First engine, even if it is only a wobbler.

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Bushranger

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Hi, all.
I've been lurking around here for a while, soaking up the knowledge. Now it's time for me to have a go at making something myself by having a go at this one: A Simple Oscillating Engine. I consider myself to be reasonably competent with machining and have access to a lathe, mill, drill press and other tools, so that shouldn't be a problem. What is a problem, though, is parts like air fittings, etc. You know, the small brass bits that connect air lines to models. Don't seem to be any in Wagga Wagga that I can find and was wondering where you people get these parts from. I don't think a 1/8" BSP fitting will work, so would probably need 1/16" BSP, are they readily available? Even though this wobbler doesn't need it, I was wondering about copper piping as well.

Anyway, that's where I'm at right now. I'll try to remember to keep taking pics so I can show my progress, if anyone would be interested.

Paul.
 

minh-thanh

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Hi !
Welcome !
I will be interested.
Take some pictures when you can .
 
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GreenTwin

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I would like to see some photos of your progress.
I learn something new every time I watch other's builds.
I guess you can always make your own fittings, although I can't offer any advice as to exactly how to do that.

.
 

stevehuckss396

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Most fittings and smaller bits you will probably just end up making yourself. Why wait for 2 fittings in the mail when you can knock them out in an hour if you have the material.

Once you get rolling in the hobby you will do alot more part making so things look scale and like they belong.
 

Bushranger

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Thanks for the responses, good to know other people are interested. I think making my own fittings will be the way to go, Will start on the air inlet probably next week.

I've completed the engine frame and most of the cylinder end cap and currently have the cylinder in the lathe setup for boring. Here's pics of two of the parts:

20211112_151056.jpg

Still need to do some more polishing, but I think they look pretty good so far.
 

GreenTwin

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When I started trying to learn how to build/machine a steam engine, one of the questions was where exactly to start, and then how to progress through the pieces.
I think what I do now is start from the inside, and work out, ie: machine the cylinder/bore, then the piston, then the piston rod, gland, etc.
I have no idea if this is a good way to do it, but it seems like this is what I settled on.

I design engines in 3D modeling pretty much the same way.

For castings, I establish a base plane on each part first, and then measure/machine everything from that reference.

Seems like obvious stuff I know, but I had to learn it, and it was not really obvious to me.
I am still learning, and have a lot to learn yet.

Your parts look good so far.
Nice clean look to them.

.
 

Bushranger

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Thanks for all the positive replies, means a lot to me.
Anyway, here's today's effort, Cylinder, cylinder pivot and nut.
20211113_153600.jpg

Stuffed up the nut, didn't have it held tight enough in the mill vice and it started to unscrew from the pivot. It's not too bad, so not going to bother making a new one. Will start on the piston on Monday.
 

kwoodhands

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Hi, all.
I've been lurking around here for a while, soaking up the knowledge. Now it's time for me to have a go at making something myself by having a go at this one: A Simple Oscillating Engine. I consider myself to be reasonably competent with machining and have access to a lathe, mill, drill press and other tools, so that shouldn't be a problem. What is a problem, though, is parts like air fittings, etc. You know, the small brass bits that connect air lines to models. Don't seem to be any in Wagga Wagga that I can find and was wondering where you people get these parts from. I don't think a 1/8" BSP fitting will work, so would probably need 1/16" BSP, are they readily available? Even though this wobbler doesn't need it, I was wondering about copper piping as well.

Anyway, that's where I'm at right now. I'll try to remember to keep taking pics so I can show my progress, if anyone would be interested.

Paul.
Make barbed fittings like 1/4" air fittings that you get in a hardware store. Plastic 1/2" OD hose is forced on the barb. The barb does not have to be perfect, just a slight taper to help start the hose. A heat gun will soften the hose if it is hard to start the hose on the fitting.
mike
If the hose pops off under pressure, add a hose clamp.
 

Bushranger

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Make barbed fittings like 1/4" air fittings that you get in a hardware store. Plastic 1/2" OD hose is forced on the barb. The barb does not have to be perfect, just a slight taper to help start the hose. A heat gun will soften the hose if it is hard to start the hose on the fitting.
mike
If the hose pops off under pressure, add a hose clamp.
Thanks, kwoohands. That's what I was thinking of doing, shouldn't be too difficult, certainly easier than finding suitable fittings around here, lol.
 

lennardhme

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Hi Paul,
I know oscillating engines are considered 'simple' but they were once pretty serious stuff.
Take a look at the Diesbar based in Dresden.....a twin John Penn engine driving a paddlewheeler in Dresden. This engine has twin 24 inch pots
with an air pump between.
Fascinating stuff.

Cheers Lennard (in Vic.)
 

methuselah1

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I think I've mentioned the Great Eastern before! Ever seen that famous photo of Brunell? It was taken at the water's edge, while they were trying to launch her- she was then the largest ship ever built! She had screws powered by conventional engines, but the paddlewheels were powered by BIG oscillators. They're not a Mickey mouse approach to steam power.

When it comes to air fittings, I use commercial male ones, with the 1/4" BSP thread ground off (they're hardened) and silver solder a brass adaptor with whatever thread I see fit in its place, typically 1/4" BSB; the old 26tpi brass gas thread.

-Andrew
 

Bushranger

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Have you ever had one of those days when you just shouldn't have gone into the shed? That was me today. What should have been an easy job making the piston turned into a disaster.
Turned the piston down to just over the bore of the cylinder then started working with emery paper until it started sliding into the cylinder. Bit more sanding then figured out the cylinder was actually tapered. No reamer so used an endmill to clean the hole out. Finally got the piston down to a nice sliding fit inside the cylinder, finished turning the piston as per drawings. Took it out of the lathe and guess what. No longer a sliding fit, only goes about half way into cylinder as if it's tapered again. Thought I'd cheat by lapping the piston into the cylinder. Next thing I know, it's all seized up and broken the con rod.
At this point I gave up for the day. Back to it on Wednesday and hopefully it will turn out to be a better day.
 

Bushranger

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Well, another day in the shed and another two parts done, main bearing and axle:
20211117_155425.jpg
Still have to drill the holes in the bearing, but waiting for the right size drills to be delivered. I'm using M2 screws on this project so definitely want the proper sized tapping drills. Would have done more, but had a couple of other jobs to do and kept getting interrupted by people asking what I was making. Might have to get a big "Do Not Disturb" sign, lol.

I'm a bit gun shy about the piston now, but hopefully will manage to get it done.
 

GreenTwin

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Have you ever had one of those days when you just shouldn't have gone into the shed? That was me today. What should have been an easy job making the piston turned into a disaster.
Turned the piston down to just over the bore of the cylinder then started working with emery paper until it started sliding into the cylinder. Bit more sanding then figured out the cylinder was actually tapered. No reamer so used an endmill to clean the hole out. Finally got the piston down to a nice sliding fit inside the cylinder, finished turning the piston as per drawings. Took it out of the lathe and guess what. No longer a sliding fit, only goes about half way into cylinder as if it's tapered again. Thought I'd cheat by lapping the piston into the cylinder. Next thing I know, it's all seized up and broken the con rod.
At this point I gave up for the day. Back to it on Wednesday and hopefully it will turn out to be a better day.
I think I mentioned this previously, but my first attempt to learn machining was by machining random steam engine parts, not for any particular engine.
It was very frustrating to say the least, and invariably I would get a part about 90% machined, or 95%, and then GLITCH, here comes the part flying out of the lathe or mill, ruined. I broke some nice carbide tool bits doing all sorts of stupid things.
I can't tell you how many times I botched parts (many).
Or I would finish a part, such as a cylinder, and start drilling the hole for the pivot, only to drill into the bore.

I tried cast iron piston rings, and totally botched a number of those.
I use to sweat profusely as I approached completion of each part, just knowing what was about to happen.

I ruined a lot of parts, but each time I ruined a part, I made another one, and another one, over and over (the next night).
For a while, the average number of ruined parts before I mastered machining a given type was four.

Slowly but surely I learned how to machine all types of engine parts, and so now it is a matter of routine to get it right the first time.
I can't recall the last time I ruined a part while machining it.

If anyone knows of a market for ruined engine parts, I can provide a large quantity, and the price will be right.

.
 

Bushranger

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Hi, GreenTwin, yeah, ruined parts are all part of the fun. I was taught by professionals, but that was a very long time ago. Only just started back with machining for a few years now. But for some reason, the bloody piston on this thing is causing me all sorts of aggravation. But I'm going to beat the bugger, lol.
 

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