Surface fin contour

[Programinator]

Im trying to put a radius around a part and the toolpath will not hit the full rad on top. It starts a little bit down on the rad. So i dont get a full rad. What am i doing wrong.

[Kannon]

check your "cut depths"

 

prolly not correct.

[Thee Rickster ™]

I believe you have to check shallow and adjust

limits in there. I don't have luck with this

 

An alternative is the high speed waterline

add cuts

set (ex):

-.01 step down

-.0001 min stepdown

-.01 max profile

This will contour like a scallop path and works

great

 

 

HTH

[Thee Rickster ™]

High speed waterline example:

 

From(without add cuts)

.

 

.

To(with add cuts)

.

[Programinator]

changed cut depths from absolute to inc and that works good for the top.

 

Also im blending a rad in a bottom corner of a boss with the same toolpath and it seems to be leaving a step in the bottom. It is not blending to the flat surface.

 

I have that surface as a checked surface and i tried it leaving stock of 0 and .0001 and im getting the same thing.

 

any ideas?

[Kannon]

Is your maximum cut depth set to the surface floor?

[Programinator]

it is set to past the floor. Maybe it just shows it in verify and when i run it it will be ok

[Programinator]

the z depth of the flat is at -.135 and the toolpath only goes to -.13

[Chris Parish]

Shawn:

 

Call me and e-mail me the part.. Me and VInce will take a look at it

[Thee Rickster ™]

quote:

---

the z depth of the flat is at -.135 and the tool path only goes to -.13

---

The path's last slice was at the .13 level

and what would be the next slice is under the

geometry. Therefore it leaves it out

 

Setting the depth to the surface floor won't

rectify this

 

Doing a separate path from -.13 to -.135

with .001" step down will only add 5 cuts to

the overall time and may blend it for you

 

I also sometimes if, the cutter is smaller than

the rad, do a 2-d profile(climb) on the line where

the flat surfaces and rads meet.(not the best

solution)but it takes that step out

 

hope this helps

 

[edit] are you using a ballnose cutter?

[Thee Rickster ™]

Kannon,

 

Is there 'a final cut' to set at surface floor.

 

(I am crunching paths and can,t check for about an

hour)

[3R!< W3NG3R]

does adding the floor depth to 'critical depth' work?

[Kannon]

Rick..

 

all its got is a critcal depth...

[Thee Rickster ™]

Thanks Kannon,

 

i started crunching again before I remembered to

check.

[Jaz]

In a situation like this I usually set my maximum Z depth to .0005 to .002 above the flat floor. Works for me.

[Programinator]

In the cut depths i had it at z-.135 and i was using a 3/32 ball em. After talking to cparish i added the dia of em to depth making it -.2285 total and that got me very close. Then i just kept adding .0001 to the depth until i got it to be at z-.1348 which was close enough for me.

 

I would still like to know why it does not just go to the depth that it is told to go to.

 

By the way i was using abs in cut depths.

[Thee Rickster ™]

Just a thought, but would pencil cut work

in this case, i believe you can do multipath

in the pencil cut.

[dvaliket]

This may not help on your part, but for me, a way to get perfect tangencies is to use the old wireframe toolpath. If its a simple radius, it always works great. For some reason, I can use the same curves to make a surface, then when I machine the surface, it leaves material at the top or bottom.