Problems getting a smooth finish

[LansB]

Hey guys,

 

I am doing some surfacing over a complex shape that has many radii and blended surfaces. I would usually use a flowline if the surfaces were good enough and maybe a pencil to trace the outlining radial areas in. The problem I have is that the model came in from a laser scanner and is composed of about 900 tiny patches.

 

I have tried a surface finish parallel with a surface finish leftover for inside the radii, but the leftover pass is making lots of bumps in the recessed areas. I tried to run a pencil toolpath over it but there are way to many tiny patches on the model. Does anybody have some good suggestions for me please?

 

Thanks

[LansB]

I tried a waterline and it looked pretty good on the toolpath screen but verify still looks very chunky.

[Ocean Lacky™]

What are your cut and filter tolerance?

[LansB]

I have tried a stepover of .010", .008", and .003" I have also tried a filter tolerance of 1:1, 1:2, and off with creating arc in xz and yz as well as no arcs.

 

Sorry I cant post a file on the FTP. It's kinda top secret stuff per the customer.

 

Thanks again

[htm01]

not sure what you mean by "but the leftover pass is making lots of bumps in the recessed areas" but have you tried increasing the overlap distance?

[3R!< W3NG3R]

try increasing the gap setting and the tol. setting.

[LansB]

yeah, I've tried all different gap settings as well. Tried to keep the tool down over the hole part and also tried smaller gaps. What it really seems to be is that the surfaces are kind of crappy and I am trying to make it smooth with the toolpaths. If I can't get anything much better that it is, I might have to go back in and recreate all the surfaces.....DOHT

[Ocean Lacky™]

What about "Cut" tolerance? what do youo mean by "bumps"? does it have a faceted look, kinda like a diamond? If so, try a cut tol. of .001 or less. This is NOT the same as TOTAL tolerance.

[Jack Neelands™]

On the 1:1 ratio I knock everything down to .0001 to give me a total tolerance of .0002...it this doesnt fix your problem you will have to redraw the surfaces ...a quick fix is to create flowline curves on the existing surfaces at a set distance and then in turn recreate your surfaces using them

[LansB]

I tried a total tolerance of .001" with the ratio at 2:1 (cut=.0003" and filter=.0007"). It seemed to cut better with a more generous setting though, maybe because the surfaces are so sketchy.

 

A friend suggested surface finish project. I think that might be my only hope of not re-creating the surfaces. As I recall, I had to use this in the past for similiar situations.

 

Thanks once again.

[terry5357]

quote:

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a quick fix is to create flowline curves on the existing surfaces at a set distance and then in turn recreate your surfaces using them

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GREAT SUGGESTION!!!!!

 

We do a lot of aircraft molds, coating tools, hydroform tools and thedrmal forming molds. about 50% of the time the models are compplete crap and we have to go in and recreate surfaces because like you said, just a rediculous amount of surfaces or edges just do not meet or blend well.

THis works best instead of trying this and trying that to get a good finish. DO be afraid to fix their junk, but remember stay true to form cause if inspected with a CMM you can get burned cause there is too much deviation.

[Matthew Hajicek - Singularity]

Garbage in garbage out.