Hey guys I have been cutting cabinets with my lowrider 2 cnc and noticed that when I design a cabinet in fusion 360 the sizes I draw are not what the machine is cutting. I figured it was a setting in estlcam but so far no luck on finding anything. So I drew our a scale .25 .50 .75 1 2 and 6 inch squares. When I cut the file I get .24 .49 .74 .99 1.97 and 5.96 is there a way to adjust for this to get accurate cuts. I have added the dxf file
scale1a_2.dxf (4.3 KB)
I have milled a lot of cabinet parts with my Lowrider 2 and occasionally the dimensions are inaccurate.
As a noob, my initial thought was to compensate using adjustments in the CAM. By the way, what is the advantage of using Estlcam over the CAM built into Fusion 360?
To date, I have not needed to adjust dimensions in CAM to achieve accurate cuts with my CNC. My issues have always been mechanical.
I have found backlash due to loose grub screws, loose belt tension, poor connection between the bearings and tubing on the router plate and loose router clamp.
I have found inaccuracies due to missed motor steps or gantry flex caused by excessive DOC or WOC. My most recent issue was that the diameter of the bit was less than the nominal dimension. For that one I created a copy of the tool I was using and changed the diameter to match the bit.
All of this to say that, personally, I would rather be sure the machine is dialed in mechanically before I start adjusting the toolpaths to compensate.
That seems pretty accurate to me for cabinet work. Wait until your perfect cabinet hits your imperfect wall.
Definitely check over the mechanics as others have mentioned (belt tension, loose bolts/set screws, machine squareness), then make sure you have a light finishing pass set up and that your bit size is actually what it is. If you are getting consistent sizing that is still off then you will need to play with the steps/mm. A dial indicator will make that step easier but you can do it with test cuts as well, it doesnt take much so work in .1 or .2 increments (that .1 or .2 might be all you need anyways from the default 100).
And he means a LOT
I think you can adjust the E-steps value in the mainboard to tweak the cutting accuracy, like calibrating extrusion on a 3D printer.