Mustafa Alkhulaitit – Project ManagerGregorio Rios – 3D Modeling

Jessica Salazar – 3D Manufacturing

ADVANCED 3D PRINTER

Our main objective is to improve Sasha, a 3D printer, by applying different upgrades and technologies while taking into consideration costs and time.

MISSION OBJECTIVES

○ precision/Accuracy – precision of Sasha must be within 2% error between theoretical and actual results

○ Reliability – consistency of printed objects. Decrease the number of trials to accomplish the desired shape (Exact number of trials TBD)

○ Cost – total cost must be within $300 - $500 range

○ Schedule – expected completion before May 7, 2014

LEVEL 1 REQUIREMENTS

○ Frame○ Heat Bed ○ Auto Bed Leveling ○ Dual Extruder Heads ○ LCD Panel/SD Reader ○ All Metal Hot End ○ Surface Toning

IMPROVEMENTS OVERVIEW

○The printer is made of 3mm laser cut steel making a strong structure.

○Pros:

1. steel is 10 times cheaper than aluminum

2. laser cutting steel is easier and cheaper than cutting aluminum

3. steel is stronger than aluminum

○Cons:

4. Steel is 3 times heavier than aluminum

○The design of this structure was made with a lot of carvings in order to reduce weight. These carvings, holes, tab and rounded corners where made to accommodate parts while providing a good fit.

FRAME

ACTUAL FRAME

○ The smart Controller is easily able to connect to your ramps board using the smart adapter

○ Contains an SD-Card reader, a rotary encoder and a 20-character x4 line LCD display

○ Benefits:

- PC is no longer needed

- G-code design stored

- Allows actions like calibration and

axes movements

LCD/SD SMART CONTROLLER

○ A Bowden extruder is part of a printer where there’s a flexible tube guiding a filament from the extruder motor also known as the cold end is located and the nozzle also called the hot end.

○ Differences:

- Typical Extruder-gear motor pulls the filament , extruder is right above the hot end

- Bowden extruder-stepper motor separated from the hot

end

BOWDEN EXTRUDER

E3D HOT END NOZZLE

○No PEEK or  PTFE○ Reach Extremely High Temperatures- 300ºC with suppl ied thermistor- >400ºC with thermocouple (addi t ional e lectronics may be required)○ CNC Machined Parts- High precis ion- High qual i ty sur face fi nish- Aesthet ica l ly P leasing ○ Pr ints a lmost every mater ia l ( inc luding PLA)○ Short Thermal Transi t ion- Improves extrus ion accuracy- Reduces 'b lobbing’  - Lowers extrus ion force- Less retract ion required

○ The all metal hot end can withstand temperatures that surpass the thermoplastic extrusion levels.

AUTO BED LEVELING

What is Auto bed leveling?

○ Auto leveling is the process of analyzing several points on the platform and from that data calculates the plane that the print bed actually sits on.

○ The printer is then adjusted so that it prints perpendicular to the bed that’s not even.

○ Auto bed leveling does NOT actually level the bed,

just helps compensate for the bed not being leveled.

○ Takes multiple adjustments to get an even platform, which can be tedious and time-consuming

○ Get one corner “Just right”, and another corner goes just a little out of adjustment, and you’re making another round to make sure nothing else moved

DIFFICULTIES WITH MANUAL LEVELING

○ sanding

○ Acetone Vapor Bath

○ Sandblasting

SURFACE TONING

○ Sanding and polishing kits also help with the sanding process

○ Start with a 100/150 grit paper and end with 220, 320 fine, 500 super fine, and finish with the micron-grade grits to eliminate sanding marks.

○ Skipping to different grit papers will not be an advantage. Too fine or too

fast will go over the ridges without flattening them.

○ After sanding a surface, a heat gun can be used to erase many of the smaller scratches and restore the original printed color

SANDING

○ It’s a common way to treat ABS 3D printed objects

○ Pros: Cleans up surface imperfections, fuses together outer layers for a tighter seal. 

○ Cons: Part becomes soft during acetone vapor bath and it may slightly distort the shape; short baths tend to minimize this.

ACETONE VAPOR BATH

○ Walnut shell as a blasting media for use on soft surfaces like plastic. Walnut shells alone leave a dull finish

○ Plastic pellets might be soft to smooth out prints

○ Different combination with walnut shells, plastic pellets and grit might work better.

○ Too soft material being sandblasted on the printed part might not give enough

smooth finish

○ Too hard materials where would deform the printed material

SANDBLASTING

○ Dual extruder heads will remove shape restriction

○ Uses dissolvable support structure such as HIPS and PVA

○ When operated by the RAMPS 1.4 and MEGA 2560 we have smoother, higher quality prints

DUAL EXTRUDERS

○ Heated beds improve quality of printed objects

○ Heated beds work by keeping the object warm during the whole printing process which keeps the material at or above heat-deflection temperature, meaning the object will remain flat on the surface

○ PCB heat bed is the most common model

○ PCB Advantages:

- Even heat distribution

- Simple implementation

- Small space required

- Lightweight

- More expensive than the Aluminum Clad Resistors

- Has two sides: top side is safer, while the bottom side is more effective and heats up quicker

HEATED BED OVERVIEW

PCB heat bed platform

No heat bed installed, ugly!

SYSTEM DESIGN

# Part Price Range (Each)

1. Heated Bed Upgrade $30 - $50

2. All Metal Hot End $100

3. Surface Toning TBD

4. LCD Panel $50 - $70

5. 2x NEMA 17 Stepper-Motor

$20

6. 2x M2.5x12mm Bolts $0.64

7. M2.5 Nuts $0.60

8. TowerPro SG-90 Mini Servo

$3.49

9. OMRON SS-5 Micro switch

$1.75

Approx. Total= $270

DETAILED COSTS

SCHEDULE