Tool path not same as drawing.

[slicric]

I am trying to cut a 1 inch by 3 inch rectangle out of quarter inch material. I am using VCP7 and drew a 1 inch by 3 inch rectangle. I used an outside profile cut. I created the G-code and loaded it into my CNC Shark control box. The final cut measured .970 by 3.0. In other works, the y axis was .030 inches short.

I have checked the lead screws for tightness and they are good, also there is no binding.
FYI, I changed the X and Y orientation over a year ago. So Y is now my gantry leadscrew!

Can this be fixed by changing any reading on the CTRL + E 787?

Does anyone have any idea what is causing this?

[drueth]

Slicric (Xiguatou)

I have spent most of my time learning and have found the Shark Pro HD can do very precise cuts ( if it is set up properly ). The thing that I have learned is the Shark is not able to go as fast as the big boys can. Often I have to go back an edit the tool path to back off on my cut . It all depends on the wood you are cutting and how sharp the bit is you are using. The other big problem is most bits are not what they say they are. ie a .25 dia EM is most likely a 0.23 dia This would cause a 1 in square to be under or over by 0.02 inch. if you cut inside or outside the line.

On the Vectric site severial people have left you some good ideas to try. What version of the shark do you have. Have you made severial test cuts and is they Y off by the same amount each time???

[slicric]

drueth,
I have the Shark Pro Plus, it is not the HD one. I have my machine slowed down and working about 80 and am cutting .25 inch poplar. I am going to do another test today and cut a 3x1 and a 2x3 and check the results. Might even reload the controller drivers.
Will get back to you with the results.
Thanks for input!

[slicric]

I have cut 2 pieces one 2x3 and the other 3x2. In measuring them, I still have a .030 short end on the Y axis. I am thinking it is a mechanical problem. I will report back in a couple days to see what I find.

[tonydude]

Have you checked the couplings on all your motors? Could be loose. Try tighting them up.

Tony

[slicric]

Tony, I have checked and also tightened the screws but did not help.
What I did find was a spindle on my router that was loose. Funny thing is the looseness was only in the Y direction. I took the router apart and center punched the bearing seat and I have recut the pieces and now it is cutting pretty true. I am happy with it now.

I will try some other pieces, but I feel pretty confident it is now good. Waa Hoo!

Thank you all for your inputs.