Author Topic: Marcher, a twin cylinder marine steam engine  (Read 4052 times)

Offline Moxis

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Marcher, a twin cylinder marine steam engine
« on: August 18, 2018, 08:57:36 AM »
As I promised in the introduce section that I will start a build log of the Marcher engine, so here we are. After I also learned how to add photos here, we are ready to start.

First a few words for background.

A few months ago we decided with two friends to start building models of a half open launch "Lempi", which is a 60 feet long steam powered ship, made on 1879 at the Ahlstrom shipwright in Varkaus Finland. The drawings of the ships made by this company are all digitized, so the original drawings can still be found in Internet.
We downloaded the plans, had them printed in the scale of 1/15, whixh corresponds a model length of about 1200 mm and started working with the hull. I am not going more deeply to hull fabrication, but want to show a special way to cover the hull, because the original ship was made of iron by riveting, and we wanted to show the riveting also at the model hull.
So after the hull was made from wood in a common way by plank on bulkhead method, we covered it with 0,1 mm thick self adhering aluminium foil. where rivetings were made with a tool made from some old toy gear.

On first photos you can see the drawing of Lempi and a hull covered with alufoil.

Because the original ship was powered with a two cylinder compound steam engine, I wanted to have the model made the same way, and this led me to search suitable engines for this project. After many ponderings and calculations I finally selected the Marcher to be the engine for this project, and ordered set of drawings and castings from a UK company Reeves.

Offline Ye-Ole Steam Dude

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Re: Marcher, a twin cylinder marine steam engine
« Reply #1 on: August 18, 2018, 09:16:13 AM »
Hi Moxis,

This will be a fun project/build to follow. The ship's hull that you built looks very nice and your shop looks as clean as an hospital operating room.

Have a great day,
Thomas

Offline Baner

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Re: Marcher, a twin cylinder marine steam engine
« Reply #2 on: August 18, 2018, 09:40:22 AM »
I'll be following.:popcorn:
Is the Marcher going to be close to scale? Looks like it might be. Are you going to do a boiler too?

Dave.

Offline Zephyrin

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Re: Marcher, a twin cylinder marine steam engine
« Reply #3 on: August 18, 2018, 10:27:29 AM »
this hull looks very nice, no visible bruising so easy to occurs with such thin foil !
how did you make the alu foil planking over the curved parts, with joined strips of metal ?

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #4 on: August 18, 2018, 03:57:47 PM »
Thank you all for your kind comments and interest to my build.

# Thomas: Enclosed are a few photos about my machines which I am going to use to make the Marcher. They are a bit bigger than the hobby machines which are normally used for model making, but not "real" power tools which lot of you guys seem to have. However accuracy should be adequate for steam engine building, because it is easy to achieve 0,01 mm accuracy, which I have been using when making for instance gearboxes for my earlier builds. Or what do you people think, how accurate the parts shall be to be able to get a nicely working steam engine?

# Dave: Yes, the size of Marcher is quite near the scale size. However the original engine was a compound, but Marcher`s cylinders have equal bore. I tried to find drawings for a small compound engine but couldn`t find any.  And concerning the boiler, I have not decided yet whether to try to build it by myself or buy one. The problem is that I do not have equipment or skills enough to make rather large silver solderings which are necessary for boiler making. I have asked a few quotations for boilers, but it seems that they are quite pricey, so we will see when the time comes.

# Zephyrin: The hull planking is made using a number of alufoil plates, typically the size 40x90 mm. They overlap each other a few millimeters and are individually cut into the shape using first templates made of paper before cutting the final plate. This work sounds very demanding, but is in reality quite fun and easy, and planking the whole hull didn`t last many days. Because the plates are relatively small, they do not need to bend in two directions. It seems that the quality of this foil is quite soft, making it easy to  follow hull curves.

Offline kvom

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Re: Marcher, a twin cylinder marine steam engine
« Reply #5 on: August 18, 2018, 08:30:05 PM »
Running on steam, you need to be aware that your parts will expand.  So a very precisely fitted assembly can jam tight.  Build it so that it's "half worn out" (at least the parts that will get hot).

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #6 on: August 19, 2018, 08:34:07 AM »
Thanks kvom, that is a good information I have to keep that in mind. So that absolute accuracy is not necessary, good!

About dimensioning.  All the measurements on the drawing are naturally imperial. But we are living in a metric country, and all my tools like drill bits, taps and dies, reamers etc. are metric, so I have to slightly adjust the dimensioning. This means for example that 5BA threads will be made M3, 8BA M2 and so on. I hope this does not bring unsolved difficulties later on. The dimensions of parts can easily be converted into metric, calculator has been invented.

Enclosed are photos of the main drawing of Marcher and castings which are included into the package.


Online b.lindsey

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Re: Marcher, a twin cylinder marine steam engine
« Reply #7 on: August 19, 2018, 02:09:47 PM »
Shaping up to be a great project Moxis!!  Looking forward to your build of the engine.

Bill

Offline Baner

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Re: Marcher, a twin cylinder marine steam engine
« Reply #8 on: August 19, 2018, 04:01:38 PM »
It's a good idea to check over all the castings with a caliper and make sure they can be machined to drawing dimensions. I can see one of the eccentric strap castings has a piece cut off. There may be other problems. This seems to be fairly common with the older casting suppliers. It's a little unfortunate that the quality doesn't match their prices. I'm sure they'll replace anything that's not as it should be.
Dave.

Offline kvom

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Re: Marcher, a twin cylinder marine steam engine
« Reply #9 on: August 19, 2018, 05:06:51 PM »
I have built a couple of engines with metric plans using imperial fasteners and drill rod.  No reason the same in reverse would be a problem.

Offline Chipswitheverything

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Re: Marcher, a twin cylinder marine steam engine
« Reply #10 on: August 20, 2018, 08:55:08 AM »
Hello Moxis, enjoying your photos and write up, look forward to the build of your engine.    The plated hull looks beautiful, and your nice workshop and machines are enviably pristine!  Hoping to see a few splashes and lines of cutting oil up and along the very clean workshop walls once you machine some of the steel components on the Marcher !   Dave

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #11 on: August 20, 2018, 04:43:15 PM »
Thank you guys for your kind words and interest to my build!

Finally we are so far to start working. I decided to start the build with crankshaft, because I thought it is the most difficult part to fabricate. If I can make a reasonable crankshaft, the rest will be easy  :embarassed:

So I took a 20 mm silver steel bar which was left over from some earlier project and cut a piece a bit longer than what is the length of the crankshaft. My purpose was to make the shaft from one piece in the lathe, because the shaft and big end journals overlap slightly each other, so it is not possible to fabricate it from separate parts.
The positions of big end journals were marked at both ends with an optical centre pop, then the part was centred in the lathe, journals centred in the milling machine, part was attached between the centres  in the lathe, and turning work was started.

After a comprehensive turning session everything was finally made, and I had in my hands a quite acceptable crankshaft.
« Last Edit: August 20, 2018, 04:53:16 PM by Moxis »

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #12 on: August 23, 2018, 01:49:25 PM »
The next item to be made was the baseplate. Very nice casting is provided for this. First some burrs had to be removed with a file, and then the part was attached into milling machine table and milled straight on both sides. The casting was attached into angle plate and holes to be drilled were marked. For the columns M3 threads were made instead of 5BA, and those for the bearing blocks M2 was used.

Offline Ye-Ole Steam Dude

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Re: Marcher, a twin cylinder marine steam engine
« Reply #13 on: August 23, 2018, 02:06:21 PM »
Hello Moxis,
Coming together very nice and a good looking crank.

Have a great day,
Thomas

Offline Moxis

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Re: Marcher, a twin cylinder marine steam engine
« Reply #14 on: August 28, 2018, 07:30:14 AM »
Next I was making the columns between cylinder block and baseplate. There is nothing special here, the only important point is to get the columns exactly same height. After a few trials and errors I finally succeeded to do that so that now the columns are equally long within one or two hundreths of a millimeter.
They were made of 5 mm silver steel, and M3 threads were cut at each end. Very handy for this work is a die holder which can be attached into tailstock chuck, and slides forward and back on it`s axle.
« Last Edit: August 28, 2018, 07:33:24 AM by Moxis »