Designing and 3D Printing Universal Parts

Do you have a broken product part and do you want to try to replace the part yourself? That is great, because this guide will help you save your product!

What is the strategy?

The method used in this manual explains how you can use your 3D printer to make new product parts, which fit on every type of the product you would like to repair. These parts are called universal and the advantage of this way of repairing is that it takes less time to design if you want to use this part for multiple similar products. This is because with universal parts, there is no need to replicate a complex part exactly as it was before. You can use specific assembly methods, as explained in this instructable, to make your very own universal parts in a simple way!

In what cases is this method applicable?

Universal parts are applicable for various scenarios, for example:

• The files can be stored in a database for you and others to find.
• You could use the part on multiple products you own while only designing it once. (For example, if you own two vacuum cleaners which are both missing the brush holder.)
• If you want to find a quick solution to the broken part, that requires less complex designing/3D modelling work. (For example, by adding a new, separate brush holder to the base of the vacuum cleaner instead of replacing the one that is one within the base itself.)

How is the strategy explained?

In this example case study, a broken brush holder from a Samsung VC07M3130V1 vacuum cleaner will be 'repaired' by adding a new and universal brush holder to the base of the vacuum cleaner using snap-fits, making sure that the part will be functioning again. The steps for this repair can be used on any type of product, so this case study is solely an example of how to use the strategy!

At the end of this instructable, you can also find the result of a second case study. Which is a TPU part to stop a vacuum cleaner hose from leaking air and dirt. This case study is there to give you an idea of what this instructables repair strategy can do!

Please note that step 2 and step 3 can either be combined or used separately depending on the nature of your project and your own preferences!

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.

Please read the master page for supply details!

For this specific repair strategy, you may need to make cuts or holes in your device to attach your replacement part which require some additional things that you might need. These are tools that are specific for the assembly method you choose to use but could include:

Tools

• Precision knife
• Box cutter
• Figure saw
• Hand saw (or other types)
• Drill

1. To start the repair process, first analyse what the function of the broken part is. In this case study, that is to hold the brush when the vacuum cleaner is stored.
2. Ask yourself how this part functions and if the part functions in the same way on every type/brand of the device in question. In this case, it does, since every vacuum cleaner uses this same type of slot, to slide the brush into.
3. Now you can determine whether or not it is better to relocate the feature to a different place on the device to replace it instead of repairing it. The brush holder is originally underneath the vacuum cleaner and it is embedded in the body. So to repair it you would have to replace the whole body part. In this case, it is much easier to put a new part on the side, as shown in the figure above.

Depending on the function of the repair part, you can start designing its shape.

A few things to keep in mind

• If you need to attach the new part elsewhere on the vacuum cleaner, make sure to decide on a location before designing and modelling. As the location of the part on the product often influences its shape. Make sure you can manipulate the surface of the product at this location if you need to apply some destruction to secure the new part.
• If you want to use your design for several different types of the same product, do some research on the range of dimensions that are used in this product part. For example, the slots for the brush holder in this case study might have a different dimension than the slot on a different brand/type. To make the slot universal consider looking up minimum and maximum dimensions amongst the product brands/types you want to design for. In this study, this information was used to create the correct pyramid shape that can hold different types of brushes.

If instead of replacing an existing part you are adding a new part to your product, the next thing to do is to model a fixture. An example of this is by using snap-fits.

There is a specific guide on how to design snap-fits for 3D printing here.

A useful tip

• If you want to make the fixture universal, take into account the location and spacing of the snap-fits or similar aspects if you are using a different assembly method. This will help you make sure that the part can be attached to different product types.

Please note that this step may be optional depending on the assembly method you are using!

Self-modelled 3D-printed guards as shown in the figure above may help you add the holes for snap-fits or other geometry for different assembly methods in a controlled manner.

For example, the guard in the figure above is for a set of three snap-fits, based off of the universal part created prior. The holes provide guidance to the user where to drill to make sure that they line up with the snap-fits.

If you use snap-fits, be careful making holes in your product as you do not want to damage surrounding parts.

In all cases it is better to disassemble the product and separate the part that needs to be adjusted to make assembly possible.

A few tips:

• Make sure to use the same dimensions that you used for the repair part in your guard model!
• You can use the guard to check if the snap-fits will work!

Make sure to test your part throughout the process so that all the aspects fit together before using controlled destruction as this is non reversible! It is an option to test different types of snap-fits too and see whch type works the best for you.

The photo above shows a different case study of a universal repair part. This part is meant to cover a hole in the hose of a vacuum cleaner and is universal due to the adjustable and flexible straps.

The straps are an example of a different fixation/assembly method. They can be used both as universal and specific by giving them either one or multiple belt holes.

As you can see, this case study shows that you can be very creative with this universal repair strategy and it is not limited to only PLA and snap-fits!