I was wondering how accurate is the Genmitsu 3018 pro? A first approximation of this can be done by measuring the piece of aluminium I machined as a test case.

I engraved the circle and square to a depth of 1mm in 0.1mm steps. I must admit that I slowed the feed rate down to 60mm/minute and there may be a better balance between depth of cut and feed rate.
However, for now this does give me a sample I can measure.
The circle was 25mm in diameter and the square was 28mm across. When I set these up in Carbide3D I asked for the cutter to run along the centreline with no offset.
As I used a 2mm diameter slot drill this means the circle outer edge should be at 27mm and the inner edge at 23mm.
The square inner edge should be at 26mm and the outer edge at 30mm.
Measuring these at numerous points with a digital caliper (Moore and Wright) I get:
- Circle inner: 22.73, 22.76, 22.74, 22.76mm
- Circle outer: 26.98, 26.97, 27.04, 27.02mm
- Square inner: 25.79, 25.78, 25.79, 25.80mm
- Square outer: 30.03, 30.04, 30.07, 30.04mm
Interesting that the tool appears to be cutting 0.2mm wide, this could be wobble on the spindle or collet.
However, interesting that the over this small X and Y distance we have an error of around +/-0.04mm
That is not a bad result to the question How Accurate is the Genmitsu 3018. A machine that costs less than £200.

Engraver Spindle Sketch to Parts
Working from an Engraver Spindle Sketch to Parts can be daunting. However, I very rarely work with more than a few sketches and key critical dimensions.
This is all about improving the spindle of the Genmitsu 3018-Pro.
My aim was to use an ER11 chuck on a straight 10mm spindle and employing the existing drive motor.