Roughing Toolpath problem!

[billlaws]

Hi,
I'm quite new to mastercam X3, i'm getting on ok with it, but have come accross a problem i just cant seem to solve.

For a project i'm trying to make some turbine blades. I have the blade file and have created an appropriate stock. I am trying to rough the top surface of the blade using a parallel toolpath.

Mastercam produces the tool path no trouble, but there is a problem with it; when i verify the toolpath and watch the stock being cut away there is a random strip of material left. I have tried to show it as best as i can in the screen shot. As the rest of the blade appears so neatly machined i was wondering why this bit was being left? I have checked the blade file and there is nothing wrong with the profile of the blade so i am at a loss as to where the problem is coming from.

any help would be really appreciated![IMG][/IMG]
thanks
will

[Matt Berube]

Hi Will,

I am wondering... Are you using a solid or surfaces to "drive" this toolpath ?

The reason I ask is because I have run into bad toolpaths when created from a solid at times. A reliable solution would be to simply "create surfaces from solid" and use those for drive instead of the solid entity. It sounds silly but it has made all the difference for me in a few situations.

[billlaws]

thanks for the quick reply!

I have tried running it with the blade as a solid and also as surfaces, but it still keeps happening. I'm sure it must be something simple, probably just my inexperience.

It works absolutely fine for the finnish cut, just keeps coming up when i rough it.

[chuy]

Originally Posted by billlaws Hi, I'm quite new to mastercam X3, i'm getting on ok with it, but have come accross a problem i just cant seem to solve. For a project i'm trying to make some turbine blades. I have the blade file and have created an appropriate stock. I am trying to rough the top surface of the blade using a parallel toolpath. Mastercam produces the tool path no trouble, but there is a problem with it; when i verify the toolpath and watch the stock being cut away there is a random strip of material left. I have tried to show it as best as i can in the screen shot. As the rest of the blade appears so neatly machined i was wondering why this bit was being left? I have checked the blade file and there is nothing wrong with the profile of the blade so i am at a loss as to where the problem is coming from. any help would be really appreciated![IMG][/IMG] thanks will

Have you tried running the toolpath at different angle? Or maybe a different toolpath all together like a flowline? I've had weird stuff pop-up on parallel toolpaths and the flowline path has worked out better for me.

[Matt Berube]

I think Chuy is on the right track. Try something else...

Maybe Surface High Speed Core Roughing or even Surface Rough Pocket...

I think from what I am seeing in the picture that the result shown is about as good as you can expect from a "roughing" toolpath. I didn't read closely enough the first time through...

[Superman]

Do you get the same problem with a zero offset on the Drive Surfaces ?

Can you offset ( shell outwards ) the drive surfaces and use a zero offset on these "new" surfaces ? ( if you offset the problem area surfaces, your problem may become very apparant )

[Mike Mattera]

Use Rough - Pocket. Dont use Rough Parallel. I've never really like the results. Or like Chuy said, change the angle of the cut and add some extensiont to the move between cuts (Smooth transition might be nice).

Mike Mattera

[billlaws]

thanks for the replies guys, i've tried a few of the suggestions and not really got anywhere useful.
The main constraint with my project is that the machine i have available only has about 70kb of memory and drip feeding is out of the question.
Because of this I am going to have to probably do one side of the blade in about 2 rough cuts and a finnish cut.

The stock setup for the second rough cut is going to be the profile after the first. However when i try and run the second cut it still thinks there is a full cuboid of stock there. I've loaded the file in stock setup and also into configuration settings. Any ideas as to why its not cooperating?

thanks

will