Looks great on preview but... cut out leaves large radius.

[jimwill2]

When I preview this cross on Vcarve the corners are pretty tight. I am using a 90-degree v-bit and engraving 1/16 in. deep. I also cut out the heart/cross with a 1/8 in. end mill (18" deep.) It looks great on the previews but makes a large radius on every corner, inside and out. What's the deal? What am I doing wrong here?

Thanks,
Jim

[zeeway]

Are you using Mach3 as the post processor for your machine? If so, click Config, and then click General. Near the center of the screen you will see a box labeled Motion Mode, in which there are two choices: Constant Velocity and Exact Stop. I think you need to have Exact Stop selected to get sharper corners. If you are not using Mach3, look for similar choices in your machine control software.

Good luck,
Angie

[david_r]

Try to add G61 in the beginning of G-code.

David

[kingjamez]

An alternative to exact stop is to increase the acceleration of your motors. I had mine down at 4 the first time I cut something out, got rounded corners. I increased the acceleration to my motors max (40) and no more rounded corners.

[jimwill2]

Thanks for all the advice! I was using the default speed of 100 ipm, when I slowed it down to 30 it made perfectr corners. What speed do you use for detail routing?

[zeeway]

The answer here will depend on your machine and its rigidity. I have made detailed crosses at 10ipm. At 50 ipm, I still can get good detail, but the edges are more raggedy.