3D Scanning & Printing

February 24, 2024

Challenge

• Group assignment:

  • Test the design rules for your 3D printer(s).🙃
  • Document your work on the group work page and reflect on your individual page what you learned about characteristics of your printer(s).🫣

• Individual assignment:

  • Design and 3D print an object (small, few cm3, limited by printer time) that could not be easily made subtractively.
  • 3D scan an object (and optionally print it).

Group Assignment:

This week’s focus involved comprehensive testing of the printing settings for the Ultimaker S5 printer in the lab. The thorough examination encompassed the entire printing workflow, starting from configuring the slicing software to fine-tuning the printer settings for the specific print job. For the group assignment page refer to this LINK

• The following test are done on the Ultimaker S5 and using the Cura Slicer.

• Below some of the specification of the printer:
  Max speed:	300 mm\s
  Max print volume (LxWxH):	330 X 240 X 300 mm
  Finest possible layer height:	0.4mm –> 200 - 20 micron
  Filament diameter:	2.85 mm
  Max nozzle temperature:	280 c
  Heated bed max temp:	150 c
  Machine type (FDM or SLA):	FDM

• For the test acquired : I have done All in one test print which contain all the needed for this assignment

This test tests Overhang, warping, size accuracy, bridge test, fine details and general accuracy of the machine. The test was created by [Marián Trpkoš/thingverse majda107] and found on link.

Slicing

• I have used Cura to generate the G-code for the printer.

• The following settings were used.
  Material:	Ultimaker Yellow PLA
  Rafts:	Yes
  Support:	No
  Resolution:	0.1
  wall thickness :	0.4
  Infill:	30% –> Cross 3D

We can reduce the time by half just by reducing the layer height to (0.2).

Printing Process

This is the easiest process to start as it only recommend cleaning the bed and adding the adhesive then starting the print.

Note: Using Raft dose not require the use of adhesive, but usually I save print time by removing the raft and adding adhesive.

Overhang

This test was somehow shocking as I thought the print would be fine until 55 degree but unfortunately it went wrong at 45 degree which is not correct in my opinion.

This will require me to watch my designs angle not to exceed 40 degree.

Bridge Test

The test are very normal at this stage it deformed at 10 mm length which is not as perfect as I thought.

• I think we can extend the bridge length by slowing down the print speed and giving the layer the needed time to dry off.

For future designs the bridging should not exceed 10 mm in length

Fine details and accuracy

The results looks great when it comes to the outside diameter result as its perfectly as designed just +0.02mm which does not affect the outcome. But the inner diameter is a bit not like what expected its -0.3mm which might effect mechanical aspects if required to have As for the length its affected also by -0.2mm which is going to be accumulated over long distance and this will be very effective in a negative way if not taken into consideration

For future designs I have to consider these data very carefully

Important Link to consider about Ultimaker S5 printer LINK

Individual Assignment:

3D Printing

For the assignment of this week it is a bit constrained as it has to be only applicable using additive manufacture process

• For this purpose I have 2 Ideas to create and I have to choose one.
• The first one is creating something like a chain and the second one is creating working gears.
• The first one I have tried it before so I decided to try the second one.

• For this one I will Use OnShape to design the gears and Ultimaker printer to print.

• Pros & Cons of 3D Printing

1. 3D printing saves cost and time.

• Not mentioning the initial cost of equipment but this process means build the design and just print within 24 hours your prototype is ready.

2. Efficient in testing.

• We can scale the Print and check if it works and re-print it as long as we have the design files and access to the printer.

3. 3D printing produce less waste.

• As known this process is just manufacture what in the design so there is no extra material to waste.
• Also if we have produced support these materials can be re-used in 3D printing again.

4. 3D Printing Equipment are expensive.

5. Print Size is limited.

• Each printer has it’s own bed size so we are limited to this size for our prototype.

Design 😒

• Now we will design the object together using OnShape.

In previous documentation I have specified how to use OnShape in details.

For more details refer to this Link

After we create new Document and prepare to design we have to download one of the needed plugins (Spur Gear)

• Press at the arrow and choose to add.

• Then choose feature script to search for our needed plugin.

• Then search for Gear.

• Then Choose Spur Gear

• Now we will have Spur Gear plugin within our custom functions.

• Now we can start making our first gear.

• The first option will decide the thickness of our gear.
• The second one is the number of teeth we want in our gear.
• The third one (Module : Is a formula that decide how small or big the gear pinion is)

Module = Circle diameter / Number of tooth

• The fourth one is the circle diameter.

This is what important for now

For the first Gear I will create 12 tooth and 20 mm diameter circle with a center bore of 10 mm and a depth of 3 mm.

• Then I will Create a sketch and I will Draw a line from the center of the first gear to decide where to put the second gear.

For this one its important to leave it after creating the gear and then decide where to put the second gear, this because we want to know the diameter of the second gear so the center of the second gear will be:

Second gear center = first gear radius + second Gear radius.

• For me I already now the diameter of my second gear, But for clarity our next gear has to have the same gear pinion so they can match.

Here comes the important of the Module formula, I will Just add the number of tooth I want for my second gear and I will add the same Module number as my first gear.

• Now you will notice that the diameter of the circuit are going to be decided according to the module number.

• Then we will create a hole in the center of the gear.

• Then I want to create a small case for these gears, so I will create a sketch on the back of the gears and I will project the center circles of both gears.

• To Project the circles I will use the function project by selecting the circles and the application will directly create a circle similar to the bore of the gear on this sketch.

• Then I will create a line between the two circles to offset this after to create a slot we can extrude.

• Now I will use the SLot function to offset the line and the circles together.

• Then I will select the line I have previously create and I will choose slot function.

• Now I can change the Slot diameter by changing the phi angle.

• When Done I will simply press left mouse key to create it.

• Then I can extrude the slot to create the back of the case I want.

• Now the back case is ready, But we need pins to hold the center of each gear.

• So we will repeat the same steps of projecting the center circles but in the front plane by choosing the front face of the back case we created previously.

• Then we will extrude them in the front direction.

• Then we will create the front case by repeating the same steps of the back case.

• Then extruding the case.

• Now The gears are ready and the case also what we have to do is just create assembly with the needed offset to then be printed.

• Before that we need to make the pins and the back case as one part in order to be treated as one object.

• Here We go our abject is now ready.

Assembly 🫤

Now I will assemble all the parts together and build mates between the objects in addition to that we will animate them.

• First of all we will go to the assemble sheet and insert the parts.

• We can Insert all the parts together or part by part, (For me I will insert them all together).

• After the selection just place the parts where ever you want on the assembly page by just clicking the left mouse click.

• Now we can separate the parts from each other to assemble them again one by one.

• Then I will fix one of the parts and use it as a reference for the other parts also for building mates.

• You will have a fixed indicator beside the part in the instance list.

• Now I will create my first mate ( Revolution Mate ) Between one of the gears and the center pin.

• Then we will add offset between the gear and the case in order to create negative spacing for the gear to freely move and not to be connected with the back case.

• Then we will do the same steps for the second gear and the same offset to create the negative spacing as the same first gear.

• Now we can see that both gears move freely.

• Now we will build a mate between both of the mates, this will be a gear relation.

• Now we can see that both of the gears are moving together in the same direction.

Note : Gear relation is the division of first gear teeth number over the second one teeth number.

• After that we have to align the pinion of the first gear with the gap of the second gear. (Interlock)

• So we need to shift the position of the first gear or the second by a number so they align together.

  Shift (Rotational degree) = (360/(Number of teeth))/2

  for me RD = (360/12)/2= 15

• Then we can see that both gear tooth almost touching, so I will need to add a backlash for both to eliminate this and to make sure when its printed I have enough clearance in between.

• To add the backlash I need to get back to the gear properties in the design file.

• Now In the assembly file it will be automatically updated.

• Now we will just close the package through using the fasten function to connect the top case with the pins.

• Then I will add offset to create clearance between the gear and the top case so the gear can freely move.

Here We go Our gears are done

• Intersection view for the pack.

• Animation for the gears moving.

• Now we will Export the Assembly file to be printed.

• Options to choose for the STL FIle.

Now we can Import the STL file to our slicer (Cura) to print it later on

Slicing 😁

• Here we will slice the file and build the needed settings in order to have it printed.

• Cura is a free to use slicer from Ultimaker. Previously I have shown how to import file and how to choose the filament On this LINK

• Below I will show how to use support by enabling the second nozzle and using PVA filament.

PVA (PolyVinyl alcohol) : is a water soluble Synthetic polymer.

• Let’s import our file and build the needed settings.

• Now after importing the file and properly putting it on the bed lets choose the filament and the support filament.

• We will print using Green PLA and we need to choose PVA as a support for our print, But before we have to make sure the nozzle is Enabled.

• Choosing PVA material from Ultimaker.

• Now we have to choose the nozzle type as AA0.4 is not compatible with PVA.

• At this point we have prepared the bed and the material type we want to use with the needed Nozzle To print.

• Now we need to build the settings of the print and preview it before we save it to print.

• Then we press on Slice to preview the JOB before we print.

• Now Let’s Preview the JOB.

Now we will save it to Portable USB and then add it to the printer

Printing 🙄

• The printing process is a very simple approach we will just clean the bed add adhesive and then choose the print and start printing.

• Now printer Started.

• Middle of the print.

• Now we need to put the printed object in water for the support to dissolve.

• After 12 to 14 hours most of the PVA dissolved and we can test our Gears.

• (Alhamodollelah After 2 tries it worked).

Reflecting on the process:

The first 2 tries failed because of the clearance as at the beginning I was choosing 0.5 to 1 mm clearance (negative spacing) but unfortunate for Ultimaker it has to be more than 1mm while using the PVA so I used 1.5 mm clearance and it worked very fine.

This can’t be made using subtractive machining because I have the whole pack printed in one shot. So as seen the gears are within the pack and I have them printed inside the pack and they are rotating. In subtractive this can be made only if we machine each part alone and then we assemble them together.

Raw Files

STL Design

Sources

• Nice to read (Print in Place)

Link

• How to build gears:

3D Scanning

3D scanning is a process of analyzing an object from the real world, to collect all the data in order to recreate its shape and appearance, digitally.

• For this purpose I will be scanning a previously made prototype using EinScan-SP device.

This Scanner comes with a turntable to make it easier to scan any object in a proper way

• The object I want to Scan is a Package for a device to measure the CO2 percentage

Now we need to start the scanning process

• Then we need to do calibration for the scanner.

This process will calibrate the scanner using a glass sheet having some patterns –> The application will ask the user to move the sheet in different ways to calibrate the sensor

The calibration failed many times because the background has not to be white or shiny.

After many trays the calibration was successful

• Then After that we need to calibrate the wight balance.

• Now we can start the scanning for the object.

• Then we can select the type of the scan.

• After that we will select the needed settings for the scan and after that we will start the scan.

• Then we will do scan for the front and back, another scan for the top and bottom.

• Here we go our object is done.

Reflection

The scanning process took time (The scanner requires calibration before use and this take long time) but its worth it because this scanner software allows me to link two scanning files together and managed to merge them together to have a full 360 part which is great, in addition to the turntable of the device which will make it easier to scan parts and objects.

The output is variant as the user can decide which quality to have but for fine qualities it takes a very long time of processing and the size exceeds 100 Mb. For me I went with the low quality output which was good but not as the fine quality, Overall I’m satisfied with the output.