Model Railroad Blog

Capturing A Sense of “Mass” (Feb.12)

Following my last blog on this subject Trevor Marshall was kind enough to point out Mike Confalone’s work with super weighting cars.

In a post on the Model Railroad Hobbyist forums Mike wrote: “Bottom line, if you want really reliable operation, and more importantly, prototypical operation, you should consider adding a LOT more weight to your freight cars. throw the NMRA standard out the window. It’s wimpy.

My proto-freelance Allagash Railway is set in 1980. We run heavy trains over terrain that is seldom flat. We have a couple of very nasty grades and a lot of curvature. I generally weight my 40′ and 50′ boxcars to between 9-12 oz. Same for covered hoppers. I use lead wheel weights. These are the little 1/2 oz or 1/4 oz self-adhesive strip weights that are used for wheel balancing. I get them by the box at my local auto parts store, instead of getting ripped off by the ridiculous A-Line weights for $5 a strip. Do they still make those? What a scam! A box from the auto parts store will last a long time, depending on the number of cars you need to weigh. I’ve gone through many boxes over the years. The guy at the counter always seems like he wants to ask me..”hey what are doing with all this lead anyway?”..but he never does!

For boxcars and covered hoppers, depending on how the car is built, I carefully pry the roof off and stick the lead strips to the lowest point in the inside (belly) of the car. I’m generally adding 6oz or so. The roofs on the new offerings from Tangent and Exactrail pop right off for an easy install. Kadee boxcars I take apart, or stuff the weight inside the door opening. Wherever I can get it so that it is not visible. For tank cars, I have to get a bit radical. I actually drill a hole in the bottom of the car and fill the car, to the brim with sifted play sand. Open hoppers are tricky, as are flats. Pretty much have to deal with them being light, and block them in the trains accordingly…on the rear. There are probably ways to solve these as well, but I haven’t experimented yet.

As-delivered these cars are all featherweight. Add the tonnage and the cars stay on the track, and they ACT like a freight car should (more prototypical switching and inertia, real tonnage simulation). They don’t jerk and jump around when switching. This tonnage, combined with lots of momentum on the locomotives actually creates a more natural response.

If you want to really simulate tonnage, you have to add weight, and lots of it. Locomotives call pull way too many out-of-the-box freight cars. The tractive effort, or tonnage rating, of a typical HO loco is way too high, especially on grades. To get a typical 25-30-car train up the 2.9% ruling grade over Holman Summit on the Allagash we NEED 4 or 5 units (4-axle Atlas or Proto 2K GP38s or Atlas C420/C424/5 for example). In other words, we don’t just put 4 or 5 on the train to make it look good, if we go with 3,we’re probably going to have to double the hill. This is prototypical. The Maine Central RR put 4-6 units on a 35-60-car train to make Crawford Notch. Other mountain railroads do the same.

The point here is to create a situation where you NEED the power to get the tonnage over the road. Not only is it prototypical, exciting and more interesting, but everything runs and rolls better, and we have zero derailments…and I mean zero. The only car that derailed at the last op. session was an Intermountain 4750 CH that I can’t seem to pry the roof off to get weight in it. Off the railroad and onto a shelf it goes.

I’ve never had a coupler fall out or a loco problem, and we operate regularly. A friend of mine lovingly predicts that I’m going to burn out a motor or decoder someday! Baloney! Make your locos work a bit. They can more than handle it. So far, so good.

Only word of caution. Use Kadee metal couplers..5’s or 58s. Throw the plastic ones in the trash. Beyond that, get to the auto parts store and buy a box of wheel weights. You won’t believe the difference!”

Regarding the difficulty in weighting tank cars Trevor wrote: “Mike C drills a hole in the bottom of each tank car, fills the car with clean play sand, and then seals the hole (with caulk, I think). A bit of paint and weathering and the small hole disappears.”

Further expanding on this subject Jason Arnot wrote: “For my very small layout, I use an extra Kadee knuckle spring and carefully place it over the needle-point end of one axle in each car.  When the wheelset is placed in the truck frame, it creates enough drag that the car doesn’t run away, but the wheelset has no trouble rotating.  I found it makes a small but noticeable change in operation.  Cars tend to stay put where the train stops; it’s also possible to couple up without the stationary car moving even the slightest amount.  If couplers are bunched, you can slowly pull out of a spur or siding and watch each car start moving individually, which I find very prototypical.”

I suggest you give it a try–it only takes 30 seconds to change a car–just one knuckle spring (you probably have thousands of spares on the workbench) over one end of one axle seems sufficient to my eye.”
Thanks Guys!

 

Capturing A Sense of “Mass”

Creative fulfillment aside, one the main reasons I model railroads is that I’m mesmerized by the full size version.   In particular, the sense of overwhelming mass and the stunning horsepower numbers it takes to move just a few cars.  (A GP38-2 tips the scales at 125 tons.)

As I watch YouTube videos such as THIS one (jump to the 1:25 mark), I’m struck by the difference between actual train dynamics and the movement of our plastic models.  Especially knawing to me is the subtle accordion like effect and jerking motion as the model freight cars snap back and forth with the rotation of the model loco’s motor shaft.  It’s subtle but it’s there.  Model trains move like plastic toys not hunks of steel that weigh hundreds of tons.

 

As the LAJ project moves forward, capturing this sense of mass is high on my list of experiments. To that end, some things that I think will work are:

Layout height:  The closer you can get the models to eye level, the more realistic the viewing experience.  Higher layout heights are a trade off though as they aren’t as easy to work on.  During construction you’ll be standing on a stool quite a bit.  Check

Sound:  The visceral sense of mass isn’t just visual, it’s auditory also.  The deep bass and high fidelity of the headphone system has done wonders.  Check.

Speed curves: Decoder pro makes setting the speed curves a snap.   A few computer key strokes allows you to get a much broader control range for the lower speed ranges the prototype typical runs under.  Check.

Hypderdrive and decoder tuning:  Section 8 of the Tsunami manual reads, “Setting Up the Hyperdrive Tsunami’s Hyperdrive system features high-frequency PWM drive for silent motor control along with load compensation (or back-EMF) to improve low speed operation and maintain constant speed regardless of changes to the motor load. There are four CVs associated with the load compensation feature: CV 10, Back-EMF Cutout CV 209, Kp Coefficient CV 210, Ki Coefficient CV 212, Back-EMF Feedback Intensity”  Friends have told me this tuning makes a huge difference.  I have yet to do this but it’s high on my list.

Trucks:   I’ve always assumed, without thought, that smoother running trucks are better. This is certainly true for over the road freights where you need to pull a lot of cars.  I’m beginning to wonder if trucks that don’t run so freely will give more realistic running qualities during switching.  I don’t know.  It’s a test worth performing.

Car Weight:  What would happen if I grossly overloaded the weight of my freight cars?  How would that change their dynamics?  It’s worth testing.  I’m not sure how practical this would be though for cars that would be difficult to add weight to such as tanks, gons, flats, etc.

 

To be continued…..

 

 

Some Vertical Details

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I spent the better part of Saturday scratch building two utility poles and one cross buck for the Everett Avenue crossing.  I’m guessing I had about six hours into the project and the cost of materials probably didn’t crack a buck. (lots of recreational play value per dollar!)  On top of that, when I was done, I had something better looking than anything I could have purchased ready made.  This would be a good project for a student or deployed military because the parts are small, inexpensive, and will, without question, be needed once you get a layout.  They are also details that create a fair amount of visual impact.

Crossbucks

Take a Tichy plastic cross buck and shave the cast on post off.  Spray paint the back of the cross buck  dark gray.

For the post, take .041″ basswood (Midwest pn 8016) representing a 4×4 and paint that gray as well.  When the paint on the post has dried, give it a few swipes with 400 grit sand paper to get the “fuzzies” off of it.  Lightly spray it with flat with white spray paint and give it another pass with the sandpaper.

Glue the post to the cross buck plate.  Take two Ticky NBW castings, paint them with dark gray primer or camo. brown and glue them in place.  All done!

Utility Poles

You’ll need:

  • Bamboo skewers from the grocery store (pole heights vary but a common length is 40 feet with 6 feet of that buried in the ground)
  • .0416″ x .0625″ basswood (Midwest pn 8017) representing 4×6 cross arms.  Cut to  scale 8 foot lengths. (8 feet is a common length although some cross arms are longer)
  • Insulators scavenged from Atlas telephone poles
  • .015″ Music Wire (K&S makes this)
  • Yellow decal stripes from your scrap box
  • Tan or earth colored solvent based paint

Lightly dilute your paint and stain the poles and cross arms.  Mark the center of the cross arms.

Start with the top cross arms.  There are two of these, back to back on the top.  Glue them roughly a foot down from the top of the pole.  Next, glue one more single cross arm a scale 6 feet below the top arms.  For adhesive use a thicker viscosity CA.  Snip off a half inch long piece of music wire, bend it in an “L” with 1/4″ sides, glue it beneath the cross arms and paint it a dark gray.

Take a spare Atlas telephone pole, spray it a light gray, snip off the insulators and glue them in place on the cross arms with CA.

Some streetside poles have yellow reflective tape near the bottom, I simulated these with yellow decal stripes from my scrap box.

Utility pole styles vary greatly and it’s simply a matter of looking at your window to get some ideas.

 

Working With Powdery Soils

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Working with powdery soils is difficult from the standpoint of getting a flat, smooth surface, free of ridges, bumps, and craters.  There are two challenges.  First is applying the material smoothly.  Second is applying the adhesive without disrupting your application.

To get a smooth application, avoid pouring the material from a cup.  Instead, use a fine meshed sifter.  Pour your material into the sifter and lightly bounce it up and down and swing it side to side until you’ve covered your entire surface area.  If additional smoothing or dress up is needed use large, soft, flat brushes.

Next comes applying the adhesive.  I prefer dilute matte medium from Scenic Express.  Pick up a spray bottle that produces a super fine, gentle, mist.  Fill it with a water and add a touch of rubbing alcohol or detergent to aid in breaking up the surface tension.  Spray your soil base that so that it’s saturated but not puddling.  I use an eye dropper to apply the matte medium.  If you’re not careful applying the drops, you’ll end up with unsightly ridges or craters.  Start at the edge of your soil area and liberally apply the adhesive around the edges.  Wait a moment and let the capillary action draw it into the soil as far as possible.  To hit the remaining dry areas, hold the dropper just a hair above the surface and very gently squeeze out a drop.  Again, see how far the capillary action carries it.  Repeat until the entire surface is saturated.  If you end up with any ridges or bumps lightly smooth them out with a flat, smooth, brush.