Author Topic: The Dickson!  (Read 34664 times)

Offline Jasonb

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Re: The Dickson!
« Reply #15 on: August 25, 2017, 08:12:06 PM »
Thanks Maury, I can see the way you are going now - a casting for each section of pipework including insulation with a flange on each end to be machined.

Looking forward to seeing some machining photos Dennis but would also be interested to see the patterns too.

J

Offline Dennis

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Re: The Dickson!
« Reply #16 on: August 28, 2017, 02:18:47 PM »
Jason,
Here are some photos of the iron parts patterns I have cast so far.  I have been documenting the machining steps and including photos of the machining steps in the drawings I make, however they are difficult to share.  And when converted to PDF files, the files are much too large to post here.  Perhaps some time in the future when time permits we will make them available in a different way.   Solid Works is a wonderful and easy program to use and document a project, until your try to share the drawings with someone else who is not using the same year release as you are. 

The parts that have been cast and partially machined so far are the bed plate, foundation, field coil rings and field coil posts.


Offline Dennis

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Re: The Dickson!
« Reply #17 on: August 28, 2017, 02:29:18 PM »
Hello everyone,

Here is a photo of the partially machined castings cast so far.  I have been working on the iron castings patterns and a prototype foundry in the Detroit area has been doing the casting.  All of the castings are ductile iron and machine very nice but quite messy. 

Maury has been working on the brass parts and making castings in his home foundry.  There are five brass castings and seven iron castings in each armature.  I have been slowly working at machining the first armature castings to prove out the design and patterns.  When complete, I update the drawings for John and Maury to use on their engines.

Dennis

Offline jeff l

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Re: The Dickson!
« Reply #18 on: August 28, 2017, 06:19:47 PM »
Top notch pattern work and machining .

Offline Jasonb

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Re: The Dickson!
« Reply #19 on: August 28, 2017, 06:41:51 PM »
That's looking very good Dennis. Could you give an idea of size, maybe the diameter of the ring?

Offline Zephyrin

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Re: The Dickson!
« Reply #20 on: August 28, 2017, 11:08:19 PM »
I wonder why there are several wooden models (beautiful in their own!) that look identical, I would have thought it was simpler to make several molds (sand?) With the same model ...

It is really a grand project, wow !

Offline Dennis

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Re: The Dickson!
« Reply #21 on: August 29, 2017, 12:44:53 AM »
Jason,

Here are some dimensions:

The field ring is about 10 inches in diameter, The foundation casting is about 15 1/2 in long.  When the model is complete with a dynamo on both ends, I thing it will be well over 100 pounds, already getting heavy with the parts in the photo.

Dennis

Offline Dennis

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Re: The Dickson!
« Reply #22 on: August 29, 2017, 01:12:43 AM »
Zephyrin,

You make a good observation Zephyrn.  On the larger parts, like the dynamo ring, there is only one pattern, split between cope and drag of the pattern board and that works quite well.  That would be the normal way to get multiple cast parts.

Here is my thinking that led to multiple parts on one pattern for this part:

The pattern pieces you see multiple copies of in the photos are the pins for the field coils.  There are 14 field coils on each dynamo,  I just started machining the field coil posts so in a couple of weeks I will have a better photo to show that will make more sense.

I made 16 copies of the pattern so I could get the poles for one dynamo cast in one mold and still have a couple of spares to cover my mistakes.  The foundry I use has a minimum charge per mold which this pattern falls into because the parts only weigh about 1 1/2 pounds each.  Because the pattern for the field coil post is so simple and easy to make, I thought it would be to my advantage cost wise to have a full set of parts on one pattern.

We thought about just machining the parts from square bar stock because the end of the post is 1 1/2 X 1 3/4 inch but the ductile iron casting will have better magnetic properties than the steel. 

Hope this answers your question.

Dennis

Offline Dave Otto

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Re: The Dickson!
« Reply #23 on: August 29, 2017, 01:22:31 AM »
Wonderful work guys, having worked with Maury on a project in the past I can only guess that you guys are having a great time!
I hope that Maury is keeping his feet dry through this terrible mess going on in Texas and the the other affected states.

Dave

Offline kvom

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Re: The Dickson!
« Reply #24 on: August 29, 2017, 03:00:02 PM »
My experience with Dennis' Joy engine led me to believe that 100lb models are pretty hard to drag to shows if you fly to them.  This is the same Dennis who told me he was out of the large engine business because the castings were too heavy to manage.  I'm glad he's abandoned that idea, as this engine looks like a winner.   :ThumbsUp:

I've seen the original at the Henry Ford a couple of times, and in fact it was Dennis who pointed out that it used Joy valves.  The radius rod is so thin that it's hard to see at first glance.  Since the engine doesn't need to be reversed I wonder why they chose this type of valve.  :shrug:

Offline Dennis

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Re: The Dickson!
« Reply #25 on: August 29, 2017, 10:40:31 PM »
Hi Kurt,

Glad you like the model.  I have been thinking about this engine since before we did the Gothic engine 20 years ago.  It is finally taking shape.

As you say, the engine would never be reversed in a power plant so it really doesn't need the Joy's Valve Gear, however, the engine itself was designed for marine use.  I do not know how many engines were built for the marine industry.  It was John Van Vleck, the chief engineer for Edison General Electric Company, who did the design work to adapt the two dynamos to the engine.  The photos and information I found of the Duane Street generating station shows seven of these engines with dual dynamos in the power station. Must have been quite a place.

And yes, I had to leave the model business because I can't lift the heavy castings any more, however I have a son who is willing to help occasionally.  I am building the engine a piece at a time and adding each part to the assembly, when complete I will invite my son to dinner and have him move it.

Offline Zephyrin

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Re: The Dickson!
« Reply #26 on: August 30, 2017, 08:34:42 AM »
Hi,
thanks for the answers, I did not notice the spliced part of the coils frame.

Even if reversing is useless here, the advantage of a geared steam distribution, Joy's in this case, lies also in the possibility of notching and adapting at best the steam expansion and reduces coal consumption.


Offline maury

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Re: The Dickson!
« Reply #27 on: August 30, 2017, 06:36:29 PM »
Dave, thanks for the concern about the storm, We were on the outskirts of it. There was a little wind, and rain for about 3 days, but the rain only totaled about 3". Conditions in costal areas are another matter.

I've been mostly hunkered down in the shop. Over the past weeks the CNC got a real workout. I've been making patterns for the castings for the Dickson piping. Over all, there will be about 35 castings or so. I've completed the match plates for the piping, except for the Governor Valve and Main Steam Valve, still need design work on those.

Some of the pipe parts will be made in halves so the interior can be milled out, then the halves will be silver soldered together before machining the flanges. These parts are small, and there will be a lot of 1-72 threading.

maury
"The trouble with socialism is that you eventually run out of other people's money."... Margaret Thatcher

Offline jeff l

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Re: The Dickson!
« Reply #28 on: August 30, 2017, 06:50:31 PM »
Those patterns look great Maury .Jeff

Offline kvom

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Re: The Dickson!
« Reply #29 on: August 30, 2017, 09:54:25 PM »
After all the 0-80 fasteners on my current project, 1-72 sounds big.   :LickLips:

 

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