Clean Earth Environmental Group
Back To Top
Custom trucks and related equipment for cleanup jobs such as industrial waste
and municipal sewage
Since 1991 Clean Earth Environmental Group (CEEG) has manufactured custom trucks
and related equipment for important cleanup jobs such as industrial waste and municipal
sewage. Every truck that rolls out of CEEG must not only get the job done, but also
comply with regulations from city level all the way up to federal level. Each level
of regulations increases the complexity of the design, providing unique design challenges
for each truck.
For years their designs were presented to the manufacturing shop
as hundreds of 2D drawings. However, as the company grew, they found that persistent
design problems were hampering company profitability. CEEG had no reliable means
of detecting potential problems with new or customized designs.
Most customization
time was spent rearranging the pieces of a truck, with a reliance on guesswork and
trial-and-error. Even in the final stages of checking the truck, it was typical
to find small problems that had to be fixed.
Each little piece of a Clean Earth
truck that has to be remanufactured must be cut, welded, painted, and attached to
the main truck. Even the smallest design error costs approximately $180 to fix,
and major revisions could run into several thousand dollars. The company tried analyzing
their 2D drawings to find the source of the errors, with little success. A solution
had to be found. Paul Comstock, CEEG Director of Engineering, already had some familiarity
with SolidWorks when he decided that 3D models would be the best way to eliminate
their design problems. CEEG computer network consultant John Thomas of TKS recommended
outsourcing the 2D to 3D conversion. He put CEEG in touch with Engineering Design
Automation, Inc. (EDA).
EDA, a SolidWorks Solution Partner with a specialty in design
automation, was able to complete a quick SolidWorks demo showing a simplified truck
with a few moving parts that utilized SolidWorks collision detection. Since collision
of truck elements was one of CEEG's recurring problems, this ignited their imaginations
about the possibilities of a solid design solution. In spring of 2001, EDA began
consulting with CEEG about their project. EDA President Hiroshi Takaki began by
conducting a thorough evaluation of the current CEEG system. Some of the major problems
he discovered:
- Lack of company-wide design standards.
- Missing sub-assembly drawings, resulting in incomplete data about how to put the
trucks together.
- Significant discrepancies between the Bill of Material (BOM) listing from their
MRP system and the BOM listing from the engineering drawings.
- Design bottleneck, where even a fairly standard truck took about four weeks to design.
- Discrepancies between manufactured trucks and specifications indicated on engineering
drawings.
The approach that CEEG and EDA decided on was to start by creating "base assemblies"
of the SafeVac and SafeJetVac, two of CEEG's most high-end trucks. A SolidWorks
design automation program would automatically assemble standard configurations of the base
assemblies. The assemblies built by the automated program would become a stable,
working foundation for later customization. EDA got to work building 3D models based
on the 2D drawings that had been used to construct the trucks. Each truck model
required more than 600 individual solids. However, the most difficult work began
when the individual pieces were being joined into assemblies and sub-assemblies.
Many necessary drawings were missing, or lacking sufficient detail for the assembly
to be clear. There also turned out to be even more design errors than CEEG thought.
"Things didn't fit," said Hiroshi Takaki. "We had to go back to Clean Earth to find
out if the mistake was ours or in the drawings. We would go back to the shop and
be told, 'yeah, we know this doesn't work, but we've been fixing it on the shop
floor.' That was a typical answer I got when interviewing the production manager."
For example, one hydraulic tank was engineered with sides that didn't actually meet
up when manufactured, so welding was used to bridge the gap. But the welding would
leak because so much of it was used--resulting in costly, inconvenient repairs.
"Also, it's a cosmetic issue--you see a big old line of weld going down one side,
and anybody who knows anything about tanks knows what that is," said Paul Comstock.
Another tank, the SafeJetVac water tank, was being placed into a cradle with the
same radius as the tank, which caused the tank to become deformed. The boom--a key
moving part that swivels around to allow hoses to be placed where they are needed--was
colliding with other parts of the tank.
|
|
|
This water tank is being forced into a cradle with the same radius as the tank,
resulting in unnecessary wear.
|
The solid model of the same water tank shows interference lines indicating the design
problem.
|
EDA staff found it particularly challenging to construct assemblies from SolidWorks
pieces that didn't quite fit together. Easy mating strategies were often impossible.
Instead, they had to create many customized planes and construction lines to join
the solids. It took about two months to complete each truck design.
"This is the main benefit of outsourcing when you make the leap to 3D. Our engineers
didn't have to stop production and learn SolidWorks. If they waited for that, they
would never have gotten it done," said Paul Comstock. Also, he knew that EDA had
the skills to build 3D models and assemblies specifically for use by automated programs.
"We really benefited from Hiroshi's knowledge and teaching of structure," he said.
The conversion from 2D to 3D is an excellent opportunity for companies to thoroughly
examine their designs, to eliminate errors and redundancy, and to improve consistency.
This is an important advantage of contracting a knowledgeable SolidWorks service
provider, rather than using a bare-bones conversion service that will simply replicate
all your 2D problems in 3D.
By late summer 2001, CEEG had their 3D base assemblies and automated program to
dramatically speed development and customization time. The Truck Configurator program
has a simple dialog box interface that allows even employees who don't know SolidWorks
to create standard truck assembly variations based on tank length, truck chassis,
and blower style. This program makes a selection using built-in SolidWorks configurations.
For each sub-assembly the designer creates 2D drawings of three major views plus
the perspective view. Then, the designer or another CAD operator uses AutoCAD to
add detailed manufacturing information.
|
|
SafeJetVac SolidWorks assembly.
|
"When a customer calls us up, 9 times out of 10 he's going to order the truck in
a configuration we've never done before," said Paul Comstock. This used to mean
coming up with new assembly drawings from scratch. With SolidWorks, it means making
modifications to existing base models. The designer uses the Truck Configurator
to create an appropriate design variation, then copies the SolidWorks files to a
different directory. The models and assemblies are modified as the client requires,
and each modification is tested thoroughly for interference or other problems. Then,
the 2D drawings are sent to the shop.
He estimates that his design time has been cut in half with the new system, allowing
them to unveil new designs with a lot more confidence. "We know we're not going
to be out there at the last minute hacking and burning trying to get stuff to fit,"
he said.
Other benefits include better documentation and communication with the shop, and
with their customers.
"We've never been able to do exploded views of our sub-assemblies before," said
Paul Comstock. They are creating a new manual for truck assembly, to increase the
speed with which the trucks are built. They are also updating an owner's manual,
which was five years out of date and not terribly detailed.
Moving to SolidWorks has speeded up company procedures, and also opened up new possibilities.
"We have never done prototypes," said Paul Comstock. "We can't afford to build a
truck that won't be sold. So if we had an idea for improving the truck design, we
would be calling up our customers and asking, 'hey, can we have permission to experiment
on your truck?'"
SolidWorks allows the company not only to build prototypes of new truck designs,
but also to apply new and powerful analysis tools such as Finite Element Analysis
with the Cosmos package.
"Right now we're making 140 trucks a year, and our owner wants to increase that
to 200," said Paul Comstock. "He's bought another shop like this one, and wants
to increase the total to 800. Last year if somebody had come and said that to me
I would have quit. I'd be out flipping burgers.
"But now it's a possibility. We're already adding seven different product lines
to our current menu--areas we would never have thought of a year ago. The fact that
we have these tools is allowing us to say, 'yes we can do it.'"
Back To Top