[sdiy] PCB faceplate large hole creation?

[Brian Willoughby]

You have to call your fab house to verify, but I'd say that 1) is normal.

Sometimes, they'll break a bit and change to a different size. If you designed for 2) and they lost the bit, they'd have to adjust the file based on two measurements rather than one.

A fab house should have tolerances advertised. That's how close they'll get to your specifications, and the tighter the specs, the more it costs.

These are great questions, but sometimes it's surprising how difficult it is to get answers even when you're talking to the folks who'll do the work. If I had a dollar for every time I've heard, "Whatever you need, we can make it work!" - I'd be a rich man. I often call because I want to find the cheapest specifications that they have so I can adjust my design to work within that, but the fab house flips that around and claims they can do anything. I always assume that it will cost more if I unknowingly challenge the limits of their setup(s).

Brian


On May 28, 2021, at 01:46, Richie Burnett <rburnett at richieburnett.co.uk> wrote:
> For PCB profile routing (milling) is it normal to:
> 
> 1. Draw the Gerber line where you want the PCB edge to end up?  (and they make allowances for the cutting tool diameter.)
> 
> _or_
> 
> 2. Draw the Gerber line where you want the centre line of the cutting tool to follow, knowing in advance what the cutting tool diameter is, so that you end up getting the right size cut-out?
> 
> I've encountered both approach, and on occasion been caught out!  Just wondered if there was a consensus on the way it is normally handled?
> 
> I can see advantages and disadvantages to both methods.
> 
> -Richie,
>