Author Topic: Greene Automatic Cutoff Steam Engine  (Read 3143 times)

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #60 on: June 14, 2019, 01:29:45 AM »
I pulled a back muscle Tuesday and it wasn't until this afternoon that I felt like having a go at the other half of the rim.  This didn't go well as it revealed some faults in the iron, as shown in the following 3 pictures.







I could continue turning down the rim, as it ought to be a lot thinner, but I'm wondering what alternatives there are for patching holes like these.

So I've abandoned the flywheel again and set about finishing the crank disk.  First op was to install aluminum jaws on the CNC mill vise and cut  them to hold the disk securely.  Then I drilled the hole for the crank pin with a 15/32 bit for a 3" throw, and reamed .499 for a press fit of the crank pin.  Finally formed the central pocket with a 1/4" endmill.


Online Jo

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Re: Greene Automatic Cutoff Steam Engine
« Reply #61 on: June 14, 2019, 07:22:18 AM »
I could continue turning down the rim, as it ought to be a lot thinner, but I'm wondering what alternatives there are for patching holes like these.

I would contact the original casting supplier and tell them about the holes - they should send you a replacement flywheel casting.

If it was a legacy casting set which is no longer available the options would be to fit a new rim to the existing centre which would allow for a shiny rim (but there will be a difference in the colour of the Iron between old and new :facepalm2: )  or fill it with something and have a painted rim.

Jo
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Offline Ye-Ole Steam Dude

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Re: Greene Automatic Cutoff Steam Engine
« Reply #62 on: June 14, 2019, 11:01:47 AM »
Hello Kirk,

JB-Weld will do a good job of filling in the bad spots and will machine down OK. Like Jo stated it will be a difference in color but if you plan to paint the flywheel it will not be visible.

Have a great day,
Thomas

Offline jeff l

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Re: Greene Automatic Cutoff Steam Engine
« Reply #63 on: June 14, 2019, 12:27:18 PM »
Kirk , Let me know how you would like to proceed with the flywheel, I can send you a replacement if you find that you want one . Sorry about the flaws that you found these things are out of my control .Jeff

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #64 on: June 14, 2019, 12:41:28 PM »
Jeff, what's the status of the 2-piece wheel?  Since this is a very long term project I could just wait for it.

Offline jeff l

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Re: Greene Automatic Cutoff Steam Engine
« Reply #65 on: June 14, 2019, 12:52:04 PM »
Hi Kirk , The two piece flywheel project would be a 6 month wait . Jeff

Offline Dennis

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Re: Greene Automatic Cutoff Steam Engine
« Reply #66 on: June 14, 2019, 03:00:53 PM »
Hi Kirk, 
Sorry for the porosity in the flywheel rim.  The porosity looks like inclusions, did you see any sand or slag when you hit the holes?  What ever the cause, it is something I will be glad to take care of.  If you don't want to wait for Jeff's new two piece flywheel, I can send you the flywheel from the Green engine kit I saved for myself when we sold the business to Jeff.  Save the flywheel you have and bring it back to me next NAMES show. 

I have been able to save some castings using a tig welder with flashing from other castings as filler, then heat treating at a higher temperature than you would normally use for annealing.  On ground surfaces, these patches were not visible but they probably would be on a polished surface.  There is definatly enough metal left on the rim to remachine after heat treating and the center bore should shrink enough in heat treating to let us ream it to the correct size.  We have never tried this on a flywheel so it would be an interesting experiment.

Dennis


Dennis

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #67 on: June 14, 2019, 07:17:37 PM »
At the rate I'm going, 6 months for a new casting, be it one or two piece, is not an issue.  Since it's essentially done other than the grub screws and final sizing, the wheel as is can be used for any testing that might be needed. 

There was some porosity  on the bottom of one of the journals, but that's insignificant and invisible.

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #68 on: June 14, 2019, 11:48:09 PM »
The next castings to be started are the two feet that support the cylinder.   Here's the 3D SW rendering:



There's a lot of extra iron on all sides of the raw castings, so lots of chips to me made.   The important dimensions to be observed are:

- Height, since I was precise on the journal and bearing height, I want the cylinder bore to line up with the crank centerline.

- length of the top surface so that it matches the cylinder width.

Start with this:



Then on the bridgeport remove the pour hole remnant.  4 flute carbide at 1800 rpm and .100" DOC worked well and quickly.





Then use face mill on CNC mill to flatten the bottom.


Offline Art K

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Re: Greene Automatic Cutoff Steam Engine
« Reply #69 on: June 15, 2019, 02:20:10 AM »
Kirk,
To bad about the flywheel, but it sounds like you can work around that. I hope your back is feeling better. I pulled a deltoid muscle and felt it in the center of my back. It was fine during the day but when I tried to sleep the dull ache drove me to visit the doctor. He gave me some pain med's and I laid off the machines at the YMCA gym.
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 #70 on: June 17, 2019, 03:57:20 AM »
Some more machining on the feet.

Second op with bottom against fixed jaw, it's a matter of lining up the part by eye  to machine the first side.



Now I can use parallels to position for the opposite side.



Next, machine the top until the length of the surface is as close to 2.3" as I can determine with a steel rule and .01 divisions.



Afterwards, reverse and machine the bottom in order to obtain a height of .875".

Finally, machine the sides equally to obtain a thickness of 1".  While not critical, I was happy to hit it.



On the second I overshot by .002", so maybe the first was just luck.

Then over to the Bridgeport to mill down the bosses for the mounting screws.



That was all I had time for as I intended to watch the US Open golf tourney.  Those annoying burrs probably need to be ground off with the Dremel as using a file will be awkward.

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #71 on: June 18, 2019, 12:28:52 AM »
Machining finished on the feet:



Can't put it off forever, so made a start on the cylinder.  The bottom surface of the casting is the flattest, so used that as reference to machine the top.



Then turned over to face mill the base.  Turns out I over cut by 15 thou, but hopefully that won't matter.  Next time in shop we'll try to square the other 4 faces.

Offline crueby

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Re: Greene Automatic Cutoff Steam Engine
« Reply #72 on: June 18, 2019, 12:47:09 AM »
         :popcornsmall:
  :popcorn: :popcorn: :popcorn:

 

Offline kvom

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Re: Greene Automatic Cutoff Steam Engine
« Reply #73 on: June 18, 2019, 10:03:56 PM »
Today I continued on the roughing of the cylinder.  First I used a long endmill on the Bridgeport to trim as close as possible the detritus sticking out from the body of the casting. 



Then the rest of the available time was in face milling the ends.  Since the back edge of the top face is quite straight, I used that as a reference to mount the cylinder vertically.



Then machined both ends removing .01" at a time until all the cast surface was gone.  Tedious but all I had to do was click a couple of buttons for each pass.  Next time in the shop I'll do the sides.  The result of milling the ends is that the cylinder's length is 4.904 vs. the 4.875 called for, 29 thou to work with.  :whoohoo:

My main concern with the cylinder is the bore.  It's a half inch longer than the Joy engine where I had taper in the bore until I bought an adjustable chucking reamer.  Other than that, there's 5 pockets to machine to size and a ton of holes.

« Last Edit: June 19, 2019, 11:17:35 AM by kvom »

Offline Dennis

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Re: Greene Automatic Cutoff Steam Engine
« Reply #74 on: June 19, 2019, 02:54:11 PM »
Good work Kirk, and thank you for the extra work to share your build with everyone watching along. 

The cylinder block and all the parts that bolt to it make up about 2/3 of the work in building the Green engine. 

Dennis