3D Contour Stepdown flat surface

[JJackrabbit]

I have a fillet of 8mm, it will end in a flat surface.

I use a 3d contour to machine the fillet. Works great.

My stepdown is 0,4mm with a 10mm ballnose. Finish is good but at the end where the fillet meets the flat surface it will also use a 0,4mm stepdown. This will result in some material left behind at the bottom. How can I remove the last material without making the stepdown smaller?

[Matthew-R]

@JJackrabbit Thanks for posting your question to the forum.  Would you be able to attach the file so that we can have a look and suggest some strategies?  Thanks again!

[JJackrabbit]

Hello Matthew

See attachment of the drawing

[523Industries]

Hi Jack, I took your file and added stock to the setup (fixed sized box) and then used 3D Adaptive Clearing to see what's left over from your Contour.

I'm new to this (CAD/CAM) so maybe something can be adjusted in the Contour operation, but for me the simplest thing would be to add a Parallel operation to clear the peak at the end of the transition from curved to flat.  I mistakenly set the Stepover to 0.8mm but you can obviously adjust that down to 0.4mm as you were using before.

Hope this helps!

[JJackrabbit]

Thanks Nick

It seems it will do the trick!

[523Industries · Accepted solution]

You're very welcome!

I've been working on this some more because I really think the Parallel strategy is a better match for what you're trying to do compared to Contour, mostly because I think all of your desired machining can be accomplished with one operation.

I'm glad this worked but hopefully one of the experts will chime in and tell me what I'm doing wrong.

Edit: Ok, just saw another post in the CAM forum and it gave me an idea.  I couldn't get Parallel to do what I want because if I chose "tool outside boundary" or added an offset to the selection/bounding box it kept wanting to waterfall or wrap over the outside edges when I wanted a straight across cut, and was worried that "tool center at boundary" was going to leave unfinished stock.  There's probably a cleaner way to do it but I extended the stock to allow the Parallel too path to go beyond the edges in a straight line.

Also, I noticed that although minimal if you change the Retraction Policy under the Linking tab to Minimum that it'll shave some time off the operation.

[JJackrabbit]

I changed all my 3d contour ops to 3d parallel. Machining time for some ops changes from 9 minutes to 3 minutes!

I will dig deeper into the settings this weekend.  I milled a test piece today and results are great 🙂

[523Industries]

Been racking my brain over this because I knew there was a better way of extending the tool path beyond the edge in a straight line.  No matter what I did I couldn't do it within the Parallel settings so I resorted to fooling the tool path in following a Loft beyond the edge of your original model.  Please see attached and check the design history to see what I did and how I did it.  I've only extended one side but if you follow what I did then you can extend the other side yourself.

A note about your model: I can't say how this might effect anything but it's always good practice to fully define any sketches before proceeding with turning them into 3D objects.  In trying to figure this out I noticed that your base sketch could be dragged around and manipulated, which if done accidentally could affect the machining later.  If you're working in a white or light-colored background a fully defined sketch will have a black outline, while a dark environment (what I use) will show it as white.undefined sketchdefined sketch