Simplifying and 3D Printing Replacement Parts

What is the strategy?

This strategy will guide you in how to simplify the part and make it appropriate for 3D printing.

The process involves looking at the part and other surrounding parts to create a functional replacement.

This guide will also help aid in design decisions and understanding that the design process is iterative.

What is important to understand is that sometimes a part can be created on the first try, and sometimes it takes many iterations before it is correct.

In what cases is this method applicable?

This strategy can be used to replace many parts. However it is important to note that large pieces may not be suitable due to difficulty printing, and products that make contact with hot or corrosive materials.

How is the strategy explained?

This guide uses the case filter part from a SAMSUNG VC07M3130V1 vacuum cleaner as an example as it has been simplified greatly and interacts with multiple other parts. Specifically this guide is following the fourth iteration of this part with images of the final version throughout.

DISCLAIMER:

This project requires you to take apart your product and to tinker with it. This will cause any warranty on the product to be void. Please approach this safely and if you're not sure, ask an expert.

ALWAYS unplug the product when taking it apart and reassembling it. If the product is hot, let it cool down first.

We and any other linked resources do not hold any responsibility for anything that you do while following this guide.

Supplies

Please read the master page for supply details!

Step 1: Examine

Examine the part you want to replace as well as the other parts that touch it. Where are the connection points? How does it fit, and how is it held in place?

The more you understand about the part and the interactions it has with other components, the easier the next step will become.

In addition knowing how the part is made can help with deciding on what to eliminate from the design as 3D printing has different limitations compared to a part that is injection moulded.

One method that we recommend is sketching the product. It doesn't have to be accurate but it may help you in realising small details that may not be obvious at first glance.

For this example, the case filter interacts with three different parts:

A silicon seal.
The body of the vacuum cleaner.
A removable filter.

Therefore when redesigning this part it is important that the silicon seal is still able to stay on the edge of the part and fit in the cavity.

The part needs to be small enough to fit into the cavity, but large enough to not move around as well as easy to remove and put in.

And it needs to be large enough to allow the filter to fit inside and allow that to be put in and taken out easily.

Step 2: Eliminate

Eliminate features that you do not think are required or are too complicated to reproduce where you can.

It is also important to consider printing time while recreating a part, and this can be reduced by removing unnecessary geometry.

Such as over hangs, unnecessary curves, and details that may have been created due to the original manufacturing method as these will most likely increase the printing time due to the requirement of supports for some of these features.

For this example, with this part the handle would be complicated to replicate as it uses a spring to allow it to flip up again. It is very difficult to remove the handle without damaging the spring or handle.

There are also many overhanging features on this part which would increase the time taken for the print as supports would be needed.

The differences between the original part and the new part have been highlighted as an example.

Step 3: Measure and CAD

Using the appropriate measuring tool, measure the part and recreate the geometry within the CAD software.

A good method of working is to have a specific point or a few points that you base measurements off of. By doing this, it is much easier to keep a track of measurements of geometry and will be useful if you need to remeasure a part again.

If you made a sketch, you can use this to help keep track of measurements!

Slowly build the part up, make the main geometry first and then details can always be added later.

Tip! If you’re not sure if the measurements are completely correct, print out that section and test it!

Also most CAD programs have the option to add an image which you can reference if something is difficult to measure. However this is not the most accurate method!

For this example the full model was created, however only the bottom portion of the model was printed to test how it fits with the other parts of the vacuum cleaner.

Step 4: Slicing

When you think you’ve finished creating the CAD model, export it as a STL file and slice it in the appropriate slicer.

On this program you can experiment with orientation of the print as well as settings such as infill, quality and supports.

Changing these settings can influence the strength, post-processing and time taken to print. Typically the higher the quality the greater amount of time required to print!

If you are using any material other than PLA, there are specific print settings required in order for a successful print so bear this in mind.

If you are testing a print to see if it fits, it is best to use the lowest quality with low infill as this will reduce the print time as well as reduce filament usage.

Export this as a GCODE and upload it to your printer.

Step 5: Printing

Make sure that the print bed is levelled and that the filament is ready to go. Keep an eye on it for the first few layers and if there are no issues your printer will take it from here.

Step 6: Testing!

Test it together with all of the other parts.

Did it work? Did it not work? Why not? Note the problems down and try it again!

Most of the time unless the part is incredibly simple it may take multiple tries to get right and sometimes very small adjustments are needed.

This was the fourth iteration which included a lip to test if the filter would fit and unfortunately it didn't. It was too small. Therefore the next iteration would include changes to accommodate for this.

For this part it took a total of 8 iterations for the final model to be made.