The Design Process With the Single Overhead Cam V8

Computer numerical control (CNC) is a manufacturing method that automates the control, movement and precision of machine tools through the use of preprogrammed computer software, which is embedded inside the tools.

In this intructables are am explaining the design process of creating an open v8 model with camshaft and valves. I used two 3d printing technologies FDM or fused deposition modelling and MSLA masked stereolithography apparatus (resin). I am currently a student in the French school lycée polyvalent Edouard Branly completing a bac techno STI2D (Science et technologies de l’industrie et du dévleppement durable) it translates Science and technologies of industry and sustainable development in and intend on specialising in ITEC (Innovation Technologique et Eco Conception) it translates technological innovation and ecological conception.

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The first step is identifying the problem in my case the difficulty of explain and visualising the different steps of an IC (internal combustion) engine. 

Image source : www.pixabay.com

Second is defining what this must be accomplished for me that is an open v8 with a head block on one side, all the moving pieces must be linked and powered by a single electric motor.

After defining the ground rules, I made some sketch and chose a v8 with a single over cam like as on the ford 427 which is a 7L v8 for the 1960s. 

imgre source: www.wrljet.com

I then went on fusion 360 to design the pieces. I regularly printed small or cut up version to check it the pieces went to together correctly and if the cams moved correctly to avoid wasted material and to speed up the designing. The camshaft took a lot of work due to the tolerances and large amount of friction with 3d printed pieces even after sanding..

Image:

Top Right) gear test to check Tolerances 

Top left ) had block and respective valves.

Bottom Right) Timing belt

Bottom Left) cut-up camshafts

Once all the pieces were finalised, I printed full scale pieces using two 3d printers using both to maximise the advantages on both. I used my FDM printer (modified Creality ender 3 pro) for the large pieces using PLA and PETG and mostly for the main block and my MSLA printer (Elegoo mars 4 pro) for the head due to the small pieces and the need for them to be transparent to respect the specification I set my self a couple weeks prior 

Once all the pieces were finalised, I printed full scale pieces using 2 3d printers using both pieces to maximise the advantages on both. I used my FDM printer (modified Creality ender 3 pro) for the large pieces using PLA and PETG and mostly for the main block and my MSLA printer (Elegoo mars 4 pro) for the head due to the small pieces and the need for them to be transparent to respect the specification I set my self a couple weeks prior 

Video 1 : FDM printer printing timing belt using TPU flexible filament

Video 2 : MSLA printer printing head block with elegoo transparent resin v1.0 (timelapse)

The assembly cam next once all the pieces were printed, I proceeded to clipping the pistons to the rods and the rods to the crankshaft before screwing the crankshaft claps to the block. I then generously applied some WD40 to minimise friction and make the load lighter on the 12v motor. The entire head assembly was complicated due to the small valves, valve caps and springs. All the gears came next and then timing belts.

Video: motion study made With solidworks.

At this point it was done. After a bit more WD40, sanding and reprinting a couple pieces that came out ugly and it is done. 😊 (it also need to be timed correctly)

With this it is not only cool to look at but a good way to explain the different steps of an internal combustion engine. (Suck, squeeze, bang and blow) It respected all or the specifications I gave it and I learned a lot making it. Thank you for taking the time to read my instructables and I wish you a nice day.

PS. A few things changed betwen the models, motion study, videos and photos primary the camshaft and the gear rails to avoid the belt slipping or derailing.

1)     Identify (what is the issue or problem)

2)     Constraint (what needs to be accomplished what to do what this will avoid wasting time, energy and money on something that is not important )

3)     Think (how can this be done, think of several and find the best of each draw your idea it way be tedious but it helps)

4)     Design (use cad to make it virtually in 3 dimensions make the most of motion studies)

5)     Prototype (just because something works in cad doesn’t mean it will work in the real word repeat as many times as needed)

6)     Finalise (finish everything in cad)

7)     Create (make the final object and be proud of yourself)