3D Modelling & Printing.



Lately I've been spending more time learning how to model parts in 3D, still new so bare with me. It's not a new concept to me, but I am using Fusion 360 mainly now and sometimes a bit of SolidWorks.

I've done some prints in the past, a good example would be the bulk head connector plate I drew up and printed. Had it installed in the car while I waited for the final piece to be laser cut from steel.


And now I'm starting to move onto slightly more detailed designs. Starting of with "remixing" a design from Thingiverse.

4AGE Black Top Velocity Stack -

And my "remixed" version, which is basically modified for Silver Top engines instead of Black Top and increasing overall length to 115mm.

4AGE Silver Top Velocity Stack -


I than scrapped that design altogether and did one from scratch, increased the radius lip profile and removed the side bracing. The print below was done in ABS and I'll be testing it for clearance and heat resistance. If all goes well, I'll most likely print my final design in ABS. If not, other materials like Nylon and Poly-carbonate are alternative options for heat resistance.




And this is another design I quickly modelled. Main differences being the bottom flange, length adjusted to 105mm and the dimpled internal surface. NO idea how that'll work for airflow, good or bad, but it's fun drawing these and 3D printing them! The idea is from dimpled surfaces on golf balls, and I've seen shops machine dimples onto the back of inlet valves and cylinder head ports.


And this is how the print came out.... About halfway up the velocity stack, the wall was a tiny bit too thin and the dimples were too deep! Not something I was expecting, but I'll learn from this one and make revisions. This print was also done at 300 micron layer height, I think it needs to be 100-200 micro next time.


And finally, this is an airbox/plenum that will mount to my current Pipercross filter plate. Still needs some work here and there, but I'm pretty set on the general shape of it and the inlet is 4.5" diameter. The final product could be moulded from the 3D print and made with carbon fibre, or possible printed entirely out of fibre infused nylon for strength and heat resistance.


More to come!

Comments (5) Trackbacks (0)
  1. Hi John,

    it’s been a while since i follow you (probably for 4 or 5 years now, and despite selling my Eunos 3 years ago – huge mistake btw) , i never commented but now seems to be a good time !

    I discovered those stacks on my facebook wall, didn’t even knowing it was yours ! All those multi colors stack were so much fun, I started looking around to print some, trying to find models, checking for length etc …
    I found Ralfs model first, on Thingyverse. Then found yours, so i came here to check it, and BOUM, mind blown ! Amazing 😀

    So i’m planning to print some, but i’ll have to modify them as it’s not a direct fit ! I’ll eventually use them on my 4AGE with 45 mm dellorto (7 replica).
    But for now, I have no clue how to modifiy them; won’t be an easy task !

    If you have STL file you’d agree to share, it’d be really nice from you.
    I don’t really know what i’ll do, and even less how, but i’d love to try the dimpled one !
    Amazing job you did there.

    Best luck for the future,
    Thanks for sharing !

    Laurent from Belgium

  2. Hey Laurent!

    Thank you for the kind words and I’m more than happy to share the STL file, it’s constantly being updated but you can find my new version here:


  3. Hi John !

    Digged a bit, found a friend with solidworks and a printer : looking good so far.
    The only thing is, we tried to modify your STL, but it seems like SW can’t really deal with STL … it can open them, but not smoothly, and we can’t modify it afterwards. Damn …
    Google the issue, know issue, and everybody recommand working with SLDPRT file !
    Would you agree on sharing it ?

    Thanks for your help !


  4. Hey mate!

    Completely understand, shoot me an email. Unfortunately I used Fusion 360 to model the velocity stacks, but luckily Fusion 360 is free to download. More than happy to share the files for that 🙂

  5. Hi John,

    Didn’t mail you, because i fixed my problem … by starting from zero !
    A friend of mine -who handles SW pretty well- agreed to help me with it.
    So we started from zero, studied a bit, and made an amazing model !
    I really like the result, and here is a pic of it, if you’d like to see the result :
    Those are pretty big (110mm high, and 100mm OD at the end of the stacks) but I love the look of them !

    Thanks again for your time and help !


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