If you look at the bottom right, it’s very shallow. I have a feeling something isn’t level
The stock system’s connection between the y-plates and 2020 base is pretty sloppy. That is the likely issue (one side lower than the other).
2 Possibilities:
- Your waste board is not flat / parallel with your gantry.
Can be fixed by surfacing your wasteboard or adjusting your gantry. - Your stock material was not flat / even thickness.
Can be fixed by planing your stock surface, first, prior to milling, with the cnc itself.
BTW Do not think of your CNC in terms of level. All measurements and cutting are in relationship to your gantry; not gravity, your table, etc…
I had the same issue. I had to level my waste board. Just took my 1/4" endmill and zeroed it on my wasteboard and set the DOC to .001. Then ran it across the whole board in the x axis. Then did the same thing in the y axis. It helped a lot.
Rather than using a small bit, get something bigger so you can flatten your waste board quicker and more accurately. I bought the following set:
http://www.ebay.com/itm/141543460612?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
I removed the bearings because I don’t need them for the way I use the bits, but they can be put back easily. I use the 1 1/8" bit to flatten my board by setting up a pocket cut to carve in both X and Y directions. My first cut takes about 0.003" in X, then 0.002" in Y. I use the 3/4" bit for cutting out boxes.
I’m not sure I want to do that to my waste board just yet. I’m more interested in trying to figure out why it’s so far off and correct it
As Jeremy pointed out above, you ideally need to take a skim off your wasteboard if you want it to be parallel and flat in relation to the axes of your machine. I guess you could spend time trying to shim things, but I suspect it’d be a never-ending process and you’d still struggle to correct for inaccuracies.
That’s kinda the reason my wasteboard is plain MDF. I love the look of those machines with wasteboards which have been beautifully silkscreened or engraved - my poor old wasteboard usually looks more like an art project; it is however parallel to my X &Y axes.
Do note that for best results, you want the machine nice and square / level before you machine the wasteboard, or you may not be happy with the results.
In particular, you will want both Y rails parallel to each other and level, and the router as square to the work surface as you can make it.