Start & Stop nodes for cutter path

Is there a way to select where the cut path will start when a polyline, circle or rectangle is selected.
I’m use to breaking a closed polyline and then rejoining the nodes at the position I would like the cut path to start. Anyway to do this with Carbide Create?

I’m afraid that Carbide Create doesn’t offer that option — you’d need to export to an SVG, then make the change, then reimport, losing any toolpaths attached to that geometry.

I’m getting curious about why you care deeply about where the cut starts… it’s “round” so you’d end up with the same thing anyway :wink:

I can’t find it right now, but I remember a post from someone about a trick to emulate the “lead-in” feature that other CAM programs have, by adding extra geometry (say adding a small loop on the edge of a rectangle), such that the generated toolpath would start the profile cut of the rectangle at a precise point and with a precise incoming trajectory (the lead-in path). Maybe this will ring a bell to whoever came up with this technique, I failed to find it again. Anyway, this technique may also be used to force the point where the cutter enters a profile path. It’s tedious anyway (to have to add geometry to do that trick)

1 Like

Some materials are anisotropic (wood) and cut direction/order can have an effect on chipout at the corners.

1 Like

Using a pressure foot attachment (http://www.widgetworksunlimited.com/CNC_Pressure_Foot_for_ShopBot_PRT_p/cnc-pressure-sb_prt.htm)

I am cutting through the material without tabs. If the start and stop points are on a straight line the part comes out perfectly. But if the start and stop are on an arc it sometimes will leave a small nick in the product.

1 Like

I’ll try this again but the artwork was created in Coreldraw with the start/stop node in the position I want. I then imported the svg file but Carbide Create ignored it and placed the start/stop node where it wanted to.

@gsam: just in case the “nick” you are seeing is caused by tool deflection, I found the old thread I was referring too, it includes the trick I mentioned:

Check out @Danelectro’s post

Yep, I know exactly what you’re talking about. On industrial CNC routers the lead in and out cutter path is usually a 3-axis motion used to reduce the Z-axis force on the spindle. The top and bottom bearing on a spindle can handle the force applied in the X & Y axis but they don’t handle the force applied on the Z-axis very well. I don’t want to admit how many 10hp spindles I destroyed before I learned this. By the way, quick change tool spindles do not have this problem they are built completely different.

I did not think about it but the lead in and out cutter path could solve my problem. Thanks!

1 Like

Create the file with that node open with a small gap, then move the added node to the node which is in the correct position and then Join to close?

If that doesn’t work, send the file in to us at support@carbide3d.com and we’ll look into it.