I’m in the process of making several US Flags. This afternoon, I vcarved stars on 2 flags. Ran the same gcode on both, used probe for x, y, z on both (first with 1/4" end mill, then z again with 60 deg vee bit) and ended up with different size stars.
These are both the first stars in the union and you can see that one is exactly 1" across and the other is 1 1/16" or so. Some of the others are even bigger. I’ve checked the belts and pulleys and they are all tight.
These were run right after the first, and as I said used the same gcode file. Any ideas what could cause this?
Adding to @WillAdams’s answer, from the picture it looks like your stock indeed has thickness variation from one plank to the next, and with a 60deg Vbit it only takes 0.05" difference in Z between the spot where you zeroed and the area being cut, to produce a 1/16" difference in width of the V-cut.
OK, I can see how a board being un-even would cause this with a Vcarve. So since I’d rather have consistency I will try pocketing with a small end mill. Obviously these are stars so ideally there should be sharp points. Can I run a 1/32 end mill safely in pine? I don’t think I’d want to do the entire pocket with a 1/32 but I could do 2 tool paths to do a clearing cut and a fine cut. Assuming a 1/32 is acceptable, what would be good F&S for that?
Hard to tell, it also depends on the variation between the place where you set your zero and the thickest part of the board. The idea of using a surfacing pass would certainly help make things more equal for consistency.
Unfortunately the piece doesn’t really lend itself to a leveling pass. I use 1 1/2" wide boards that are stained blue / red or just blue, put it together then do the stars. A planing pass would remove the blue. I have thought about doing the union as a separate piece and assembling the rest of the stripes around it. Right now I have an order for 12 flags that I need to get done and all the wood is cut into strips. Maybe I’ll look into a solid union after this.
at least when you do the Z probing, do it where the stars are (probably in the middle of the stars area), not at the very edge of the wood… got to be closer than actually at the edge
To salvage your job, I would pocket the union area, re-blue it and cut the stars out of the flattened area. Use a ballnose bit to outline the union area and de-accent it.
