holes vs cuts
--------------------------------------------------------------------------------
Wow...thanks to everyone who gave me input. From what it looks like it
is kind of dependant on what you desired end product is as to whether you
use a hole or cut (that make sense). So anyway, I thought I would go
ahead and post all the responses I got for anyone who might be interested. It's
kind of long, but worth the read.
Thanks again,
tED
Here are the comments I received:
The hole feature will have a parent/child relationship with the surface
that is goes into. The revolved cut feature can be used without adding
another parent/child relationship. Some users may prefer the hole to
have this relationship. Others prefer the revolved cut since it can be
located independent of the surface. Personally I prefer less
parent/child relationships and like my features to stand alone.
Bruce Trotter
If it's important to you to be able to show the tick marks for the
axis of the hole you will get it for free when you use holes. If you
want to do this with a cut you will need to create an axis thru a
cylinder or on a surface normal to a plane (do-able but it's a bit more
work).
Duane Salbashian
Unless you need the slightly faster regen times, a CUT is ALWAYS better (in
my opinion). For the most part, with a HOLE you are locked in to the
design. There are only a few options you can redefine. If you use a cut
with a round sketch, then realize you need a keyhole shape, just redefine.
If you had used a hole, you then need a second feature. So much for the
quicker regen time....
I forgot.... The inportant one is between Hole/Sketch and slot. The slot
feature will not let you pick the "inside" of the sketch. If Pro/E assumes
incorrectly, you have no recourse to change it. With HOLE/SKETCH, you can
select which side is out.
Steve Brillhart
In earlier versions of Pro/Manufacturing (17 and earlier), the automatic
selection of holes in a holemaking sequence did not recognize round cuts
as holes. Because of this, you had to manually select each hole rather
than select a specific hole size and let Pro/Man automatically select all
holes of that size in a particular surface. Also, you lost the ability for
Pro/Man to detect the depth of a blind hole. All that changed in rev. 18
and now a round cut is treated the same as a hole.
There may be other reasons, but this is one from a machinist's
Bob Dixon
Over here at Sanders, I've been told by the machinists and sheetmetal
technicians, that in order for ProManufacture to locate centers you must use
holes. If you use cuts, that means more work on the manufacturing end. Use
holes, and their job is a little easier. Thats it was explained to me in a
nutshell.
Leon Surprenant
I guess I prefer using holes because it is a pick and place feature. You
don't have to go to the sketcher environment and it requires fewer model
references, which will help reduce parent/child references.
Example: a linear hole requires a placement plane and 2 placement
references. A cut requires a sketching plane, view orientation plane and
(in most cases) 2 placement references. Addtionally you must naviagte the
sketcher environment. Even if I wanted to use a sketched cut, I would use
"slot" instead of "cut" because there is one less selection
(inside/outside) because a slot always removes the material inside the
sketch.
There is not a steadfast rule here.
Additonally, using holes prevents users from putting multiple holes in one
sketch, which is a no-no because if one fails, they all fail. Patterning
is a better approach because of the benefits in assembly (ref pattern).
Joe Schneider
One of the most basic reasons to us a hole is that Holemaking
in Pro/NC only sees holes. It does not know what to do with a
cut.
I find that using "slots" is the best practice for me. I can do everything
with a slot that can be done with a hole or a cut, i.e... pattern, show axis.
The advantage I see with slots is I can redefine the shape of the sketch, if
I start out with a hole in my design and later need to change this to a
different shape the task is very easy. If I had used a "hole" I would then
have to delete the feature and re-sketch and this could lead to missing
references in the assembly.
Dan C. Estabrook
One thing about a cut is that you can put several holes through your part
with one feature. (providing they all start and end at the same locations) I
think with a hole they can only be put in one at a time. I'm sure it's just
preference, but I never use the hole feature.
DeWayne Davis
In older versions of Pro/MFG, this was more critical. Now that Pro/MFG
has matured a little bit (IMHO), it becomes less important how the "hole"
features are created.
If the hole I am defining is in a casting, I prefer to use revolved cuts
because I can control the profile and incorporate draft angle into my
hole feature. Otherwise, I must add another draft feature to accomplish
this.
Dan McCaherty
I think it used to have something to do with Pro/MFG in that it new a hole
was a drilled hole vs. milled????? I remember hearing something like that
awhile ago.
Sean Ryan
I always looked at it like this. Both can be patterned and moved around.
But a cut can be changed into a square or something by redefining the section
and the hole can’t. It stays a hole forever.
I think a hole also automatically gets an axis in its center. A round cut may not.
It’s a good thought though..
Justin Jackson
We never use hole. There is nothing like putting in a "hole" and then deciding it should be a
slot or a keyed hole or three holes or a square cut...
Why use an inflexible feature when a flexile one is available.
Paul Gregory
I don't know if this is really any better, but I use cut-revolve when I need
to have drillpoints.
Otherwise, I have to create the drill point as a separate feature.
Paul Gilmore
From what I understand, there are some Pro/MANUFACTURING issues
pertaining to the usage of #Hole vs. #Cut. Not exactly sure what they are, but I
have heard that from a Pro/MAN user before. If I can get some more Pro/MAN
related info pertaining to this topic out of the guy, I'll post it.
Ron Marion
I have not been warned either way about hole or cut!
Same goes for slot, what is its benefit?
I often use hole, sketch to get drill points in because our company likes to
see them. I too, would be interested in some discussion on the pros and cons.
Mark Howard
I was told that using a "hole" for a hole will generate a
drill operation, while using a "cut" for a hole will generate
a mill operation.
Debbie Yates
one reason is you get the centerline with holes and not with cuts. Thus you
have to go back and make datum axle in the cuts.... more time and more
features to resolve if they fail later....
Mark E Hissey
I would like to use sketched holes where possible, but you must have a
planer placement plane/face (unless that's an update I have yet to find in
R20).
Our parts rarely have flat sides, and we must include drill points on
occasion, so cuts are it for us.
I would like to know the advantages of holes Vs cuts also, (slots also).
Cindy Cahill
A Hole can usually be created in fewer steps than a Cut. On the other
hand, if you decide that a hole needs to be turned into a cut with
something other than a circular shape, you can't just Redefine it.
One small benefit of "Slots": you don't have to respond to the prompt
asking which side of the sketch line to remove.
Gary Garnier
There are probably a number of reasons of why one would use a hole vs. a cut but
the simplest answer might be regen time. Make a 20X20 pattern of holes and a
20X20 pattern of cuts on a flat plate. You will fine that the plate with the
pattern of holes will regen much faster than the plate with the pattern of cuts.
Stan Balish
For sheetmetal applications, I like cuts.
I typically will pattern a group of axes, and then create the hole as a
sketched cuts and reference pattern them onto the axes. Then it is easy to
switch the hole to an obround or a square punch by changing the sketch.
The pattern updates automatically.
A hole is just a specialized cut far as I know.
John Durston
One of the great things about Pro/e is that it was somewhat created to mimic
the manufacturing process. The difference between a cut and a slot is a cut
doesn't have to be closed section but a slot does. Chek out Pro/Sheetmetal
it creates cuts in the sheetmetal perpendicular to the surface you are
placing the feature on. That way the cut is square to the metal like a
press or punch would do.
Corey Brenner
My understanding was that in the feature type list, they were in
order of complexity. Hole being simplest, Intersect most complex.
If you need to redefine a hole feature, ex. - from a straight hole to
a c'sunk hole, your'e out of luck. A revolved cut or slot will allow
this.
Cut vs. Slot - the only difference is that slot always removes the
"inside" - it doesn't let you flip the arrow. Thus, it is a slightly
simpler feature.
Wes Smith
There are some distinct advantages to each of the features, but here is some basic information:
holes - always circular type feature, usually faster to model cuts - can be used to create either
holes or slots - advantage in that if you need to later change your design to have a short slot
instead
of a hole (which does sometimes happen), you can do it without deleting a feature then adding
another one
slot - same thing as a cut except you don't indicate a direction, it always takes the inside of the
geometry
Lisa Schmitt
I was told once that some CNC software may interpret these differently...imagine
it trying to use a small diameter end mill to machine a circular cut, rather than
just use a drill bit.
This may or may not be true; I'm no CNC programmer, this is just what I heard at
a Pro/E training class.
Matt Gawlowski
don't forget about patterns and hardware in assembly. I have found that if
a person uses a cut to represent a hole he will use a cut to represent a
hole pattern thus requiring you to assemble each piece of hardware to each
hole. Whereas if the holes had been made with a hole and then patterned
the hardware could automatically be inserted in the assembly by using the
REF Pattern option.
Kirk Darroch
A hole will always have a circular cross-section, as if formed by a
stationary spindle. A cut or slot may be any shape imaginable, and would be
formed by moving a spindle along a tool path.
Tim Biggs
Okay let's see. In general the same procedure is used for a hole as it is
for a cut. The hole is simply customized to be easier (faster) to use. So
far so good. Now, if you start talking patterns it's a whole new issue.
Putting lots of holes in one cut to create your pattern reduces the
regeneration time but at the same time it reduces your usability as well.
Just think of having bolts assembled to each hole. By using the hole ->
pattern approach, your bolts are entirely dependent on the hole pattern and
adjust in number and position as the holes do. Flexibility is the magic
word! Now, with a cut including multiple holes, besides the fact that you
have to assemble each and every bolt, you simply don't run into problems as
soon as your number of holes changes.
Does that answer your question? As always it's a little bit "To each his
own", but especially in the meaning of patterns I see an advantage of
discrete features vs. one section contains it all. How you create your
single feature is almost entirely up to your preference.
Thomas Theuerkorn
Cuts vs holes: the issue here is what you use the model for after it has been
designed. If you use PRO/MANUFACTURE it does not recognize cuts as holes. I
have found that since we do not use PRO/MAN... cuts are faster.
Terry Smith
It has become a standard to always use cuts to create holes for us. The cost
of time spent creating cuts has been saved many times over when the time
comes to redefine as a slot or other geometry without having to delete the
feature ( and hang whatever is assembled to it). We almost always have flat
parts. I have created map keys to speed up the cut creation. Also we name
every cut. (within reason)
Kevin Corr
It has become a standard to always use cuts to create holes for us. The cost
of time spent creating cuts has been saved many times over when the time
comes to redefine as a slot or other geometry without having to delete the
feature ( and hang whatever is assembled to it). We almost always have flat
parts. I have created map keys to speed up the cut creation. Also we name
every cut. (within reason)
Kevin Corr
If you'll be passing this model onto a Pro/MANUFACTURING user, they'll
appreciate hole features for holes. This way the system will use a
drill bit rather than say, a ball end mill where appropriate
George Leonard
Let's clear this up once and for all.
A cut has only one profile which is perpendiular to the creating plane.
A hole can have a sketched profile which can includes a chamfer a drill
point or any other profile that you want to sketch.
Dave Christy
I just wanted to point out a config option that a few people seem to be unaware of.
By setting this option, all cylindrical features created in sketcher will automatically
have an associated embedded axis.
SHOW_AXES_FOR_EXTR_ARCS YES
I've always wondered why someone wouldn't want this functionality..............
Joe Schneider
Dave (reply to Dave Christy)-
Cleared up once and for all? Not yet anyway.
Revolved cuts can also have any sketched profile that you may want.
Personally, I have yet to come across a good reason to use "hole"
instead of "cut" (I don't use Pro/Manufacture).
Kevin 作者: 孤独剑 时间: 2002-10-28 12:13
是的，
不错谢谢作者: cmk123cn 时间: 2002-10-28 12:38
CUT比SLOT好用作者: lhtom1976 时间: 2002-10-28 13:07
建议用CUT，SLOT也可以画开放截面，但是不能控制切除方向。作者: setai 时间: 2002-10-28 13:42
我同意其中一则说法，即Cut有较大的修改自由度。
