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bille1906 06-10-2020 02:58 PM

Milwaukee Road N3
The N class were 2-6-6-3 Freight trains used in the Northwest
The N1 was a saturated steam compound which was not very successful
The N2 was an improvement as it was superheated but still had power problems as the slide valve LP cylinder could not handle the exhaust volume and had a top speed of 20 MPH
The N3 was a simple Mallet with four superheated cylinders. A Coffin feedwater heater was added and attached to the front of the smokebox. A fold back stack extender was also added.

The model of this standard gauge loco will be in 1/32 scale with 5/8" cylinders and a butane fired ceramic burner.

Last week I ordered the wheel castings from Walsall and gave my frame drawings to Dennis to CNC mill. he also cut my gaskets on the laser and brought them over today.

In looking at the photo of the front chassis, I see that there is a lot going on with lots of fittings on top of the cylinder and a huge exhaust collection cylinder built into the cylinder casting with a U shapped pipe going from the front of the cylinder to the rear. I figure it was done like that to allow enough room for a flexible fitting at the smokebox.

I started the cylinders by rounding off one corner of the 1" square block on the router and then cutting it and all of the flat stock to the same dimension on the table saw.

The cylinders are then bored out to .615 and then reamed to size with a .625" reamer

The mount holes are drilled out in the mill and then tapped out on my Mycromark tool.

I am using slide valves so I make a cross porting plate do display the correct valve positions. in the photo, there are two plates showing both sides of the plate.

A side cover is made from .032 brass sheet, rivet embossed and bent to shape.

End caps and a test bent tube are added and I think it is ready for paint.

fsts2k 06-10-2020 03:09 PM

Super cool! Can't wait to see this go

David Leech 06-10-2020 07:16 PM

Which side of the rear truck are you adding the extra wheel!!!
You just keep getting better and better at this.
Stay safe,
David Leech,Delta, Canada

bille1906 06-10-2020 07:56 PM

Actually David, the third wheel is trailing the first two to keep it from popping a wheelie if the throttle is opened too quickly

bille1906 06-13-2020 05:49 PM

Dennis came by Weds and dropped off the CNC frame rails and the laser cut gaskets.

I showed the photo of the front in my last posting but it wasn't very clear. I then noticed this drawing on the cover of a book I have which shows how the exhaust piping goes. You can see that it picks up the exhaust from two chambers in the valve body and then makes a U turn onto a larger fitting that was either a ball joint or a dog bone type of fitting. The reason for the front fittings and the U joint was to allow enough room for the swivel and telescoping fittings needed to connect to the smokebox.

It would be impossible to bend 3/8" tubing that sharply. Solid may have worked but it surely wold have been distorted. I had some 3/8 od and 1/8 id silicone tubing which fit the bill. I annealed a piece of 1/8" copper rod and ran it through the tubing to get the bend I needed

Leaving extra rod in place the tubes were bent to shape

I taped them with masking tape to mark the cut needed

And cut them on the band saw. A piece of wood held one end up to get the angle I wanted for the rise in the tubing

A fitting that may resemble the ball joint was made and everything was glued on with E6000

Finally everything is painted and a buffer beam and deck are started.

bille1906 06-23-2020 01:06 PM

I soldered up the boiler last week. It is quite large and should produce plenty of steam.

The smokebox is relieved at the bottom so I mark it off and do the cut out on the band saw

I then silver solder the flat pieces on and sand them flush after pickeling.

The boiler and smokebox are then set on blocks to make sure the front truck will have the proper clearance.

The cow catcher is a tube type mounted under the coupler. It has 18 tubes which scale out to 1/16" so I use 1/16" brass rod for the tubes as it is stronger that tubing and easier to bend. The lower frame is drilled out with spacing of .135" and the upper will get .113" spacing. everything is silver soldered together except the tubes which use Staybrite.

A headlight with the proper square bezel for #52 id made and everything is painted

ddrum31 06-23-2020 07:57 PM

Looking amazing! Love your builds!


bille1906 07-01-2020 07:40 PM

The ceramic burner is huge on this engine as it will take up the firebox and the combustion chamber area
The area between the drivers needs to be narrow so I cut out the bottom to that shape and bend the front of it up before soldering it to the sides.

Then pieces are soldered in place

The critical part of this is making the jet holders as the dimensions must be exact. Not shown in the drawing is the inside bore which is the same as the outside of the jets which is 5/16"

now the burner is tested while held in a vise. The little standoff barriers are adjusted for size, shape and position till I get an even burn.

The edges are sealed with high temp RTV and the job Is done.
One final test is done in the boiler to make sure it will pop back when lit through the stack.

Stan Cedarleaf 07-02-2020 12:09 AM

Bill, I read these posts and see the images of your creations and I truly amazed at the fine work you do. My father was a tool designer and tool maker back in the 40's and 50's. None of that craftsmanship rubbed off on me but I can sure appreciate the detailed work you do!!!!!!!

Great job.. :):):):):):cool::cool::cool::cool:

ferroequinologist 07-02-2020 01:32 AM

Hi Bill, another good model you are making and also many thanks for sharing your knowledge, so regarding the ceramic burner and it's design I have a few questions... I see you make two standoff barriers are they to deflect the gas to feed more of the area of the ceramic for an even burn and how critical are these barriers in both two jet and single jet designs?
Is there any height/ width / angle that is a good starting point and how far from the nozzle should they be? How much "space" do leave for gas under the ceramic and how critical is that?
While I am not making a ceramic burner right now it is your expertise and knowledge that will help if I do in the future and also trouble shooting existing designs.

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