Robert Latham - Portfolio of CAD Work done for Bucket Warehouse

Portfolio of CAD Work done at Bucket Warehouse (HardLife UK)

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Robert Latham Portfolio of CAD Work done at Bucket Warehouse

(HardLife UK)

From October 2014 to September 2015, I worked at Bucket Warehouse (trading as

HardLife UK) in Leighton Buzzard, UK as a computer-aided design engineer.

To accomplish my work, I was utilising the computer software, SolidWorks.

Brief explanation of the nature of my work:

Bucket Warehouse (trading as HardLife UK) is a “middleman organisation.” Digger

components are purchased from one of several suppliers. These are then retailed on

to individual customers.

To gain ownership in the design of their products, they hired me to replicate some of

their existing products in SolidWorks. Much of this involved “reverse engineering.” I

would use rulers, tape measures, protractors, etc. to measure the various dimensions

of a given bucket (or other product); then make rough, hand-drawn sketches of the

parts with their dimensions. Subsequently, I would systematically create a CAD

model in SolidWorks of the given product.

Often my colleagues would give their input, in terms of communicating any design

changes they wanted to see in the model. Accordingly, I would modify or develop

my CAD models to their specifications and/or ideas.

When they were satisfied with a particular model, they would ask me to produce the

necessary technical engineering drawings for manufacture. These, with the

SolidWorks’ DXF files of the individual 2D profiles for the various parts, would be


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sent electronically to a supplier. (I would create these files, and they would send

them off for manufacture.)

There were several instances where they asked me to use my own initiative in the

design process. For example, they currently sell a product known as a tilting bucket,

which has the ability to tilt through an angle of approximately 70°, using hydraulic

rams. They asked me to study the operation of this mechanism and to replicate the

same onto a rake, thus making a tilting rake.

This was initially challenging due to the fact that in the tilting bucket, the tilting

mechanism is mounted on a flat, horizontal surface (the lid of the bucket). However,

a rake has a naturally curved profile; there is no lid in that design. I therefore had to

create a compromise between both designs to marry the two shapes together.

My former colleagues also asked me to scale existing CAD models up or down for

different sizes of digger. This has been achieved successfully.

Moreover, there have been instances where I have been asked to modify existing

CAD models that were not of a SolidWorks origin. These, being in the imported form

in SolidWorks, were more challenging to edit. However, in this I have been

successful.

During my time at Bucket Warehouse, I have learned how to use a wide variety of

tools in SolidWorks to create some diverse and highly technical models. These skills

include:

Sketching:

o Adding/deleting sketch relations and dimensions

o Converting solid sketch lines to construction lines and vice-versa

o Wrapped cuts, embosses, engraving etc.

o Lettering

o Linear and circular sketch patterns


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o Mirroring

o Copying jpeg logo designs into SolidWorks’ 2D sketches

o Converting DXF files to SolidWorks’ 2D sketches

Assemblies:

o Importing parts

o Standard mating

o Advanced mating (including symmetry mating, screw mating)

o Reference geometry

o Creating mirror components within an assembly

o In-context assembly part creation

o Assembling models with moving parts

o Some FEA analysis

o Copying and scaling assembly models; (scaling each individual part;

after-editing)

o Working with imported (non-SolidWorks) CAD files

Creating models with moving parts:

o Intelligently assessing distance/angle variables in kinematic

mechanisms created in SolidWorks

o Manipulating key dimensions to amend kinematic motion

Sheet metal:

o Sheet metal parts typically created using the “base flange/tab” feature

in SolidWorks

Curved profiles were created in this way; each section of the

curve had to be derived from a circle or radius

o Sheet metal “flattening” or “unfolding”

Technical drawings:

o Full technical drawings, including BOMs, material specifications and

assembly instructions, usually created in the PDF or E-Drawings format

o Parts and assemblies effectively explained with all the necessary

dimensions, annotations, explanations, etc.

o Automatic pagination


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DXF files:

o Ability to create 2D profiles in DXF format from designed part files

Nuts and bolts:

o Proven ability to create a wide range of nuts and bolts

o Male and female threads created

Mould cavity parts:

o Ability to subtract one shape from another using the “mould” feature

in SolidWorks

Tolerances:

o Learned about appropriate clearances and tolerances

o For example:

3 mm diameter tolerance for holes that are to be laser cut

0.035 mm diameter tolerance for interference fit

0.25 mm diameter tolerance for an ordinary rotating fit

Soft competency skills:

o Keeping on track of several projects at once

o Team working and communication skills

The above skills were used in creating a wide variety of excavator buckets, rakes,

grapples and other equipment for the construction industry. These include:

Buckets:

o Cable buckets – 2 sizes

o Cable profile buckets – 1 size

o Digging buckets – 1 size

o Ditching buckets – 2 sizes

o Grading buckets – 5 sizes; 2 varieties

o Screening buckets – 1 size

o Telehandler buckets – 2 sizes

o Tilting buckets – 5 sizes; 4 varieties

o UK-style digger buckets – 6 sizes

o V-buckets – 2 sizes


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Grapples:

o Manual-box grapples – 1 size

o Selector grapples – 5 sizes, including 3 design profiles

o Timber grapples – 3 sizes

Links:

o Combi-links – 3 sizes

o Crosslinks – 9 sizes

o Harford-hitch links – 2 sizes

o Headstock links – 9 sizes

o Rotator links – 1 size

o S-Links – 13 sizes

o UK-style links – 6 sizes

Rakes:

o Rakes with no link – 8 sizes

o Rakes with an S-Link – 8 sizes

o Rakes with a UK-style link – 6 sizes

o Tilting rakes (S-Links) – 6 sizes

Other:

o Extension jibs – 1 size

o Fixed-combi pallet forks – 3 initial designs; 1 final model

o Pallets – 2 sizes

o Pallet-fork lifting frame – 1 size

o Rotating mechanisms – in 3 models

o Special components, such as:

DP4 bushes (in at least 21 different models)

Grease nipples

Hydraulic rams (9 different models of ram)

Motor (1 model)

Special pins: with extra holes, cut grooves, etc.

Various nuts and bolts


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Customers have been satisfied with products that have been manufactured using

my CAD blueprints.

What follows below is a brief portfolio of my work completed at Bucket Warehouse:

CABLE BUCKET:

CABLE PROFILE BUCKET:


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DIGGING BUCKET:

This was my first ever model. They asked me to leave out the cutting edge.

GRADING BUCKET:


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The typical way in which I would create a grading bucket:

1. Create the cutting edge, side pieces and link pieces individually.

2. Assemble the link and save the assembly.

3. Start a new assembly, placing the cutting edge as the first component.

4. Make the right plane to be the central plane in the assembly.

5. Insert the left side pieces and mate appropriately (usually at an angle).

6. Mirror the side pieces (opposite hand rule).

7. Create the back plate using in-context assembly design: sketch the profile on

the right plane using the “base flange/tab” feature in SolidWorks, to make a

sheet metal part. Extrude the profile “up to surface” (each side edge); edit the

material and ‘fix’ it in place.

8. Create the tube, lid and lid support in the same way as above.

9. Insert the HardLife logo. Fix it onto one side; mirror it on the other side.

10. Insert the corner pieces in a similar way as above (in step 10).

11. Insert the link assembly (from step 2), using a symmetry mate to align it

symmetrically about the central plane, and mate to the lid.

12. Create the wear bars (usually 5 or 6 bars) along the outside of the back plate,

repeating step 7. These would be evenly spaced and of equal breadth.

13. After the assembly is finished and has been carefully checked, I would then

create the DXF files of each part (all except the tube and the pins). For the back

plate and the wear bars, I would open each file separately; flatten/unfold it

using the tool; highlight the surface (by clicking on it) and then doing “save

as” DXF file. I would type the required sheet metal thickness within the file

name itself, so that the manufacturer would know in what thickness of steel to

cut each part.

An example of step 13 is set out below, in the “V-bucket” section.


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SCREENING BUCKET:

This model took over two months to complete. (I was working on more than one project at the

time.) It contains nearly 150 different types of component and over 250 components in the

final model. Size-wise, it is over 2 meters high and approximately the size of a small car. This

model contains some special components: a motor (shown in blue), a slew ring and a set of

hinges. I also made two sizes of curved mesh for it, as seen below:


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TELEHANDLER BUCKET:

TILTING BUCKET:

This bucket can tilt through an angle of 70°. It achieves this through the use of one or two

hydraulic rams. Several sizes are shown below.

This is the smallest model. It has one ram. The one shown below has an S-Link attached:


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This is the next size up. This size comes with either one or two rams. Shown below is the

model with two rams. Attached is a 4-5-ton UK-style link:

This is the largest size. Shown below are the models with both the 20-ton UK-style link and

the S70 Norwegian-style link:


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The design of the tilting bucket

fundamentally utilises some DP4 slipping

bushes. These are used with an interference fit of 0.035 mm. This is illustrated below:

UK-STYLE DIGGING BUCKET:


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V-BUCKET:

How I would create the DXF file of the flattened back plate of this bucket:


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Explanation:

After the assembly is finished and has been carefully checked, I create the DXF files

of each part that is to be made from sheet metal. For the back plate, I would open up

the file; then “flatten” or “unfold” it using the tool. Next I would highlight the

surface (by clicking on it). Then, by performing “save as,” I can create the DXF file as

shown above. Finally, this file would be sent to a manufacturer to be laser cut.

MANUAL BOX GRAPPLE:

This was the first grapple I made for Bucket Warehouse.


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SELECTOR GRAPPLE:

A couple of months after I first began work on these projects, Bucket Warehouse asked me to

incorporate “stoppers” into these models, to prevent the device from over-pinching.

The kinematic motion involved in this design is derived from the relationship between the

“compensation links” and the “central connectors.” When angels and/or distances are edited

in these parts, the device moves differently. It was my job to make sure that the grapples

moved (a) evenly (each side moving at the same speed) and (b) symmetrically (each side

meeting the middle at the same time).

Shown below is the final version of the 3-ton sector grapple with flat top. At this stage in the

design, Bucket Warehouse had asked me to create matching headstock links and bolt-hole

patterns, which were to be fitted onto these grapples:


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This is the 4-5-ton selector grapple:

This is the 6-8-ton model:


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These models incorporated DP4 slipping bushes, as shown below. These went inside the main

bush welded to the outer housing or body. The purpose of the grooves is to allow grease or oil

to lubricate the pin (which goes inside one of these bushes):

This is the penultimate-largest model, the 13-ton selector grapple:


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The part highlighted in blue is the reverse stopper on the 13-ton selector grapple model:

Bucket Warehouse asked me to design the 13-ton selector grapple in two ways:

1. With the base of the ram mounted on its own axis, separate from the axis

upon which the legs pivoted. This is shown above.

2. With the base of the ram mounted on the same axis upon which the legs

would pivot on. This is shown below.


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At one stage, Bucket Warehouse asked me to put a rotator link on the former of the two

versions. This is shown below:

TIMBER GRAPPLE:


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The timber grapple was a challenging project – due to the nature of the gabbing

motion it performs. Either the legs must have different sizes, or they have to move

somewhat asymmetrically and yet appear as if the motion is symmetrical!

After much trial and error, I finally perfected the motion in the first of the models I

made, the 6-8 ton, which is the medium of the three sizes. I then proceeded to scale

this model larger and smaller, to make two new sizes of the same design:

LINKS:

What follows below are some of the headstock links I created for Bucket Warehouse. The bolt-

hole patterns in these links are designed to perfectly match up with the same patterns on top

of the selector grapples and timber grabs.

I will first show you the combi-headstock links that I created. The purpose of these links is to

allow two different sizes of digger machine to pick up the same end-effector, which would be

bolted onto one of these links. It should be noted that only two of the pins would be

used at any one time.


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This is S40-S50 combi-headstock link:

This is the S50-S60 combi-headstock link:

This is the S60-S70 combi-headstock link:


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HARFORD-HITCH LINK:

CROSSLINK HEADSTOCK LINKS (IN VARIOUS SIZES):


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S-LINK HEADSTOCKS (IN VARIOUS SIZES):

RAKES:

Three types of link (S-Links, UK-style links and tilting rake arrangements) were each added

onto 6 sizes of rake for Bucket Warehouse:


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Tilting rakes:


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Tilting rakes:

An example of a standard rake with a UK-style link:

EXTENSION JIB:


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FIXED-COMBI PALLET FORKS:

The purpose of this product is to allow diggers to be used as fork-lifting trucks. Using a 13 &

20-ton combi-link arrangement; a 13-ton digger would be able to use this product when one

set of pins is used; a 20-ton digger would be able to use this product when the other set of

pins is used.

There was much deliberation and debate in the team over this design. There were several

design constraints that needed satisfying. There were also one or two design conflicts that

seemed really tricky to resolve. In the end, the team elected to refine and develop the simpler

(and cheaper) of the two main designs that had been suggested. This final, refined and elegant

solution is shown in the illustrations below:

Whilst designing this, I made much use of the symmetry and mirroring features in

SolidWorks:


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Two versions of this model were produced: one for our company, HardLife; the other for a

company that Bucket Warehouse was interested in trading with, Hewden. Accordingly, the

company logos were incorporated as follows:

PALLETS:

When Bucket Warehouse orders its stock, it arrives

on wooden pallets, similar to the one shown on the

right. However, for some of the heavier products,

these were breaking too easily.

Accordingly, my manager asked me to model some pallets very similar to the ones currently

used by the company. However, these were to be made out of steel. Hence, lightweighting was

essential.

This design was not developed to its fullest potential. This is because it was done close to the

end of my time at Bucket Warehouse; it was very busy; and the next day my manager asked

me to amend something on another project.


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These pallets are shown below:

PALLET-FORK LIFTING FRAME:

This device is similar to an extension jib; but whilst an extension jib is designed to be held by

a digger, a pallet-fork lifting frame is designed to be used by a fork-lifting truck. The forks are

to slide into the two tubular sections at the rear.


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TECHNICAL DRAWINGS – SOME EXAMPLES:

What follows below, are some examples of the technical engineering drawings I have

produced for Bucket Warehouse:

SG-100 – 13-ton selector grapple (version A) – 13 pages

Shown below are all the engineering drawings produced for the 13-ton selector grapple. These

drawings, in addition to the necessary DXF files, are sent to supplier/partner companies of

Bucket Warehouse, to manufacture this product “in the flesh.”

(This is the model where the base of the ram is mounted on its own axis, separate from the

axis upon which the legs pivot. In the latest version of the 13-ton selector grapple, the inner

stoppers were removed from the design, as shown below.)


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Selected pages from the other selector grapple models:

SG-040 – 4-5 ton selector grapple – 7 pages


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SG-060 - 6-ton selector grapple – 4 pages


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Fixed-Combi Pallet Fork, 13 & 20 ton; (selected pages) – 3 pages


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Grading buckets; (selected pages) – 2 pages


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S-Links: two examples of complete S-Link drawings – 4 pages


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Cable profile bucket – 1 page

Thank you for reading through my portfolio!

Documents

Robert Latham - Portfolio of CAD Work done for Bucket Warehouse