Author Topic: Greene Automatic Cutoff Steam Engine  (Read 7573 times)

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #135 on: September 02, 2019, 10:04:43 PM »
After a few days spent pondering the crankshaft machining with 4th axis, the Greene didn't make a lot of progress.

Two small jobs on the lathe were done.  The brass bearings for the inlet shafts were turned to fit the bracket, and the two small brass rounds that restrain the slide from rising off its shelf were made.


Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #136 on: September 03, 2019, 10:36:28 PM »
The next parts to be attempted are the actuator housings. The attach to the front ends of the inlet shafts and "house" the actuators that contact the trips on the slide.  Here's the SW model:



The vertical hole guides the shaft of the actuator, the horizontal hole is tje 3/16" shaft, and the two small holes are for 3-48 set screws to secure the part to the shaft.

The first op is on the CNC mill drilling the inlet shaft hole and machining the side profile in some 3/8" tool steel.  The stock is 2x1".  The cut in the bottom will be made later to mate to the actuator to prevent it from turning.



Here is the actuator and housing assembly:



The upper part of the actuator shaft is threaded, and a pair of jam nuts prevents the actuator from descending too far.
« Last Edit: September 03, 2019, 10:45:29 PM by kvom »

Offline Art K

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Re: Greene Automatic Cutoff Steam Engine
« Reply #137 on: September 04, 2019, 04:03:54 AM »
Kurt,
After watching all these parts take shape I think I will stick with a simple 4 stroke. :lolb:
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #138 on: September 05, 2019, 12:23:58 AM »
Art, I think you'd be surprised.  Nothing from bar stock so far has been problematic. 

Anyway, continuing with the catch housings this afternoon, I freed them from the parent stock and milled to target thickness.  Then mounted each in the machinist vise for drilling and tapping.



In order to round the side, I'll have to dig up a 1/8" corner rounding bit and dial it in.  That will be the last op if I even decide to bother.  Any further ops will be done while fitting the catches.


Offline Art K

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Re: Greene Automatic Cutoff Steam Engine
« Reply #139 on: September 05, 2019, 01:53:22 AM »
Kurt,
I'm sure they wouldn't be overly difficult just some peculiar shapes.
Art
"The beautiful thing about learning is that no one can take it away from you" B.B. King

Offline Dave Otto

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Re: Greene Automatic Cutoff Steam Engine
« Reply #140 on: September 05, 2019, 06:57:42 PM »
You have a 1/8" corner rounder; its called a CNC Mill.  :lolb:
Just surface them with a ball end mill.

Dave

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #141 on: September 06, 2019, 03:07:34 AM »
Dave, I suppose that's possible and worth a test.

In any case, today I started on the trips with a length of 1/2" drill rod on the lathe.  Drilled and tapped 3-48 3/8" deep in the end, and then turned down to 3/8" for a length of .708, and .40" for a further length of .2".



The interior of O1 drill rod doesn't turn that well, but the turned lengths aren't visible in operation.  After parting:



On the Bridgeport, mill to a width of .25" turning the block 180 degrees for each pass to ensure the result is centered.



The profile of the end was the milled on the CNC mill using a 1/8" endmill.  I wasn't paying attention to the drawing and fubared the first housing, so I'll have to remake it.  The second one turned out better.