Feature Based Modeling! Streamlined Sketching! Defined!
The History of Sketching
When I was introduced to 3D Computervision
CADDS 4 in 1982 it was 3D wireframe while on contract with
Williams International in Walled Lake, MI. It had a
mini-mainframe computer in a refrigerated room, a Versatec 34
inch roll plotter, an admin room with a control terminal,
removable hard drive and a tape back up system.
Are you ready for the price? $250,000 per
seat with a minimum purchase of three.
The 19 inch monitors were monochrome: Green on Black. You
could have highlighted green to help distinguish a bit.
Look at the lower image, are you look up or down at
the part? Yes, that was a constant problem. Especially when working with the
It was really in 3D!!
I quickly became an expert and probably was
the first to get a job due only to my CADDS 4 experience. My
rate went from $20.00 to $35.00 per hour! With loads of overtime
I was soon rolling in dough.
I took a contract at Boeing in 747 Flight
Deck in 1986 as a manual board draftsman just to get home to my
young family. I was a "3D CAD designer". Boeing had just
switched to Catia 2. It also was a 3D wireframe system. Only the
direct prima dona draftsmen got on the system. No hope to get on
I was whining about not being on CAD and a
fellow said there was a PC based 3D CAD system on a couple of
Compaqs. I took a look and it was PC based CADKEY. It was
incredibly similar to CADDS 4 and I was up and running in 2
weeks of lunch hours. I convinced the boss to allow me to do a
project, the first observers workstation. It was such a success
that they started buying CADKEY by the dozen. I was the main
trainer. I purchased CADKEY, a 286 Compaq and a 19 inch
CRT for $8500.00. But at $20.00 per hour my job at Boeing was
short lived. They offered me a dollar to stay, I laughed and headed out
to Square D, in Lincoln NE for $35.00.
I founded TECH-NET and made my first sale
for 3 seats of CADKEY to Square D, the rest is history.
I continued to sell CADKEY for another 22
years. They went direct and got rid of the dealers in 2009. But
I had quit using it as my main design system moving to IronCAD in
1998. CADKEY was rereleased as KeyCreator in 2003, basically
duplicating CADKEY with a bit different UE. It still was a dumb
system, but was a fairly good highbred modeler, with a mixture
of 2D/3D wireframe, surfacing and Boolean solids. I replaced it
with ZW3D which is a much more robust hybrid modeling system.
With that under out belt
let's get to the subject.
Why do we call them Sketches?
All CAD operators in the beginning were
brought our drawing practices to 3D CAD. We would draw like you did on the board with
sliding triangles. Mostly vertical and horizontal parallel lines offset. We would add
the lines and arcs to complete the 2D graphics. We did not
use the term "sketch" at the time. We called it "2D graphics" and
was made up of lines, arcs and splines. Can anyone tell me why
they called them "Splines"? We could extrude and revolve only.
The program would create the graphics by joining the graphics
I will show you with the original concept
in KeyCreator 2009. Yes, it still has this capability. I had to
do a refresher course on how to do it. As we moved to Solids,
CADKEY offered a solidify function that would turn wireframe to
solids. We just had to make sure there were no spherical
I have set up KeyCreator as CADKEY was in 1986.
Black background, I will set the color to green, even though
CADKEY had 16 colors, to emulate the even more convoluted CADDS 4 experience.
Color did finally show up on CADDS 4X around 1984 at a $25,000
option. We would fight for the colored station.
Welcome to living history! LOL
Actually I could bring up CADKEY, last
released in 1998 and can still load on Windows 10, but it really
isn't much different than KeyCreator which I am used to.
We are going to create the "U" shaped
channel. I will be using this channel later to show a variety of
modeling techniques as compared to "Constrained Sketching".
Inside fillet is 5mm.
We open KeyCreator and it comes up with a
new file we will set the units to mm.
We will switch to view 5 or right view and
create a horizontal/vertical line at X0Y0Z0. No there are no
separate planes, they are implied in a flexible Cartesian work
Now we will create the basic rectangle with
Now we will create the 5 mm walls.
We now will create the fillets and they
automatically trim. We will trim the other lines with a variety
of trim commands. We had a few options for trimming since it was
part of our process. Remember in manual drawing you would
lightly create construction lines put in the fillets with a
"hole template" and erase the lines and darken the object lines.
As you can see there are no constrained dimensions. Even though
these entities knew what they were, you could not edit them.
We are done with our sketch.
We will turn to an iso view and set the
plane separate from the view. This feature was always in CADDS 4
but was introduced to CADKEY a few years later. You can see the
view coordinates different than the global system in the lower
Now to extrude it. Join lines will be
created. This feature was included with CADDS 4. I cannot
imagine how much work it would be to have to connect the dots.
We just create the extrusion with the Xform
delta copy and join and set the distance for 30 mm. You can not do this
type of wireframe modeling in any of the
popular CAD systems. But you can simulate it by turning on 3D
wireframe. Again I ask, are you looking up or down at the part. That was a
huge problem when we would work with the engineers. Poor guys.
Now they are proud to be 3D CAD jockeys. LOL
Now we add the hole. We set the CPL
(Construction Plane) to View 2 or front. We set the depth on the
from the end of an entity on front side of the channel. You can
see the change in the gnomon or axis indicator in the upper
right and the X0Y0Z0.
We will lock the depth of the plane and change the
view to 2 or front and create the 6 mm diameter circle. We
rarely located anything explicitly. You can see I created
parallel lines and put the circle at the intersection. I still
create my sketches this way, it is part of "Streamlined
We delete the construction lines and change
the instance to ISO to project the circle. This is an
interesting process. First we will Xform project copy join for
the first side to the inside by selecting the 2 lines that form
the plane of the destination. The next will do the same command
to the inside of the channel, but we will just copy. Then we
will use the same command this time with join. I am hesitant to
call them faces. Remember there was no concept of faces in the
Welcome to probably your first exposure to
3D wirefame design. Only surfacing is worse. LOL
But we are not done. The selling point of
3D CAD in the beginning was faster drawings. So let's see how that worked. It was
not pretty. Since we did not draw these, the term "drawing" was a
misnomer. Boeing draftsman called them the "Flat File". In the
beginning this was the only purpose for the 3D model. Later they
added surfacing and CNC programs like SurfCam, MasterCam and
SmartCam showed up that could drive 2.5 Axis from the wireframe
and 3 Axis with the surfaces. I coined the term AID (Associated
Information Document) since we were now sending the 3D model and
the needed pertinent additional information to
manufacturing as a paper print.
CADKEY had a documentation module called
the layout mode. Those CADKEY guys were experience professional
engineering personnel and knew that these were not drawings.
We will set up the views. Sadly, this part
is very simple and needs little modification. But I will include
an ISO view to show what we had to do to create a clean document
(flat file). CADKEY called the views instances. Like I said
these folks were a bit more with it as compared to the Pro/e
folks with little actual engineering experience.
I will set up the different instances. We
would have to manually align the instances. Later offered a bit
more flexibility with instances but not like todays solid
modeling CAD systems like IronCAD, ZW3D and others. Notice that
all of the entities are displayed in the ISO view.
I will clean up the views. That is what we
called erasing and trimming the affected entities. We call the
graphics entities. Another wise generic terms by the developers.
You can see cleaned up the ISO. I even had to add the silhouette
line on the bottom. Can you imagine doing this with a complex
part or an assembly. You can see that changes would not be easy.
But it was faster than drawing on the board. It was funny that
the electronic drawing package were by passed by the large
Aerospace and Automotive firms by going directly to 3D.
There you go. 3D CAD Circa 1982 to 1995!
CADKEY was the only 3D CAD system that was compatible with Catia
3, 4 and 5 for 20 years. Boeing probably never noticed that
TECH-NET alone was responsible for making all of Boeing's
suppliers completely compatible. Sadly, with the introduction of
Catia 5 and PLM/MBE/MBD they have made that compatibility
So there you go 3D wireframe design in a
nutshell. It was done like we did it on the drafting board.
Industrial/mechanical engineering never use point to point
drawing. We slid triangles, T-squares, Parallel bars or drafting
machines. We use circle templates for circles up to a couple of
inches then we would use a compass. AutoCAD was and still is
based on architectural drawings. Mostly drawing from point to
point using lines. Infact the way you trimmed two intersecting
lines was to put in a "zero" fillet.
Pro/e sketching is very point to point as
you can see in the example of the Fusion 360 presenter. Then the
added dimensional constraints are very time consuming even on a
simple part like this. You will see how Streamlined Sketching
and Feature Based Modeling can increase productivity 5 to 10x.
One more interesting point, when surfacing showed up it did not add to
documentation creation. While you could render it it was only
useful for 3 axis CNC and 3D printing. We would send the model
as an IGES file along with the print of the "flat file".
Enter Solid Modeling
Pro/e, the only solid modeling system
designed from the ground up, showed up in 1988. It was expensive, very complicated and
delivered on a single UNIX workstation, making it available to
the single user and much cheaper than the mainframe networked Computervision's
and Catia's at the time which were just beginning to dabble in solid
modeling. But its history based design was unique and
quite viable for initial design. When it came to changes it
completely failed in so many ways and still does.
In 1995, solid modeling hit the PC! I was
selling CADKEY and a third-party company developed FastSolid. It
was a Boolean modeling system. Which you designed by adding or
subtracting shapes or by trimming. This was followed by the very
powerful, flexible and productive direct editing of today.
As you use direct editing for your design you used a
mindset like machining or manufacturing. Which was a bit more
realistic concept in 3D modeling. You basically designed like the part would be
By subtracting and adding features based on 2D
graphics. But they were not constrained "sketches" they were
basically just 2D graphics. Solid modeling in direct edit only
package is just like 3D wireframe but the solid is created.
Also in 1995 there are many solid modeling
CAD systems showing up due the the release of the Parasolid and
ACIS solid modeling kernels. At that time I was introduced to
Trispectives that became the basis for IronCAD developed by a company that
was an OEM for CoCreate, now Creo direct. It was a drag and drop of smart shapes
from a catalog. They incorporated much of the direct edit
functionality which made IronCAD the only truly
integrated history/direct edit modeler. You use both concepts
freely in your design. But you basically start by dragging and
dropping positive or negative shapes, pushing and pulling
features to create your design. You also have robust sketching
when the need arises. So, it is the best of both worlds.
With direct edit you have a more real-world
view point of how the parts are made, plus a very flexible way
of making changes with no limits.
With the introduction of Solidworks in the
same year, we had the duplication of the Pro/e paradigm on the
Many tout the innovation of the
Solidworks team, it was nothing of the sort it was a simplified
Pro/e on the PC not even using a custom solid modeling kernel.
They were even sued by PTC.
Enter constrained sketching for the masses!!
This is quite different than the direct
edit concept. I found this as I was doing product comparison
with Solidworks and Fusion 360. I noticed that the CAD designer was sketching
point to point and dimensionally constraining everything. When they could have created a basic shape and added
another shape, used shelling or creating a blend, they would
create time consuming overly complicated constrained sketches,
as shown here, even on very simple parts.
I truly was
shocked at how limited this "Constrained Sketching Only" Box was. The
engineering time wasted must reach into the millions of hours
and is obviously still going on.
I realized this was a industry wide mindset. I found even
old board designers that was a Pro/e designer from the very
beginning falling into this convoluted modeling process.
I bumped into this Creo expert. He could
not conceive not using constrained sketching. He did the model
to show me. It was just like the SW user. He said it only took 7 steps!!
But he didn't consider each sketched entity and constrained
dimension a step. He would not even look at the way I told him
to give it a try. Create a cylinder, add blends, create the center
extruded cylinder cut, split and shell for the basic shape.
I gave up on him. But I should have asked
him if he ever tried Creo Direct. The direct edit only package
Funny, he came back and purchased a perpetual seat of ZW3D Standard after
evaluating Fusion 360 and Onshape, not being fond of the
subscription only. He was starting his own design consulting
service. I gave him a very good price. He is an highly
experienced engineer and it will be fun working with him.
Here is that part. It shows and incredible difference
between "Constrained Sketching" only and Feature Base Modeling
and Streamlined Sketching
I have watched the Solidworks and Fusion 360
presenters in the following exercises sketch features that could have easily
been put in later. They sketch fillets or blends and other shapes that take
up a huge amount of time consuming constraining. I will use the shelling
command instead of sketching profiles. You will also see how I use primitive
shapes to cut 30% of our design time. Sketching is part of our design
process but not the whole process. Take some time to review the following
exercises and see if you can incorporate some of these very productive
is one of the more blatant examples of feature based modeling as
compare to extensive sketching.
Here is a incredibly simple exercise that shows my point.
is one of the most blatant examples of overly
complex sketching. There are many more examples of Fusion 360
and Solidworks users wasting huge amounts of engineering man
hours on constrained sketching. I will tell you it is not
require, not at all. We now have direct editing only package
that offer a non-constrained sketching based on how we did I on
the board. I have coined this Streamlined Sketching and along
with Feature Based modeling you can cut your design time 5 to
I will do these in ZW3D that is basically a
sketch based system. IronCAD is first, drag and drop design,
sketching is a secondary process. I will be using streamline
sketching to save time.
I could do the sketching in IronCAD,
but that would not show its unique design benefits.
We activate the plane. We will be using streamlined
sketching, which means we will not use any constrained
dimension. Compare this to the Fusion 360 wasting precious
engineering time by locating sketched features with dimensions
and adding constraint dimension for the simplest sketched
features. Can you imagine a complex part?
We create a vertical line from X0Y0, which is already
located in the correct position to locate our part.
I will then use offset to create the outside lines
We will create a line on the bottom and add the fillets,
then delete the center reference line. I do not usually sketch
fillets but I will do it here to stay with a complete sketch. I
create a 5mm offset.
I create the two end lines to closer the sketch and exit to
the model mode
We now just extrude the sketch symmetrically and add the
top fillets. Notice that ZW3D turns off the sketch
automatically. This is streamline sketching, not one constrained
dimension. I think all Pro/e clones can design this way. It is 5x
to 10x more productive.
Now for the holes. I just create a sketching plane on the
front face. Even just creating this feature is overly time
consuming in Fusion 360. I just create a 10mm line from a
recognized mid-point on the upper edge and create a 6mm circle
on the end. Then delete the reference line.
Exit the sketch and extrude the circle,
creating the hole. We are done much, much faster than the Fusion
2. Feature Based Mindset with Streamlined Sketching
Again we start with creating a sketch plane.
We now create a reference line and then a
center based rectangle using the mid point of the reference
line. Again we are using Streamline Sketching with no
We delete the reference line and exit the sketch.
We now extrude the rectangle and create as separate
component and add the 10mm and 5mm fillets
We now shell the part 5mm and combine the two parts.
We add the hole as we did before.
And we are done. Much faster than even my streamline
sketching only. No company can tolerate the time that the Fusion
360 took to sketch this incredibly simple part.
3. Bonus: Designing with Primitive shapes!
No Sketching at All.
A few programs now offer primitive shape design. It is
quite amazing that this was not incorporated in Pro/e in the
beginning. But you can see the sketch only mindset can not
conceive of designing this way. Even fillets as features are
rarely used, at least by the Fusion 360 and Solidworks presenters.
Starting with the existing support, we first insert a
primitive block as a separate component and size it
We add the fillets and shell it as we did with the feature
Now for the hole. We just insert a cylinder, size it,
locate it from the mid-point on the upper edge and set it to
And we are done.
Just too easy and fast. Not one sketch???? How can that
be?? That is how I have been modeling my complete career.
All three parts are sent off to
manufacturing and they load them into their CNC package. Nope,
This shows that Feature Based Modeling and
Streamlined Sketching is superior modeling paradigm as compare
to constrained sketching. Not twice the productivity but 5 to 10
times. Give me a call if you need more information or
introduction to this concept. It will work with any 3D MCAD
If you would like
to try ZW3D please download for a 30 day evaluation.
If you are interested in adding professional
hybrid modeling capabilities or looking for a new solution to
increase your productivity, take some time to download a fully
functional 30 day evaluation and play with these packages. Feel free
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