MY CORLISS

ENGINE BUILD

Part four by Vince Cutajar

I bought a round (40mm) piece of phosphor bronze for the crank block as I just could not find any square section.  The plan is to use the same material for the eccentric.

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Flycut the other face...

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...and sawed and milled it to extract a block from it.

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Milled the block to size and then drilled the four 3mm mounting holes.

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Next I drilled and reamed 10mm the bearing hole. I step drilled the hole from 5mm to 9.8mm and then reamed it. Did not encounter any grabbing problems during drilling. I then marked the top of the bearing for some profiling. 

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I did some step milling to rough out the curve.

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As can be seen, it is a bit flat at the top but with some filing and sand paper I managed to round it off.  Not a perfect curve but it will do.

I counterbored 8mm the area around the mounting holes...

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...and then separated the bearings with a slitting saw.

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After some more milling and sanding this is the final result.

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And a try out with the crankshaft and flywheel.


I found a piece of mild steel to be carved out to make the outrigger bearing pedestal.

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Like the big bad wolf, I huffed and puffed to get that piece of steel like this:

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I then milled the "I" section to dimension.

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Then drilled the four 3mm clearance holes.

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It was cleaned up and the bottom corners of the pedestal rounded of freehand.  A couple of coats of primer and this is the result:

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I did not clean it up as much as I did for the flywheel just to see if this primer I am using will hide light machining marks.  It sure does and it is good to know.

And the final family shot with the bearing sitting on top of the pedestal.


DRAWINGS HERE

Part three here  Part five here

 
https://www.sarikhobbies.com/model-engineer-builder/

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