PROJECTED CUT FEATURE WF2 HELP!!

[ronbak]

I am trying to model this cut as if it was being machined with 0.125" end mill on an index. I highlighted the area that are wrong, at the vertex I want it normal to the offset datum curve.








How would you build it? I included pics or I can email pics....Thanks AllView attachment 2708


View attachment 2709





I created a datum normal to Datum1, which is controlled by angle dim, and select cut to curve and selected my offset datum.

 

[jeff4136]

You haven't described the cutter's relationship to the
workpiece very well (or is "on an index" the description
and I'm not catching it?) but if I go with some
assumptions what I'd do is sweep a line constrained
normal to cylinder surface to create a cutter axis
trace surface. Thicken to cutter diameter and
treat the ends.

 

[ronbak]

yes...an index holds the piece radially like a lathe and turns the piece while the end mill stays stationary. The mill will come in and cut the openning of the slot and at the bottom of the openning the index will being turnning the part to make the length of the slot.


sounds like it may work.I will try it later.

 

[jeff4136]

"an index holds the piece radially like a lathe and turns the piece while the end mill stays stationary"


Ok, thank you. Should work well; will create a more representative groove than sweeping a planar area section or "emboss" type features.

 

[ronbak]

I sketched curve that looks like a my slot (like a side ways J) on a tangent datum. Then projected it down to my surface. Then I created a sweep cut selecting the projected curve as my traj. I get a weird undercut at the center of the curve where it makes the 90 degree transition, my transition is actually 93 degrees. I want a sharp inner edge at this transition and the outer edge should match my end mill diameter. If the J radius id too small I get a failure, which makes sense but this weird cut at the inner corner is killing me....HELP!!

 

[jeff4136]

I think you'll want to Wrap the curve onto the cylinder rather than Project?


Is the undercut because your "cutter" ends at the intersection of the cyl face and traj (e.g. does not extend out of the cylinder)?

 

[ronbak]

i tried wrap, it gave me the same resultant curve with I used as my traj. I still get this weird sharp inner corner. View attachment 2714

 

[jeff4136]

It's hard to say what, exactly, is happening but for something like that I'd probably put a simple revolved cut or hole feature at the intersection of, presumably, an extruded axial cut and revolved annular cut. Either that or open up the radius on yourplanar sketch. What's the specific intent? If you can list all the relevant specs or just post a representative model (WF2? I can read) I or somene will take a look.


Wrap and Project may "appear" toyeild the same results but they don't.

 

[ronbak]

jeff..your input is invaluable. I will try it. Heres my model.





2006-09-21_105745_lower_hsg.prt.zip

 

[jeff4136]

2006-09-22_114403_prt0001.prt.zip (WF2)


Sorry to leave you hangin'. Been internet challenged the last
couple of days.


Your main problem is from having too tight a radius in your wrap
profile sketch. If you'll sweep a line along the wrapped curve
(constrain mid point and dimension to .045 groove depth) and
then do an Offset analysis on the quilt you'll see the main
cause of the problem.


You won't really care about the inherent inaccuracy of using a
swept area profile (tangent to the cutter changes with depth so
a swept planar area cannot represent it). You might find that a
combination of model accuracy and setting the area profile flush
with the cylinder wall (something I avoid if possible) will
cause some intermittent problems. I'd just extend the
rectangular section outside the cylinder it that happens. If you
need a pretty tight transition I'd tighten model accuracy. If
you need a Sharp transition it looks like (?) it might take a
lot more futzing around to get something to work nicely.

 

[ronbak]

i like it. Not sure why you created the copy surface(feature 19)..explain?


Also is the first datum group part of your start part...i like it.





I created a similar group of features to give me the desired slot however I can not pattern it axially which I would like to do. any suggestions





2006-09-25_203325_slotted.prt.zip

 

[jeff4136]

2006-09-26_151401_slotted_v02.prt.zip


The datum group is in my start part.


Creating quilt (not the surface Feature) copies is sort of a
habit, mostly so I've always got an unaltered (trimmed, etc.)
original to reuse later. In that particular case it prevented
the original from being "consumed" and made invisible by the
Solidify and the copy was used as reference for downstream
features which simplified Patterning. I have a real slippery
grip on Patterning requirements in Pro/E but do understand in a
vague sorta way that dependancies are important. If it can't
reuse necessary parent references the pattern fails. Quilt and
curve copies (vs. surface features and sketch features) don't
rely on the same references as their parent objects so are a
little more flexible in some ways.



You'll note in the attached that I copyied the quilt.
You could also ...
_ Create the first cut.
_ Copy the cut solid faces.
_ Solidify them (it seems redundant but ...)
_ Pattern the solid surf copy.
_ Reference Pattern the Solidify.


You might also look at ...
[url]http://www.mcadcentral.com/proe/forum/forum_posts.asp?TID=26 213[/url]
There's a referenced tutorial and patterned group bug(?).