Uneven finished surface

[wateague]

How can I correct an uneven surface?
I have Aspire 10.012 and using V-Carve/Engraving toolpath.
Set at a depth of 0.125 deep and using 3 clearance tools.
I also use a touch plate to set tool depth.
First using a V 60 degree by 0.5 dia. First clearance tool a 0.75” End Mill, second tool a 0.25” End Mill and at last a 0.125 EM.
I have a Shark HD 2.0 with a new H5 Gantry upgrade and 3 HP spindle.

[TReischl]

A picture would help since an "uneven" surface can mean a lot of things.

But, since you are using a touch off plate that eliminates at least one issue.

Without seeing a pic my best guess is that your spindle is not perpendicular to the spoilboard. Flattening a spoilboard with a spindle not perpendicular will produce "scalloped" looking cuts.

A spindle is NOT trammed to the surface by using a square, it is not accurate enough. A typical method that works real well and is cheap is to bend a rod that fits your collet (usually 1/4 inch diameter) so that it has two opposing 90 degree bends, sort of like an S but without all the curves. This does not have to be precise. Then you use feeler gages as you swing the gage around in the spindle. A feeler gage can be nothing more than a piece a metal, does not matter what thickness. When you get the same amount of drag all the way around your spindle is perpendicular. If you are a fussy sort of person you can spend upwards of $100 to buy a fancy gage with dial indicators to do the same thing.

Edit: You should always use your touch plate in more or less the same position for all tool setting for obvious reasons.

[SteveNelson46]

Shopbot has a great video on Youtube on how to level a log slab.