Unofficial way to surface your wasteboard

[Aiph5u (Aiph5u (not affiliated with Onefinity))]

Hey Jeremy,

@JeremyS

What speed did you use on the X-Y direction? Do speeds and feeds matter when trying to flatten an MDF board like this?

Of course it matters since you can always overload your hand trim router if you use one. Especially you should only remove the wasteboard material with a shallow depth. It is known that when the hand trim routers burst into flames, it was usually when they used one of these large (ø > 25 mm / 1") flattening bits

@JeremyS

Are there any downsides that anyone can think of about using the z-axis near its limits? This is my first cut with my machine and don’t want to break anything. But moving the z-axis to the lower bolt holes seems silly if the machine can reach the board with the flattening bit.

Of course with a CNC you can destroy the CNC, or, at least, you can make a hole into your wasteboard But if you want to flatten your wasteboard, this is exactly what you want: Mill lower than the top of the wasteboard.

@JeremyS

The Onefinity video with this approach has the presenter talking about “Extreme limits” a few times which makes it seem the things is going to fling itself apart if you aren’t careful. Flattening A Wasteboard On the Onefinity CNC - YouTube at 1:49.

Don’t worry, should your g-code program to flatten the wasteboard be outside the workarea of the machine, all you will get is one of the famous “limit errors” and the machine refuse to execute it…

What the video means is that because you want to flatten the entire wasteboard (and not leave out some part of it), the file is as large as the machine’s workarea, so the workpiece zero has to be set accurately, or you will get a limit error.

There is a lot of info about flattening your spoilboard in this forum.

Before flattening the wasteboard, did you make the checks that the machine is rectangular (“squared”) and that it is coplanar (not twisted)

Welcome to the forum!