Jerry Howell's V-four in 3d printed form

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Mar 3, 2023
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So I have started this monster project whereby I purchased the PDF drawings for Jerry Howell's V-twin and his V-four, with the plan to convert those drawings into 3d models good for printing on a normal FDM printer we all have at home, right?

Well as it turns out the drawings are not ready part drawings with measurements, but rather manufacturing notes with drawings of intermediate stages of the process. This is much harder then I anticipated, since in 3d modeling you refer to faces, lines, features of the part, and when they get taken away later on in the process, your whole model fails.
But slowly I am getting there and it is in this post I would like to show progress as and when there is any. Sometimes it will be a jump while other times it might be 3 different failed modifications of a piston rod, nobody knows yet where this will lead.
So I have started with printing the most unlikely first item anybody would consider the best part to begin with, The radiator! Don't ask me why, I just felt that way. Oh, I remember now, it has absolutely no links with the rest of the engine except for the mounting rails it sits on. So, it will not change later on when I convert imperial fasteners to miniature metric ones or when I change bushings for bearings and the like.
For now it sits mounted with the wrong screws. I have not yet purchased the correct fasteners, so I used some second hand miniature self tappers after cleaning off the dust of them, and together with glue it has been told to stay put. I hope it does.
here is the link to Jerry Howell's own web site for this engine. Sadly Jerry died so his son is maintaining the website.
Enjoy the ride so to speak, updates may come slow at times.
Just to note: the vernier calipers you see in the shots is a 70mm one, so this engine is not as big as it may look at first. The calipers are holding the mount rails open to size while the glue sets.


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Well-Known Member
Mar 27, 2013
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This is total bullshit Howell plans are very good drawings dimensioned it’s American orthographic Took me a while to work this out .I have made the vtwin I can get it to fire won’t run cam gears not so good can I be bothered trying again not likely. I have made the Vicky Stirling engine it almost works and almost finished the farm boy again trouble with ignition im pretty happy with the process .Seriously doubt you have original Howell plans Alan Howell has accomodated my questions with good grace

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