N scale 2900 Class ATSF Northern Build

[up1950s]

Jason , all these hat tricks and your not retired . Did you have a heart transplant with one from a 150lb  hummingbird , or replaced the sugar in the sugar bowl with speed ?

[RWCJr]

On some classes of ATSF steamers, flip over smoke bonnets were added to help lift the smoke up and over the (passenger) consists.
But the telescoping extension for the northerns were to help improve the draft rate, which in turn helped the flow of exhaust steam from the cylinders. Back pressure in the cylinders was an issue with all of their northerns, and several different approaches to minimize the problem were used.
Robert

[carlso]

Very nice looking Jason. But an AT&SF? That's Ok, I am thankful for the AC-9 and am happy to see goodies for AT&SF.

Carl

[superturbine]

Jason , all these hat tricks and your not retired . Did you have a heart transplant with one from a 150lb  hummingbird , or replaced the sugar in the sugar bowl with speed ?

Ha!!  Thanks Richie,

I am a little on the obsessive compulsive side! 
One thing I do know is that we all patiently await your return to steam builds.  The weekend update isn't quite the same without some fantastic steam build at the beginning.

[superchief]

can I get an AMEM please!!!!!!!!!!!!! Thanks Jason  the 2900 is a favorite engine of mine(besides #3751) all the Santa Fe foamers will be watching closely. Thanks SSB(super steam buddy) Gordon

[superturbine]

Ha!- """AMEM"""  SSB!!   (See what a lack of sleep will do!)
I do believe 2926 will be at home on the SANTA FE ALL THE WAY.

First off I highly recommend TIX Flux for the next few steps.

Whether you are installing a decoder or not the procedure will be pretty much the same.
Directions are for decoder install-
Using your Tix flux, brush the flux onto the sides of the motor brush caps.  Be very careful not to get flux or solder down the holes of the cap it will ruin the brush springs and you will likely end up replacing the motor.  Solder the orange and the grey wire to the "sides" of the brush caps.

Next, install Kapton take at the location where the brush caps can make contact with the GS4 frame to avoid a dead short and fried decoder.  Be sure that the motor drive shaft to the worm has play ( that its not pushed all the way to the back of the inside of the flywheel to avoid friction and wear).

For securing the motor in place I usually use a Rubberized super glue produced by Bob Smith Industries-   

 http://bsi-inc.com/Pages/hobby/ca.html

IC-2000™ is a rubber-toughened cyanoacrylate that forms superior shock resistant bonds on non-porous surfaces. The black colored CA has added flexibility for the bonding of metals, fiberglass, rubber, carbon-fiber and other advanced materials. For model use, IC-2000™ is ideal for the bonding of bulkheads, formers and servo rails to the inside of fiberglass hulls and fuselages. Setup time is 20-40 seconds, which can be accelerated with INSTA-SET™. When cured, IC-2000™ is pliable enough to be carved with a hobby knife. IC-2000™

Be careful not to install too much superglue to avoid to getting it between the frame halves down in the gears.  Once the motor is centered and aligned, hit the super glue with accelerant.  The drive shaft will be at a slight angle.


Handrail are installed using Gold Metal Models Steam detail kit and simple to install.  I have always used the gap filling superglue by BSI.


This engine build will use for operations.....a standard Bachmann Pilot is installed.


Jason Smith
Tomball Locomotive Works

[peteski]

Jason, I would discourage anybody from using Tix flux on motor brush holders.  I often use Tix flux for soldering structural brass parts together. It works well, but it is very acidic (Zinc Chloride). As such, it is not recommended for making electrical connections.  My safer alternative is Radio Shack Paste flux. It is rosin-based. It works great, and it is safe for electrical/electronic work.  Then of course is Robert's water-based Super Safe flux. 

http://www.radioshack.com/product/index.jsp?productId=2049774

[superturbine]

Thanks Pete,  Good point, but-
I am aware of the corrosive and electrical conductive nature of TIX flux.  The label states not for use on circuit boards In this particular application I am not concerned with corrosion that could damage nearby very thinly etched circuit printing.  The reason I use TIX for an electrical connection is how fast it heats up the solder point and then cools off.  If the bush caps receive to much heat they will melt the plastic motor frame and back out, ruining the motor for some. Also, Tix flux provided a far superior bond.

I have heard of circuit board problem but that is largely due to the electrical conductive nature of TIX, which in this case I think is a benefit!

With that said, do not allow any flux to get inside the bush holder and into the brush spring, which would be the case for any flux but TIX is very thin. 

[robert3985]

Jason, I would discourage anybody from using Tix flux on motor brush holders.  I often use Tix flux for soldering structural brass parts together. It works well, but it is very acidic (Zinc Chloride). As such, it is not recommended for making electrical connections.  My safer alternative is Radio Shack Paste flux. It is rosin-based. It works great, and it is safe for electrical/electronic work.  Then of course is Robert's water-based Super Safe flux. 

Trollface aside   you should get the gel if you're thinking about getting Superior Supersafe #30 Soldering Flux since it is more precisely placed.  You can get it here: http://www.ccis.com/home/hn/

[superturbine]

Thanks for the advice guys!

I got a little side tracked with a new Southern Pacific boiler build over the last week and the ATSF Northern got put on hold.  However, work on the tender has restarted.  To begin with I am building a 2900 class engine and will be using the Bachmann Tender trucks ….adding power pick up is a must.  Adam Draskovich was the first to figure out that the GS4 tender power pickups are almost perfect for the wheel spacing needed on the 4 axle tender trucks of the 2900.  However, there are a few problems, the Axles of the Bachmann trucks are wider and require shims to be installed to properly hold the GS4 trucks and power pick-ups in place.  And of course only 3 of the 4 truck will have power, but that should be sufficient.
Bachman trucks-

Kato GS4 trucks-


Using a proper size shim I drill three holes at the correct points to install the power pick up strips (the holes are for the axel point of the power pick up)


Secure the shim on the tender truck frame making sure the axel points are in the correct locations and in line with the point on the other side of the truck.  I used Rubberized superglue to secure the shims and axel power pick ups.  Install the wheel and make sure the trucks are square and free rolling. If they do not roll freely it is likely that the axel power pick up are installed too tight.  If only a little adjustment is needed, I recommend removing the truck and use a clean soldering iron to heat the power pick up strips and melt the points into the frame to provide additional clearance (only touch the copper strips for a few seconds)

I used only one shim on one side of the truck to make it easier to properly align the axel points of the power pick up.  When finished with the first truck make sure the second truck will be shimmed on the same side of the tender.  And yes, by this method the tender will be offset on the track by 1mm.  The offset will not be noticeable.



Jason Smith
Tomball Locomotive Works

[wcfn100]

Why could't you reguage the wheels?

edit - nevermind, I suppose the Kato wheels are in gauge as is and the Bachmann's are wider because of the wide tread.

Jason

[superturbine]

Yeah, the axles of the Bachmann tender trucks are longer.

[wcfn100]

Yeah, the axles of the Bachmann tender trucks are longer.

I get that, but technically you could reguage the Kato wheels to fit the Bachmann trucks without the spacers.  But I imagine that would make the Kato wheels too wide then.

Jason

[eja]

RE: Flux .. it's simple folks

Plumbing = Acid core

Electrical + Rosin core

Always has been , always will be  ....

[peteski]

Jason,
if you had a small arbor press, you could simply push the Kato half-axles out slightly further out.  I found a small press in an electronic surplus store for about $20.  Harbor Freight also sells arbor presses (but they are slightly larger).  my press comes in very handy for taking worms off the motor shafts, and all sorts of wheel/axle work.