cnc pumpkin carver

CNC Pumpkin Carver

A Baccalaureate thesis submitted to the Department of Mechanical and Materials Engineering

College of Engineering and Applied Science University of Cincinnati

in partial fulfillment of the

requirements for the degree of

Bachelor of Science

in Mechanical Engineering Technology

By

Adam J Frueh

April 2016

Thesis Advisor:

Professor Janet Dong, Ph.D.

CNC Pumpkin Carver Adam J Frueh

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TABLE OF CONTENTS

TABLE OF CONTENTS .......................................................................................................... II

FIGURES AND SURVEYS ................................................................................................... III

TABLES .................................................................................................................................. V

ABSTRACT ............................................................................................................................ VI

INTRODUCTION .................................................................................................................... 7

PUMPKIN CARVING IS BECOMING MORE COMPLEX AND DETAILED ..................................................................... 7

TECHNICAL KNOWLEDGE ................................................................................................. 7

CNC MACHINES ................................................................................................................................................. 7 CAM AND G-CODE ............................................................................................................................................ 8 MACHINE COMPONENTS ..................................................................................................................................... 8 COSTS ................................................................................................................................................................. 9

SAFTETY ............................................................................................................................... 10

HAZARDS ......................................................................................................................................................... 10 SAFE TOOLS AND PUMPKIN CARVING KITS ........................................................................................................ 11

EXISTING PRODUCTS ........................................................................................................ 12

CUSTOMER FEED BACK .................................................................................................... 13

RESEARCH CONCLUSION ................................................................................................. 13

PRODUCT FEATURES & OBJECTIVES ............................................................................ 13

ALPHA DESIGN / CONCEPTS ............................................................................................ 14

DESIGN #1, STATIONARY TOOL AND X AND Y AXIS ROTATING OBJECT. ........................................................... 14 DESIGN #2, X AXIS ROTATING OBJECT AND Y AXIS TOOL (ROCKING) ............................................................... 15 DESIGN #3, X AXIS ROTATING OBJECT AND Y AXIS TOOL (LEAD SCREW) ........................................................ 15

BETA DESIGN/PART SELECTION .................................................................................... 16

MAIN ASSEMBLY COMPONENTS ........................................................................................................................ 16 Z-AXIS - CARRIAGE .......................................................................................................................................... 17 Y-AXIS – CURVED RAIL AND LIFT .................................................................................................................... 18 X-AXIS – PLATFORM AND VICE ....................................................................................................................... 20 LINEAR RAIL ASSEMBLY .................................................................................................................................. 22 CURVED RAIL ASSEMBLY ................................................................................................................................ 23 SPINDLE AND ACCESSORIES ............................................................................................................................. 24 STEPPER MOTORS AND ELECTRONICS .............................................................................................................. 25 CNC PROGRAM, MACH3 .................................................................................................................................. 26

CRITICAL DESIGN COMPONENTS .................................................................................. 28

COMPONENT ONE, BOTTOM VICE...................................................................................................................... 28 COMPONENT TWO, GEAR TRAIN ....................................................................................................................... 28 COMPONENTS THREE AND FOUR, TIMING BELT CENTER DISTANCE ................................................................. 29 COMPONENT FIVE, COMPRESSION SPRINGS ...................................................................................................... 30


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MANUFACTURING ............................................................................................................. 32

STRUCTURE ...................................................................................................................................................... 32 Z-AXIS - CARRIAGE ..................................................................................................................................... 33 Y-AXIS – CURVED RAIL AND LIFT ........................................................................................................... 34 X-AXIS – PLATFORM AND VICE ............................................................................................................... 35

TESTING ................................................................................................................................ 36

CONCLUSION ....................................................................................................................... 37

WORKS CITED ..................................................................................................................... 37

APPENDIX ............................................................................................................................. 38

A. RESEARCH .............................................................................................................................................. 38 B. SURVEY .................................................................................................................................................. 39 C. QFD ........................................................................................................................................................ 40 D. BILL OF MATERIAL/BUDGET OF MATERIALS ........................................................................................... 41 E. SCHEDULE............................................................................................................................................... 42 F. BUDGET .................................................................................................................................................. 43 G. DATE SHEETS .......................................................................................................................................... 44 H. DRAWINGS .............................................................................................................................................. 46 I. FABRICATED PARTS ................................................................................................................................ 50

Figures and Surveys

1 Older traditional pumpkins

2 Intense carving

3 Professional CNC milling

4 DIY CNC milling machine

5 Carving Kit

6 PunkinBot

7 PunkinBot 2.0


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8 Design Concept 1

9 Design Concept 2

10 Design Concept 3

11 Near Final Product

12 Dremel Rendering

13 Compression Housing

14 Compression Housing Connector

15 Z-Axis Moving Assembly

16 Z-Axis Carriage

17 Curved Rail & Carriage

18 Lead Screw connection

19 Y-Axis Assembly and Z-Axis Assembly

20 Platform, Mounting Arms, and Vice

21 Complete X-Axis Platform and Vice

22 BRA and Gear Train

23 The XYZ Axis together, templates highlighted

24 Aluminum Rails

25 Bearing Assembly

26 BRA

27 BRA riding the rail

28 Complete curved Rail

29 Rail individual Sections

30 Slider w/ V groove bearings

31 Slider on Rail

32 Slider on Rail

33 Finished, Z Axis w/ Nose Cone

34 Nose Cone

35 Protruding Milling Bit

36 Milling Bit

37 NEMA 17

38 NEMA 23

39 2.5 amp Driver

40 Breakout Board

41 Electronic Board

42 Main Screen of Mach3

43 Computer setup

44 EasyCAM

45 Finished Wired Board

46 Deflection visualization

47 Deflection Scale

48 Gear Train Sketch

49 Center Distance

50 Spring Mechanism

51 Front view in the works

52 Left Side view in the works

53 Dremel and Clamps


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54 Complete Housing

55 Z-Axis Carriage

56 Brackets

57 Gluing the Rails

58 Final Lead Screw Platform

59 Top Mounting Arm

60 Bottom Mounting Arm

61 Front wall w/Rail

62 Back wall w/Rail

63 BRA in place

64 Complete Assembly

65 Electronic Panel in place

TABLES

1 Lacerations requiring repair (1)

2 Tendon Laceration (1)

3 Bill of materials and costs

4 Schedule


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ABSTRACT

Halloween is a special holiday for a lot of people in America. It’s hosts event for

children and adults alike. Many take to decorating their homes in tombstones, webs, and

lights. But the most widely accepted tradition is pumpkin carving. Millions of pumpkins will

be grown and sold to families with the intention of carving faces or characters on them.

Designs from the simple to the artistic will made and then be displayed for the holidayed.

However hundreds of accidents happen while carving. This is due to improper use of tools

from the kitchen which are not design to carve up the hard uneven flesh of a pumpkin.

Carvers end up slipping causing severe injuries to their hands and fingers that can lead loss of

function temporarily or permanently in the worst of cases. Some products that have been

released are special carving tools slimier to a saw and dale edge tools. While these do remove

a lot of risk they are not entirely safe. In order to reduce the number of accidents, my senior

project is to design and build an Automated Pumpkin carver and remove the human eliminate

entirely. The end result will be a three axis CNC machine that will be able to milling out a

predetermined design. Allowing the user to make high quality designs at no risk and in a

fraction of the time.

No existing patents, although one similar product. PunkinBot is a father-son project

attempting the same thing. They currently have a machine available upon order and has been

able to live up to the description. However I wish to take the idea forward and design a self-

contained unit to prevent any injury as I would design this as a kiosk type machine to be run

in a store for customer use.

This project can be broken down in to a few key factors. The design will need to

support a wide range of pumpkins that would be specific to carving. The spindle will be

mounted and rotated normal to the pumpkin via a curved rail. The z-axis will need to respond

to an uneven surface that a pumpkin would have.


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Introduction

Halloween is celebrated every year in numerous countries around the world. The holiday

and similar ones like it, are times in the year dedicated to honoring the dead, including saints

or hallows, martyrs, and other member of the respective faith. The tradition is using themes

of humor and ridicule to confront the idea of death. So what do we do for Halloween? Some

people will dress up in costumes (scary or not) and have fun with trick-or-treating. Others

will fixup their house with lights and decorations in the form of webs, tombstones, and other

scary things. But the most popular decoration is Jack-o-Lanterns. A Jack-o-Lantern is a

hollowed-out pumpkin in which holes are cut to represent facial features. This has become a

family tradition for a lot of Americans and others that celebrate Halloween. As digital

imaging technology has improved and simple-to-use media sharing websites have appeared,

the complexity of Halloween jack-o-lanterns being created has been increasing. (2) The past-

time is now deeply rooted into our culture but we have also found it to be a hazardous one.

Improper technic, tools, and supervision for children leads to many cases of hand injuries

reported throughout the holiday. (3)

PUMPKIN CARVING IS BECOMING MORE COMPLEX AND DETAILED

Figure 1 & 2 (4)

Technical Knowledge

CNC MACHINES

If you come from a technical or manufacturing background, then you most likely are

familiar with what a CNC machine is. If not, you should know CNC is an abbreviation for

computer numerical control. A CNC machine, then, is a machine that carves out objects in


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three dimensions from a solid block of material. CNC machines are commonly used in

industry to produce small parts such as bicycle stems and tools. Low-cost CNC machines are

increasingly used by serious hobbyists, especially woodworkers, to carve creations out of

materials such as wood and aluminum (5). Because it’s become so popular, there’s plenty of

different sources referencing “do-it-yourself” CNC machine builds. Although there is a

fundamental difference between a typical CNC and my pumpkin carving CNC Machine.

We can divide the most basic CNC machines into two categories: turning machines and

milling machines. Turning machines works by spinning a work piece at high speed and a tool

(sharp edge) is brought to the surface which begins to shave off the undesired material from

the work piece, the tool will move forward and

back to the center, or up and down the length of

the work piece until the desired shape is

achieved. Milling machines work much

differently, where the machine that has a

spindle or drill that can cut in various directions

and moves in a standard three axis cartesian

motion (5). Figure 3, Professional CNC milling

http://chopshopcnc.com/services/cnc/

CAM AND G-CODE

These configurations have been around for a long time and wouldn’t need a computer to

create parts. But by adding a computer to the machine controls we can achieve higher level

of quality and repeatability. Today CNC machines produce parts from computer aided design

(CAD) files, which are digital three dimensional parts. To produce the part we just need to

specify to the machine how we what the part to be cut, and that comes from a computer-aided

manufacturing (CAM) file or G-code file, there are also other types but are essentially the

same (5). The CAM file contain all of the steps and operations that the machine will follow

to make the part.

MACHINE COMPONENTS

http://chopshopcnc.com/services/cnc/


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The typical CNC Machine will have motors and rails which will give the tool motion.

And because the work on a flat plane the design of this can be fairly simple. The turning

CNC machines use a motor to rotate the part and motors and rails to guide the tool. Of these

devices a few speculative design could involve a combination of motions. Choices of the

motors/actuators, CAM, build materials, and tooling depended on the desired performance of

the machine. Some will design their machine for speed, others for a maximum work envelop.

But these choices are directly related to the intended purpose and material worked.

COSTS

A personal CNC machine can be upwards of $3000 dollars to purchase (5). Which is

partly the reason so many engineers, inventors and hobbyist have turned to do-it-yourself

CNC machines. The material for one can be as low as $390 for a small desktop machine. But

the average DIY CNC machine will cost between $700-$800 (5).

Figure 4, Example of a ‘do it yourself’ CNC milling machine

http://www.wired.com/2011/01/diy-cnc-machine-just-390/

http://www.wired.com/2011/01/diy-cnc-machine-just-390/


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Saftety

HAZARDS

Traditional pumpkin carving is dangerous if you don’t have the right tools and technic.

A true story of one Kim Sillcox. (3)

The mother of two had the pumpkins lined up in the kitchen

of her Aurora home, ready to carve with her children.

Like most, it is a family tradition to turn the bright orange balls

into jack-o'-lanterns to thrill trick-or-treaters, who were set

to arrive on her doorstep. But her pumpkin carving would have consequences.

"I was rushing and we were carving more pumpkins than usual," she said.

"I used a knife I shouldn't have been using." The hand holding the knife,

which was coated with the slippery innards of another pumpkin, slid down to

the blade and she cut right through the tendon of her index finger.

It happened in a flash.

These lead to Ms. Sillcox having to undergo surgery and was involved in three months

of rehabilitation. “Afterwards it still left her without the ability to use, touch, or

independently wash the injured hand” (3). Her hand surgeon, Dr. Deborah vanVliet and her

therapist Lucy Winston both agree pumpkin carving wounds can be very serious and may

need intensive surgeries and recovery times of up to four months (3).

"Flexor tendons are like elastic bands and are under a tremendous amount of tension

from the muscles in the forearms," Dr. vanVliet said. "One small and simple cut can cause

the tendons to retract like an elastic and the whole hand can lose its ability to move and

bend." (3). Southlake alone will see close to 30 cases of tendon injuries yearly, spiking in

numbers around Thanksgiving and Halloween, when people get caught up in celebrations. (3)


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SAFE TOOLS AND PUMPKIN CARVING KITS

Because it has become fundamentally known that you

should take extra precautions when carving pumpkins,

some companies have made up and released special kits for

carving pumpkins safely. The design off these tools do

make it easy to carve a pumpkin, they do not have a single

long blade but instead fashion a serrated or saw like blade.

Some resemble band saws like the ones meant for sawing

wood. While this does reduce the likely hood of injury, the

tool can still cause still cause injuries. (6) Figure 5 Carving kit (7)

Natalie Greaves, mother in the U.K. was shocked to learn her young son was able to go

to the local grocery store and purchase a pumpkin carving kit, which contained several sharp

serrated knife. “I went berserk when he came home with it. I couldn’t believe that he could

pick that sort of thing up as a child - there should have been an age restriction on it,” said

Greaves. (7)

Studies have been done on a variety of tools and compared also with house old kitchen

knives. “Examination of the fingers after being tested with each knife revealed that more

laceration injuries occurred with either of the kitchen knives than the pumpkin knives” (1)

The four knife types demonstrated that there were statistical differences in the number of

lacerations in the skin, the FDP and the FDS slips between knife types.


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Table 1

Existing Products

Besides Pumpkin carving kits, what about other CNC machines. The idea of carving a

pumpkin with a CNC machine is not new. The first one to do it were most likely shop

technicians and hobbyist simply fixing his pumpkin under a mill and just tried it. You can

find a few videos online giving examples of this. While it has potential to look great and

produce detailed images, it can only approach the pumpkin from one side. Giving the image

an extended cut appearance.

I’ve only found one machine that has tried to tackle this problem as it was designed to

carve pumpkins. The brainchild of a father and son project, the PunkinBoT & PunkinBot 2.0

(8). The quality of their work is impressive, it is accomplishing what I intend to do when my

design but when I look at the machines I see it has a lot in common with Halloween, big and

scary. “…sadly, the PunkinBoT 2.0 has a little less of the Halloween macabre: The original

carried out the carving with what looked an awful lot like a severed arm.” (8) This can be

bought online and is built to order. I believe this would be suited for either a Halloween

hobbyist or interested machinist.

Figure 6, PunkinBoT Figure 7, PunkinBot 2.0


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Customer Feed Back

The project needs more information from potential end users to determine the best

method and design concepts for the CNC machine, surveys were sent out, few were returned.

But currently we are in the Halloween season and there’s jack-o-lanterns everywhere, I can

survey more and have a better idea of what we should take in to consideration. At the

moment I will be making my assumptions based of my research and few survey results.

The design should be able to make continuous revolutions

The design should be CNC capable, with slight demand for manual controls

The design could be suitable for a hobbyist the is into machines or Halloween

The design could be suitable for use is a Walmart or other garden center.

A standing model will be the focus

And the machine does not need to be FDA certifiable

The work area must be easy to clean.

It must have noise generated to a minimum

Research Conclusion

In summary the project will be following basic instructions from do it yourself guides

on CNC machine construction. Including a textbook and potential other future examples. By

simply changing out a few methods of motion and mechanical drive we can archive a process

that will work martial in a spherical work envelope, much like the PunkinBot but made to be

more marketable, safe, and user friendly.

Product Features & Objectives

Based off of all the research and customer feedback, along with my asumtions we have a

good idea of what to expect. Our purpose is to make a CNC Machine available high quality

jack-o-lantern carving. Top priorities are to make it safe and simple, while taking up the

smallest amount of space. The intention is to have this machine run similar to a vending

machine, or coin counting machine. The intended operation is to run a consumers store

bought pumpkin with or without a clerk to assist. Since it will be in open corporate spaces it

really needs to consider safety and reduce it liability. The machine will then have

preprogramed designs or the possibility to upload a design with a thumb drive. To make this

simple a type of free sourced software will be decided and it needs to mesh with the possible

constraints of the CNC. Tolerances need to be made on the sizes and quality of pumpkin.

What qualify as a good pumpkin? In this case its fresh, round, and not compromised. Still I’ll

need to consider the worst case scenarios.


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Objectives

-Achieve a fast cutting speed, Goal of under ten minutes.

-Slim profile and small foot print

-Match power and size of the tooling to desired cutting speed

-Simple design, minimize electric systems and part count

-Sealed work space for safety

-Designed for vending, (Walmart, Garden Center, Pumpkin Farm)

Alpha Design / Concepts

It’s very important to know everything that will go into the product and to have set goals

in mind. There’s a big difference between what I want to do and what my capabilities are.

My thought pattern has changed on how I could build this machine within my budget, time

frame and design complexity. When I talk about these designs, know that the z axis was

always implemented where the tool will be driven in to the medium.

DESIGN #1, STATIONARY TOOL AND X AND Y AXIS ROTATING OBJECT.

This was my first idea, I was trying to make the device as small and possible. I wanted to

remove the necessity of parts rotating around the pumpkin in long arcs. I planned to have the

pumpkin rotate on an axis and the axis assembly would rock for the other axis. I quickly

noticed this would not work because of how difficult it would be to design this. Keeping the

pumpkin stationary and on target while it’s begin machined is a difficult task. Plus the added

factor that a pumpkin is heavy and comes in many sizes, I would be fighting gravity in a

worst ways. Cleaning the machine would have been more difficult. I needed to design

something that had more flexibility over machine size.


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Figure 8, Design Concept 1 (right)

Figure 9, Design Concept 2 (left

DESIGN #2, X AXIS ROTATING OBJECT AND Y AXIS TOOL (ROCKING)

This designed had the object upright on a rotating platform and was also held in place

from an above pressure plate. A Counter balanced tool would rock on the Y axis, while It

might have worked, the main reason this idea faded out was the power transition from the

motor to the Y axis would have been to slow and require a lot of torque. The rocker would

have also gotten in the way of the x axis, I tried to work around this but the machine was far

too big. The loading window would be small as well. I was hoping the machine could be

entertaining to watch, since the customer would be standing by waiting for it to finish and

this concept doesn’t do that for me.

DESIGN #3, X AXIS ROTATING OBJECT AND Y AXIS TOOL (LEAD SCREW)

This was the design I’ll be going for my project. This is because it follow everything

good about concept two but more so towards my goals. It’s simple and easily buildable with

in my time frame. The device will run the tool along a curved track which will be powered

by a lead screw. The machine will be smaller since all of the components are off to one side,

leaving plenty of viewing space. Also it will require less material and smaller motors. Plenty

of open area to work with for other functions that could be implemented. After going with

this I also designed a self-centering vice to position the medium in a range of sizes. This will

be hand cranked for the prototype and locked in with a pin. Later models will motorize this

process.


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Figure 10, Design Concept 3 (left)

Figure 11, Near Final Product (Right)

Designing this unit is heavily dependent on the size of the medium. To do this sketches

on the motion axis plane were made. The original range of sizes was determined from the

typical size of pumpkins sold for carving, this is 8 to 15 inches in diameter.

This means our carver needs to have a z-axis range more then 3.5 inchs plus what ever

distance is required to completely remove a drill bit from a 15 inch diameter pumpkin and

another inch for compression. *Originally the z-axis had a distance of 6inch

Beta Design/Part Selection

After completing the basic design, fabrication capabilities were considered. Before and

during the build some parts were changed to make things simpler. Although some of these

changes did make unintended conflicts, the changes were necessary.

MAIN ASSEMBLY COMPONENTS

The CNC Pumpkin carver can be broken down into three main assemblies. This would

be the Y-Axis lift, the Z-Axis carriage, and the X-axis Vice.

First designed was the Y-Axis Lift but more specifically the Curved Rails. As seen in the

concept design the rail radius is concentric for the pumpkin template. Design at 12 inch

radius. The final rails became hollow with a frame over on side for strength and to allow

mounting to panels.

Next this Y-Axis Assembly needed to be built alongside the Z-Axis Carriage, This is

because the lead screw position and length depended upon final dimension of the Dermel

housing.


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Z-AXIS - CARRIAGE

The Z-Axis Carriage would be need to be designed around the Dremel 200 series body.

For the CAD representation an already built

model was found on the website GrabCAD.com

This provided a close to accurate model to work

from, although after sourcing my own tool found

minor changes that needed to be made in

diameters of surfaces critical to mounting the

tool.

Figure #, Dremel 200 Series by username: Vlad

https://grabcad.com/library/dremel-body

Figure 12, Dremel Rendered

The next step was mounting the Dremel tool in such a way as to provide ridged mounting on

to plane and still allow some linear motion for the spring compression mechanism.

The end product was a series of clipping mounts, fixed together by threaded rods.

Figure 13, Compression Housing Figure 14, Compression housing Connector

Notice the cuts on the rear two claps. These provide connection to the Z-Axis Carridge but

will allow a sliding action.

The connection piece also serves as a

push off point for the compression

mechanism. Two of these piece would be

combined by a sheet two pieces of sheet metal

arcing over top. On top of these pieces would

also lay the rack that will transmit motion to

the assembly. This is attached with small

threaded bolts. Also attached to the connector

piece is the slider rail, It’s attached by strong

forces of friction from a reverse angled flange. Figure 15, Z-Axis Moving Assembly

What you see to the right is everything that moves on the Z-Axis, The compression is

https://grabcad.com/library/dremel-body


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activated when the drill coming into full

contact with the specimen.

The rest of the Z-Axis Carriage includes

the linear rails the bearing rest on, the

motor that will drive the Z-Axis and the

sides of the carriage that will mount to

the Y-Axis rails.

*Orignial Designs had carved away

access material but in interest of saving

time was excluded.

Figure 16, Z-Axis Carriage

Y-AXIS – CURVED RAIL AND LIFT

From this point the outside walls of the carridge need to be attached to the Y-Axis. We

will do this in theory by first attaching the carridge to the Curved rails that will rotate the Z-

Axis Assembly around the Templete. This is done by

attaching to the sliders designed for these rails.

Now that the carridge has the ability to rotate around

the templete we need to power it. This is done by the

main installing a vertical lead screw somewhere centered

behide the carriage. It should be far enough away to not

impede the carriage motion and but also made as close as

possible to reduce the length of the lead screw. The

further away this lead screw the longer it must be to

interact with the next feature.

Figure 17, Curved Rail & Carriage

We attach to the lead screw with a vertically

linear moving platform with rotation ends. The ends

have a linear bearing in them and will rotate with the

angle of the carriage. The linear bearings will prevent

the platform from rotating and also provide the

connection and lift for the carridge. Mounting blocks

for the rods will be attached to the carridge.

Figure 18, Lead screw connection


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Figure 19, Y Axis Assembly and Z-Axis Assembly


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X-AXIS – PLATFORM AND VICE

This sub-assembly is very different from the Y-Axis and

the Z-Axis as they are not directly connected. They will have

their own template at an opposite plane from the Y-Axis’s

template. The Templates in SolidWorks were center and acted

as one in the complete assembly.

The first things designed are the platform for the

pumpkins. This goes along with the mounting arms and the

attachments that will hold the platforms in place. The

mounting arms need to be long enough to be out of the way of

the biggest pumpkins but strong enough to not deflect under

the weight of the pumpkin or the heavier watermelon. The

platform also acts as the X-axis rotating the pumpkin on the

platform driven by a stepper motor. This stepper motor is best

to be also attached to the lower mounting arm to have a direct

and simple drive train to the platform. Although this will

increase the deflection on the arm.

The platforms will

together work as a vice,

driven by a central gear

that will pull them

together. Compressible

foam will hold the

pumpkin in place. The

central gear is on a gear

train leading towards a

hand crank. The goal of

this train is to easy the

lifting of the weight on the

platform and also move

the crank to the front of

the unit.

Flanking each mounting

arms is a set of BRA and

rails to match. These hold

everything together in the

horizontal directions.

Sandwiched between two

walls.

Figure 20, Platform, mounting

arms and vice

Figure 22, BRA and gear train

Figure 21,

Complete X-Axis

platform and Vice


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Figure 23, The XYZ Axis Together, Templates highlighted

Now that we have the main components of a CNC we need to build the structure around the

device. Seen in the above picture we have attached the curved rails to panels with a cut out

for the carriage. We start to see the chambers of our CNC machine.

The forward left chamber will be our viewer/working section. Here is where the Pumpkin

will be loaded and the vice will close on the fruit by the user.

The left rear chamber simply leaves room for the gears and timing belt, in a final model this

would be closed off.

The right chamber will have the Y & Z Axis. There is plenty of room to store other things in

the future like the electronics board.


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LINEAR RAIL ASSEMBLY

Bearing-Rail assembly, I’ve used the term BRA in

other sections of this report to represent this since it’s used

to a hand full of locations. In the test book BYOCNC (5) in

order to get the best movement along all three axes, my

CNC machine is going to use an inexpensive solution that’s

also extremely smooth and accurate. Here’s how it works.

Lengths of aluminum angled rail. These rail consists of two

1/8"- thick walls that meeting at a 90 degree angle (right

angle). Rail width is measured on the outside wall from the

outside edge to the edge where the two walls meet.

This figure shows a few of the pieces of hardware that you’ll

be purchasing—bearing, bolt, and nut. It also shows the three

items assembled. The bearing is the same type of bearing

you’ll find used in skates, 22mm very low-cost

Attaching the BRA can be done in a few ways, the book

suggests drilling pilot holes and screw the rails done, this

works pretty well depending on the heads used. Thou I’ve

Attached mine using bolts, adhesives, zip ties, friction, and

a combination of these for temporary and permanent

placement.

Figure 24, Alum Rails

Figure 25, bearing

assembly

Figure 26, BRA

Figure 27, BRA riding the rail


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CURVED RAIL ASSEMBLY

This design concept calls for a curved rail to

run the z-axis carriage around the pumpkin. This

enables us to stick to a 3 axis CNC machine. What

is more important is it will keep the drill working

the pumpkin normal to the surface. By that I mean

parallel.

The way to do this is to center the arc of the

rail to where the center of the vice will be. It’s also

important to note that the size of the pumpkin Figure 28, Complete Curved Rail

doesn’t effect this.

Much like the linear rail system these rails

keep the movement of our axis confined. The main

difference is since the rail is curved we need a

better way to fix the movement to the rails. The

solution is instead of simple bearings we will need

to use special v-groove bearings to grip the rail,

ranged properly the bearing can also mesh with a

curved rail seen in figure #.

Figure 29, Rail individual sections

When fabricating this rail it is very important

to make sure the curve is perfect. Making this rail

would be very difficult by hand and very costly if

made in a CNC machine. The solution is to make

a rail in a 3D Printer. The rails you see here are

made in the Universities Rapid Prototyping lab.

They are made out of a plastic filament. To make

thing simple the “Slider” is also made on the

printers and allow attachment of the bearings. It’s

important when making 3D parts that need to fit

tight specs that you add a slight tolerance on your

drawings. These parts then to expand slightly in Figure 30, Slider with v-groove Bearings

the heating process, therefor

add .05” to any critical

measurement. The entire rail

wouldn’t fit in the printer, it

was a simple measure to split

them into thirds and design

pegs to hold them together.

Figure 31 & 32, Slider on rails


24

SPINDLE AND ACCESSORIES

The spindle choice is very important. We need to consider what is necessary for our

needs. Most CNC machines are designed for metal or wood products and require something

powerful but this also means heavy. The heavier the gantry the bigger motors you’ll need and

that means more expensive machinery.

For our needs, carving a fleshy pumpkin, we won’t need anything heavy duty. I’ve chosen to

use the Dremel 200 series because I already owned this tool and would help negate some

costs. The tool is only 2lbs and has a small profile.

Part of this assembly not included in the drawing

is the nose cone. This part extends the physical

connection from the drill to the pumpkin surface that

will compress the springs. The nose can be swapped

out for different lengths. The one shown here will give

us a cutting depth of a quarter inch.

Figure 34, Nose Cone

The milling bit is a special tool. It’s from the RotoZip

sabre cut set. This particular one is meant for drilling

in and milling sideways into wood and plastic sidings.

It will definitely be suited for cutting into pumpkins

and engraving designs.

Figure 35, Protruding milling bit

Figure 33, finished Z-Axis w/nose Figure 36, Milling Bit


25

STEPPER MOTORS AND ELECTRONICS

When picking my stepper motors and the electronics

everything was sourced and suggested by BuildyourCNC.com.

They have very convenient packages and tutorials for the

equipment, not to mention the online forums and quick

customer service has been very helpful.

I decided to go with the NEMA 23 100 Oz-in and the

NEMA 17 62 Oz-in Stepper motors. The X-Axis and the Y-

Axis are going to require some decent torque and the NEMA

100 Oz-in is suggested for my purposes. I decided to do the

NEMA 17 for the Z-Axis for two response, first the reduce Figure 37, NEMA 17

weight and size the second reason is the 100 Oz-in is far more

then what’s necessary.

To drive these motors we will be using the DRV8825

Stepper Motor Controller IC made by Texas Instruments. Each

motor will require its own module to run. This model is a

standalone stepping motor driver that is rated at 2.5 peak amps

per phase. The driver will also accept a range of 8.2 to 45 volts

and can be microstepped up to 1/32 (the step modes are: full,

1/2, 1/4, 1/8, 1/6 and 1/32). The driver chip has all kinds of

built-in protection including protection for heat and over

current. Figure 38, NEMA 23

Connecting the electronics together is the Breakout Board.

I’ve chosen to go with an old fashion parallel port thinking this

would save money thou I didn’t relies my desktop didn’t have a

parallel port. Therefore I went ahead and purchased one for my

computer.

The break out board simply works with the computer Figure 39, 2.5 Amp Driver

program. This board has a relay that controls signals, such

as the router/spindle. There are 11 output pins that can

control various devices such as stepping motor drivers,

coolant, spindle, mist, air, etc. 10 of these pins can be

dedicated to motor axes for a total of 5 axes. 4 Input pins

are provided for limit or home switches.

Lastly to power all of this we purchased a 24 Volt Figure 40, Breakout Board

power supply for the drivers and also a 5 volt adapter for

the breakout board


26

Figure 41, Electronics board

CNC PROGRAM, MACH3

There are three types of software that you’ll be using with your CNC machine. The first

is CAD (computer aided design). This is specialized software that allows you to design two-

and three-dimensional objects for the CNC machine to cut, drill, and perform other actions

on. The second is CAM (computer-aided manufacturing). Easy CAM is the computer-aided

manufacturing). CAM software takes the design you created with the CAD software and

converts it into a “language” called G-Code. This G-

Code is then used by the final type of software,

Control. Control software is the actual application

that talks to your CNC machine; it takes the G-Code

from the CAM software and uses it to send the

proper electrical signals (via the breakout board) to

the three motors.

The Mach3 Control Software is a control

application, It’s from ArtSoft USA and is available

in a free version and a commercial version. Both

versions are identical, but the free version

is going to limit you to 500 lines of G-Code. Figure 42, Main Screen of Mach3


27

When everything is wired on the electronic board, when then connect the computer to

the breakout board using a male-to-male 25-pin cable.

Figure 43, Computer step up Figure 44, Easy CAM

Figure 45, Electronic board

hung up and wired


28

Figure 48, Gear Train

Critical Design Components

By itself, the Pumpkin carver’s parts and components are not heavy enough to cause

failure with the material I’m building with, sheet metal and steel gears. I’ll be using abs

plastic for a few none load bearing parts. This is not designed to hold and drill metal or

wood, just fleshy fruit materials. Pumpkins can weight on average 18 pounds, and I’ll be

designing this for a max load of 30 lbs. Therefore we will need to prevent as much deflection

in our design as possible. Also the hand crank device will need a gear ratio that will allow

ease of use to lift the material.

COMPONENT ONE, BOTTOM VICE

Description: Cantilever

Purpose: Lift and hold material into place

Safety Factor: 2

Load: Static, Moment, 16N at Motor Mount, 130N at the end, 2X factor

of saftey

Figure 46, Deflection visualization

Conclusion: component passes, Max deflection is .01823inchs

and will not be a concern.

COMPONENT TWO, GEAR TRAIN

Description: one timing belt link, one gear link, and two diameter changes

Purpose: Centers both top and bottom platforms

Gear ratio: turn 200N of force into 45N

N1 = 72teeth, 3in Pitch diameter

N2 = 76teeth, 4.72 Pd

N3 = 20teeth, 1.25 Pd

N4 = 48grooves, 3.056 Pd

N5 = 24 grooves, 1.528 Pd

N6 = 3 in Crank wheel

Gear ratio equation: 𝑀𝑣 = (−𝑁2

𝑁3) (−

𝑁4

𝑁5)

𝑀𝑣 = (−76

20) (−

48

24) = 7.6

Figure 47, deflection

scale


29

Central Gear Moment: 200𝑁 × 3𝑖𝑛 = 600𝑁in

After Gear Train: 600𝑁 ×1

7.6= 78.94𝑁

Minimum Crank Moment: 78.94𝑁𝑖𝑛

3𝑖𝑛= 26.31𝑁

Conclustion: Gear Train passes the 45N force required.

COMPONENTS THREE AND FOUR, TIMING BELT CENTER DISTANCE

Description: Two timing belts pulleys positioning

Purpose: Determining bearing mounting positions for no slack blet

Distance Targets: 7in and 9.5in

Originally the supplies website had a center distance calculator to figure out the optimal

distance and belt choice. The actual Distances are Vice platform belt Desired: 9.5 in Actual: 9.587 in X-Axis Belt Desired: 7 Actual: 6.9151in C=Center Distance (in) L=Belt Length (in) = pNB p=Pitch of Belt (in) NB =Number of Teeth on belt = L/p N1=Number of Teeth (grooves) on larger pulley N2=Number of Teeth (grooves) on smaller pulley

=One half angle of wrap on smaller pulley (radians)

=/2 – = angle between straight portion of belt and line of centers (radians)

R1=Pitch Radius of larger pulley (in) = (N1) p/2

R2=Pitch Radius of smaller pulley (in) = (N2) p/2

=3.14159 (ratio of circumference to diameter of circle)

Nomenclature And Basic Equations

2C sin = L – (R1 + R2) – ( – 2) (R1 – R2)

𝐶 = 𝐿 – 𝜋 (𝑅1 + 𝑅2)– (𝜋 – 2𝜙)(𝑅1 – 𝑅2)

2𝑠𝑖𝑛𝜙

Exact Center Distance Determination – Unequal Pulleys The exact equation is as follows: 𝐶 = (1/2)𝜙 [(𝑁𝐵 – 𝑁1) + 𝑘(𝑁1 – 𝑁2)]

where 𝑘 = (– 1) [𝑡𝑎𝑛(– 𝜋 – – 𝜙) + 𝜙 ] is determined from:

1

𝜋(𝑡𝑎𝑛𝜙 − 𝜙) =

(𝑁𝐵 – 𝑁1)

(𝑁1−𝑁2)


30

Figure 49, Center Distance

COMPONENT FIVE, COMPRESSION SPRINGS

Description: Spring mechanism attached to the spindle. Calculate strength

Purpose: Eliminate the need for feedback signals to the controller.

Details: Because a Pumpkin and other possible mediums have a drastically uneven surface

we need a way to keep the z-axis in contact with the surface. The expensive way to do this is

have a feedback signal to the controller with surface distances, typically with CNC machines

this will cause a delay for travel thereby lengthen the process time.

However this could be easily fixed as long as the tool is able to “float” on the surface. A

spring mechanism could achieve this. In theory the tool would fully compress against the

surface triggering a limit switch. Then the z-axis would back of half the compression length.

The result is a tool pressing against the medium. If an uneven surface is more than the

compression distance allow then the limit switch will be activated given a little more room

for moment in that direction

Alpha: Assume frictionless, over engineer

Weight: 5lb

SF:2

10lb ~ 4.53 kg

𝑚𝑔𝑐𝑜𝑠(𝜃) = 𝑁 At 30° 4.53 × 9.81 × 𝑐𝑜𝑠(30) = 38.5𝑁

At 0° 4.53 × 9.81 × 𝑐𝑜𝑠(0) = 44.439𝑁

2 Springs

Choice: Music Wire Precision Compression Spring

Zinc-Plated, 1.5" Length, .48" OD, .063" Wire

Load: 22.94 lb

Conclusion: Two should be enough force


31

Problem: Testing shows the force is far more than necessary to compress.

This error accorded because I converted to Newtons and never converted back.

Solution: Bought several springs to test.

Final Choice: 6lbs/inch rating

Figure 50, Spring mechanism


32

Manufacturing

Fabricating the CNC machine was a huge undertaking, more than I thought it would be.

Several things were changed during the process because they would be too difficult or we

didn’t have the methods available. Regardless, I was able to put together all of the

mechanical components and mechanism. These were made similar to how the design process

went however all at once instead of one element at a time

STRUCTURE

First put together was the outer frame, I did

this because I was going to be aligning everything

and they were going to need a place to be hooked

up to first.

This step was simple, starting with the floor I

installed legs at the same time as mounting the tall

corner beams. The beams are attached to the legs

with several metal corner brackets. This goes the Figure 51, Front view in the works

same for the roof.

For easier caring, I’m attached two sets of

handles to the beams.

Figure 52, Left Side view in the works


33

Z-AXIS - CARRIAGE

The first main component fabricated, like in

the design process is the Z-Axis Carriage.

The clamps are made in the 3D printers and

they are handle together with nuts, spring washers,

and the threaded rods.

Figure 53, Dremel and Clamps

Next was fabricating these sheet metal pieces,

attaching them, the BRAs, and the rack on the top.

This took about 3 days to complete. I’ll be saying this

a lot from now on but the hardest thing about this

projects build is aligning parts and properly drilling

holes. Even then I wasn’t getting smooth spring

action and instead getting binding. After a little

tinkering and grinding of some thread I achieved very

nice linear action.

Figure 54, Complete Housing

The carriage was built alongside the z-axis and

the y-axis. Built as a box, the brackets holding it

together were slightly bent so the box would hold

pressure on the z-axis BRAs. This eliminated some

tolerance issues.

The motor was then mounting and given small

slots so positioning on the rack could be dialed in.

Also attached now is the curved rail sliders seen on

the sides.

Figure 55, Z – Axis Carriage

It was at this point that I recognized some issues.

My designs were very dependent of accuracy of the

components. The straightness and angles of these

even slight off would cause some problems. In a few

instances it wouldn’t be an issue, many cutting and

drills I could make accurately in the shop but since I

needed more time than the shop was open much of

this was made by hand and with a power drill. The

biggest fault came when fabricating the Y-Axis

connections Figure 56, Brackets


34

Y-AXIS – CURVED RAIL AND LIFT

My biggest issue came after mounting these rail to

in the figure #. They were mounted with gorilla glue like

many other pieces in this build but I quickly noticed

how impossible it would be to align these with the linear

bearing on the lead screw platform. There was no trying

to make it work, I ended up breaking the blocks and lost

an expense linear bearing.

However I found a good solution I should have

thought about before. I removed the guess work with

aligning the rails and sampling lifted them with the new

platform seen in figure #. My biggest worry about doing

this before is the platform would simply rotate. Well it

was an easy fix to put a rail behind the platform to

prevent this.

Figure 57, gluing the rails.

After do this and connecting the y axis motor on

the roof the whole thing just came together and

had smooth motion.

Figure 58, Final lead screw platform


35

X-AXIS – PLATFORM AND VICE

The X-Axis had its own issues. The first step was

constructing the mounting arms. They are made out of

sheet metal with hammered flanges to prevent

bending. The top arm only has a rotating point. The

lower arm has this but also holds the x-axis motor.

The issues with this build first arrised in aligning

the rails with the BRA rails and have them both

straight. All while trying to mesh the two with Figure 59 Top Mounting Arm

a central gear. After a very late night I discovered the

rails were crooked. This had set me back a whole day,

thou at least I knew what went wrong. Imagine trying

to sandwich these arms together, align a gear and

bracket the frame into the machine.

Even after I successful put the x-axis into the

chamber, I had discovered I was about half an inch

further back then I needed to be.

Figure 60, Bottom Arm

Figure 61, Front wall w/ rails Figure 62, Back Wall, w/ rails Figure 63, BRA in place

The rest was simple, attaching the gears train and the belt to the back and transferring the

motion to the front. With a drive shaft thou even this was misaligned


36

Figure 64, Complete Assembly

Testing

Everything mechanical is in place to

work, however I can’t get the breakout

board to talk to the motors. I believe this is

because I don’t have a complete

connection with the driver or improper

wiring. I tired following the websites

instructions but they were made for another

set of electronics. These are very similar

but do have some differences. After

contacting the company they have had this

issue before and are working to release

instructions for this product. What they

told me is to have a professional look at it.

Figure 65, Electronic

Panel in place


37

Conclusion

It’s hard to judge the failure of success of this project, since it’s uncomplete with no time

left. I plan to make this work, I might be able to take it to a train electrician, but it would be

simpler to ether wait for the company to release the instruction or to exchange the drivers and

other electronic for the parts they have instructions for.

On what I can judge, everything mechanical is running smoothly with no binding. Each

axis when manually moved act like they should. The biggest issue I see is alignment. The

curved rails are not centered to the vice’s center point. This would mess with the final image

and cause the CNC machine to run slightly awkward on a pumpkins surface.

Knowing what I know now I wouldn’t have constructed this out of wood. I would have

shoveled out the extra bucks to have the panels cut and drilled with precision out of sheet

metal like the original plan. Too much time was wasted in construction and alignment that

could have gone to figuring out the electrically work.

This project simply had two much for just me to do. I could have seen this split into a

two person project. This isn’t the end of the Pumpkin Carver, I plan to complete this in my

spare time and hopefully finish by this next Halloween. This might also be something a

future student would want to work on.

Works Cited

1. The safety of pumpkin carving tools. Marcus, Alexander M, Green, Jason K and

Werner, Frederick W. 6, s.l. : Elsevier Inc, 2004, Preventive Medicine, Vol. 38, pp. 799 -

803. 0091-7435.

2. Pumpkin carving as an exercise in design process thinking. Genereux, William E and

Lewis, Katrina M. Salina, KS : IEEE, 2014. 2014 IEEE Frontiers in Education Conference

(FIE) Proceedings. Vols. 2015-, pp. 1 - 7. 1539-4565.

3. Latchford, Teresa. Don't let pumpkin carving become scary. Newmarket Era-Banner.

7th, Oct 25, 2015, 0844-4072, p. 1.

4. Carlson, Meghan. Lifestyle: The Realistic Person's guide to Pumpkin Carving. Julep.

[Online] 10 15, 2014. http://www.julep.com/blog/halloween-how-to-pumpkin-carving/.

5. Hood-Daniel, Patrick and Floyed, James. Build your own CNC machine. New York :

Apress, 2009. p. 240. 978-1-4302-2489-1.

6. Hazards of Pumpkin Carving. Hankin, F M, Noellert, R C and Wilson, M R. United

States : American Family Physician, 09 1988, American Family Physician, Vol. 38, pp. 221 -

222. 0002-838X.

7. Dominic, Kelly. 10-Year-Old Purchases Pumpkin Carving Kit With Sharp Serrated Knife.

OPPOSINGVIEWS. [Online] 10 20, 2014. http://www.opposingviews.com/i/society/mother-

shocked-after-10-year-old-son-purchases-pumpkin-carving-kit-serrated-knife.

8. Brandeisky, Kara. Slate, future tense, The citizen's guide to the future. A Robot to Carve

Your Jack-o-Lantern for You. [Online] 10 23, 2014.

http://www.slate.com/blogs/future_tense/2012/10/23/punkinbot_from_brian_and_alex_vandi


38

epenbos_carves_pumpkins_automatically.html.

9. Sorrel, Charlie. DIY CNC MACHINES JUST $390. www.wired.com. [Online] Gear, 1

10, 11. http://www.wired.com/2011/01/diy-cnc-machine-just-390/.

10. CHOP SHOP. Fabrication (CNC & Laser Cutting). Chop Shop. [Online] [Cited: 10 14,

2015.] http://chopshopcnc.com/services/cnc/.

11. Vlad. Dremel Body. https://grabcad.com/library/dremel-body, s.l. : s.n.

Appendix

A. RESEARCH


39

B. SURVEY

Survey Questions Please fill out and return to Adam J [email protected]

Product: CNC Pumpkin Carver

This survey will be used to figure out the primary need and features desired for a product.

Please circle the appropriate choice

Freedom of movement Capabilities, would you want:

Continuous rotation Work only one side is all that’s

(Necessary for most Halloween designs)

Input of Design, would you want?

Computer driven, CNC Manual, control knobs

Work Environment, circle all that apply

Inside a store Workshop/Home Garage

Work Configuration

Countertop Standing Model

Does this need CNC need to be made FDA certifiable for what is carved

Yes or No

How much would you be willing to invest in such a device?

$400-500 $600-$750

How much would you be will to pay to use this in a department store or garden center?

$1-2/per pumpkin $3-4/per pumpkin


40

C. QFD

Quality

Characteristics

(a.k.a. "Functional

Requirements" or

"How s")

Demanded Quality

(a.k.a. "Customer

Requirements" or

"Whats") 0 1 2 3 4 5

1 9 11.8 4.0 4 1 2 30.95

2 9 14.7 5.0 5 1 3 40.85

3 9 11.8 4.0 4 5 4 20.75

4 9 8.8 3.0 3 5 5 40.65

5 9 8.8 3.0 2 5 4 20.55

6 9 10.3 3.5 4 3 4 30.45

7 9 7.4 2.5 3 2 3 20.35

8 9 10.3 3.5 4 5 5 20.25

9 9 5.9 2.0 2 5 5 30.15

10 9 10.3 3.5 4 5 5 40.05

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Our Company

Tradition Pumpkin Carving

Pumpkin carving kits

PunkinBot

N/A

N/A


41

D. BILL OF MATERIAL/BUDGET OF MATERIALS

Table 3, bill of materials and costs

Part # Description Cost ($) qty

From SDP/SI A 1T 2-Y24042 Nylon Gear, 24 DP, 1.75PD, 5/16 bore, 20 PA 8.46 1 8.46

A 1M12-Y24 Nylon Rack, 24 DP, 12" stock length, 20 PA 3.51 1 3.51

A 1T 2-Y24060 Nylon Gear, 2.5 PD, 5/16 Bore, 24 DP, 20 PA 10.11 1 10.11

A 1T 2-Y24039 Nylon Gear, 1.625 PD, 5/16 Bore, 24 DP, 20 PA 8.07 1 8.07

A 6J 3-48DF03710 Polycarb, .2"(XL), 5/16 Bore, 3.056 PD 11.46 2 22.92

A 6Z 3-21DF03710 Polrcarb .2"(XL) 5/16, 1.528 PD 8.71 1 8.71

A 5C 9-0812 0.25" to 0.375" Coupling 17.77 1 17.77

A 6B 3-130037 Back Timing Belt, 130 Grooves, .2(XL) 7.06 1 7.06

A 6R 3-101037 X-axis Timing Belt, 101 Grooves, .2(XL) 7.78 1 7.78

A 1C12MY04B150 Metric Rack, 150mm Long, .4 pitch 17.93 1 17.93

A 1P 2MYD04045C Brass Insert, Gear, 5mm bore, 18PD, .4p 13.02 1 13.02

A 1B14-32064 Brass Rachet 7.14 1 7.14

A 1C14-04 Carbon Steel Pawl 3.78 1

A 6K 3-13DF03706 Small Timing Belt Pully 6.22 1 6.22

138.7

From McMaster 6655K35 Steel Thrust Bearing, 3/8" 3.43 1 3.43

9533T2 Linear Bearing, 5/16 14.58 2 29.16

91831A009 8-32 SS Nylon Locknut, 100/pack 5.59 1 5.59

92141A009 General Purpose Washers 2 1 2

95412A312 8-32 SS Threaded Rod, 8" 2.4 1 2.4

98804A104 8-32 SS Threaded Rod, 12" 3 2 6

9120K33 Zinc-Galvan Rod, 5/16 Dia, 3ft long 4.68 1 4.68

6061K423 14" Shaft, 3/8" dia 8.42 1 8.42

88985K93 HSS, 6"lg , Rod, .25 Diameter 4.27 1 4.27

9434K121 Spring, 5/pack 5.11 1 5.11

6435K13 3/8 Collar 1.91 1 1.91

6432K13 5/16 Collar 0.97 6 5.82

78.79

Essentrl Components HW-4 Hand Crank 13.22 1 13.22

from VXB KIT8405 3/8" V-Groove Guide Bearing, Sealed 3.95 6 23.7

608ZZ 8X22X7 bearings, 10/pack 7.37 3 22.11

KIT14240 5/16X7/8X5/16 Bearing 5.49 6 32.94

KIT8992 5/16 Bearing 3.77 2 7.54

KIT8993 3/8 Bearing 2.77 2 5.54

91.83

Build ur CNC 14 Teeth, .2"(XL), bore .25" 7.4 1 7.4

3/4 X 3/4 X 1/8 Alum Rail 1.2 8 9.6

Lead Screw, 3/8" 2.1 3 6.3

Anti Backlash Nut 27.95 1 27.95

Power Supply, 24 volts, 8.3 amp 43.96 1 43.96

NEMA 17 motor, 62oz-in 1/4" duel Shaft 19.95 1 19.95

NEMA 23 motor, 100oz-in 24.95 2 49.9

With Relay (Breakout) 28.5 1 28.5

2.5 AMP Motor Driver 45 3 135

Adjustable Rotary Limit Switch 13.95 1 13.95

Limit Switch, 6/pack 30 1 30

E-Stop 14.95 1 14.95

Motion 20 AWG CABLE 1.5 15 22.5

402.56

725.1


42

E. SCHEDULE

TASKS 8/24

/201

58/

31/2

015

9/7/

2015

9/14

/201

5

9/21

/201

59/

28/2

015

10/5

/201

510

/12/

2015

10/1

9/20

1510

/26/

2015

11/2

/201

511

/9/2

015

11/1

6/20

1511

/23/

2015

11/3

0/20

1512

/7/2

015

12/1

4/20

1512

/21/

2015

12/2

8/20

151/

4/20

16

1/11

/201

61/

18/2

016

1/25

/201

62/

1/20

16

2/8/

2016

2/15

/201

6

2/22

/201

62/

29/2

016

3/7/

2016

3/14

/201

6

3/21

/201

63/

28/2

016

4/4/

2016

4/11

/201

6

4/18

/201

64/

25/2

016

Design I

Design Draft

Final Design Report

Design II

Proof of Design Agree (advisor)

Concepts/Selection (advisor)

3D Model - (name sub-assmby)


Design Presentation

Design III

Manufacture

Test

Tech Expo

Project Presentation

Name(s)Project title

Sun - SatDesign presentation to faculty (12 min) Jan 27 – 31Design report to advisor Feb 3- 7Demonstration to advisor Mar 24-28 Tech Expo(Thur. Apr. 3)Project presention to faculty (15 min) Apr 7 - 11Project report to advisor for review before library submission Apr 14 – 18Library pdf file in BB (fall course link) Wed. Apr 23

Schedule Columns are by week starting with the first design task (Concept sketches/selection)Columns give datesTasks are broken into 1-2 week intervalsEach task line has 2 rows in the spreadsheet to allow for the actual interval to be addedDeadlines are typed as dates in the interval (earliest option)Deadlines match the MET and advisor requirementsOne deadline is the Proof of Design AgreementParts/materials are ordered as early as possible Readable (break into pages if needed)Informative heading

Table 4 Schedule

TASKS 8/24

/201

58/

31/2

015

9/7/

2015

9/14

/201

5

9/21

/201

59/

28/2

015

10/5

/201

510

/12/

2015

10/1

9/20

1510

/26/

2015

11/2

/201

511

/9/2

015

11/1

6/20

1511

/23/

2015

11/3

0/20

1512

/7/2

015

12/1

4/20

1512

/21/

2015

12/2

8/20

151/

4/20

16

1/11

/201

61/

18/2

016

1/25

/201

62/

1/20

16

2/8/

2016

2/15

/201

6

2/22

/201

62/

29/2

016

3/7/

2016

3/14

/201

6

3/21

/201

63/

28/2

016

4/4/

2016

4/11

/201

6

4/18

/201

64/

25/2

016

Design I

Design Draft

Final Design Report

Design II

Proof of Design Agree (advisor)

Concepts/Selection (advisor)



Design Presentation

Design III

Manufacture

Test

Tech Expo

Project Presentation

Name(s)Project title

Sun - SatDesign presentation to faculty (12 min) Jan 27 – 31Design report to advisor Feb 3- 7Demonstration to advisor Mar 24-28 Tech Expo(Thur. Apr. 3)Project presention to faculty (15 min) Apr 7 - 11Project report to advisor for review before library submission Apr 14 – 18Library pdf file in BB (fall course link) Wed. Apr 23

Schedule Columns are by week starting with the first design task (Concept sketches/selection)Columns give datesTasks are broken into 1-2 week intervalsEach task line has 2 rows in the spreadsheet to allow for the actual interval to be addedDeadlines are typed as dates in the interval (earliest option)Deadlines match the MET and advisor requirementsOne deadline is the Proof of Design AgreementParts/materials are ordered as early as possible Readable (break into pages if needed)Informative heading


43

F. BUDGET

From my sources a small CNC machine can be built for at least $390. But can be as high

as $3000 dollars. But the average someone might spend is around $700-800, therefore I’m

setting my initial budget at $1000 dollars.

CNC Pumpkin Carver Budget

Raw Materials $300

Electrical components $250

Motors/parts $350

Odds and ends, special tooling $100


44

G. DATE SHEETS

NEMA 17

NEMA 23


45

Limit Switch dimensions


46

H. DRAWINGS


47


48


49


50

I. FABRICATED PARTS


51


52

cnc pumpkin carver

Documents