Re: Which Mini CNC mill #mill
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I keep seeing this post about getting your bed flat.
I don’t even worry about it.
I get great results using the height mapping routine in candle.
You cannot trust within .05mm a flat bed.
When I height map there is almost always .5mm difference across a 10mm X 20mm piece of PCB.
It gets even worse when the pcb piece is bigger.
I don’t know how anyone can do this without height mapping.
Sent from Mail for Windows 10
From: John Ferguson via Groups.Io
Sent: Monday, February 10, 2020 8:01 PM
Subject: Re: [pcbgcode] Which Mini CNC mill #mill
how did you get your bed flat?
On 2/10/20 6:03 PM, Dan.Staver wrote:
> I get good results using very thin double-sided sticky carpet tape to
> hold the PCBs down for milling.
> Dan Staver
> Tave Tech Corp.
> 3130 Hollycrest Dr.
> Colorado Springs, CO 80920
> +1-719-359-5352 - office
> +1-719-502-1675 - cell
> tavetech - Skype
>> On Feb 10, 2020, at 11:06 AM, John Ferguson via Groups.Io
>> <jferg977@...> wrote:
>> Maybe there should be a subject change. Have a look at the two
>> fixtures whose photos I've attached.
>> I make printed circuits which are about 2 inch by 3 inch. I found
>> that I couldn't get reliable trace widths unless the board was
>> absolutely level to the machine. So I started with an MDF fixture
>> bolted to the milling table and drilled and tapped in four places so
>> I could use nylon screws to hold the pcb down. Every time I do a new
>> setup, I mill the surface of the fixture with a fly-cutter to level
>> it. This works 100% of the time. I've had no bad experience with
>> PCB's not being of constant thickness.
>> I had such good luck with the MDF board that I made a better one for
>> HDPE. I also made a jig to drill the holes in the pcb so they would
>> be sure to align with the ones in the fixture.
>> Frankly, I don't see how you could ever get reliable cuts without
>> leveling the surface the pcb is secured to while etching.
>> DSC07301.JPG: https://groups.io/g/pcbgcode/attachment/8053/0