"Nina", a Gauge 1, 0-4-0 live steamer. Progress and updates

[xo18thfa]

Thanks guys: It's coming down to the home stretch for sure.

Just a short update on two little jobs completed before starting on the fuel system.

A good buddy in Australia sent me a note saying that their boiler codes require a means to lock the pressure setting on a safety valve. It is possible over time for the safety to jiggle loose and come apart. The usual method to lock the safety is with a jam nut. It’s the right thing to do and the fix is so simple; there is just no reason not to do it.

The fix requires a simple modification to the existing valve body and fabrication of a jam nut. Chuck the valve body in the chuck spigot and turn off 3/32”. That’s it. With the jam nut here’s our safety valve mod:

The safety is not set for pressure yet. It gets set later during a steam test of the boiler.

The second job is a new throttle body. The boiler nipple on the old throttle body is too short, making it difficult to install on the boiler. The drawing I made for the throttle body is correct. If you follow the drawing, the throttle body will install just fine.

In making the new throttle body, I used the fly-cutter method to machine the linkage tab. Make a threaded jig to hold the nipple.

Use the parting tool to shave down the sides of the linkage tab. It worked out sweet.

The new throttle body sits taller and is easier to get on the boiler.

Next week we’ll start on the fuel system. The fuel tank is going inside the cab. The other day on the Internet I found a micro sized pressure regulator that might be worth an experiment. If Nina runs good, it may end up a test bed for “do-dads” like a pressure regulator. So for now I want to keep the fender position available.

 

[joe d]

Bob

Your project just keeps getting better and better... :bow:

I've been enjoying following along, and have learned a lot.

Thanks!

Joe

 

[4156df]

Bob,
Been away for awhile, so just caught up on your posts. Very informative thread. Keep it coming, please.
Dennis

 

[zeeprogrammer]

Bob, thanks for the info on the sight glass.

This is a really interesting thread. I appreciate the tips and techniques.

 

[GailInNM]

Bob,
"Nina" is looking really nice. I am enjoying the thread.

On the last Gauge 1 loco I built I bolted the gas tank on the footplate about 1-1/2 inches from the burner mount which also supported the rear of the boiler. Vertical cylinder butane tank with a bush in the bottom so it pulled down solid to the footplate. I wanted it to stay warm so the falling gas pressure due to he cooling of the gas as it was drawn off would be offset.

The heat conduction from the burner/boiler was greater than anticipated and the tank would warm up on long runs so the tank pressure would rise. This would "build a bigger fire" and the tank would warm more so every lap around the track I would have to turn down the fire. Final solution was to put a piece of 1/16 ply between the fuel tank and the footplate. Kept the tank temperature about constant with the heat input canceling out the gas tank cooling as fuel was drawn off.

If you build a gas pressure regulator for Nina then this should not be a concern.

Gail in NM

 

[xo18thfa]

Thanks men. It's getting there. Looking forward to doing the fuel system. Then we'll get this thing on the track.

Gail: It's surprising how touchy butane burners can get on a Gauge 1 loco. I chase ours around the track and adjust 3 or 4 times during a run. On the big main line engines they put the fuel tank in the tender tank and add warm water to take out the temperature problems. The idea of a pressure regulator is appealing

 

[xo18thfa]

Today let’s get started on the fuel system by fabricating a fuel tank. Since Nina is a gas fired locomotive, the fuel tank is a pressure vessel. So build the fuel tank in the same manner as the boiler. Before starting there are some design considerations to go thru.

The filling adapter is a valve held closed by a spring. The fuel enters the tank thru the adapter while in liquid form. Almost like pouring water into a glass. Filling adapters are commercially available or you can “cannibalize” one from a refillable lighter or a small torch. Adapters screw into a bushing on top of the tank. Here are three adapters I have:

The adapter on the left came from a small Harbor Freight torch (that crapped out immediately). The thread is metric M5.0 x 0.5. The center adapter came from a micro pencil torch and also has a thread of M5.0 x 0.5. The adapter on the right came from Sulphur Springs Steam Models (unfortunately out of business) and has a M4.5 x 0.5 thread. That’s the one I will use, because I have a tap for it.

The next consideration is the pressure inside the fuel tank. We need to test our tank as with the boiler to ensure it operates safely. The question is what kind of pressure are these tanks under? There are two types of fuel commonly used: 100% butane (lighter fuel or Chinese tabletop cooker fuel) or a mixture of 70% butane and 30% propane (Coleman brand camp stove fuel).

I found a chart that shows the pressure of these fuels under various temperatures:

At 110 degrees F, the 70/30 mix fuel has a pressure of 93 PSI. As with the boiler, we’ll test the fuel tank to twice the maximum operating pressure or 186 PSI. It is interesting to note that 100% butane “boils” at about 32 degrees F. Below that temperature, butane stays liquid. 70/30 mix boils at about –5 degrees F. In cold weather run with 70/30 mix or the burner may not work right.

With that done, let’s build the tank. Here is the drawing for the tank parts.

http://1stclass.mylargescale.com/xo18thfa/Nina%2003/Fuel%20Tank.jpg

Use the exact same techniques for the fuel tank as with the boiler. You are an expert at this, so not much more to explain. Here are the parts turned up and ready to silver solder.

And fresh out of the pickle tank.

Now for the pressure test. For the boiler we used a regular air compressor, but mine only goes to 120 PSI. My little hand water pump only goes to about 140 PSI. So for this test I used a mechanical oil pump I made for a 7.5” gauge live steamer. Here is the test set up.

Fill the pump and fuel tank with 30 weight motor oil and screw everything together. Start pumping.

At 200 PSI the oil pump bottom had a very small weep, but the fuel tank held strong.

If your pump does not reach 200 PSI, test the tank as high as you can. If you can only test to 120 PSI for example, then from the chart above you would have to use 100% butane fuel above about 85 degrees F. Or for added safety, use 100% butane all the time.

Next time we’ll get on the fuel valve.

 

[xo18thfa]

Well – change 1. The fuel tank I made last time is not going to work out very well. The fill adapter and gas valve are too close together, making a generally bad arrangement. So send that tank to recycle. The new fuel tank is horizontal. It is also made from 1” nominal copper pipe and is 3” long. It will have a slightly higher capacity and won’t stick out quite as much.

All the parts are the same, with two exceptions. First, the new tank requires two mounting bushings instead of one. Second, the end plates are solid.

Without holes in the endplates, we cannot use the #8 sheet metal screw and wood block trick to secure the plates for turning. Instead soft solder a piece of brass round to the endplate blank.

And chuck the assembly in the 4-jaw for turning.

Next, find the jig you used for aligning the water gauge bushings in the vertical boiler barrel. We’ll need it to align the mounting bushings on the new fuel tank.

The remainder of the new fuel tank assembles and tests just as before.

With the new fuel tank done, let’s switch to the fuel valve. The fuel valve is similar to the bottom end of the water gauge. It’s a needle valve with the addition of a packing nut to stop gas leaks around the needle stem when the valve is open. Here’s the drawing of the major parts.

http://1stclass.mylargescale.com/xo18thfa/Nina%2003/Fuel%20Valve.jpg

The first part to make is the needle valve stem. We will use the old machine screw/rod trick to make the needle stem. Tap a #4 x 40 about 1/4" deep into a length of 1/8” stainless steel rod. Loctite a #4 machine screw.

Set the compound slide on the lathe to 5 degrees. Chuck the stainless rod and turn a 10-degree included taper for about 1/8” length. The small end of the taper should just fit into a #57 hole.

Cut the stainless rod to 1/2" length. Tap again for #4 x 40 and loctite another screw. Fashion an appropriate knob for the needle valve.

Loctite the knob and the needle valve stem is ready to go.

The fuel valve body and packing nut are silver soldered assemblies as you did for all the plumbing parts.

Silver solder the valve body parts. Chuck the fuel valve body in a chucking spigot. Drill #31 to 1/4" depth. Drill #43 and tap #4 x 40 to 1/2" depth. Finally drill #57 thru.

Drill #57 in the output side, just breaking into the passageway. Make two jam nuts. Here are the parts ready to assemble.

And the finished valve. The bottom end screws into the fuel tank. The horizontal leg is the takeoff to the burner.

Here’s the new fuel tank and fuel valve. Eventually the tank gets covered up by a cab and a coal bunker maybe.

Standing on the footplate is Jennifer. She’s the company president’s niece and the new payroll clerk. Since Jennifer came on board, there’s been a lot of pay problems. Most of them are imaginary, but many are for real. The guys back in the shop are spending way too much time in the front office these days. I don’t know how long she’ll be around.

Anyway, next time we’ll get started on the burner.

 

[zeeprogrammer]

How many of you noticed the fuel tank first?
How many of you noticed the girl first?
'Tis the classic separator.

Nice post. Thanks.

 

[Maryak]

How many of you noticed the girl first?
'Tis the classic separator.

Girl ???.......................Surely she's NINA ;D

Best Regards
Bob

 

[Deanofid]

Another nice job on things, Bob. Everything you've done here looks top rate.
It's like you're a machinist, or something!

Keep up the good work, and thanks for all the pics.

Dean

 

[4156df]

Bob,

The engine is really looking good. Thanks for posting.

Re: Jennifer...In the words of an old supervisor of mine, "There are work horses and there are show horses. You should hire work horses."

Regards,
Dennis

 

[doubletop]

I don't know why I've missed this post, but a fuel tank is something I've been meaning to tackle. Thanks for this, a perfect reference for me.

Pete

 

[xo18thfa]

Thanks a lot guys for taking a look at this project and help keeping me going.

In Gauge 1 railroad modeling a lot of builders use a human figurine like "Jennifer" to gauge size and proportion. They also use the figurine in the write-up log to give it an anecdotal story affect. Makes for fun reading. So -- Jennifer -- well, she's a very nice young lady, but a real "box of rocks"

Question for Dean Williams and/or Bogstandard: On the Jerry Howell Mini-Burner, is the "Venturi" a press fit into the "Body Sleeve"?? A modified Jerry burner may go in this engine.

 

[Deanofid]

Question for Dean Williams and/or Bogstandard: On the Jerry Howell Mini-Burner, is the "Venturi" a press fit into the "Body Sleeve"?? A modified Jerry burner may go in this engine.

That's the way I made mine, Bob. The venturi tube has a small step turned onto the bottom
end, and it is just a snug fit into the body sleeve part. I just made it tight enough to be firm
when pushed in, but still can come apart if you pull hard on it, to make changing jets easy, if needed.

Dean

 

[xo18thfa]

That's the way I made mine, Bob. The venturi tube has a small step turned onto the bottom
end, and it is just a snug fit into the body sleeve part. I just made it tight enough to be firm
when pushed in, but still can come apart if you pull hard on it, to make changing jets easy, if needed.

Dean

Thanks Dean, that's what I will do.

 

[xo18thfa]

I am going to build two different types of burners, then have a “burn off” to see which works better. One burner is the standard “poker” type used widely in gas fired engines. The other is the blow torch type burner that Mr Glaser originally used for “Cracker”. Might still do the Jerry Howell Bunsen burner too, but we'll see. I don’t recall seeing a blow torch burner in a Gauge 1 loco, so this will be an interesting experiment.

Let’s get started by making gas jets. Gas jets are normally made with highly precision drilling machines capable of drilling the 0.006” to 0.008” holes. I don’t have that kind of machine, so we will have to use a different technique.

The technique to make gas jets comes from Mr Dean Williams (Deanofid). His technique is shown on his website for the fabrication of Jerry's Bunsen burner. Here is Dean’s page on the Bunsen burner, and while you are at it, check out his main page. He does incredible work with a Taig lathe.

http://www.deansphotographica.com/machining/projects/burner/burner.html

Dean’s technique uses commercially available wrist watch bushings as the gas orifice. The bushings are the “KWM German Made” type available from the TimeSavers Company in Scottsdale, Arizona (http://www.clock-parts.com/index.htm). TimeSavers has two bushings that will work for our applications. The size L-01 (part number 11301) and the size L-56 (part number 11356). The idea for the gas jet is to insert a wrist watch bushing into a 2 x 56 brass model hex bolt and install in the burner.

Here’s the dimensions of the wrist watch bushing.

To make a jet, start with a jig to hold the model hex bolt. Cut a 1 1/2" or so length of 1/4" brass rod and face both ends clean. Drill # 42 hole 1/16” deep. Then drill and tap 2 x 56 about 1/4" deep. Screw in 1/8” 2 x 56 model hex bolt. The #42 spot drill ensures the bolt rests flat on the head.

Chuck the assembly in the 3 jaw. Lightly center drill and then drill thru with a #56 drill. Number 56 drill provides a very nice press fit for the 1.2mm diameter watch bushing.

For best results, rough drill with #57 or #58, then finish drill with #56.

Finish the bolt drilling with a very small chamfer to break the sharp corner left by the drill. Just twist a countersink bit with your fingers.

Now chuck the hex bolt and fixture in the drill press. Place a watch bushing on the drill press table with the flat face down. Lower the drill chuck, aligning the watch bushing with the hole in the hex bolt. Use a needle or long pin to move the watch bushing around. When aligned, press the watch bushing home.

Don’t be intimidated by the small size of the watch bushing. Getting it aligned and pressed in is easy to do. They key is the little chamfer, it helps align the watch bushing and prevents getting hung up on the hole edge.

Now fabricate two jet bodies that will screw into the back of the burner. Make them in the same fashion as the other plumbing and gas parts. You are an expert at this. Here is the drawing:

http://1stclass.mylargescale.com/xo18thfa/Nina%2003/Jet%20Body.jpg

Here are the jet bodies ready to install. The jam nuts will give some backward/forward adjustment for the jet.

I think these watch bearings will work great for jets. Looking forward to setting something on fire. Next time we will get the burners done.

 

[xo18thfa]

I've been playing around with Dean William's gas jet method. They work great. I plan to order some more bushings to have a larger assortment. Only have the L-01 and L-56 sizes now.


Today we are going to get the burners done and do an initial test to see how they do. The first burner is the “blow torch” burner that Mr Glaser used in the original “Cracker” engine. The burner consists of only two parts: the burner body and a gas defuser. I want to use Mr Glaser’s burner as is, so convert the dimensions from metric to inch. This is Mr Glaser’s drawing for the “Cracker burner, with dimensions changed to inch.

The gas defuser is the difficult part to machine. It has eight equally spaced holes that fall on a pitch circle. Set up a pitch circle drilling operation, just as with the safety valve. It is not shown on the drawing, but the pitch circle diameter is 0.266”. Machine the defuser shell first and then drill it out. Here is the drilling set up for the gas defuser.

Just as with the safety valve, I found it more accurate to traverse each hole from the center position.

The burner body is a straightforward turning and drilling job.

Ream the large hole in the burner body to accept the defuser. The reamed hole will make a nice, light push fit for the defuser.

Lastly, turn a 3/16” thick mounting ring that just fits inside the boiler flue. Blow torch type burners need more air to operate then the mixer holes provide. Drill some 5/32” holes thru the mounting plate. Silver solder the mounting plate to the burner body and tap a couple 2 x 56 for mounting screws.

The photo shows six auxiliary air holes, but four are enough.

Let’s see how it does.

This burner requires a small jet. Use the L-56 watch bushing with a 0.15mm (0.0059”) bore to make the jet. The L-01 bushing will not work; the burner won’t light at all. With the small jet, this burner is a micro sized nuclear furnace. It burns wicked hot.

Next let’s do a regular poker style, “Ruby” type burner. This burner is just a brass tube with slots sawed along the top. Here is the drawing:

http://1stclass.mylargescale.com/xo18thfa/Nina%2003/Poker%20Burner.jpg

There is a couple of ways to do the burner tube. You can drill out a 3/8” solid brass rod with 5/16” or use a 3/8” OD, 5/16” ID tube. I used tube, which is available from McMaster-Carr and others. There are 12 slots in the burner tube, each 0.020” wide on 7/32” intervals. The slots are wider at the rear end and get progressively narrower towards the front. Two options to cut the slots: cut them by hand with a jeweler’s fret saw and a very thin blade, or with a circular slotting saw on the lathe. The fret saw is easier and would work fine, but we never do anything the easy way.

To cut the burner slots on the lathe, rig up a tubing holder from the wooden parts leftover from boring out the boiler barrel.

Mount the jig on the lathe cross slide and a 0.020” thick slotting saw blade on an arbor.

Advance and traverse the lathe carriage the required depths and intervals to make the slot cuts. They actually sell saw blade arbors for this kind of work, but I don’t have one. Had to “jerry-rig” this arbor. It worked fine.

As with Mr Glaser’s burner, turn, tap and silver solder a mounting ring from 3/16” brass plate. Poker burners don’t need auxiliary air holes. They draw all their air from the mixer.

Here is a test burn in open air using a larger, 0.20mm jet.

I played around with the poker burner in the boiler and discovered is worked best with a small jet. In open air, it would not light at all with a small jet. What happens inside the boiler is the important part.

I changed my mind and decided to mount the fuel tank on the fender. All the “contraption” stuff looks nice. Rig up a fuel line. Use a nut and cone type connector on the burner end of the fuel line. They seal very tight and handle heat better then a packing type connection.

With that, all the mechanical work for “Nina” is done, just cosmetics to do. Next time we will experiment with the burners, set the safety valve, re-assemble and pack all the glands. Then it’s ready for the first steam trial.

Getting nervous……..

 

[Deanofid]

Nice burner work, Bob. There seems to be quite a bit of opinion on how to make one, but both
of the ones you made show how to do it with excellent results.

This thread sure has come a long way since the first post! Impressive work throughout.
Thanks!

Dean

 

[xo18thfa]

Thanks Dean. Your technique with the wrist watch bushings absolutely saved the day. I have some commercially made jets from a Gauge 1 supplier. They are huge and clunky and require a 2BA tap. Plus I don't know what size they are. Your method gives a lot of options. The small jets works best. So easy to make.

Just got the safety valve set for 30 PSI lift using the poker burner. Works good, sputters a bit then closes.

Fuel tanks gets too warm for my liking. I will try to insulate the mounting bracket.