What toolpath would work best here? **2015 Update**

[Mic6]

I have a tube with a square hole in it. I'm trying to roll the edge into a r.03 fillet. I've tried Surface Highspeed Hybrid, Scallop and Waterline and those went all crazy. I've the most normal looking success with Surface Finish Flowline, but even then I get weird gouges and a lot of jumping around. Any suggestions?

TUBEWINDOW.MCX-7

[crazy^millman]

Try flowline and in the advanced setting turn the % percentage of step over to 10000% and that should go away.

[Colin Gilchrist]

Looks like a perfect candidate for the Blend Toolpath. Are you doing this 3 Axis, or involving the rotary?

[Micromoldmaker]

Surface Contour or Scallop should work for finishing.

[Mic6]

File attached in OP if anyone wants to take a stab at it

 

 

Try flowline and in the advanced setting turn the % percentage of step over to 10000% and that should go away.

 

Still seems a bit crazy.

 

Looks like a perfect candidate for the Blend Toolpath. Are you doing this 3 Axis, or involving the rotary?

 

3-Axis, blend did some crazy stuff as well

[Joe788]

Mic, did you try changing the gap settings to "follow surface", and the "keep tool down" set to a large number? That should fix up the path you've got in the original screen capture.

[rickcact1]

I unchecked "check flowline motion for gouge" and the jumping went away. Oh and I changed the tolerance to .0001 instead of .001 too

[Mic6]

The jumping looks to have turned to feed moves. I also move my part Origin Z0 to the top of the part and that eliminated some gouging, but still not the smooth rolling motion I'm looking for. I tried Blend, created a curve at the top/bottom tangent points of the radius and used those chains in the Geometry>Blend selection and had no luck with that.

 

[Joe788]

Yikes. Didn't expect that.

[rickcact1]

Set tolerance to .0001.

[brandon b]

I just created surfaces from soild and then used the blend toolpath.

[Mic6]

Blend looks good, but I can't seem to get it to go deep enough as shown

 

Flowline results from changing the tolerance sure are smoother, but why does it go so deep?

[Micromoldmaker]

Surface scallop looks OK.

[rickcact1]

Leaving all your parameters the same, in the file in OP, except for unchecking the flowline gouge and changing the tolerance I don't end up with the cutter going that deep.

[brandon b]

You need to offset the inside chain in by at least the radius of the tool. The center line of the tool follows the blend curves . I didn't do that on the pic.

[brandon b]

Sorry I would upload my file but I don't have permission to upload HLE version. Got other work going on the only seat of MC we have here.

[Colin Gilchrist]

Here is an example using the Blend Tool Path. You need to offset the inside chain by at least the tool radius, as Brandon mentioned. I offset the chain .02.

 

To get this to work I got the best results by: changing the method to "spiral", and set the option to "Along". I also set the Gap setting to "1.0" distance, and set the option to "follow surfaces". Under the Blend settings, I changed the 3D project setting to "thorough", and set the distance to .001.

 

Hope that helps,

 

Colin

TUBEWINDOW_BLEND_SPIRAL.MCX-7

[Colin Gilchrist]

After looking again, I realized the cutter was going from the top down. I'd normally rather go from the bottom up in this case. To do that, you just need to change the order of the chains in the Chain Manager. So I moved Chain 5 above Chain 3. This also meant I needed to change the "Direction" setting for the Lead In move onto the surface...

TUBEWINDOW_BLEND_SPIRAL_REVERSED_CHAINS.MCX-7

[Mic6]

Man what a day. All the prompt help is greatly appreciated. I finally got the blend nailed and will be cutting first thing in the morning. Although, some lollipop tools will be here in the morning to cut a radius on the same opening but the backside

[Mic6]

You need to offset the inside chain by at least the tool radius,

 

Colin

 

Colin, how do I offset the inside chain in 3d like that? I've been projecting and doing Offset>Contour

[brandon b]

Create edge curves and then just use xform>offset contour.

 

Or create a contour toolpath with stock to leave and turn all leads/depth cuts/multi passes off and then save the geometry?

 

 

For 2D boundaries I use the create boundary C-Hook and use the xy offset option.

If Iam not mistaken I don't think you need 3d drive curves for blend?

[Guest]

THis was the smoothest path I was able to to get

 

I projected the 3D geometry up to .5.....I converted all of the splines to lines and arcs, I uses the 3 point arc to create the arcs over the splines, then removed the splines, created the connecting straight lines

 

I offset the internal contour by "just" under half the ball size to keep it from falling into the window

 

and BTW, watch your rapid height, you have these set so you'll actually be IN the part

[Mic6]

Thanks for all the help everybody. Parts came out great.

[fastercam]

Sometimes, the good old coons tool path is your best option. Someone did a great job on the algorithm years ago and it's really a shame this tool path option hasn't been further developed. On-the-fly filtering and approach and retract options would be an excellent addition. Here's a screen shot of coons using 8 along patches and 1 across patch. It looks great in Verify.

 

 

[Mic6]

Hey guys.  Well, the job is back again and we finally have an indexer on order. (A axis)  Can I simply activate axis substitution with this blend toolpath?  I tried it and the tool is coming from the back and a bunch of other crazy stuff.  Tips on where to start converting this into a rotary toolpath?  TIA