5-axis toolpath recommendation

[Bob W.]

There is a feature I need to machine in 5-axis and I am looking for some ideas as to the best toolpath to tackle this.  The feature is a cavity that consists of a cylindrical hole that is .25" diameter x .75" deep with six cylindrical splines protruding inwards.  We are currently machining this with the parallel to surfaces toolpath but it runs slow because the tight spaces between the splines.  If this could be run with the tool motion running vertically (parallel to the hole axis) it would run much faster because there wouldn't be as many tight spaces, they would be in-line with the cutting direction.  Is there a good toolpath that would accomplish this?  One idea was a 3-axis radial toolpath converted to 5-axis but the radial was giving me issues because the cavity walls are vertical.

[Rstewart]

Bob, I think you may need to post a file.  If your unable to, then you could model up something very similar for someone to put a path on.

[crazy^millman]

Multi Axis Rough. Also remember you can take more than one surface and remake into one surface and do some neat stuff with this toolpath.

 

HTH

[Tyler Robotson]

There is a feature I need to machine in 5-axis and I am looking for some ideas as to the best toolpath to tackle this.  The feature is a cavity that consists of a cylindrical hole that is .25" diameter x .75" deep with six cylindrical splines protruding inwards.  We are currently machining this with the parallel to surfaces toolpath but it runs slow because the tight spaces between the splines.  If this could be run with the tool motion running vertically (parallel to the hole axis) it would run much faster because there wouldn't be as many tight spaces, they would be in-line with the cutting direction.  Is there a good toolpath that would accomplish this?  One idea was a 3-axis radial toolpath converted to 5-axis but the radial was giving me issues because the cavity walls are vertical.

 

Not sure I understand - in parallel to surfaces you can set the tool axis to a line, or a vector and have it parallel to the hole axis?

[Bob W.]

picture the cavity that would be needed to cast a .25" diameter Torx bit that is .75" long.

[Tyler Robotson]

You could project lines that follow the splines onto the spline surfaces, then use parallel to multiple curves to get the path to act like a radial.    Some of those options are already there in Multiaxis Rough like ron said but sometimes it waterfalls in ways I don't like.

 

also in the multiaxis paths you can use stock recognition to do some cool trimming stuff

[Bob W.]

Multi Axis Rough. Also remember you can take more than one surface and remake into one surface and do some neat stuff with this toolpath.

 

HTH

I have merged surfaces in the past but it was a long time ago.  What is the best way to go about this? - merging surfaces

[crazy^millman]

I have merged surfaces in the past but it was a long time ago.  What is the best way to go about this? - merging surfaces

 

Bob sorry been slammed with work. Really comes down to the shape and the part you are cutting. We just did an inverse impeller for a customer and they wanted us to stay off the check surfaces on the top rail and the lower rail. We projected the lines then offset them to clear like we wanted and then we turned the different entities into one spline using spline and a tolerance of .0001. We then revolved to make a new floor surfaces to drive the 5 Axis Roughing path from. The 5 Axis roughing path only like one surface and maybe in some box people only cut one surface at a time, but out here in the real world we almost never are cutting one floor surface.

 

I am an old school model guy so if I need to break out parent surfaces that are blanked I will. People forget with surfaces there is the trimmed surface you see and the original shape not trimmed blanked in Mastercam. Going back to that blanked surface can sometimes save you a lot of time. 

 

There there is just grunt get it done surface modeling where you project lines across the part to make your net chains from. Then make sure you turn each one into one spline. Then make a net surface out of it bigger than what you need and come back and trim to the shape you want.

 

Many different ways to approach 5 Axis machining and being creative and getting out of your comfort zone is rule #1. Yes every tool has basics you need to think about, but how you get the material off the part and the process you use is very open in my book. Get it done, make it efficient and show people where you can push the envelope will always be how I approach things. Edison learned 1000's of ways not to make a light blub. I have learned 1000's of ways not to make parts. By learning many different ways to not do something I have got pretty good and making things the right way. Not that I still don't make mistakes. We all do, but I can make pretty sound decision using my almost 30 years doing this. Point is 5 Axis Rough is a good toolpath, but the programmer has to get out of the box and look for ways it fails to really see how it will help them succeed. Seems like an oxymoron, but I see every mistake as an investment. Problem is to many people get beat down they quit looking to try and are just happy staying in the box.

[Chipmakr]

What if you put a vey slight draft into the vertical walls? Say measured in tenths of an inch. Woud that make your radial behave better and still keep you in tolerance?

 

A projected path\blend path might work as well.

[steven mileskie]

In the multiaxis rough I also have a toolpath I am using it on. The backplot looks great my issue is no matter what I try I cannot get the depth cuts to work it will only do the two passes I put into the first and last cut. I have tried multiple ways of getting the depth cuts to work, constant step, number of slices but it seems no matter what I do I get the same results any help would be great.

[Tyler Robotson]

The depth cuts literally just project out into space based on your 'final' cut  - try turning off your  collision control settings, it may be that your depth cuts are colliding and getting wiped out

 

worst case if you're having trouble with this and you need to get a job done you could copy the toolpath and add a drive-offset for your depth