zeeprogrammer
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Very very nice.
I really appreciate all the tips throughout your posts.
I really appreciate all the tips throughout your posts.
"Nina", a Gauge 1, 0-4-0 live steamer. Progress and updates
- Thread starter xo18thfa
- Start date
Help Support Home Model Engine Machinist Forum:
I'm enjoying your build. I'm not very knowledgeable when it comes to trains, even though my bedroom was a mer 200 feet from the RR tracks when I was a kid. They have always fascinated me though.
1 question: Can someone explain to me how the Loco number system works or what it means? 0-4-0???
Keep up the great work!!
Matt
1 question: Can someone explain to me how the Loco number system works or what it means? 0-4-0???
Keep up the great work!!
Matt
Maryak
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Matt,
My understanding.
0-4-0 etc is a system for showing the wheel layout of a steam loco
0 no front bogey wheels, 4 driving wheels, (the powered wheels); and 0 no rear bogey wheels.
Hope this helps, and I also hope it's correct. :
Best Regards
Bob
My understanding.
0-4-0 etc is a system for showing the wheel layout of a steam loco
0 no front bogey wheels, 4 driving wheels, (the powered wheels); and 0 no rear bogey wheels.
Hope this helps, and I also hope it's correct. :
Best Regards
Bob
Maryak said:Matt,
My understanding.
0-4-0 etc is a system for showing the wheel layout of a steam loco
0 no front bogey wheels, 4 driving wheels, (the powered wheels); and 0 no rear bogey wheels.
Hope this helps, and I also hope it's correct. :
Best Regards
Bob
That's it. The first number is always represents an unpowered leading truck, or pilot. The last number represents an unpowered trailing. The numbers in the middle are the powered wheels. All numbers are even. Mine is 0-4-0, no unpowered pilots or trailers, just 4 powered wheels.
To add to it, most steam locomotives have names associated with the wheel arrangement. For example a 4-6-2 is called a Pacific. It has a 4 wheeled pilot, 6 drivers and a 2 two trailing truck. A 2-6-0 is a Mogul.
Do a Google search on "steam engine wheel arrangements"
Its been a while since the last update. Reason for that is because I was having some trouble getting the cylinder done right. The original plan was to drill and ream the 1/2" bore in a bronze cylinder blank. Reaming that size turned out difficult for my little lathe. There was too much chatter and the resultant bore not very clean. I decided to abandon the ream and use a traditional boring bar instead.
In preparation for turning the cylinder, my old Atlas 6 lathe got an upgrade this past week. I ordered a quick-change tool post set from Littlemachineshop.com
A quick-change tool post allows you to set the tool in its holder just once and then quickly change the holder as needed. This post is much faster than the original rocker style post and light years ahead of those 4 position turret things that come with most lathes.
Before getting started on the cylinder, we need to fabricate a special little measuring tool called a center test indicator. They are also known as a wiggler, or wobbler. The wiggler helps get an odd shaped piece centered in the 4 jawed chuck. Here is an article I found on how to make one.
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Wobbler.jpg
Modify this idea to suit you lathe. And here is an illustration of how to use it.
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Wiggler.jpg
My homemade wiggler is a 2-piece contraption using a ball for the pivot point.
With that done, lets get started on the cylinder. Here is the drawing:
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Cylinder.jpg
The cylinder body is bronze, alloy 932. Bronze only comes in round bar and our cylinder is more or less rectangle. So we will have to start with an oversized bar and work it down. First, face off a length of 7/8 diameter bar to 1 3/8 long. Grip the bar sideways in the 4 jawed chuck and turn it flat to a width of 5/8
This face spot will eventually be the port face.
Locate and lightly center punch the cylinder bore center. Grip the cylinder in the 4 jawed chuck and center it up with the wiggler.
Drill a 1/8 pilot hole thru the cylinder. With the lathe set at the slowest speed, preferably in backgear if your lathe has one, drill thru with 7/16.
Set up the boring bar in the lathe. Since there is 1/16 of material yet to remove from the bore, you have plenty of time to set-up, practice and make adjustments before taking the final cuts.
Take very light cuts. Even the most rigid boring bars find a way to spring. So take a cut occasionally without any adjustment. Let the bar relax out. Test the bore with a short length of 1/2" stainless steel piston material. The piston material will eventually go in very tight. Dont force it. Take another super light cut, and test the piston again. When the piston just goes in, its time to stop the boring bar operation and finish the bore.
Be patient boring out he cylinder. Expect 18 to 20 passes with the boring bar to get it right.
High quality cylinder bores are finished with a process called lapping. Lapping uses a fine abrasive powder mixed in oil on a lapping mandrel to polish the bore. Since our cylinder is bronze, a hard wood mandrel will work fine. Turn a 4, or so length of maple or oak to exactly .500. Wipe on some abrasive powder mix. Slide the cylinder over the mandrel and turn it by hand. It will be tight at first, but the wood will smoothen down and the cylinder will turn freely.
When the cylinder is turning freely, hold it buy hand and turn on the lathe. Work the cylinder over the entire length of the mandrel. It will only take about 30 to 45 seconds for the lap to polish the bore. The bore comes out free of scratches and with a lightly frosted surface. The piston material should slide smoothly with no air blow-by.
In the lapping process, the mandrel must be a softer material the cylinder material. The abrasive lapping compound embeds itself in the softer mandrel and polishes the cylinder walls. For brass and bronze cylinders, wood mandrels work fine. For steel or cast iron cylinders, use a brass or copper mandrel. Lapping only removes micro scratches and burrs left from the boring bar. The initial bore has to be straight, round and reasonably smooth. If the bore is bad to start with, lapping will not fix it.
Thats it for now. Next time we will shape the cylinder, put on a top cover and hang it on the standard.
In preparation for turning the cylinder, my old Atlas 6 lathe got an upgrade this past week. I ordered a quick-change tool post set from Littlemachineshop.com
A quick-change tool post allows you to set the tool in its holder just once and then quickly change the holder as needed. This post is much faster than the original rocker style post and light years ahead of those 4 position turret things that come with most lathes.
Before getting started on the cylinder, we need to fabricate a special little measuring tool called a center test indicator. They are also known as a wiggler, or wobbler. The wiggler helps get an odd shaped piece centered in the 4 jawed chuck. Here is an article I found on how to make one.
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Wobbler.jpg
Modify this idea to suit you lathe. And here is an illustration of how to use it.
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Wiggler.jpg
My homemade wiggler is a 2-piece contraption using a ball for the pivot point.
With that done, lets get started on the cylinder. Here is the drawing:
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Cylinder.jpg
The cylinder body is bronze, alloy 932. Bronze only comes in round bar and our cylinder is more or less rectangle. So we will have to start with an oversized bar and work it down. First, face off a length of 7/8 diameter bar to 1 3/8 long. Grip the bar sideways in the 4 jawed chuck and turn it flat to a width of 5/8
This face spot will eventually be the port face.
Locate and lightly center punch the cylinder bore center. Grip the cylinder in the 4 jawed chuck and center it up with the wiggler.
Drill a 1/8 pilot hole thru the cylinder. With the lathe set at the slowest speed, preferably in backgear if your lathe has one, drill thru with 7/16.
Set up the boring bar in the lathe. Since there is 1/16 of material yet to remove from the bore, you have plenty of time to set-up, practice and make adjustments before taking the final cuts.
Take very light cuts. Even the most rigid boring bars find a way to spring. So take a cut occasionally without any adjustment. Let the bar relax out. Test the bore with a short length of 1/2" stainless steel piston material. The piston material will eventually go in very tight. Dont force it. Take another super light cut, and test the piston again. When the piston just goes in, its time to stop the boring bar operation and finish the bore.
Be patient boring out he cylinder. Expect 18 to 20 passes with the boring bar to get it right.
High quality cylinder bores are finished with a process called lapping. Lapping uses a fine abrasive powder mixed in oil on a lapping mandrel to polish the bore. Since our cylinder is bronze, a hard wood mandrel will work fine. Turn a 4, or so length of maple or oak to exactly .500. Wipe on some abrasive powder mix. Slide the cylinder over the mandrel and turn it by hand. It will be tight at first, but the wood will smoothen down and the cylinder will turn freely.
When the cylinder is turning freely, hold it buy hand and turn on the lathe. Work the cylinder over the entire length of the mandrel. It will only take about 30 to 45 seconds for the lap to polish the bore. The bore comes out free of scratches and with a lightly frosted surface. The piston material should slide smoothly with no air blow-by.
In the lapping process, the mandrel must be a softer material the cylinder material. The abrasive lapping compound embeds itself in the softer mandrel and polishes the cylinder walls. For brass and bronze cylinders, wood mandrels work fine. For steel or cast iron cylinders, use a brass or copper mandrel. Lapping only removes micro scratches and burrs left from the boring bar. The initial bore has to be straight, round and reasonably smooth. If the bore is bad to start with, lapping will not fix it.
Thats it for now. Next time we will shape the cylinder, put on a top cover and hang it on the standard.
zeeprogrammer
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Great post! I am learning so much from this thread. Thanks!
Thanks Carl.
Last time we got the cylinder bore finished, today we will get the rest of the cylinder done. When the cylinder came off the lapping mandrel, it looked like this:
There is a lot of excess material to remove. Chuck the cylinder sideways in the 4 jawed chuck and face down the sides.
At this point start using strips of paper as packing to prevent the chuck jaws from marring finished surfaces.
With the sides faced down, draw file the rounded surface of the cylinder to get the mill marks cleaned off.
Set up the cylinder in the drill press vice to drill and tap for the 4 x 40 trunnion pin.
The cylinder block is essentially finished. The next parts are the cylinder top cover and trunnion pin. First the top cover. Heres the drawing:
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Top%20Cover.jpg
The top cover is brass and is soft soldered to the cylinder. Start by cutting a 1/4" length of 3/4" round bar. Soft solder on a chucking spigot, just like we did for the engine standard.
Chuck up the top cover and face down to clean metal. Dont worry about getting the cover centered in the chuck. We are just cleaning this face off. This faced surface is the top of the cover.
Melt the chucking spigot off and re-solder it to the faced off side. Chuck it up in the lathe and turn the outside diameter to 5/8
Face the top cover to length and turn the should that fits inside the cylinder.
Melt off the chucking spigot. Use a file and sandpaper to clean of the excess solder.
Now soft solder the top cover to the cylinder. Use just a TT of solder to put the cover on. Dont run the risk of a solder blob running down the inside of the cylinder.
The last part for the cylinder is the trunnion pin. The trunnion is the pivot point of the oscillating cylinder. Heres the drawing:
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Trunnion%20Pin.jpg
The usual method to make this pin is to turn a shoulder on the bar stock and cutting the threads with a die. That is nearly impossible to do with threads this small. Instead make the pin with a length of stainless steel rod and two 4 x 40 machine screws.
Cut a 7/16 length of 5/32 stainless steel rod. Tap both ends for 4 x 40.
Use Loctite #242 to lock the machine screws into their holes. When the Loctite cures, trim the machine screws to length.
With the trunnion pin installed, the cylinder is pretty much done.
Next time we will drill the port holes and lap the faces. Maybe even get on the piston. The air test is right around the corner.
Last time we got the cylinder bore finished, today we will get the rest of the cylinder done. When the cylinder came off the lapping mandrel, it looked like this:
There is a lot of excess material to remove. Chuck the cylinder sideways in the 4 jawed chuck and face down the sides.
At this point start using strips of paper as packing to prevent the chuck jaws from marring finished surfaces.
With the sides faced down, draw file the rounded surface of the cylinder to get the mill marks cleaned off.
Set up the cylinder in the drill press vice to drill and tap for the 4 x 40 trunnion pin.
The cylinder block is essentially finished. The next parts are the cylinder top cover and trunnion pin. First the top cover. Heres the drawing:
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Top%20Cover.jpg
The top cover is brass and is soft soldered to the cylinder. Start by cutting a 1/4" length of 3/4" round bar. Soft solder on a chucking spigot, just like we did for the engine standard.
Chuck up the top cover and face down to clean metal. Dont worry about getting the cover centered in the chuck. We are just cleaning this face off. This faced surface is the top of the cover.
Melt the chucking spigot off and re-solder it to the faced off side. Chuck it up in the lathe and turn the outside diameter to 5/8
Face the top cover to length and turn the should that fits inside the cylinder.
Melt off the chucking spigot. Use a file and sandpaper to clean of the excess solder.
Now soft solder the top cover to the cylinder. Use just a TT of solder to put the cover on. Dont run the risk of a solder blob running down the inside of the cylinder.
The last part for the cylinder is the trunnion pin. The trunnion is the pivot point of the oscillating cylinder. Heres the drawing:
http://1stclass.mylargescale.com/xo18thfa/Nina%2001/Trunnion%20Pin.jpg
The usual method to make this pin is to turn a shoulder on the bar stock and cutting the threads with a die. That is nearly impossible to do with threads this small. Instead make the pin with a length of stainless steel rod and two 4 x 40 machine screws.
Cut a 7/16 length of 5/32 stainless steel rod. Tap both ends for 4 x 40.
Use Loctite #242 to lock the machine screws into their holes. When the Loctite cures, trim the machine screws to length.
With the trunnion pin installed, the cylinder is pretty much done.
Next time we will drill the port holes and lap the faces. Maybe even get on the piston. The air test is right around the corner.
Great looking work Bob, I am surprised that you did not do an undercut of of the central portion of the sliding face in order to reduce the frictional area and that you did not drill the steam ports before the attachment of the pinion stud. Very cool looking engine it is so far and I am anxious to see it as it develops.
BC1
Jim
BC1
Jim
Dennis I don't remember where I first saw that trick. Back when castings were widely used in model engines, a spigot was cast in and then cut off after machining.
Jim: That may still happen. I would only take a few minutes to do. The stud is not permanently installed yet. But you are right, I should have drilled the port when it was set up.
The air test is soon. I am getting nervous.
Bob
Jim: That may still happen. I would only take a few minutes to do. The stud is not permanently installed yet. But you are right, I should have drilled the port when it was set up.
The air test is soon. I am getting nervous.
Bob
We still have some work to do on the cylinder. One of the things to do is drill for the steam, exhaust and cylinder ports. According to Mr Glasers original Cracker design, the ports are 1mm. Using the scale of 1mm = 1/16 our ports should be 1/16. This just seems too small to me, so I am going to try 0.0785 (#47 drill) first and see how that works. If its too small, I will open them up some more. But for now, we will try that.
First drill the port in the cylinder. I should have done this last time when it was set-up for the trunnion pin.
Now drill the ports in the engine standard for the steam and exhaust. The best way to do this is with a drilling jig. It would probably be impossible to lay these holes out any other way. Here is the jig plan:
http://1stclass.mylargescale.com/xo18thfa/Nina%2002/Port%20Jig.jpg
Here is the jig and a little spacer piece.
The jig simulates a rigid piston/cylinder. It puts the port holes in the right spot. Set up the jig with the engine standard and crankshaft.
Before trying to drill this, build up a cradle from a piece of plywood or MDF. Drill recesses to clear the bearings and screw heads and the engines firmly on the side frame.
Use the drill press to drill ports. Prop up the engine standard your thumb under the manifold to keep everything level. Drill deep enough to break into the manifold center. Reverse the jig to drill the other side.
The next step is to lap the port faces on the engine standard and cylinder. The port faces need to be perfectly flat and smooth. To lap the faces we need a surface plate. For hobby purposes a small slab of thick plate glass is flat and true enough. Go to a good glass shop and have them cut a piece of 3/8 or 1/2" thick plate glass to about 8 x 10 and round the edges. They will mostly likely have a scrap piece ready to go in the junk bin.
The lapping material is a sheet of good quality wet/dry sandpaper in about 320 grit. Wet the paper with water and lay it on the glass. The paper will lay done tight against the glass. Rub the port faces of the cylinder and engine standard on the paper in a circular motion.
Continue to work the port faces until all scratches are gone. The faces will have a slight frosted appearance.
The frost is a good thing. My mentor taught me that the frost is microscopic scratches that help hold oil in place and lubricate the surfaces. Highly polished surfaces will squeegee the oil away and cause wear or binding. I have had that happen, I believe my mentor.
Thats it for now. Next time is the piston. Maybe the air tests too. I am getting nervous.
First drill the port in the cylinder. I should have done this last time when it was set-up for the trunnion pin.
Now drill the ports in the engine standard for the steam and exhaust. The best way to do this is with a drilling jig. It would probably be impossible to lay these holes out any other way. Here is the jig plan:
http://1stclass.mylargescale.com/xo18thfa/Nina%2002/Port%20Jig.jpg
Here is the jig and a little spacer piece.
The jig simulates a rigid piston/cylinder. It puts the port holes in the right spot. Set up the jig with the engine standard and crankshaft.
Before trying to drill this, build up a cradle from a piece of plywood or MDF. Drill recesses to clear the bearings and screw heads and the engines firmly on the side frame.
Use the drill press to drill ports. Prop up the engine standard your thumb under the manifold to keep everything level. Drill deep enough to break into the manifold center. Reverse the jig to drill the other side.
The next step is to lap the port faces on the engine standard and cylinder. The port faces need to be perfectly flat and smooth. To lap the faces we need a surface plate. For hobby purposes a small slab of thick plate glass is flat and true enough. Go to a good glass shop and have them cut a piece of 3/8 or 1/2" thick plate glass to about 8 x 10 and round the edges. They will mostly likely have a scrap piece ready to go in the junk bin.
The lapping material is a sheet of good quality wet/dry sandpaper in about 320 grit. Wet the paper with water and lay it on the glass. The paper will lay done tight against the glass. Rub the port faces of the cylinder and engine standard on the paper in a circular motion.
Continue to work the port faces until all scratches are gone. The faces will have a slight frosted appearance.
The frost is a good thing. My mentor taught me that the frost is microscopic scratches that help hold oil in place and lubricate the surfaces. Highly polished surfaces will squeegee the oil away and cause wear or binding. I have had that happen, I believe my mentor.
Thats it for now. Next time is the piston. Maybe the air tests too. I am getting nervous.
Thanks Dean.
Today we are going to get this motor unit finished and Nina running on air. The piston is the last part to do. By now you have enough machining expertise that the piston is easy to knock out.
The piston is in 3 parts and just screws together. Start with the bottom end, known as the big end. The piston big end is a drilling and turning job from 1/4" square CRS. Here is the drawing.
http://1stclass.mylargescale.com/xo18thfa/Nina%2002/Piston%20Big%20End.jpg
Start by facing off the stock and drilling and reaming the 1/8 hole for the crankshaft wrist pin.
We are going to do something different. We are going to completely machine the big end with just one set-up in the lathe. The finished part will be ready to install. Chuck the square stock in the 3 jawed chuck using that collet you made for the spreaders. Hope you did not throw it away. Drill and tap for the #4 x 40 piston rod.
Now turn a little shoulder.
Its time to try a new gadget that came with the quick-change tool post set. It is a parting tool. A parting tool is basically a knife tool that plunges into the stock to cut the finished part off. This particular parting blade is only 0.040 wide, which is about the thinnest available.
Run the parting tool at a somewhat lower speed then regular turning and use oil.
Next is the piston rod. Make it exactly as you did for the trunnion pin. Drill and tap both ends of a 5/8 length of 5/32 stainless steel rod. Loctite in some #4 x 40 machines screws and trim to length. Too easy, heres the drawing.
http://1stclass.mylargescale.com/xo18thfa/Nina%2002/Piston%20Rod.jpg
The piston is straightforward too. Chuck some 1/2" round stainless steel stock. Face, drill and tap for #4 x 40 to accept the piston rod. With the lathe running, polish the rod with #320 grit wet/dry sandpaper and oil. For an extra smooth surface, repeat with #440 grit. Cut off the polished piston and face to a length of 9/16. Here is the drawing
http://1stclass.mylargescale.com/xo18thfa/Nina%2002/Piston.jpg
Here are the piston parts ready to assemble.
Put it together with some Loctite #242 and its ready to go.
Time for the air test. Put the engine together including the drive train. Everything needs to run. Oil all the moving parts. Secure the chassis to the bench and attach an air source. Turn on the air, give the flywheel a spin and see what happens.
And there it goes.
It started up, ran jerky for about 15 seconds, then smoothened out. I stopped it after about 2 minutes, disassembled and cleaned it. The oil was blackened a lot. I suppose it cleaned out the last of the gook. The engine ran about 2 hours, stopping every 15 or 20 minutes to clean and add oil. The speed was about 250 RPM.
Some observations:
- The spring used to retain the cylinder was way too light. It is 1/4" wide and 1/2" long, 0.015 diameter wire and about 8 turns. The slightest air pressure lifted the cylinder off the port face. After clamping down nearly all the way, it ran normally. I will need to order a slightly stiffer spring.
- The motor runs with a lot of power. I was surprised. If the torque-o-meter (finger on the wheels) is any measure, it was difficult to stall.
- It took very little air to turn the drive rain. Seemed like just a trickle. I need to find a low pressure gauge and see what it is really running at.
- Almost no friction between the cylinder and port face. The oil seems to form a film so there is no real metal-to-metal contact. The piston is airtight and no friction.
- After 2 hours of running there are no signs of wear.
We are calling this air test a success.
Next time we will start on the boiler.
Today we are going to get this motor unit finished and Nina running on air. The piston is the last part to do. By now you have enough machining expertise that the piston is easy to knock out.
The piston is in 3 parts and just screws together. Start with the bottom end, known as the big end. The piston big end is a drilling and turning job from 1/4" square CRS. Here is the drawing.
http://1stclass.mylargescale.com/xo18thfa/Nina%2002/Piston%20Big%20End.jpg
Start by facing off the stock and drilling and reaming the 1/8 hole for the crankshaft wrist pin.
We are going to do something different. We are going to completely machine the big end with just one set-up in the lathe. The finished part will be ready to install. Chuck the square stock in the 3 jawed chuck using that collet you made for the spreaders. Hope you did not throw it away. Drill and tap for the #4 x 40 piston rod.
Now turn a little shoulder.
Its time to try a new gadget that came with the quick-change tool post set. It is a parting tool. A parting tool is basically a knife tool that plunges into the stock to cut the finished part off. This particular parting blade is only 0.040 wide, which is about the thinnest available.
Run the parting tool at a somewhat lower speed then regular turning and use oil.
Next is the piston rod. Make it exactly as you did for the trunnion pin. Drill and tap both ends of a 5/8 length of 5/32 stainless steel rod. Loctite in some #4 x 40 machines screws and trim to length. Too easy, heres the drawing.
http://1stclass.mylargescale.com/xo18thfa/Nina%2002/Piston%20Rod.jpg
The piston is straightforward too. Chuck some 1/2" round stainless steel stock. Face, drill and tap for #4 x 40 to accept the piston rod. With the lathe running, polish the rod with #320 grit wet/dry sandpaper and oil. For an extra smooth surface, repeat with #440 grit. Cut off the polished piston and face to a length of 9/16. Here is the drawing
http://1stclass.mylargescale.com/xo18thfa/Nina%2002/Piston.jpg
Here are the piston parts ready to assemble.
Put it together with some Loctite #242 and its ready to go.
Time for the air test. Put the engine together including the drive train. Everything needs to run. Oil all the moving parts. Secure the chassis to the bench and attach an air source. Turn on the air, give the flywheel a spin and see what happens.
And there it goes.
It started up, ran jerky for about 15 seconds, then smoothened out. I stopped it after about 2 minutes, disassembled and cleaned it. The oil was blackened a lot. I suppose it cleaned out the last of the gook. The engine ran about 2 hours, stopping every 15 or 20 minutes to clean and add oil. The speed was about 250 RPM.
Some observations:
- The spring used to retain the cylinder was way too light. It is 1/4" wide and 1/2" long, 0.015 diameter wire and about 8 turns. The slightest air pressure lifted the cylinder off the port face. After clamping down nearly all the way, it ran normally. I will need to order a slightly stiffer spring.
- The motor runs with a lot of power. I was surprised. If the torque-o-meter (finger on the wheels) is any measure, it was difficult to stall.
- It took very little air to turn the drive rain. Seemed like just a trickle. I need to find a low pressure gauge and see what it is really running at.
- Almost no friction between the cylinder and port face. The oil seems to form a film so there is no real metal-to-metal contact. The piston is airtight and no friction.
- After 2 hours of running there are no signs of wear.
We are calling this air test a success.
Next time we will start on the boiler.
zeeprogrammer
Well-Known Member
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I 2nd what Dennis said...you do make it look easy.
Wow...it's really coming together.
Wow...it's really coming together.
All the spring clean up chores are done, so we are back on the Nina project.
The boiler is a single flue, gas fired, T shape. The T shape allows for large water capacity in the vertical barrel and extra heating surface on the flue in the horizontal barrel. The vertical barrel is from 2 1/2" nominal copper pipe. The horizontal barrel is from 1 1/2" copper pipe. The flue is a length of 3/4" copper coupling pipe. Coupling pipe is used for plumbing repairs and is larger in diameter then the nominal pipe. 3/4" couple pipe is almost 1 diameter.
The end plates and flue sheet are from 1/8 flat copper plate. In small, low-pressure boilers for Gauge 1, there is no need to flange the end plates. The plates just get turned on the lathe to fit their barrels.
Before getting started we have to make some decisions. Mr Glasers original Cracker design is very basic. His boiler has neither a throttle, nor a safety valve. His design is satisfactory that way. There is an unobstructed path from the boiler to the engine. The engine runs when boiler builds enough pressure. If there is too much pressure, the oscillating engine acts as a safety valve, just as we saw during the Nina air test.
I want to put a throttle on Nina. With a throttle, we need a safety valve. We will do a lubricator, which Mr Glaser left off of the Cracker. I also want a site glass and a water fill plug. So basically, all the boiler fittings.
Here are the drawings for the boiler:
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Boiler%20D1.jpg
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Boiler%20D2.jpg
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Boiler%20D3.jpg
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Boiler%20D4.jpg
Start off the boiler by cutting the barrel sections and flue slightly over length. Square the sections by clamping a block of wood at a right angle on the disk sander. Turn the barrel as you sand. It squares up in no time.
Next, drill the 3/8 holes in the vertical barrel for the site glass bushings. Securely clamp the barrel and set the drill to very slow speed.
Rough saw the top and bottom boiler sheets from 1/8 copper plate and drill for their bushings. The top plate gets 3 bushings: throttle, safety valve and water fill. The bottom plate gets 2; both are blind mounting bushes.
The boilerplates get turned on the lathe to fit the vertical barrel. Use a square block of hard wood, oak or maple, as a sacrificial faceplate to turn the plates. Fix the plate blanks to the wooden faceplate with #8 sheet metal screws.
Use your center test indicator (wiggler) to center the plate in the lathe. Turn the plate down so it just fits inside the boiler barrel. Not too loose, not too tight, just right.
Run the lathe tool well into the wooden faceplate to ensure the cut is complete. Do the top and bottom plates the same way.
The front flue plate has 2 turning operations, a hole for the flue and the outside to fit the horizontal barrel. Drill 2 holes for #8 sheet metal screws in the center, wasted out area of the flue sheet. Mount the flue sheet to the faceplate and center in the lathe.
Turn the outside to fit the horizontal barrel. With the flue sheet still in the lathe, drive in 3 sheet metal screws around the perimeter.
Pull the center sheet metal screws out and turn the center of the flue sheet to accept the flue.
Here are the plates all cleaned up and ready to silver solder.
Thats enough for now. Next time we will work on the boiler barrels to get the outer shell fitted up.
The boiler is a single flue, gas fired, T shape. The T shape allows for large water capacity in the vertical barrel and extra heating surface on the flue in the horizontal barrel. The vertical barrel is from 2 1/2" nominal copper pipe. The horizontal barrel is from 1 1/2" copper pipe. The flue is a length of 3/4" copper coupling pipe. Coupling pipe is used for plumbing repairs and is larger in diameter then the nominal pipe. 3/4" couple pipe is almost 1 diameter.
The end plates and flue sheet are from 1/8 flat copper plate. In small, low-pressure boilers for Gauge 1, there is no need to flange the end plates. The plates just get turned on the lathe to fit their barrels.
Before getting started we have to make some decisions. Mr Glasers original Cracker design is very basic. His boiler has neither a throttle, nor a safety valve. His design is satisfactory that way. There is an unobstructed path from the boiler to the engine. The engine runs when boiler builds enough pressure. If there is too much pressure, the oscillating engine acts as a safety valve, just as we saw during the Nina air test.
I want to put a throttle on Nina. With a throttle, we need a safety valve. We will do a lubricator, which Mr Glaser left off of the Cracker. I also want a site glass and a water fill plug. So basically, all the boiler fittings.
Here are the drawings for the boiler:
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Boiler%20D1.jpg
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Boiler%20D2.jpg
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Boiler%20D3.jpg
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Boiler%20D4.jpg
Start off the boiler by cutting the barrel sections and flue slightly over length. Square the sections by clamping a block of wood at a right angle on the disk sander. Turn the barrel as you sand. It squares up in no time.
Next, drill the 3/8 holes in the vertical barrel for the site glass bushings. Securely clamp the barrel and set the drill to very slow speed.
Rough saw the top and bottom boiler sheets from 1/8 copper plate and drill for their bushings. The top plate gets 3 bushings: throttle, safety valve and water fill. The bottom plate gets 2; both are blind mounting bushes.
The boilerplates get turned on the lathe to fit the vertical barrel. Use a square block of hard wood, oak or maple, as a sacrificial faceplate to turn the plates. Fix the plate blanks to the wooden faceplate with #8 sheet metal screws.
Use your center test indicator (wiggler) to center the plate in the lathe. Turn the plate down so it just fits inside the boiler barrel. Not too loose, not too tight, just right.
Run the lathe tool well into the wooden faceplate to ensure the cut is complete. Do the top and bottom plates the same way.
The front flue plate has 2 turning operations, a hole for the flue and the outside to fit the horizontal barrel. Drill 2 holes for #8 sheet metal screws in the center, wasted out area of the flue sheet. Mount the flue sheet to the faceplate and center in the lathe.
Turn the outside to fit the horizontal barrel. With the flue sheet still in the lathe, drive in 3 sheet metal screws around the perimeter.
Pull the center sheet metal screws out and turn the center of the flue sheet to accept the flue.
Here are the plates all cleaned up and ready to silver solder.
Thats enough for now. Next time we will work on the boiler barrels to get the outer shell fitted up.
Plenty of metal cutting and fabrication work to do on the boiler before silver soldering everything together. First up are the bushings. There are 2 boiler mounting bushings and 5 for the plumbing. When planning the boiler it is a good idea to add extra bushings for the plumbing even if you dont plan use them. For example, you may not want a sight glass on this boiler, but in the future you might. So add the sight glass bushings now and just cap them off. Another thing to consider is the boiler fittings you want to install. You can purchase commercially made fittings, if so, tap the bushings to suit. We will fabricate our own fittings for Nina.
The bushings turn up the same way as the wheel and countershaft bearings. Not much more to add, you are a pro at this by now. Here are the drawings.
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Bush%201.jpg
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Bush%202.jpg
The next task is to cut 2 large holes in the vertical barrel to accept the horizontal barrel in the front and the flue in the back. The usual way would be to rough cut the holes, then finish with files. Instead of that, we are going to set up the lathe to bore these holes out. First, chain drill and saw out the hole.
Now take the compound slide off the lathe and see whats under that we can use to mount a barrel holding fixture.
Fabricate a fixture from hardwood to secure the boiler barrel to the lathe carriage. Years ago I tapped a 5/16 x 24 hole in the cross slide so I could screw in a long bolt if I ever needed too. Some of the import lathes have T slot tables for cross slide. Those would be ideal for this job.
Secure the boiler barrel to the fixture and align so the center access of the lathe passes thru the centerline of the barrel.
Chuck up a little home made fly cutter in the 4 jawed chuck. This hurry up fly cutter has a small set screw to hold a short length of lathe tool ground for this particular job.
Set the lathe to run at a slow speed and engage the carriage. Take light cuts by making small adjustments to the fly cutter in the 4 jawed chuck.
A real machine shop would have a special attachment called a boring head for this task. A boring head can be set to take a very precise, known cut. Our fly cutter is not as precise, but does the job very well. Very small adjustments to the chuck make for even smaller cuts. It took a lot of passes and time, but the result was right on.
Turn the barrel around in the fixture and machine the hole for the flue in the same manner. All the copper parts are cut out and almost ready for soldering
Sorry, there is one more thing to do. Re-cycle the fixture to machine a hole in the horizontal barrel to accept the smokestack
You can certainly cut these big holes by chain drilling and filing. But part of the whole process is to find different ways to use our limited shop equipment to do complex tasks. Now we know how to set-up a lathe as a horizontal boring machine.
Next time we will do some little house keeping tasks and get ready to solder this thing together.
The bushings turn up the same way as the wheel and countershaft bearings. Not much more to add, you are a pro at this by now. Here are the drawings.
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Bush%201.jpg
http://1stclass.mylargescale.com/xo18thfa/Nina%20Boiler/Bush%202.jpg
The next task is to cut 2 large holes in the vertical barrel to accept the horizontal barrel in the front and the flue in the back. The usual way would be to rough cut the holes, then finish with files. Instead of that, we are going to set up the lathe to bore these holes out. First, chain drill and saw out the hole.
Now take the compound slide off the lathe and see whats under that we can use to mount a barrel holding fixture.
Fabricate a fixture from hardwood to secure the boiler barrel to the lathe carriage. Years ago I tapped a 5/16 x 24 hole in the cross slide so I could screw in a long bolt if I ever needed too. Some of the import lathes have T slot tables for cross slide. Those would be ideal for this job.
Secure the boiler barrel to the fixture and align so the center access of the lathe passes thru the centerline of the barrel.
Chuck up a little home made fly cutter in the 4 jawed chuck. This hurry up fly cutter has a small set screw to hold a short length of lathe tool ground for this particular job.
Set the lathe to run at a slow speed and engage the carriage. Take light cuts by making small adjustments to the fly cutter in the 4 jawed chuck.
A real machine shop would have a special attachment called a boring head for this task. A boring head can be set to take a very precise, known cut. Our fly cutter is not as precise, but does the job very well. Very small adjustments to the chuck make for even smaller cuts. It took a lot of passes and time, but the result was right on.
Turn the barrel around in the fixture and machine the hole for the flue in the same manner. All the copper parts are cut out and almost ready for soldering
Sorry, there is one more thing to do. Re-cycle the fixture to machine a hole in the horizontal barrel to accept the smokestack
You can certainly cut these big holes by chain drilling and filing. But part of the whole process is to find different ways to use our limited shop equipment to do complex tasks. Now we know how to set-up a lathe as a horizontal boring machine.
Next time we will do some little house keeping tasks and get ready to solder this thing together.
