Offenhauser Mighty Midget Racing engine

[Eccentric]

3D Model Complete

I feel that the 3D model of the Offenhauser 97 cu in. Mighty Midget is complete enough to take it to the next stage and start building the prototype. Including the hardware, there are 86 different part types in the model and over 300 individual parts.

I have 3D printed a few of the major components to get a sense of scale.

The gear tower is pretty small and has very intricate details.

I am going to machine the crankcase top first. Working on the mill, I square up the work piece and drill 4 holes as entry points for the 1/4" flat end mill that will rough out most of the inside material.

I create the tool paths in Fusion 360 then output G-code for the LinuxCNC router.

Then I start making chips.

I believe that this will wrap up this thread in the "Plans" section. I will start a new thread in the "Work in Progress" area to document the machining of the prototype. As I build the prototype, I will be feeding back what I learn into the 3D model and the drawings.

Thanks for tagging along,

Greg
GregsMachineShop.com

 

[propclock]

Fantastic I will follow .

 

[stevehuckss396]

See you there!

 

[CFLBob]

I don't see the building thread this morning, so when you get started, post something here about it. Could be just the name of the thread, or a link. Anything so that those of us watching this thread will know to move over there.

 

[Eccentric]

The build log for the Offy can be found here:
Offy Build Log

 

[petertha]

Will be following the build!
Maybe I missed it or maybe my brain has been devoted to my own after-the-fact gear issues, but what is the plan to key the timing gears to the shafts once clocked in?

 

[Bentwings]

Will be following the build!
Maybe I missed it or maybe my brain has been devoted to my own after-the-fact gear issues, but what is the plan to key the timing gears to the shafts once clocked in?

I saw that too. What’s the plan?

 

[propclock]

Man that is small!! it is one thing to look at your cad drawings but with a real life block next to
a caliper. It really brings it in to reality. Too much like watch making for me. Perhaps 2x would be
big enough for these old eyes.