Inside square corner "over-cut?"

[woodturner]

Hello all. Wondering if there is a setting I can modify for this. I've searched the archives to no avail. Trying to make an mdf Shaker style door. I used to get pretty clean corners with "Free Doors" before I got got into V Carve Pro. Using a 90 degree bevel bit and the inside profile with the square corner option. The tool "over-cuts" the corner in the M3 move. I've tried editing the bit setting from 80 degrees to 110. Under 90 gives straight a straight line segment over-cut corner. Over 90 and it starts to do a rounded over-cut. FYI, Alpha, spindle, 3mm per pass to 6mm deep, 8k rpm at 20mm/sec. Any thoughts are appreciated. Thanks.

[steve_g]

I wonder if this will do what you need?
SG

[srwtlc]

A picture of the issue would be helpful. Maybe even the problem vcp file.

[steve_g]

Well… I thought maybe the allowance box was something magic… I took the time to learn what it was about and no, it’s not. I guess Scott’s suggestion for pictures or code is the next step to help us understand the problem better!
SG

[woodturner]

Hi and thanks for the responses. Steve, that is the option I've been using for the inside square corner. I will take a few pics and post on Monday. Below is a test to 3mm deep (1 pass) and the bit (lie to software) at 89 degrees.

MS,14.9,14.9
JZ,8.000000
J2,200.000000,300.000000
J3,2006.500000,324.450012,6.000000
M3,2006.500000,324.450012,0.000000
M3,2009.448120,327.398102,-3.000014
M3,2009.448120,381.501892,-3.000014
M3,2006.500000,384.450012,0.000000
M3,2009.448120,381.501892,-3.000014
M3,2043.551880,381.501892,-3.000014
M3,2046.500000,384.450012,0.000000
M3,2043.551880,381.501892,-3.000014
M3,2043.551880,327.398102,-3.000014
M3,2046.500000,324.450012,0.000000
M3,2043.551880,327.398102,-3.000014
M3,2009.448120,327.398102,-3.000014
M3,2006.500000,324.450012,0.000000
J3,2006.500000,324.450012,6.000000
JZ,8.000000
J2,200.000000,300.000000


Thanks Again!

[Brady Watson]

How's the preview look? Is this where you are seeing the overcut corners or at the machine?

Post the VCP file (after you WinZIP it) - otherwise, there isn't a whole lot we can do for you...

-B

[woodturner]

Thanks Brady. I can't really see it in the preview. I have to zoom in to where it gets blurry. I see it in the test cuts. Pics on Monday will (hopefully) show it clearly.

[woodturner]

Good Morning...

1st pic shows results of inside square corner using 95 degree included angle (rounded over-cut) on the left and 90 degree included angle (straight line over-cut). 2nd pic shows extremes, 80 degrees-top, 100 degrees-btm. 89 degrees used to work best with "Free Doors" and I started with that, but it was worse than 90.

This morning I tried another "work around." I had it profile cut (with 89 degree setting) inside the vector using inside square corner (actually listed as "Sharp internal corners 3D) to 3mm deep. Then I offset the vector (inward) by 4mm and re-cut 4mm deep WITHOUT inside square corners checked . The deeper pass sort of caught up to the over-cut and gave a much better result. What a pain it'll be to do every custom door this way but I don't know what else to try.

Again, any ideas are appreciated. Thanks,

[srwtlc]

Are you sure about the angle of the bit? Is this the same bit that worked before? Has it been sharpened lately? Are you zeroing on the surface of the material or on the table? If on the table, do you have the exact thickness of your material set in VCP.

[woodturner]

Hi. Pretty sure about the bit angle. Tucks in nicely to a machinists protractor set at 90. Not sharpened, carbide insert though, but unchanged since the last run with free doors pgm (dedicated bit for doors). And, yes, zeroing to the top of the material. Thanks.