Lost steps ?

[Xray]

Unusual problem here that has me stumped, as you can see in the lower right corner, the cut started too deep and rough ,, Then at a certain point, the cut elevated and the majority was fine. Did one of these very similar the other day and had the opposite problem in the same corner, started off way too high at the same spot, the leveled off and the rest was fine. That one I sanded out the hump, not much I can do for the overcut. Was thinking about filling the recess with clear epoxy, then once that dries do an epoxy pour on the whole thing ,, Might look nice but the cut would be just as visible. Think I am going to just recut it a little deeper, this one I used a 45 angle cause I didn't use a roughing pass, with all the material hogged out now I can do a straight 0 and see what happens. Nice looking tiger striped grain, this thing will really pop once its coated. Used a brand new bit, wasn't loosened up at all, in fact if it was the results would have been far worse than this.
IMG_9529.jpg IMG_9531.jpg

[Ken Rychlik]

If you are running that without a roughing pass on a stinger 1, my opinion is you are asking to much from the little machine. Depending on feed rate and acceleration settings, you can probably get it corrected, but when you re-run this, you will see what a roughing pass will do for you.

[SteveNelson46]

Doug,

Are you using V-Carve or Aspire? Did you initialize the machine before starting? Did you create the component yourself or import it as s photo and create the component with the software? What bit are you using? What is the stepover of the bit? What is the X-Y feed rate? Need a little more info to give any good advice. I'm not trying to be snarky. Just trying to help as best as I can.

[Xray]

Ken, using a 45 angle is a common strategy to cut without roughing and has always worked until now, it starts out with a tiny bite in the corner and works its way diagonally instead of width wise, well within the capability of the Stinger but if this continues, I'll have to try a rough pass to see if that solves the problem, am, doubting it.
I use roughing when I feel its necessary, this is pretty soft wood and stress shouldn't be a factor.

Steve, aspire, I tend not to initialize, I center my workpeice then 0 x/y which accomplishes the same thing. Have had this model for years and have done dozens of them. 1/32 TBN bit, probably 13% stepover, feed rate probably around 200

[rcrawford]

Does look like lost steps. Really strange that it happened in a similar spot twice though. Since you are losing steps on the z-axis and not on the x or y axis, I would tend to think its NOT because your machine is overworked (the x and y axis are doing the heavy work when you cut without a rough pass), but maybe you have the z-feed too high and the stepper motor can't keep up on those rapid changes?

Or maybe you are getting a little slipping in the z-axis linkage. Does your machine have the air assist to reduce the weight of the z-carriage? Are the set screws tight on the ballscrew? Maybe its time to swap out the z-motor (especially if you run 3D cuts all the time). Could also be electrical interference, maybe from static built up on the dust collector. Or maybe a loose wire somewhere. Check the wiring on the driver.

[Xray]

Well I reran the same toolpath just a little deeper and it went off without a hitch.
This would rule out alot of things, including toolpath/software errors, everything was the exact same except the material had been hogged out so maybe it was a stress issue, just tough to see why it eventually raised, and at the exact same spot a similar model lowered [sure can see those fuzzies in high res, will have to do a bit more sanding on this]

[Gary Campbell]

I've seen that happen during file run at a similar place due to the dust hose moving and coming in contact with the Z car