how do I size PCB images?

[ilovetherat]

Hey guys I am new to eching I have built a few pedals.

I am having trouble getting my PCB layouts to the size I need them with the software I am using. Everything I print is either to big or to small.

Is there a universal PCB layout size?
Do you have any advice?

[sevenisthenumber]

good question...  I wanna know myself. 

[davent]

What software are you using to draw your PCB's?

dave

[served]

I am currently Using Microsoft's Visio for that.
I know, MS is not a good thing and its not free. But I just got it and so far I am sadisfied. Will use it untill I get some time to look something else.

[nosamiam]

For me it helps if the PCB has an opamp on it. Adjacent opamp pins are 0.1" apart. Pins across the chip from each other are 0.3" apart. Resistors with "standard" lead spacing are also 0.3" apart. If the program you are using has some sort of grid or ruler you can figure it out that way.

If you can't do it that way and you have an IC on the board you can print on regular printer paper and use the actual chip to check hole alignment with the pins. If it's off, resize, reprint, and recheck. Repeat until it come out right, then print that on your Press & Peel or photo paper or whatever.

If there's no IC in the circuit and you're just dealing with resistors, caps, & transistors, pad spacing isn't that critical.

[KazooMan]

I use the print and compare to an IC socket that Nosamiam mentioned for the final check.  I start out by printing and then measuring some distance on the board such as the distance between several pins on an IC.  You can compare that to what you are targetting and see what correction you need.  Just go into the printer properties dialog box and scale the print to the proper percentage.  Once I have determined the proper scale I usually record the value right on the PC layout for future reference ("print at 87%" for example).

[PRR]

Visio is a "chart" tool. You might want to print a chart small for a sidebar or big for a poster. Visio isn't about things which need an exact size.

Proper tech layout tools let you say THE SIZE. 0.1" between pads will BE 0.1" between pads.

But you have Visio, and it is good stuff. Test-print to scrap-paper, measure, note what correction is needed to make your pads fit your parts.

[John Lyons]

If you can set a grid pattern in Visio you can scale the layout to that grid.
I do this in photoshop.