Wrong radius!!!

[nakaroto24]

Hello, I'm machining a part with two thru windows the print calls out for 1/8 radius on the corners of those windows. I used a 1/4 flat endmill to do a pocket toolpath but for some reason my corners are coming out with a way bigger radius about 9/64. The arcs on my geometry are 1/8R. Could this be a machine parameter problem? Or am I missing a setting in mastercam?? I got the geometry out of a solid model. Do i need to convert my arcs to square corners???

[WallyL7]

post the file...

Could be the machine cutting the corner. At .015" larger than your actual radius it would seem to be machine error.

Can you read g-code? Is it correct? (it shouldn't be using any G2's or G3's)...you can start by taking out the corner radius' but it shouldn't be your problem.

[nakaroto24]

/( finish windows -level 12- )
N5080 X5.9362 Y-3.0247
N5090 Z.1
N5100 G1 Z-.325 F50.
N5110 Y-3.137 F70.
N5120 G3 X6.0484 Y-3.2492 I6.0484 J-3.137
N5130 G1 X7.2996
N5140 Y-.7468
N5150 X4.7972
N5160 Y-3.2492
N5170 X6.0484
N5180 G3 X6.1607 Y-3.137 I6.0484 J-3.137
N5190 G1 Y-3.0247
N5200 G0 Z.25
N5210 X5.9362 Y-3.0267
N5220 Z.1
N5230 G1 Z-.325 F50.
N5240 Y-3.139 F70.
N5250 G3 X6.0484 Y-3.2512 I6.0484 J-3.139
N5260 G1 X7.3012
N5270 G3 X7.3016 Y-3.2508 I7.3012 J-3.2508
N5280 G1 Y-.7453
N5290 G3 X7.3012 Y-.7448 I7.3012 J-0.7453
N5300 G1 X4.7957
N5310 G3 X4.7952 Y-.7453 I4.7957 J-0.7453
N5320 G1 Y-3.2508
N5330 G3 X4.7957 Y-3.2512 I4.7957 J-3.2508
N5340 G1 X6.0484
N5350 G3 X6.1607 Y-3.139 I6.0484 J-3.139
N5360 G1 Y-3.0267
N5370 G0 Z.5
N5380 X2.3928 Y-3.2511
N5390 Z.1

[nakaroto24]

I know a little of G-code. I tried taking out the arcs and just mill square corners but still a 1/4 endmill wont get me a 1/8R. Im using a hurco machine by the way.

[holbieone]

Does your tool have run out , check it from the tip

[nakaroto24]

Its a brand new zrn coated endmill and i only use for finishing and i never plunge into material with it. The holder looks in very good condition.

[holbieone]

I'd still check it

[nakaroto24]

alright i will check it. If that doesnt work ill will just use a smaller diameter endmill. Thanks for the help.

[cadcam]

DO you hve a 3/16 to roll the corners instead of forcing the corner. Is the corner a clean cut or is there chatter?

[nakaroto24]

DO you hve a 3/16 to roll the corners instead of forcing the corner. Is the corner a clean cut or is there chatter?

Yes i was thinking of using s 3/16 to clean my corners. The corners using 2 different 1/4 endmills (carbide coated, carbide non coated) do chatter a little bit.