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3D Printing & Modeling + Ed3DP

Educator 3DP Manual and 3D Modelling with TinkerCAD

Site: StemAcademy: Projects & Resources - Maker Space - Coding & Robotics
Course: StemAcademy: Projects & Resources - Maker Space - Coding & Robotics
Book: 3D Printing & Modeling + Ed3DP
Printed by:
Date: Monday, 20 May 2019, 12:50 AM

1. Educator 3DP Manual

Educator 3DP comes pre assembled, tested and ready to use.  The following chapters outline usage and maintenance of the Educator 3DP

1.1. Educator 3DP Overview

Educator 3DP Overview



Educator 3DP Design Features:

• Tough and Robust – suitable for inexperienced and constant student use. Full aluminium structural frame. Industrial strength fully supported “rolling bed” design.

• Safe - emergency stop and optional hinged polycarbonate front protective screens.

• Large Colour Touch Screen – no computer required for control.

• Automatic Filament Out Sensor Option – Automatically pauses printing at the end of the filament roll.

• Single all metal extruder with large heated Aluminium Print Bed - 200mm x 200mm

• Pro Upgrade Option: Dual all metal extruders and ultra large heated bed 300mm x 300mm

• High Temperature Stainless Steel Thermocouple Extruder and Nozzle with silcone heat insulator- suitable for specialist polymers up to 300 degrees Celsius

• Auto-Levelling Bed Compensation Sensor – you do not level this bed manually with screws or nuts by hand- rather the bed is probed to determine its "level" and the print adjusted. This means fast reliable prints with no lifting and warping and no filament wastage with rafts.

• Four Roll Filament Holder – print from any of the four filament roll positions without moving spools.


• Network Capable - comes with LAN support - allows networking and browser based applications at all stages of the design and printing process. You can network the Educator 3DP like any photocopier and send your files from anywhere on the school network.

• Multiple File options: SD Card - USB Memory Stick – Network (LAN) or optional Wifi

• Easy Access Maintenance - nothing to remove to clean up extruder drive cog - just a 30 second job that 8 year old students could easily do properly and safely.

• Inexpensive Consumables and Replacements – Takes standard 1.75mm 1kg filament rolls which are about $20/Kg (which compares to over $125/Kg for cartridge type filament printers).

• Locally Designed and Manufactured – Using open sourced 3D printer hardware with custom design for harsh classroom use.

• Full Training and Support Available – Online training resources, support forum, technical workshop support etc.


1.2. Software and Drivers

Educator 3DP can be completely controlled from the touch screen and you do not need a computer to control the printer or print files.  You will need a computer to create the 3D model file and then to "Slice" (convert to GCode) ready for the 3D Educator and this is covered in further chapters.

Files for 3D printing can be either sent via memory card (either SD card or USB flash drive) via the right hand side of the touch screen.  The printer can also be networked.  

It is also possible to use any 3D printer console software like Pronterface for Windows or MAC in which case you will need to install smoothie windows usb driver unless you have windows 10.  This allows you to control Educator 3DP from a computer using GCode commands.  Please check that the driver is installed and COM port number via "Control Panel" and "Device Manager" (see video below)

Educator 3DP is built around a Smoothieboard and for more advanced information please refer to the Smoothieboard Documentation.

 

  


1.3. Firmware Updates

The Educator 3DP has a Smoothieware CNC control board system which is configured for our printer.  This firmware and configuration will need updating periodically.   The touch screen also has its own firmware and config files.


Current Firmware & Config Version: 21st July 2017

Update Smoothie Mainboard Firmware & Config:  

  • The smoothie board is inside at the rear of the printer and the sd card slot is just accessible (you may need pointy nose plyers)
  • There are two ways to write files to the SD card of the Educator's smoothie mainboard:

  1. remove the micro SD card and put it into a card reader or adapter for your PC
  2. use a usb cable to the mainboard (not the touch screen) and the SD card comes up as a removeable media but you may need to instal the smoothie board USB driver (windows 10 works straight up)

  • Ensure the integrity of your SD card- delete files and perhaps format?
  • Download the latest firmware.bin (right click "save as") and write to the SD card of the mainboard (note: when the smoothieboard reboots "firmware.bin" will become "firmware.cur")
  • Download the latest config.txt (right click "save as") and write to the SD card of the mainboard
  • Replace the SD card or disconnect the computer
  • Power off and reboot Educator 3DP (never reboot printer with usb cable connected to computer or the SD could be corrupted)


Update Touch Screen Firmware & Config:

  • turn all power off to the printer
  • the following files need to be placed on either an SD Card or USB flash memory stick (depending on which one you have set as your media type in the file menu of the touch screen
  • Touch Screen Firmware
  • Touch Screen Config
  • place the media with the above files into the touch screen media port (sd or usb)
  • power on the printer (you should see it displaying update message)
  • remove media when done and the files have been transferred to the onboard memory of the touch screen


1.4. Interfacing Options

The main Smoothie control board is inside the 3D printer and has a USB port, Ethernet Jack and micro SD slot and is accessible from the rear of the printer.   The SD in the rear of the printer is for the Smoothie firmware and should not be removed- you don NOT use this SD card for file transfer.  By default, Educator 3DP comes with a colour touch TFT screen at the front that has both a SD card slot and a USB port which can be selected in the "Set" menu then "File Sys".

Do Not plug in the RJ45 ethernet cable to the printer unless you want to use this interface method as it will disable all the other methods i.e. you will not have control via the touch screen.

Educator 3DP can be controlled via:

  1. Touch Screen (Default)
  2. Computer and USB cable
  3. LAN RJ45 Jack.  You can only have one in control at the same time.

If you want to many put GCode files for printing into the 3D Printer via either the USB/SD ports on the Touch Screen then everything is already done by default- just set either SD or USB.  Network or Computer interfacing to Educator requires extra setup detailed in following chapters.

1.5. Network & PC Interfacing

Network Setup:

The Educator 3DP can be controlled and connected to your Network via the RJ45 ethernet port at the rear and will need to setup as follows:

  1. Web app needs to go onto the SD of the Smoothie control board in the rear of the printer as per these instructions.
  2. Setup up and config for your network



PC Setup:

Educator 3DP can also be controlled via "host" software on a computer via a USB cable to the back of the printer (not the touch screen).  Pronterface is the most common "host" and full instructions are here.  Other software options are here.

1.6. Printer Bed Calibration




Educator 3DP- Printer Bed Calibration Procedure

The Educator 3DP automatically adjusts or "compensates" the printing level of the actual print bed using a stored map of the bed contours.  This compensation grid is generated in step 3 below- calibrate bed.  It works by going to a known point and then taking a grid of bed heights at different x & Y points using the inductance sensor which is then stored as a type of grid contour height map.  The inductance sensor should be manually set at 2mm above the tip of the extrusion nozzle (if its too low then it will hit your 3D prints or if too high then the extrusion nozzle will smash into the bed while it attempts to lower to take height readings with the inductance sensor.  Once done, this should provide perfect printing directly onto the aluminium bed.  This only needs to be done infrequently or when the nozzle is changed etc.  There are four steps to get the printer bed calibrated (compensated).

1.       Level the X-axis:

a.       Turn on the printer and “home all”

b.       Use the “move” menu and jog the extruder head down till it is just above the bed on the LHS about x=20mm

c.       Using a piece of copy paper jog the nozzle down “Z-“ in 0.1mm increments until there is light pressure on the paper- this is about 0.2mm between the bed and nozzle i.e. thickness of the paper

d.       Move the nozzle to the RHS to about x=180mm

e.       Adjust the RHS Z-axis drive stepper (large vertical threaded rod) either clockwise or anticlockwise as needed to get the same height and pressure with the paper

f.        Repeat this process to check that he x-axis is level across the bed

2.       Set the “Z0” height (z zero):

a.       Turn on the printer and “home all”

b.       Goto the “more” menu on the touch screen- the buttons are basically in order of use from top LHS

c.       Press “Goto Z0”- the printer will home first and then go its currently set Z zero point i.e. where the nozzle is just above the bed for printing

d.       Using a small piece of copy paper use the “Z up” and “Z down” keys to “jog” (move) until there is firm pressure on the paper from the nozzle

e.       Press “Set Z0”

f.        Press “Home XYZ axes”

g.       After the printer has homed and stopped press “Save ALL Settings” and reboot printer

h.       Repeat the process and check correct Z0 i.e. firm pressure with copy paper from the nozzle


3.       Calibrate Bed Level:

a.       Complete this step immediately after step 2 above

b.       In the “more” menu press the “Calibrate BED Level”- the printer will “probe” a grid of 11 x 11 points using the inductance sensor

c.       Press “Save ALL Settings” to permanently keep new values and reboot printer

d.       Repeat the Z0 height setting procedure from step 2 above and double check- reboot between checks i.e. power off.


4.       Fine tune Z0 with test print:

a.       Setting the nozzle height for Z0 i.e. the bed as in step 2 above is a good approximation however due to differences between people’s perception of “firm” pressure and variances of paper thickness and errors like waste filament under the nozzle giving a false result it is wise to do a test print.

b.       Create a plain rectangular prism about 100 x 100 x 1mm in your 3D modelling software or use this Bed Plate Test GRid STL model

c.       In the “Slicer” i.e. Cura etc turn off raft and all other support and set the “Platform Adhesion Type” to “none" and creat your gcode or use Bed Plate Test Grid GCode for 3DP.

d.       Pre-heat and prepare the printer- both extruder and bed

e.       Perform the test print (you only need a few lines) and examine the resultant first layer shape and characteristics as follows:

                i.      The ideal result is the first layer will lay down like flat pasta-  even thickness and well adhered to bed (touch it with your fingers once printer is stopped)

                ii.      If the filament lays down like rice paper i.e. very thin or there are bubbles or excess filament pushed outwards then the nozzle Z0 is too low- move it up 0.1mm as in step 2 and repeat

                 iii.      If the filament lays down like a cylindrical sausage without being “capped off” and pushed into the bed a bit then the Z0 is too high-lower it 0.1mm and try again


1.7. Extruder Setup

Educator 3DP- Extruder/Filament Setup

The filament is driven through the hotend nozzle by a filament drive cog and filament idler which is tensioned with a pivoting arm and compression spring and bolt.  It is important that the compression force of the filament idler on the filament and drive cog is correct such that there is no grinding and sheering of filament nor slipping and failure of the filament to move.  The nozzle also needs to be free of obstructions.

1.       Clean the nozzle and drive cog:

a.       Turn on the printer- home all

b.       Goto “Preheat” menu and adjust the extruder temperature up to 190 from its default of 180 degrees Celsius

c.       Once the extruder is at 190 degrees remove the existing filament

     i.      Release the tension on the filament by turning the tension bolt anticlockwise

     ii.      Depress the filament idler arm without putting downward force on the whole extruder assembly itself- keep your fingers away from the hot nozzle underneath

    iii.      Withdraw the filament by pulling up while depressing the filament idler arm

   iv.      Clean the filament drive cog with the small wire brush by starting at the back and brushing forward thus brushing the ground filament forward and out not backwards and into the assembly- rotate the drive cog and repeat till the drive cog is completely clean

d.       Load the “cleaner filament” into the extruder and tighten the idler tensioner bolt clockwise till “firm by finger”

e.       Extrude about 50 to 100mm of “cleaner filament” till extrusion is completely clean with no residual  filament by going to the “Extrude” menu and pressing “Extrude Filament”

f.        Remove the “cleaner filament” as in step c

2.       Load new filament:

a.       Make sure that the extruder is preheated and clean as above

b.       Straighten the filament end by running your compressed fingers along filament

c.       Make sure filament is clean and undamaged and not “brittle”

d.       Cut filament at 45 degrees to the vertical- cleanly with side cutters so that it forms a “spear”

e.       Load the new filament while releasing the idler compression- unscrew the tensioning bolt and depress idler arm

3.       Nozzle clear test:

a.        While releasing the idler compression on the filament and drive cog- you should be able to slowly push the filament down through the nozzle and have it extrude

b.       If you can’t do this the nozzle may be partially blocked- see the above steps for cleaning

c.       If the nozzle is completely blocked it will need to be removed and replaced while hot

4.       Tension filament idler:

a.       Screw the filament tensioning bolt clockwise till “finger tight”

b.       Goto “Extrude” menu and extrude 10mm of filament- at the same time pinch the filament between your fingers tightly- the filament should drag through your pinched fingers directly above the extruder

c.       Tension is too low if you can stop the filament with your pinched fingers or if it slips on the drive cog while printing but does not slip while doing a test extrude

d.       Tension is too high if the drive cog gouges and grinds the filament


2. 3D Printing

This chapter covers the process of converting your 3D model file into GCode ready for the 3D printing.  This is commonly known as "Slicing" because the 3D model file which are "vectors" (mathematical formulae) are turned into geometrical coordinates (x,y,z) layer by layer.  The layers are horizontal and are also called "slices" hence the term "Slicing" your 3D model into GCode.

You can use any open source or commercial 3D modelling and Slicing software with the Educator 3DP as long as it produces standard GCode.

We recommend and support Cura for "Slicing" which is open source.  This version of Cura has been in use for many years and is easy to use yet complex enough for tweaking your print settings.  It suits an educational environment well. There is a new version of Cura available but we have not started using this yet.

The biggest problem with 3D Printing is job adhesion and warping.  This usually relates to nozzle distance from print bed, bed temperature, nozzle restrictions or bed level issues.  Try this extensive 3D Print Troubleshooting guide for detailed hints.  These issues will be covered in subsequent chapters.


2.1. Slicing- CURA


This chapter covers the process of converting your 3D model file into GCode ready for 3D printing.  This is commonly known as "Slicing" because the 3D model file, which are "vectors" (mathematical formulae), are turned into geometrical coordinates (x,y,z) layer by layer.  The layers are horizontal and are also called "slices" hence the term "Slicing" your 3D model into GCode.  You can use any open source or commercial 3D modelling and Slicing software with the Educator 3DP as long as it produces standard GCode.

We recommend and support this version of Cura for "Slicing" which is open source.  If you have a Mac or Linux please download Version 15.04.6 from the Cura Site.  This version of Cura has been in use for many years and is easy to use yet complex enough for tweaking your print settings.  It suits an educational environment well. There is a new version of Cura available but we have not started using this yet.

While installing Cura select "other" and just define the printer as "180 x 180"- that way when you use Cura the print bed in Cura will be the same size as the Educator 3DP print bed i.e. 180mm x 180mm.  Please also make sure that the "heated bed" box is checked- otherwise Cura will not display a bed temperature dialogue box.

Once you have installed Cura you can load our Fast PLA Profile or Fast HIPS & ABS Profile (right click and "save link as") into Cura via the "File" menu then "Open Profile".  All the settings are adjusted for quick classroom prints and you can make adjustments from there.

Hovering over the input boxes in Cura brings help a help box that explains what that printing parameter does.  


Start&End Gcode should be in the "Start/End-GCode" TAB of CURA:

You must have the following "start.gcode" in Cura: (in the "Start/End-GCode" Tab)

G21; set to mm

M375;  Load the bed compensation grid from sd card

G90  ;absolute positioning

M82 ;set extruder to absolute mode

G28  ;auto home

G92 E0 ;zero the extruded length

G1 F200 E10 ;extrude 10mm of feed stock

G92 E0 ;zero the extruded length again


You must have the following "end.gcode" in Cura  (in the "Start/End-GCode" Tab):

M104 S0;extruder heater off

M140 S0;heated bed heater off (if you have it)

G91;relative positioning

G1 E-6 F300;retract the filament a bit before lifting the nozzle, to release some of the pressure

G28 ;home all axes

G0 Y170; move the bed forward

M84 ;steppers off

G90 ;absolute positioning


If you have not already setup "Educator 3DP" as your "machine" during the Cura install process then goto the "Machine" menu and then "Add new machine": the only data you need to change from default is a square build area of 180x180 and height of 200mm, 1 extruder, check the heated bed box, and Gcode flavour is RepRap(Marlin/Sprinter).  It should look like the settings below:


2.2. Filaments

Beginners should start with PLA (Polylactic Acid) filament as it's easy to work with and very forgiving.  PLA has a lower supple point, doesn't need much heat in the bed, doesn't warp much and sticks easily to the bed.  However, PLA is brittle and doesn't suit structural parts but is great for general prototyping. 

Once you have some skill and require a more impact resistant model, then HIPS (High Impact PolyStyrene) or ABS (Acrylonitrile Butadiene Styrene) is suggested.  HIPS and ABS have a higher supple point than PLA and will deform with impact rather than crack like PLA.  HIPS has similar structural characteristics to ABS but doesn't warp as much as ABS during printing and is much easier to achieve successful prints than ABS.  ABS is much harder to work with as it warps during the print process and doesn't stick to the bed as easily and requires higher print temperatures both in the extrusion nozzle and print bed.  ABS is not recommended for beginners but is relatively easy for attentive educators and students to master but requires more precise fine tuning of print parameters.

Educator 3DP has a high quality all stainless steel heat tube with a wrap around heating element that provides more uniform heat distribution to the filament.  Additionally Educator 3DP uses a thermocouple temperature sensor in the extruder which is stable for temperatures above 300 degrees celsius unlike normally used thermistors that start to breakdown at about 275 degrees Celsius.  Our all stainless steel hot end with thermocouple temperature sensor means that you can confidently extrude the many speciality filaments which often require temperatures above 275 degrees Celsius which is usually the limit of normal 3D printers.  

An inexpensive source of good quality filament is available from Hobbyking.com (ex Sydney) with modest shipping costs.  When ordering just make sure that you have selected the Australian warehouse and you have 1.75mm filament not 3mm.  A huge advantage of the Educator 3DP is that consumables are cheap.  We do not sell filament at inflated prices (we don't sell it at all).  You can get good quality PLA and ABS for about AUS $25 per 1Kg from Hobbyking.com (ex Sydney) with modest shipping costs.  Many 3D printer manufacturers and retailers are pushing "cartridge" type 3D printers because they will make double the purchase price from cartridge filament sales- typically cartridge filament costs about $40 to $80 per 1/2Kg cartridge which is $80-$160 per 1Kg of filament.  A 3D printer in a school might consume about  1 to 5Kg per Term or 5 to 20Kg per year. So a school 3D printer might use about 10Kg per year which is only about $250 in filament for the Educator 3DP but at least $1000 in filament cost for the cartridge system or name brand filament.

TinkerCAD's Filament Guide  

Filament

Special Properties

Uses

Stre-
ngth

Flexi-
bility

Dura-
bility

Print 
Skills

Print 
Temp. 
(˚C)

Bed
Temp.
(˚C)

PLA

Easy to Print, Biodegradable

Consumer Products

★★

★★

180 - 230

No

ABS

Durable, Impact Resistant

Functional Parts

★★

★★

★★★

★★

210 - 250

50 - 100

PETG (XT, N‑Vent)

Flexible, Durable

All-Rounder

★★

★★★

★★★

★★

220 - 235

No

Nylon

Strong, Flexible, Durable

All-Rounder

★★★

★★★

★★★

★★

220 - 260

50 - 100

Flexible, TPE, TPU

Extremely Flexible, Rubber-Like

Elastic Parts,
Wearables

★★★

★★

★★★

225 - 235

No

Wood

Wood Finish

Home Decor

★★

★★

★★

★★

195 - 220

No

HIPS

Disolvable, Biodegradable

ABS Dual Extrusion, Support Structures

★★

★★★

★★

210 - 250

50 - 100

PVA

Disolvable, Water Soluble, Biodegradable, Oil Resistant

PLA/ABS Dual Extrusion, Support Structures

★★★

★★

180 - 230

No

PET (CEP)

Strong, Flexible, Durable, Recyclable

All-Rounder

★★★

★★★

★★★

★★

220 - 250

No

Metal

Metal Finish

Jewelry

★★

★★★

★★★

195 - 220

No

Carbon Fiber

Rigid, Stronger Than Pure PLA

Functional Parts

★★

★★★

★★

195 - 220

No

Lignin (bioFila)

Biodegradable

Looks and feels cool
Stronger than PLA

★★

★★

190 - 225

55

PC Polycarbonate

Strongest, Flexible, Durable, Transparent, Heat Resistant

Functional Parts

★★★

★★★

★★★

★★

270 - 310

90 - 105

Conductive

Conductive

Electronics

★★

★★

215 - 230

No

Wax (MOLDLAY)

Melts Away

Lost Wax Casting

170 - 180

No

PETT (T‑Glase)

Strong, Flexible, Transparent, Clear

Functional Parts

★★★

★★★

★★★

★★

235 - 240

No

ASA

Rigid, Durable, Weather Resistant

Outdoor

★★

★★★

★★

240 - 260

100 - 120

PP

Flexible, Chemical Resistance

Flexible Components

★★

★★★

★★

★★★

210 - 230

120 - 150

POM, Acetal

Strong, Rigid, Low Friction, Resilient

Functional Parts

★★★

★★

★★★

210 - 225

130

PMMA, Acrylic

Rigid, Durable, Transparent, Clear, Impact Resistant

Light diffusers

★★

★★★

★★

235 - 250

100 -120

Sandstone (LAYBRICK)

Sandstone Finish

Architecture

★★

165 - 210

No

Glow-In-The-Dark

Luminous, Flourescent

For Fun

★★

★★

★★

215

No

Cleaning

Cleaning

Unclogging of Nozzles

N/A

N/A

N/A

150 - 260

No

PC/ABS

Rigid, Durable, Impact Resistant, Resilient, Deflecting Heat

Functional Parts

★★

★★★

★★★

260 - 280

120

Magnetic

Magnetic

For Fun

★★

★★

★★

★★★

195 - 220

No

Color Changing

Changes Color

For Fun

★★

★★

★★

215

No

nGen

Like PETG, but Easier to Print, Heat Resistant, Transparent

All-Rounder

★★

★★★

★★★

★★

210 - 240

60

TPC

Extremely Flexible, Rubber-Like, Chemical-/ Heat-/ 
UV Resistant

Elastic Parts,
Outdoor

★★★

★★

★★★

210

60 - 100

PORO-LAY

Partially Water Soluble

For Fun, Experimental

★★★

★★

220 - 235

No

FPE

Flexible

Flexible Parts

★★★

★★★

★★

205 - 250

75


2.3. Bed Adhesion

Prints warping, lifting and not sticking properly to the bed can be an issue with 3D printing.  Normally, 3D printers blast down a huge "raft" that essentially pints a preparatory base that the actual print job sits on but this is time consuming, wasteful and causes a lot of issues with separating the job from the raft.

Ed3DP has designed out the need for a "raft" with a bed calibration routine using an inductance sensor that stores a contour map of the print bed and adjusts the height as it prints to compensate so that the nozzle is always precisely at the correct height.

PLA will require some water based glue stick applied to the Aluminum bed before each print.  "UHU" brand is best as it is very moist and stays sticky for a long time while the first layer is printed.  Other brands are too dry and turn into "rice paper" upon application and the print doesn't stick.  "Bostik" aslo works satisfactorily but "UHU" is superior.  Just clean the bed occasionally with scraper or stainless scourer pad and water.  The bed is best left a bit "dirty" rather than perfectly clean as this actually aids print adhesion.

Filaments other than PLA - HIPS, ABS & Nylon etc will require a small application of either Hairspray or "Filament Juice" which is the filament dissolved in solvent.  The solvent is commonly acetone, however, a far superior solvent is printing "ecosolvent" which is also a ketone but with a much higher boiling point and lower vapour pressure so it doesn't evaporate quickly like common acetone.  Simply get a sauce bottle and cut up pieces of HIPS/ABS and put in the bottle and top up with ecosolvent (or acetone) and let sit for a week with shaking.  Make an applicator with a paint brush and plastic bag and rubber band and brush onto the hot bed just before the print starts.  Clean the bed occasionally with a scrapper or stainless steel scourer with some ecosolvent and paper towel.  Leave the bed a bit dirty as this aids adhesion.



2.4. 3DP FAQ

3D Printing: Frequently Asked Questions


3. 3D Modelling- TinkerCAD

3D Modelling is the process by which a virtual computer generated model of an object is created in 3 planes or dimensions i.e. x,y,z.  There are many 3D modelling packages however most are unsuitable for beginners or non-designers.

TinkerCAD was created for Primary school students to make it easy to develop 3D models specifically for 3D printing.  TinkerCAD is now part of the AutoDESK family which includes autoCAD and Inventor etc.



3.1. Class Tips for TinkerCAD

Classroom Tips for TinkerCAD

Like any technology or teaching aid, its success or failure to produce learning outcomes and successful classroom management depends greatly on utilising that technology wisely.  Based on many years of project based STEM education utilising TinkerCAD I can offer the following advice to aid successful learning, engagement and classroom management.  This refers to mainstream mixed ability large classes not specialist design or extension classes.

  1. Common Logon:
    •  Its best not to ask students to create their own TinkerCAD accounts -partly for online safety reasons and partly to aid student work monitoring, assessment and class flow
    • Create a generic TinkerCAD account with your teacher email and allow students to log in with that- its no problem having 30 students logged into the one account at a time
    • Get students for put all their work in the one project and name it with their name
    • Teacher then has immediate access to all student work and this also helps with getting the files onto the 3D printer
    • It is a risk that students may modify other students work but this has never happened accross many years as students are usually so engaged they don't even think of such a thing.
    • TinkerCAD does have a new "Teacher" account that can link to your student accounts and it is a great system technically but be advised to check with your admin as this could lead to unwanted outcomes and may expose you to duty of care issues- if you are going to direct students to create a TinkerCAD account then get admin approval first.
  2. TinkerCAD is a cloud based system and must be accessed with a browser that has WebGL (Chrome or IE11)- it is rather bandwidth friendly and runs fine with a full class on the internet in schools but please check your bandwidth and test as some regional schools may have a problem.
  3. TinkerCAD has a great Learn/Tutorial system:
    • Utilise the Learn tutorial projects as a unit of mainstream work or as differentiated curriculum for not so abstract learners.
  4. 3D Modelling is inherently abstract:  To make your TinkerCAD based projects accessible to all types and levels of learners it is crucial to make the inherently abstract task of creating a virtual 3D model as concrete as possible
    • Use real physical props and modelling aids
    • Utilise rulers and measurement aids and sketches 
    • Focus on simple design projects that all students would have concrete familiarity (like a key ring, name badge or ring for their finger
    • Set multiple simple design projects that are quickly prototyped with the 3D printer to help keep the process concrete for all learners 

3.2. Design Project Tips

It is presumed that you are combining the 3D modelling in Tinkercad with 3D Printing, so most of these tips relate to easy, fast, successful 3D printing for classes with multiple prototypes for an introductory mainstream class (not a specialist design or extension class).

Project Design Tips:

  1. Small and Simple Designs
    • Its possible to not do any lessons using the TinkerCAD tutorials and just use Project Based Learning (PBL)- so keeping the design projects to about 1-2 hours of class time allows for repetition to consolidate TinkerCAD techniques.
    • Simple basic shapes with vertical faces- for example making a ring for your finger is just two cylinders (hole + solid)
  2. Limit "overhangs": 
    • "overhangs" are parts of the model or print job that do not have anything directly beneath and are defined as degrees from the vertical i.e. straight up is a zero degree overhang while a horizontal protrusion is a 90 degree overhang
    • Limit overhangs to 30 degrees or 45 at most- this means that you don't need any "support" material when 3D printing and makes printing faster and simpler for beginners- so a pyramid has no overhangs while human with outstretched arms has lots of overhangs and is not suitable for beginners to 3D print
    • Consider simple model rotation:  for example a table standing upright would be horrendous to print but if you flip it so that the table top is on the bottom plane and legs sticking up then it would be simple to print with no overhangs
  3. Avoid projects with large surface area to volume ratios:
    • such projects, for example a thin tall wall has a large surface area and a small volume so it dissipates heat quickly and unevenly which will cause "warping" and lifting of the print job from the print bed.
    • "Squat" and "Chunky" models have low surface area to volume ratios and are thus less prone to warping and lifting issues.
  4. Use a minimum of 3mm wall thickness
  5. Avoid fine features with lots of detail- stick with simple coarse designs- for example a key ring with your name and phone number that's about 40 by 70mm in total would be easy to print,simple to design and look good- however putting an embossed photograph of your loved one on that same keyring is an advanced project and would look amazing but takes considerable design and 3D printing experience.
  6. Set specific design guidelines: it is unwise to set the task as "make a key ring of your choice" as this leads to dubious learning outcomes and is not suited to Project Based Learning in mainstream classes- Rather the task should be "design a key ring that has 70mm x 40mm base of 3mm with your choice of end shapes and your name perfectly centred with a 5mm border with the text either embossed or cut through
  7. Do not allow students to "drag" and redimension objects- insist they use the ruler and directly enter dimensions with the keyboard or they will find it extremely difficult to progress to complex designs and it is poor design and engineering practice.

3.3. TinkerCAD Intro

Resources for Learning TinkerCAD:

If you are completely new to 3D modelling then allocate about 5 to 10 hours to become reasonably proficient with create models in TinkerCAD.  If you have experience with design or modelling then you'll be creating immediately and probably don't need to do the tutorials.

There is a TinkerCAD Youtube Channel with "Tinker Tips" and general TinkerCAD videos.

The following is a good introduction to TinkerCAD:


Learning to change your position of view is probably the most important skill which involves, panning, zooming and rotating.  Its highly recommended that you use a mouse as touchpads are very difficult for beginners.


3.4. Embedding Models


It is highly prefered that you "embed" your TinkerCAD models into webpages and digital portfolio so that an interactive model appears in your page not just a static hotlink or image etc.  An embedded model is above.

To embed TinerCAD models:

  1. Make you TinkerCAD model "public"
  2. use the global search box (top right) of TinkerCAD and find your username
  3. Click on the required model and down the bottom you will see an "embed code" box which you click on and then copy the "iframe" code
  4. paste the "iframe" code into this window using the advanced editing tools (top LHS button) and the html tool "<>"
  5. Your TinkerCad model should now be embedded as a 3D viewable and interactive mode

3.5. TinkerCAD Tutorials

TinkerCAD have some great self paced tutorials that cover basic modelling skills:  You will need to be logged into tinkercad to access these tutorials.  Also note that if all your students are using a common login account for TinkerCAD then it will think that the tutorials are done after the first time.  However, this is not a big problem as students can just use the "step" button on the top left to go back to the beginning i.e. step 1.  Also, the teacher could model the tutorial from the front of class and students could follow along but not actually be using the TinkerCAD tutorial but just create a normal project.

               

     



3.6. Steminabox Tutorials

Steminabox Tutorials-TinkerCAD:  


     



3.7. TinkerCAD Projects

TinkerCAD has a heap of supported projects.  However most will not be suitable for beginners to 3D print.  

The following TinkerCAD supported project tutorials are suitable for easy 3D printing:

              

          

3.8. STEMinaBOX Projects

All of the public TinkerCAD projects from STEMinaBOX are available.  There are catapults, bridge trusses, robots and examples for our tutorials.  Eventually all the free projects will be written up and presented below.

3.9. Example Unit

Introduction to 3D Modelling & 3D Printing using TinkerCAD

Level: Introductory level appropriate for Middle Primary and Up- no prior skills required

Time: approx 10 to 15 hours (example 2 or 3 hours per week for 5 weeks)

Resources: TinkerCAD accounts, computers with internet access running browsers with webGL (Chrome or IE 11 or above)

Assessment options: Students could screen shot evidence of completed models into a word assignment or a portfolio etc


Unit Tasks (10-15 hrs):

1. TinkerCAD Basics (2-4 hours):

2. Design Task: Name Tag (2-4 hours)


3. Design Task: Personalised Ring (2-4 hours)

  • When printed the ring must properly fit your chosen finger (measure your finger diameter and add 2mm- this is the ring inner dia)
  • Ring should be "chunky" (use a wall thickness of 3mm) but comfortable to wear
  • Your initials or symbol on the ring
  • Use primitive shapes not the ring tool
  • no "overhangs" greater than 40 degrees (i.e. unsupported print areas)
  • This TinkerCAD tutorial may be useful
  •  TinkerCAD Model of Simple Ring: