Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines
Builds, Repairs, Show Your Machines! => Technical Tips, Builds, and Help => Topic started by: millwright1163 on March 12, 2022, 06:03:47 am
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just some updated pictures of the progress thus far,[attachimg=1][attachimg=2]
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I am thinking that I will try to balance the crankshaft similar to an IC engine. Maybe if I am lucky, I can get by without a dedicated flywheel. Thanks to all who have helped so far.
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I have a few pictures of progress so far.
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Hi,
Now I have to figure out how to balance the crankshaft.
The easiest way is to put the flywheel on the crank shaft and add weight or drill holes or a bit of both to it to get a balance.
Take care.
Tony.
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Thanks for the replies. The engine I am building is double acting and reversing. I have thought it over, after reading the replies to this post, and I think I understand the placement of the ports. Basically, they are at the ends of the travel. As far as the cylinder travels in its "wobble " motion. This makes sense when I think about the reversing. If they were any place else, the timing might be good in one direction but bad in the other rotation. Now I have to figure out how to balance the crankshaft. I will post some pictures of what I have so far as soon as time allows.
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Hi,
I am in the process of scratch building a two-cylinder, 90Degree "V" steam powered wobbler. The bores are 3/4 inch, and stroke is 1-1/4. Cast iron cylinders, brass pistons, steel frame. I have the cylinders, covers, pistons, connecting rods completed with no known issues. My question relates to the inlet and exhaust ports in the frame. I know how to align them above and below the cylinder pivots, however I am unsure about the lateral positions. As the port in the cylinder makes its arch, at what point along that arch, should the port in the frame align with it? I know the steam should ideally enter a bit before TDC. Is there a placement that relates to the crank? for example; the ports should be in full alignment when the crank is about 5 degrees before TDC. I hope I am making sense to at least some of the experts here.
Your engine is double acting and will it need to reverse?
Usually on a oscillating engine when the piston is at TDC both inlet and exhaust ports are closed and only start opening together after the cylinder moves a few degrees past TDC. The only oscillating engines that I know of that emit steam before TDC are single acting and are designed for high speed, often they are also uniflow. Given the size of your engine I assume it will run at a normal speed?
Take care.
Tony.
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Well any model i have worked on has inlet and outlet
when the crank is at O and 180 assuming crank is at 90 for piston TDC and 270 for BDC
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I am in the process of scratch building a two-cylinder, 90Degree "V" steam powered wobbler. The bores are 3/4 inch, and stroke is 1-1/4. Cast iron cylinders, brass pistons, steel frame. I have the cylinders, covers, pistons, connecting rods completed with no known issues. My question relates to the inlet and exhaust ports in the frame. I know how to align them above and below the cylinder pivots, however I am unsure about the lateral positions. As the port in the cylinder makes its arch, at what point along that arch, should the port in the frame align with it? I know the steam should ideally enter a bit before TDC. Is there a placement that relates to the crank? for example; the ports should be in full alignment when the crank is about 5 degrees before TDC. I hope I am making sense to at least some of the experts here.