Author Topic: Another MEM Corliss (in .40 scale)  (Read 5052 times)

Offline gbritnell

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Another MEM Corliss (in .40 scale)
« on: July 03, 2018, 01:20:10 AM »
Since the MEM Corliss drawings were posted quite some time back I had mentioned that it would be on my to-do list. Well I got started on it this morning but not in the usual fashion. I took the smallest screw size on the drawings, 0-80, and scaled it to M1.0 x .25. The scale factor came out to a little less than .40 but I rounded it off and went with that number.
The majority of the screws on the full sized model are 1/8 (5-40) these work out to M1.2 x .25. The cylinder is made from 12L14 steel. I trued it to size then drilled and bored the bore, .45 inch.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Another MEM Corliss (in .40 scale)
« Reply #1 on: July 03, 2018, 01:30:05 AM »
The porting from the valve chamber on the full sized model is drilled with a 1/16th drill. With my scale factor this came out to .025. I laid out the drawing to see exactly how the porting looked. Not having a center drill long enough or small enough I went with my only option. I drilled out a piece of 3/16 brass rod for the .025 diameter drill. I turned a 15 degree taper on the nose to match the port angle. The drill was cleaned up and Loctited into the brass. I left only enough sticking out to break through into the cylinder. Before using it I pushed on it with my fingernail and it seemed quite rigid.
My mill only goes up to 2600 rpm so that's the best I can do for this small drill. I set the cylinder on 15 degrees and picked up the center of the valve hole. I cranked up the spindle and very lightly touched the drill to the bottom of the valve hole. Once I felt that it had centered itself I felt my way through the metal into the cylinder. There are 5 holes spaced .037 apart. When I got done the holes looked quite uniform and in line. Whew!!!! I would hate to have put 8 hours into this cylinder only to have the small drill wander or break.
Talent unshared is talent wasted.

Offline b.lindsey

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Re: Another MEM Corliss (in .40 scale)
« Reply #2 on: July 03, 2018, 01:35:23 AM »
Another tiny project to look forward to. The penny shows how small that cylinder is....wow. I'm hooked already George!!

Bill

Online crueby

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Re: Another MEM Corliss (in .40 scale)
« Reply #3 on: July 03, 2018, 01:40:51 AM »
Oh my!!  What a wonderful project!  As usual, will be watching this one with a prop under my chin to limit the drooling.


 :popcorn: :popcorn: :popcorn: :popcorn:


Any chance I can get you to do a teensy Marion shovel to fit in the bucket on mine?   :Lol:


 :cheers:

Offline Craig DeShong

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Re: Another MEM Corliss (in .40 scale)
« Reply #4 on: July 03, 2018, 02:35:04 AM »
The start of another amazing project.  Can't wait to see the future installments.  :popcorn:
Craig

Offline Larry

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Re: Another MEM Corliss (in .40 scale)
« Reply #5 on: July 03, 2018, 04:13:36 AM »
Have thought about giving the MEM Corliss a try but not to this scale. Like the Wheat Penny ! Will follow with interest.

Offline kvom

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Re: Another MEM Corliss (in .40 scale)
« Reply #6 on: July 03, 2018, 11:49:19 AM »
Scaling 0-80 screws down by half?  Oh my!   :ShakeHead:

I'll look forward to seeing it at NAMES.

Online steamer

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Re: Another MEM Corliss (in .40 scale)
« Reply #7 on: July 03, 2018, 03:11:20 PM »
I love it George!

Dave
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Damned ijjit!

Offline Dave Otto

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Re: Another MEM Corliss (in .40 scale)
« Reply #8 on: July 03, 2018, 03:34:10 PM »
Nice start George, looking forward to following along with this one.


Dave

Offline 10KPete

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Re: Another MEM Corliss (in .40 scale)
« Reply #9 on: July 03, 2018, 05:42:21 PM »
This is nuts! Making things sooo tiny on purpose!!

George, I envy your ability to work with such small bits. You must have been a watch maker in a previous life!

 :lolb:

 :popcorn: :cheers:

Pete
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Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline scc

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Re: Another MEM Corliss (in .40 scale)
« Reply #10 on: July 03, 2018, 07:32:20 PM »
I'm hooked :popcorn:

Offline gbritnell

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Re: Another MEM Corliss (in .40 scale)
« Reply #11 on: July 06, 2018, 02:32:39 PM »
I have the heads finished, front and rear with packing nut. I finished the crosshead guide although the bore didn't come out too nicely. I think the reamer was dull and it must have rubbed the chips as it went. Yesterday I finished the main frame. There were options to make it in two pieces but with the small size it didn't use up much metal so for simplicity sake I went with the one piece. This morning I finished the two pedestals that the cylinder mounts onto.
I haven't decided on how I'm going to make the flywheel. The drawings show it fabricated with hub, spokes inner outer rim and outer covering rim. I suspect it was made that way to simplify machining the larger wheel.
Talent unshared is talent wasted.

Online steamer

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Re: Another MEM Corliss (in .40 scale)
« Reply #12 on: July 06, 2018, 02:39:25 PM »
I believe that was the original intent George, to make building the wheel easier and less expensive.  Bob ( maryak)  will be along shortly I'm sure.

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline gbritnell

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Re: Another MEM Corliss (in .40 scale)
« Reply #13 on: July 06, 2018, 02:47:13 PM »
Here's a couple of close up pictures of the frame. For some reason my good camera decided not to take good pictures any longer so I had been using my backup everyday point and shoot camera. This morning I 'rebooted' my good camera and went back to the original settings and all of a sudden the pictures are coming out better. Gotta love these electronic instruments.
Talent unshared is talent wasted.

Online steamer

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Re: Another MEM Corliss (in .40 scale)
« Reply #14 on: July 06, 2018, 02:48:53 PM »
When I grow up I wanna make parts just like you George!    :ThumbsUp:


Sweet!...
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!