New to the forum, have owned a SO3 XXL since the summer but just now really starting to try to get it up and running. Haven’t made any real cuts so far other than trying to surface a couple of supplementary spoil boards.
My machine is on a homebuilt wooden workbench with a 1.5in thick MDF top. The machine is mostly square, and by that I mean one side is 1/16" off from the other (Y1 front to Y2 rear specifically), but I was told that for woodworking (guitar building, mostly), this is good enough. The machine is also as close to levelled as I can get it using the stock feet.
I trammed and squared the spindle as well as I could on the supplementary spoil board prior to surfacing it, hoping that it would then be able to tram it a second time afterwards to get it perfect.
While running a surfacing job on the spoil board to take off 3/64" hoping to level it, I noticed that the router speed “sounded” like it slightly dipped at certain points. When the job concluded, I noticed that it was at the same spot along the X axis throughout the job. I noticed that the router “sounds” like this even when not under load (running a job above the stock). I tried different endmills and the sound is still present.
On the spots where the router sounded like it ran at normal speed, the board is smooth as if the router is perfectly tram. But where the speed seemed to dip, I notice a slight ridge. Likewise, the transition when running my hand right/left or left/right feels like a slight bump as if the dark spots are slightly higher. Note the darker spots mid-right which were barely touched on this first pass. See attached picture.
Not sure about our router but the picture of your spoil board looks like ridges that run from front to back. This would indicate that your router is not square. Depending on what Z axis you have first take hold of the z axis and try to move it round. If it feels loose then look at your v wheels. If they are loose tighten them and flatten your spoil board again. If the ridges are running from front to back then you need to adjust your router mount. To adjust the mount you can do that with several methods. One method is to put a dial indicator in our router and rotate the router around by hand and see the variations. I use 123 setup blocks and that requires removal of the router from the router mount. Then put the blocks on the spoil board and level your mount side to side. Then reinstall your router and flatten your spoil board. The ridges from front to back indicate the router is skewed side to side. If the ridges are accross from side to side then your router needs to be shimmed to level it front to back.
Take a look around the forum for exact procedures.
One very critical step before doing any adjustments is that your Y axis are level and square. Also check your base plate that it is level. If your machine is not level you have no reference from which to check.
If you need to adjust your v wheels you insert an allen in the bolt and loosen slightly. The nut is an eccentric and you rotate it to change the level. When you are satisfied hold the wrench on the nut so it cannot rotate further and tighten the allen bolt. If you only tighten the allen bolt the eccentric will move.
Assuming your surfacing op runs in a raster fashion in the left/right direction (horizontally), and given that those light and dark stripes are much wider than the tool diameter, I would look at the v-wheels on the X/Z carriage first. If one of them is slightly loose, or (my bet) one of them has a crack or is not perfectly round, you could end up with a subtle pattern like this, the width of the stripes corresponding to one full revolution of the vwheel, producing a ridge/bump each time the wheel rolls over its crack.
The diameter at the inside of the V groove is somewhere around 18-20mm I think (I can’t find the exact dimension right now), so the circumference would be near 2* Pi * 9 to 10mm ~= 2" and change. I notice your board shows 16 stripes, so that would loosely match the 32" inch X travel of the XXL. Or maybe I’m just trying to convince myself this is that, and it’s a coincidence Still worth checking vwheels I think.
Still worth checking vwheels I think.