Auto-relocating of part placement problems


#1

Hi,

unfortunately i’m facing an error which totally breaks usability for me.

When inserting a via1-part into the pcb sketch and trying to set up his placement whenever i filled one of the location textboxes fritzing seems to alter my dimensions. I’ve got a PCB of 400x90mm, and i was trying to insert row of 5 pcs of vias in a row to make a custom header (standard 2.54 spacing), i was trying to place the first via at x= 28.1mm y=14.75mm
When i enter those dimensions my 28.1mm are being altered to 28.077mm and my 14.75mm to 14.739… I tried disabling the snap to grid feature, thought it might be a problem with the imperial measurements in the grid, switched to mm in the grid, but nothing changes. There seems to be an internal bug that prevents me from placing whatever elements where i actually want/need them. This wouldn’t be a big problem if i would be able to not care about relative measurements between seperate rows of via’s, but i need to mount some stuff at those exact locations, thus need the placement to work. Propably just a minor, well hidden though, bug.

That aside the whole component creating/altering thing has to change to make it actually usable, but i’m sure you’ve heard that 1-2 times already.

I’d appreciate help of any kind, i really like the look&feel of fritzing and want to use it, but for now i can’t.

Thanks!


#2

Assuming you are trying to do this from the parts editor, you may be able to work around it by saving the part and then using Inkscape or another svg editor to move the vias to where you want them in the pcb svg and then re save the part to import back in to Fritzing.


#3

Well, that workaround is not looking far enough. If there is a problem with placing elements precisely i could of course try to build the component completely in inkscape or whatever, but when i’m aligning those parts in the pcb editor i’ll have the exact same problem again. Ok, i could then build an svg of all of my parts together, but then… why use fritzing at all, if i have to do everything in an svg editor anyway?

Thats the problem. I’ve specified a bug, and that bug will likely make others turn away from fritzing too.

It seems to be related to this: Exact placement of holes on boards
What are the chances of someone looking into the code and actually fixing that issue?


#4

If you need zero tolerance, something that you don’t see in machining, you should not be using FZ, or probably not any free EDA. 9 micron way good enough for beginners, which is what it was designed for, so if you need better try the free version of Altuim, which is practically the same as the version that is worth $1000s.


#5

Sure, i see. It obviously is a feature. Was i blind!
I can always use something else, but i was hoping that somebody would care about bugs in their beloved software. If you ever actually tried to place a lot of components with those offset measurements, you’ll propably know that it gets annoying to recalculate every position of every part that you add to the sketch.


#6

Yeah I know. I put a request for bigger X,Y coord box and a ruler as a patch, but that was a while ago.

In actual fact if you could position stuff perfectly in the drawing, that actual machining centre can’t drill it in the perfect position, because it has a tolerance.

If this is a thing that you will use a lot, you could make it a part. I went through this last week with my DENSO ECU connector, and I could get the svg perfect dimensionally. But when I checked the exported gerber it wasn’t perfect - the error averaged out 6/10,000 of a mm -, but that could be the conversion of units.

It was out about 6 - 1000 of a mm ADV, now it’s 6 - 10,000 of a mm.

Gerber - Actual - ABS Difference
3.50012 3.50000 0.00012
3.50012 3.50000 0.00012
3.09880 3.10000 0.00120
2.99974 3.00000 0.00026
3.00228 3.00000 0.00228
2.99974 3.00000 0.00026
2.99974 3.00000 0.00026
2.99974 3.00000 0.00026
3.00228 3.00000 0.00228
2.99720 3.00000 0.00280
3.10134 3.10000 0.00134
3.50012 3.50000 0.00012
6.20014 6.20000 0.00014
3.09880 3.10000 0.00120
2.99974 3.00000 0.00026
2.99974 3.00000 0.00026
3.00228 3.00000 0.00228
2.99974 3.00000 0.00026
2.99974 3.00000 0.00026
2.99974 3.00000 0.00026
2.99974 3.00000 0.00026
3.09880 3.10000 0.00120
3.50012 3.50000 0.00012

The node coordinates are perfect in INK now, so I assume it must be the conversion in the Gerber from inch to mm.

Old drawing had mysterious XML somewhere, so the problem is solved by making a new one.