecessary problems (and extra work) with the "solution" you have chosen.

Regards
Martin Marriott
mlmSolutions

--- In pcb-gcode@..., Roy Emeny wrote:
>
> Hi
> Sorry if there is an answer elsewhere - found lots of references but nothing helpful.
> Having a great time making PCBs thanks to Eagle and pcb-gcode.
> Problem using Eagle conventionally is it produces nice looking boards but often tiny areas of copper are left between tracks and around components. These can give rise splinters and shorts.
> My mill isn't the most accurate - so simple functional, non-artistic boards are fine by me. The best method I have found so far is create ground planes on both sides using polygons with thermals off - (thanks for previous help in this respect). Then routing the board with thin tracks so I can see how everything connects on both sides. Then filling the board with rectangles over these thin tracks on either top or bottom layer - rectangles are so quick with only two defined points (using alt and finest grid setting).
> Milled results are good and tend to contain only half as many gcode instructions, thus quicker.  By ensuring that the gap between adjacent rectangles is only say 0.2 mm the mill effectively goes in almost the same path twice clearing any splinters.
> But there is an issue, because you can't name a rectangle as you can a polygon, Eagle doesn't recognise them as part of your nets so they can't be speedily ripped up. There is also a danger of nudging them out of place when moving component names etc when tidying up an eagle file to pass on to others. I wonder what others are doing? Is there a way of naming rectangles or creating a polygons as quickly? - I find the latter very fiddly and slow to use for creating in large quantities.  Have attached a jpg - as you will see the quality of my soldering doesn't warrant an artistic board - really must get a new poker ....
>
> Roy
>



mlmcnc
 

Hi Roy,

You don't say what your cnc is. Is it home made? What are your linear bearings and drive screws. What tools are you using?
If your boards were taking 3 hours, what feed rate were you using because that's quite a long time. Your Proxxon 50E is supposed to be capable of 20000 rpm and if you are using something like a V bit 30 deg with 0.2mm tip then there should be very little load on the spindle (you would break the tip if there were). Given the above you should be able to have a feed rate of at least 250mm/min. At that speed it would be a very big board to take 3 hours.

You don't need to be concerned about unconnected copper between track. Whats the problem. In fact, using your technique you are not allowing Eagle to be able to do a ground pour properly as you are not leaving any gaps for it to connect through.

As for reading material, that's a tough one. CNC's are so interesting partly because it is hard. It wouldn't be so much fun if it was easy. Google is your friend.

For a diy CNC this is NICE http://www.cnczone.com/forums/diy_cnc_router_table_machines/182294-computer-numeric-control_router_aluminum_frame_pics.html

Feeds and speeds - https://www.onsrud.com/xdoc/FeedSpeeds

Autolevelling - http://www.autoleveller.co.uk/

Have fun

Regards
Martin Marriott
mlmSolutions

--- In pcb-gcode@..., Roy Emeny <forjacdf@...> wrote:

Hello Martin,
Many thanks for taking the time to reply.
I must admit I haven’t paid much attention to the isolation feature so
perhaps I need to study that carefully.
Perhaps a little more detail will help you understand why I took this
route:
The original milling motor supplied was quite big but created huge
amount of vibration and noise. I was afraid it would wear the movement screws
rapidly apart from being extremely annoying.
I replaced it with a tiny proxon unit (50E).  Really quiet and smooth in comparison but of
course has to mill quite slowly. Boards were taking around 3 hours per side to
mill at this speed with anything fancy.
Using the rectangle approach means that there are virtually no areas of
unconnected copper everything either carries a signal or is ground plane. The
only milling done separates these areas and is mainly straight lines.  No little triangular bits left near circular
bits. Previously I would have had two tracks separated by thin strip not
connected to anything. With rectangles and no gaps (just a cutter bit width) times
and mill wear are thus almost halved.  
 
In total I have only a couple of months active experience being new to
everything â€" Eagle, PCB-GCODE and Mach 3.  When I use the system I always have a job to do and a time limit so I am
not as well read as I should be.
 
If you can suggest what I need to read / do to improve my technique I
would be most grateful.
 
Roy



On Tuesday, 4 February 2014, 19:16, mlmcnc <martin312@...> wrote:

 
Hi Roy,
I noticed that nobody has given you a response so I thought I would chip in.
I would normally try to directly answer the question you asked to help solve your problem but in this case I find myself puzzled by your solution to what seems to be the trivial problem of copper slivers.
As you say about Eagle "it produces nice looking boards". PCB-Gcode can then do an excellent job of reproducing these nice boards.
Why then would you want to make them less nice.

If the slivers are the only problem then there are a couple of things you can do.
1) Buy yourself one of those small wire brushes with copper bristles. The type used for cleaning suede shoes. A few strokes with one of these will soon clear away the slivers and also clean the board ready for soldering.
2) Use the "Isolation" feature in PCB-Gcode which was designed specifically for this purpose. Appropriate settings will clear away for your chosen distance around the tracks.

I think you are causing yourself unnecessary problems (and extra work) with the "solution" you have chosen.

Regards
Martin Marriott
mlmSolutions

--- In pcb-gcode@..., Roy Emeny <forjacdf@> wrote:

Hi
Sorry if there is an answer elsewhere - found lots of references but nothing helpful.
Having a great time making PCBs thanks to Eagle and pcb-gcode.
Problem using Eagle conventionally is it produces nice looking boards but often tiny areas of copper are left between tracks and around components. These can give rise splinters and shorts.
My mill isn't the most accurate - so simple functional, non-artistic boards are fine by me. The best method I have found so far is create ground planes on both sides using polygons with thermals off - (thanks for previous help in this respect). Then routing the board with thin tracks so I can see how everything connects on both sides. Then filling the board with rectangles over these thin tracks on either top or bottom layer - rectangles are so quick with only two defined points (using alt and finest grid setting).
Milled results are good and tend to contain only half as many gcode instructions, thus quicker.  By ensuring that the gap between adjacent rectangles is only say 0.2 mm the mill effectively goes in almost the same path twice clearing any splinters.
But there is an issue, because you can't name a rectangle as you can a polygon, Eagle doesn't recognise them as part of your nets so they can't be speedily ripped up. There is also a danger of nudging them out of place when moving component names etc when tidying up an eagle file to pass on to others. I wonder what others are doing? Is there a way of naming rectangles or creating a polygons as quickly? - I find the latter very fiddly and slow to use for creating in large quantities.  Have attached a jpg - as you will see the quality of my soldering doesn't warrant an artistic board - really must get a new poker ....

Roy



Roy Emeny
 

Hi Martin,


The mill is a sable - bought 2nd hand  of ebay - has an issue with suddenly missing pulses and losing registration on the X axis - which was another reason for driving slowly - doesn't seem to have helped but at least I can hit the panic button before it mills too much incorrectly.  Obviously I need to find the fault (suspect stepper motor driver board). This is becoming a long story!!


As you say all interesting stuff - a challenge.


Will follow your links and try to get myself back on track - many thanks for your advice - much appreciated.


Roy