Opti rough never cuts faces?!?!

[jaydenn]

So... Why does Opti rough always seem to mess up flat surfaces?

Whenever I use it, it leaves 1 stepdown worth of stock on flat faces, totally ignoring the stock defined for floors and walls? What gives?

There is no option like "critical depths" or "machine flats". nothing.

Other than "get better software", are there any options to solve this basic, basic, function?

J

[gcode]

Depending up the structure of your part, you can build a flat drive surface below your part

the control the last cut with depth limits

[Colin Gilchrist]

Post up a sample file, showing us the problem you are having. There are usually some tricks you can use to get the motion you desire, but it is so much easier to work with a sample file, so we can just show you...

[jaydenn]

1 hour ago, gcode said:

Depending up the structure of your part, you can build a flat drive surface below your part

the control the last cut with depth limits

This is what I ended up doing, but it's a band-aid at best. Set stock to zero and use limits to stop where I want.

You end up with 10 operations instead of 1 because you need a "cut depth limit" for each critical depth; then another OP to continue deeper. Terribly messy.

Oh... also 1 stock model per OP or you cut miles of air too...!

I've solved the problem with workarounds, but I'm so sick of working around; I just want the software to work.

 

Colin,

I cannot share files.

You just need to cut any flat surface on any model and it will ignore the flats. My testing file leaves .080" on all the flats.

The catch is....It only behaves this way if you choose to leave stock on your model. If you put the stock to zero, it cuts everything just fine.

if you add .001" it will completely ignore flats, and leave ALL the stock on the part.

J

 

 

[Rstewart]

You have to play with your cut depths to get it to cut where You want.

Copy down the tool paths and change your cut depths.

It is a roughing pass, one toolpath doesn't always get all the material you want...

[mkd]

I've had the same issue with legancy roughing paths for a Looooooong time.

some bug in the algorithm that carries through?

 on the plus side horizontal surfacing works awesome.

[jaydenn]

UPDATE:

After some more testing, it would seem that "step-up" helps a lot.

It looks to me, that optirough uses a very strict "constant Z level" approach to slicing the model, and if a flat doesn't just magically land on one of these slices, it completely ignores it. Not very "opti" if you ask me...

Allowing "step up" lets the system go "up" and re-cut those faces. Problem solved(-ish).

J

[ajmer]

try making the step up the same as the step down

that should take a pass at all the flat areas

[Reko]

Yep... you nailed it... you must use "Step Up."

[specv]

2 hours ago, jaydenn said:

UPDATE:

After some more testing, it would seem that "step-up" helps a lot.

It looks to me, that optirough uses a very strict "constant Z level" approach to slicing the model, and if a flat doesn't just magically land on one of these slices, it completely ignores it. Not very "opti" if you ask me...

Allowing "step up" lets the system go "up" and re-cut those faces. Problem solved(-ish).

J

Yes, that's how it works. Though it would be better if MC had a range for the stepdown instead of being a fixed value. 

[Rob Dusenbury CAD/CAM CONSULTING]

If you make your step up equal to your step down then it will hit every flat.

[crazy^millman]

I did an Inconel 718 part last week where I broke it up into 3 operation with 2 Opti-Rough operations and 1 Surface Finish Bottom to top. I needed to catch one depth that was only 45% of the tool and the next 2 cuts were 100% of the tool for a total depth of 2.0 using a 3/4 endmill. One operation was not giving me what I needed and I could have made the 1st cut the 45% using step and shallow, but just made the 1st one the 45% cut and the next one the 100% cuts and it did exactly what I wanted then I got the step up at the very end using the Surface finish contour. I didn't want the step till after everything was roughed and only needed it in the 45% area of the part. With soft Materials letting it step is not normally a big deal, but hard metals let it do the heavy cutting 1st then the step up after you will get the best tool life out of the tool. The other way around and you see edge degeneration effect your full cuts.

Sometimes you have to use the software in way to get what yeild you the results you want.