3D Print Replacement Car Parts




Here is a simple instructable to 3d print new replacement parts for virtually an object with plastic parts that are hard to obtain or no longer available in this case a 1950's classic car water pump component. Be mindful of your intended parts use, 3d printing may not be suitable for high stress, heat and generally extreme functional uses. You may need to make a two part silicone mold and reproduce the print in a resin of suitable properties.


Step 1:

Collect as much information you can. In this case the original broken part that needed replacing was available broken but still in good enough condition to take measurements.
I can highly recommend getting a set of Digital calipers, normally under $30 from ebay and amazon etc. measure all facets of the part twice before inserting the dimensions into your computer model. Currently I'm using Solidworks but feel free to use google sketch-up Rhino, 3ds max or any other 3D software you can get your hands on. Its easier to check twice now than it is to fix mistakes from incorrect measurements after the fact.

Step 2:

Print out to 1:1 scale drawings of each view of the new part design, be sure to adjust your printer setting so that it is at 100% scale not "scale to fit page" as this can cause a lot of confusion. This step is to save time and money by triple checking you 3D files before getting them 3D printed. 

Step 3:

Prepare parts for 3D printing. First find a company whom you will get you parts printed through. Due to my budget I went with Shapeways. To get your parts printed first familiarize yourself with the process you will be using in this case SLS or laser sintering will be used. The only part of my design that may be an issue is the intricate holes that water passes through but after reading about it on the suppliers website it's clear that this process is able to produce such details.

Step 4: Finishing Parts

Parts arrived and fit perfectly. As sls produces a rough finish i coated the part with some epoxy, I just used the 2 part kind in a syringe from my local hardware store.



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    10 Discussions

    Dr Benjamin

    3 years ago

    All the comments in these postings are true but let's not forget the other aspects of classic cars, somethings as simple as a clip that holds the inner door skin on or say a dash board button may be very hard to replace and with the right colour and technical 3D printers can be a great solution


    7 years ago on Introduction

    I am no plastics expert but I think you should check if ABS plastic used in most 3d printers is good for your application of hot water under pressure. They don't make ABS plastic fittings for normal household hot water supply lines. Worse thing to happen is for your classic car to overheat on the road due to a failed part.

    5 replies

    Additionally, check it's engineering grade ABS. Many printed parts are not good for use in contact with water. Many of the intended applications for 3d printing are not as a replacement for traditional methods of manufacture, but as a prototyping tool. Checking fits, proof of concept and showing people how something will look so as to secure funding, not as an end product. If the part you had made was made by Shapeways, the materials used WILL be sensitive to UV light, and it WILL degrade if left in contact with water for a long time. The surfaces will start to peel and bloat.

    Your instructable, photos and process are excellent, please don't take the above as an attack on that, but don't be surprised if in 6 months the part you have fails.

    Your points on the longevity have been a concern through this project, I chose an SLS produced part as it uses Nylon and is non-hygroscopic and will not be affected by the ambient temperature of an engine bay.
    The part will luckily not be in direct UV light at any point which I know yellows and degrades nylon. I know currently this wont be a long term solution I might make a mold of this component for my next step, and cast it from an epoxy if it shows any of your listed points coming through.

    Thanks, for the encouragement. The point of this Instructable is to utilize 3D printing to replace a broken car part that can no longer be obtained, so I've given it a try and will improve the method upon peoples comments and trials.


    If you're still paying attention, I was just wondering how your part was holding up, since there was a lot of speculation after the initial post, and since you were thinking you might make a mold and cast the part in a different plastic if the 3DP part did not hold up.

    A classic car that gets driven only occasionally may be a good application for direct use, since most people drive their classics a lot less than daily drivers, so although your part has been exposed to water and glycol, it probably has seen less than 10,000 miles of heat and vibration over the past year?


    5 years ago on Introduction

    I've already made many non structural ABS parts for my 1970s Lotus with my MakerBot. Nylon filament is now available from Taulman (look for it on Amazon). It comes in 1 lb spools in 3mm or 1.75mm sizes. Nylon is a true engineering plastic and is appropriate for some higher strength/pressure/heat parts. I've experimented with it and while it's a bit more difficult to print, it holds to painter's tape. As PaulMakesThings says, more things 3D printing are coming.

    While I understand people's concerns here, you clearly started with this part for a reason. Obviously a home 3D printer can't make a drive train or engine component, or even a coolant system component. Not yet anyway, but as 3D printers transition into real use someone is going to have to experiment with using them for real machine parts. You can't knock him for not starting by titanium arc printing a transmission gear out of titanium.

    1 reply

    That's great that you thought about it. The instructables lab's 3d printer is a Polyjet which squirts out ABS. The guy installing it couldn't stress enough that we had to remember it was a prototyping not a production tool.