Eagle PCB and metric vs imperial grids

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Elysiumtech
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Eagle PCB and metric vs imperial grids

Post by Elysiumtech » Thu Jun 30, 2011 8:30 pm

Howdy all,

I swear PCB design was never this hard in other tools but Eagle seems to hate me when it comes to grids.

Last night I was trying to lay out a matrix of LEDs on a non-square PCB. I layed down some initial LEDs on a matrix using the default 0.05mil grid and then changed to a 1mm grid to map out the PCB outline to fit within the enclosure I have. Without thinking I moved the LED matrix to better fit within the PCB outline. As a result, now when I go to add extra LEDs (I've tried changing back to the 0.05mil grid), I simply can't get them to line up on the same uniform pattern as the first lot of LEDs.

Without starting again, is there a way to re-align all the LEDs to fit on the same grid so they are uniformly spaced.

Argh...

Et

trialex
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Re: Eagle PCB and metric vs imperial grids

Post by trialex » Thu Jun 30, 2011 11:06 pm

hold down the control key when you select the items to be moved.

Elysiumtech
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Re: Eagle PCB and metric vs imperial grids

Post by Elysiumtech » Thu Jun 30, 2011 11:19 pm

trialex wrote:hold down the control key when you select the items to be moved.
Doesn't that just use the alternative grid which by default is 0.025mil grid? this unfortunately still doesn't line up with where the LEDs are currently.

I've also tried deleting and re-placing (on the re-schematic) the majority of the LEDS and even then, not all the new LEDs line up on the same grid as each other.

It would seem as if Eagle gets it's knickers in a knot when you switch from one grid spacing to another.

Et

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leon_heller
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Re: Eagle PCB and metric vs imperial grids

Post by leon_heller » Fri Jul 01, 2011 2:11 am

I constantly change grids with the Pulsonix software I use, and reset the coordinate origin and set it to zero on the object I need to align other objects to. You should be able to do something similar with Eagle.
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trialex
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Re: Eagle PCB and metric vs imperial grids

Post by trialex » Fri Jul 01, 2011 2:50 am

Elysiumtech wrote:
trialex wrote:hold down the control key when you select the items to be moved.
Doesn't that just use the alternative grid which by default is 0.025mil grid? this unfortunately still doesn't line up with where the LEDs are currently.

I've also tried deleting and re-placing (on the re-schematic) the majority of the LEDS and even then, not all the new LEDs line up on the same grid as each other.

It would seem as if Eagle gets it's knickers in a knot when you switch from one grid spacing to another.

Et
Nope, thats the alt key. Control moves it onto the current grid. Even easier than Pulsonix!

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leon_heller
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Re: Eagle PCB and metric vs imperial grids

Post by leon_heller » Fri Jul 01, 2011 2:58 am

I can switch between an unlimited variety of grids, though, including polar, with the same dialogue box.
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Elysiumtech
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Re: Eagle PCB and metric vs imperial grids

Post by Elysiumtech » Sat Jul 02, 2011 5:32 pm

trialex wrote:
Elysiumtech wrote:
trialex wrote:hold down the control key when you select the items to be moved.
Doesn't that just use the alternative grid which by default is 0.025mil grid? this unfortunately still doesn't line up with where the LEDs are currently.

I've also tried deleting and re-placing (on the re-schematic) the majority of the LEDS and even then, not all the new LEDs line up on the same grid as each other.

It would seem as if Eagle gets it's knickers in a knot when you switch from one grid spacing to another.

Et
Nope, thats the alt key. Control moves it onto the current grid. Even easier than Pulsonix!
Hmm I tired that and it didn't seem to do that. Maybe it's because I'm using a Mac and the keys are different but I tried all posibilities and no luck.

Ultimately I couldn't use eagle anyway as my board is larger than 80x100mm limit.

So far Kicad has been simple enough to use but I'll give eagle another chance for my next board.

Thanks all

Et

JonChandler
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Re: Eagle PCB and metric vs imperial grids

Post by JonChandler » Sun Jul 03, 2011 11:49 am

One easy way to position parts exactly where you want them is to select the metric or imperial grid as desired - the spacing doesn't matter.

Then select the part with the I properties tool. In the properties box that pops up, you can enter the X and Y coordinates. This is often easier than moving a part with the mouse. IT especially makes positioning mounting holes easy.

Regarding the control key in Eagle.... If you press [ctrl] when selecting a part to move, it selects the part by the origin. If you don't do this, where ever the cursor happens to be will be considered the origin and used to position the part on the grid.

One additional note than may save some frustration. The tOrigin (or bOrgin) layer must be turned on to move pats.
Jon

trialex
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Re: Eagle PCB and metric vs imperial grids

Post by trialex » Sun Jul 03, 2011 3:32 pm

JonChandler wrote:One easy way to position parts exactly where you want them is to select the metric or imperial grid as desired - the spacing doesn't matter.

Then select the part with the I properties tool. In the properties box that pops up, you can enter the X and Y coordinates. This is often easier than moving a part with the mouse. IT especially makes positioning mounting holes easy.

Regarding the control key in Eagle.... If you press [ctrl] when selecting a part to move, it selects the part by the origin. If you don't do this, where ever the cursor happens to be will be considered the origin and used to position the part on the grid.
That's definitely not how it works for me, at least when moving a single part.

When you move a group of parts, it matters where you click, but that is true whether you are using CTRL or not.

pstemari
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Re: Eagle PCB and metric vs imperial grids

Post by pstemari » Thu Jul 07, 2011 3:07 pm

A single part will be selected at the grid point nearest its origin. I.e. if the grid is 0.05", and you click on a part at (0.052", 0,049"), the part will be grabbed at (0.050", 0,050"). If you then click at (1.100", 1.150") to place it, the part will wind up at (1.102", 1.149"); in other words, the part's offset from the grid is preserved.

Elysiumtech
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Re: Eagle PCB and metric vs imperial grids

Post by Elysiumtech » Thu Jul 07, 2011 8:11 pm

pstemari wrote:A single part will be selected at the grid point nearest its origin. I.e. if the grid is 0.05", and you click on a part at (0.052", 0,049"), the part will be grabbed at (0.050", 0,050"). If you then click at (1.100", 1.150") to place it, the part will wind up at (1.102", 1.149"); in other words, the part's offset from the grid is preserved.
And there lies my problem. How to make it 'reset' that offset and snap back to whatever grid I'm currently working with.

This as well as Eagles insistance on routing on the grid even if a parts pins don't line up on the grid are the reason why I've switched to kicad. Maybe I just don't know how to use Eagle properly but given kicad does it without arguing...why make it harder than it needs to be.

Et

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leon_heller
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Re: Eagle PCB and metric vs imperial grids

Post by leon_heller » Thu Jul 07, 2011 11:19 pm

I think that the trick to use with Eagle if a pad is off-grid is to start from that pad. If you need to join two pads that are off grid you start a track from each pad, and join them. It's messy, but it works, apparently. I can't see why it doesn't centre a track properly when finishing on an off-grid pad, like most other packages do.
Leon Heller
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musiq021
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Re: Eagle PCB and metric vs imperial grids

Post by musiq021 » Thu Jan 31, 2013 2:34 am

Had to revive this thread. The OP's issue is a platform inconsistency. I JUST NOW figured out (thank the gods) that you need to hold down Command / Apple in order to enforce the grid during a move. Hold it down, then click on the parts origin. Nice. Hope that helps some other poor soul.

macegr
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Re: Eagle PCB and metric vs imperial grids

Post by macegr » Fri Feb 01, 2013 12:52 am

That's why I have my Command key remapped to Control on my USB keyboard :neutral:

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