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Questions relating to designing PCBs
By Elysiumtech
#129553
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
#129560
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
#129562
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.
By trialex
#129564
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!
#129625
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
#129652
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.
By trialex
#129656
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.
By pstemari
#129813
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.
#129820
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
#129823
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.
By musiq021
#154924
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.