Author Topic: Another MEM Corliss (in .40 scale)  (Read 5149 times)

Offline crueby

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Re: Another MEM Corliss (in .40 scale)
« Reply #75 on: August 01, 2018, 03:08:52 PM »
 :popcorn:


Offline zeeprogrammer

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Re: Another MEM Corliss (in .40 scale)
« Reply #76 on: August 01, 2018, 03:36:15 PM »
Then a throttling valve, beautiful base and stands, and now a governor. Just wow.  :popcorn:
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
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Offline vcutajar

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Re: Another MEM Corliss (in .40 scale)
« Reply #77 on: August 01, 2018, 08:36:41 PM »
That is a real gem George.  Looking forward to see it with the governor.  I chickened out on mine and did not do it.

Vince

Offline gbritnell

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Re: Another MEM Corliss (in .40 scale)
« Reply #78 on: August 02, 2018, 03:46:20 PM »
I started on the governor parts, first the gears and then the column. What you see is two pieces. I turned, drilled and reamed the lower piece then put it on the mill to cut the square area for the gears. It then went back to the lathe to cut the taper and flange. The top was threaded 6-40 to receive the upper part of the column. Assembling the gears I found the lengths needed to be tweaked to get a proper mesh.
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Offline b.lindsey

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Re: Another MEM Corliss (in .40 scale)
« Reply #79 on: August 02, 2018, 03:56:13 PM »
That will add another nice focal point for the engine, not that it is lacking for "wow" features as it is :) Very nice George.

Bill

Offline Tennessee Whiskey

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Re: Another MEM Corliss (in .40 scale)
« Reply #80 on: August 02, 2018, 07:21:18 PM »
Im just blown away by the whole thing George. Gee, youre stepping up to a 6-40 thread size; kinda big for you isnt it? 8)

Whiskey

Offline gbritnell

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Re: Another MEM Corliss (in .40 scale)
« Reply #81 on: August 04, 2018, 12:43:59 AM »
I got some more parts made. The main shaft is .062 stainless steel. It's threaded M1.2 x .25 on the top to hold the upper weight arm bracket. The lower bracket was made in one piece, incorporating the weight. I ground a forming tool bit to shape the radius next to the bracket. The remainder was filed to shape. The tiny decorative nut at the top has a .078 hex and holds the upper bracket to the main shaft.
Talent unshared is talent wasted.

Offline crueby

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Re: Another MEM Corliss (in .40 scale)
« Reply #82 on: August 04, 2018, 01:03:36 AM »
I need to order a new box of "Wow"'s.


 :popcorn:

Offline zeeprogrammer

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Re: Another MEM Corliss (in .40 scale)
« Reply #83 on: August 04, 2018, 03:45:46 AM »
I need to order a new box of "Wow"'s.

Well put. And get me a case too.
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Offline Craig DeShong

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Re: Another MEM Corliss (in .40 scale)
« Reply #84 on: August 04, 2018, 04:15:00 AM »
I need to order a new box of "Wow"'s.

Well put. And get me a case too.

Me too !
Craig

Online 10KPete

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Re: Another MEM Corliss (in .40 scale)
« Reply #85 on: August 04, 2018, 05:18:09 AM »
And three!  Just amazing especially when we all know just what that kind of work takes.
Bravo!!

Pete
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Offline gbritnell

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Re: Another MEM Corliss (in .40 scale)
« Reply #86 on: August 07, 2018, 11:50:28 PM »
With the flathead work out of the way I got back on the Corliss. I had reservations about making the ball arms with the hinge pad in the middle.
I first turned the long end, .046 diameter x .347 long, then transferred the collet chuck to the mill. I milled a flat at 0 and 360 but only enough to drill the hinge holes, .040 diameter. I then slowly worked the stock down until I had a section .075 square. The collet was then screwed back onto the lathe spindle and the short area of round between the hinge point and upper joint was turned. It was here I expected the tool to grab and twist the whole thing like a pretzel, but it didn't. Once the shaft was turned I put the collet back in the mill and indicated across the flat of the hinge joint. Using a sharp .125 end mill I cut the upper pivot joint to thickness, .026 wide. I left a couple of thou. to file and fit it to the upper bracket.
The collet chuck was once again put on the lathe and the piece was parted off. I then filed the radius on the upper end and fitted the flat area to the bracket.
The balls are .187 diameter bronze that I have had for years when I used to do more steam stuff. I sorted through my split collets to find a 3/16ths one and clamped the ball in the 3 jaw chuck. I drilled about halfway through with a .046 drill. The ball was fixed to the shaft with Loctite.
One more to go.
Talent unshared is talent wasted.

Offline Admiral_dk

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Re: Another MEM Corliss (in .40 scale)
« Reply #87 on: August 08, 2018, 12:45:36 AM »
Oh man, the potential for failure in this size is immensely  :o and while I gotten used to have the CNC router at work do hole diameters down to 0.6 mm. in PCB material without any problems, I do remember the swearword ratio before when doing it by hand  :cussing:

I really like your approach with drilling when you have a bit more material, but it is still not easy.

How "fast" is your mill ? - I'm sure one of the major reason the CNC do a much better job than I can do manually is the extreme high RPM's it is running (20-30K) as this prevents much of the tendency these tiny drill bits has to wander compared to the old manual drill (2-3K) + high feed rate.

Offline gbritnell

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Re: Another MEM Corliss (in .40 scale)
« Reply #88 on: August 08, 2018, 03:35:45 AM »
Top speed on my mill is 2500. I have learned to drill down to .025 with it without breaking drills. For milling with really small end mills I have a speeder head that was designed by Jerry Howell. It consists of a high speed spindle that fits into a .875 R-8 collet and is driven by a 24 volt DC motor mounted on a bracket off to the side. The way I have it set up I can get 7500 rpm out of it. It works good for .062 and .032 end mills. It takes a lot of feel but my mill is small enough and sensitive enough that I can feel the cutter working.
Talent unshared is talent wasted.

Offline gbritnell

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Re: Another MEM Corliss (in .40 scale)
« Reply #89 on: August 08, 2018, 06:40:18 PM »
All is finished on the governor except the pulley. All the joints are nice and free but it still doesn't have enough weight to return the balls so I'll add a tiny spring above the weight on the shaft. Now I need to disassemble the crankshaft so that I can trim down the eccentric. The rods will need to be moved in also. This will give me enough room between the eccentric and the flywheel to put the other pulley.
Talent unshared is talent wasted.