The rise of FrankenEngine - An engine for the VP-21

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Aviacs

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Oct 21, 2019
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My dad had one with the cast SOHC motor and loved it. So did us kids. It was so...elemental! & made all the right noises. Winding through the straight cut non-synchro gears on back roads, with the little aluminum propeller spinning merrily on the front, it seemed like flying. Not so much on larger highways where everyone blew by like you were standing still, though. :)
I picked up the block for one at a Cabin Fever (machinist) show a few years ago not immediately realizing what it was, and they really are tiny and light. OTOH, IIRC, displacement is around 750cc?

Looking at 3/4 to 1 liter, there are much better, even lighter options to start with today.

smt
 
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sming

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Apr 10, 2019
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Juste saw this video of myfordboy with a 300$ electric furnace and thought of this topic:
So clean!
I must say that i'm really looking forward to your engine experiment Hot Wings, and if these so promoted "New" and "21th century" techniques (3d printing...) can actually allow a mere individual to do something unthinkable a few decades ago. Bring it on!
 

Hot Wings

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can actually allow a mere individual to do something unthinkable a few decades ago.
Well.............
It can be done be mere mortals.
But the learning curve for the individual skills takes time and money. The ratio of the 2 is inversely dependent.
CAD takes time to learn, and software.
3D printing takes hardware, software and time to learn.
Casting, made to look easy in the YouTube videos, takes hardware (lots of it), practice/experience or luck to get good defect free castings ......... and is potentially dangerous.
Of the 3 skills 3D printing is probably the easiest to learn and may have a greater day to day use. I just printed up a couple of plugs to replace the lost inserts on my router table. Took less time than ordering new - if they are even available.

Right now I'm focused on getting my casting equipment sorted out again. It's been quite a few years since my last pour. I need a couple of parts for the inverted Briggs project and it is on hold until I can cast them. 3D parts just aren't up to the temperature requirements.
Induction furnaces which are clean quiet and potentially efficient are cutting edge for hobby casters but are limited to smaller melts for the eBay scale equipment.

Side note:
Seems YouTube videos no longer play 'in situ' here on HBA. Have to open them thru YouTube to get them to play. Just me or a change in one of the 2 platforms software?

Edit:
MFB really needs to build a casting bench. It is soooo much easier than working on the ground.
 
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Pops

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So much to learn and so little time. I grew up with my Grandfather ( 1876-1959) , he was a blacksmith and could make anything. Built wagons, buggies, etc from scratch . Made hunting knifes, tools, etc. I grew up turning the fan for the forge. Wish I had his knowledge.
Like to learn metal casting.
 

Hot Wings

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Thread drift:
Lost PLA is already useful for one of a kind parts but 3D print speeds are low and the amount of material needing to be 'burned out' is high. At least with lost wax we can recycle a lot of the wax.

This - foam 3D printing - may be able to solve both problems.
 

Bigshu

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Jun 7, 2020
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Thread drift:
Lost PLA is already useful for one of a kind parts but 3D print speeds are low and the amount of material needing to be 'burned out' is high. At least with lost wax we can recycle a lot of the wax.

This - foam 3D printing - may be able to solve both problems.
That foam printing is crazy! I wonder what the other projects mentioned looked like? I think the boat hull alone could open some peoples' eyes. It would be amazing to come up with an engine block.
 
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