I am starting this thread in the hopes of future advice

A special section just for steam engines and boilers, as without these you may as well fit a sail.
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joe36
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I am starting this thread in the hopes of future advice

Post by joe36 » Fri Apr 17, 2020 6:05 pm

I am starting this thread in the hopes of future advice.
While I know masses have been written about steam engines and steam design. I will be the first to admit I am ignorant in many ways with other than the fundamentals of steam engines and boilers.
I have been working on a 2”X 2” cylinder mold. The COVID19 thing has stopped most movement. With the shop 14 miles away. I will not see it for a while.
The cylinder is to be used on a conversion that will be brought in further post. This is to be the first of 2 engines. It will be as much a test of building process and casting.

Joe
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Re: I am starting this thread in the hopes of future advice

Post by Lopez Mike » Fri Apr 17, 2020 7:19 pm

Some small thoughts.

A 2 x 2 engine will only drive a fairly small hull. Like maybe a row boat. You will learn a great deal from building an engine of this size but it will have limitations.

A passing thought is that you might start thinking about using this cylinder as the high pressure half of a compound for later design and construction.

Welcome to the forum. Lots of advice and experience here. Where are you located?
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joe36
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Re: I am starting this thread in the hopes of future advice

Post by joe36 » Fri Apr 17, 2020 8:17 pm

The first one is very close to a model. I have a 12’ flat bottom boat that is under 100 Lb. If It pushes that I would be very happy. I am in northern Indiana USA 46947 and retired 5 years ago with bad health.
I am just beginning to get back to where I think I can start accomplishing a couple of things I have always wanted to do. One is to build a steam engine and then to couple that to a boat.
Most of the work has been on a new foundry. I have not been completely out of the foundry industry in the past 25 years but have not poured metal nor owned a foundry since then.
I have built the standard fuel motor oil furnace and am very close to having a dedicated building at least of use.
The small cylinder will be made for a conversion of an older cast iron air compressor.
This was chosen only because it had a very nice crank and lower end. The piston in the compressor will remain but have vent holes for oil passage. This will bolt to a push rod to the steam cylinder. I have machined a new crank sleeve to increase the length and diameter. The extra length will allow a carriage bearing to follow the eccentric on the crank
The eccentric driving the slide valve will be external to the 2 original crank bearings. Above the compressor will be all new castings. I plan on using gun metal 85-5-5-5 for the alloy and at this time am leaning in the direction of bonded sand.
Joe
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Re: I am starting this thread in the hopes of future advice

Post by fredrosse » Sat Apr 18, 2020 4:32 am

"This will bolt to a push rod to the steam cylinder."

On single acting engines using an IC engine lower end (or compressor, same thing), I have machined the steam piston to take a forced fit connecting tube, and machined out the top of the IC engine piston to also take a forced fit of this tube. The connecting tube is rather large diameter, about 75% of the cylinder bore. The bore for the connecting tube is made so that there is adequate metal wall thickness, at least about 1/8 inch, between the tube outside diameter (press fit region) and the piston ring grooves in both the IC engine piston and the steam piston.
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Re: I am starting this thread in the hopes of future advice

Post by fredrosse » Sat Apr 18, 2020 4:35 am

Alignment of the two cylinder bores must be co-axial with good precision. One solution is to have both pistons running in a single long iron cylinder.
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Re: I am starting this thread in the hopes of future advice

Post by joe36 » Sat Apr 18, 2020 2:23 pm

The engine you have built from the IC engine sounds interesting. I have plans to build this one along those lines. Instead of a tube connecting the cylinders. I plan on a flange that will be machined to match the new head on the IC engine. Above that I would like to put a 2” X 2” duel actuating cylinder.
I can chuck up anything on this project in my lathe to keep the bores in line if I must but have hope that with some care I will be within tolerance.
Joe
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