Do Steam Engines with "Out" traction tires run smoother?

Dan you didn't say which locos they are, or how many cars you're trying to pull.  If the loco is a 1655, 1666, or 2026, some of the difference could be due to the greater friction from sliding shoes vs. roller pickups.  If the tension isn't correct the shoes can actually lift the driving wheels off the track!!  Another possibility is the tender.  Just like a real railroad, you have to think in terms of NET pulling power at the tender coupler.  A lot of post-1950 tenders were lighter than their 1940s counterparts, leaving less reserve pulling power for the train. 

Adding weight will help.  Lionel did exactly that with 726 Berkshire beginning with the 1948 model.  The prewar 763E had a hefty weight above the gearbox.  The 773 got Magne-traction instead.  Don't overdo it.  Weight adds wear to the bearings, and you still want the driving wheels to spin.  A little wheelspin when starting is prototypical, and if the loco stalls when overloaded you can burn out the motor.

I believe that sintered iron wheels get a better grip on the track than the steel tires used on 1940s locos.  If the wheels aren't worn smooth, a non-magnetized loco from the 1950s may still pull more than its 1940s counterpart.  A much fairer test would be a 2037 vs. a 2018, or a 2046 vs. a 2056 with identical tenders in each case.  I would bet the added pull from Magne-traction is at most one or two freight cars.  It mostly depends on how clean the wheels are, and how worn they are too.

I'm a big fan of MPC and newer cars with fast angle wheels.  I had an O27 layout for years.  Pretty much any die-cast, 6-drivered loco I tested could pull enough MPC cars to chase its own tail around the 4x8.  What are you trying to pull?  When was the last time you lubricated your car axles?  And if you have a 110 trestle set, all bets are off.  Nothing realistic about it, that's roller-coaster territory!!

Dan Padova posted:

So the next step, in my mind, would be to add weight at the factory.  Isn't that what gives locomotives in the real world the power pull heavy trains ?

This is a picture I've posted before, though I've actually added weight to a bunch of different locomotives.  The before and after for this unit was like night and day.  I added a bit over a pound of weight near the trucks, and this went from an anemic puller to a robust locomotive.  It was having trouble pulling five 18" cars on a 2% grade, after adding weight it was hauling a dozen cars the same grade without any issue.

BTW, it already does have traction tires, so weight is certainly a major factor.

Dan Padova posted:

... If post-war Lionel didn't have them...

Lionel has had traction tires since 1962.

gunrunnerjohn posted:

Dan Padova posted:

So the next step, in my mind, would be to add weight at the factory.  Isn't that what gives locomotives in the real world the power pull heavy trains ?

This is a picture I've posted before, though I've actually added weight to a bunch of different locomotives.  The before and after for this unit was like night and day.  I added a bit over a pound of weight near the trucks, and this went from an anemic puller to a robust locomotive.  It was having trouble pulling five 18" cars on a 2% grade, after adding weight it was hauling a dozen cars the same grade without any issue.

BTW, it already does have traction tires, so weight is certainly a major factor.

GunrunnerJohn, where did you get those weights, and how much does each one weigh?

Your weights look like they are the ideal shape and size for installing them inside a locomotive. I imagine you used double stick tape to affix them. Arnold

Those are 230 grain .45ACP Lead bullets.  I didn't like them for their intended purpose, but they work great as weights for trains.  Those are around 18 oz of weight.

FWIW:

Think of traction tires as the model equivalent of the real thing having sanders on permanently.' If the real thing was running on our grades I expect that would be the condition.
I suspect that if the driver rims are steel and the track is brass/nickel silver, running w/o traction tires *should* not cause significant wear.
On occasion when a traction tire has expired inconveniently (no replacement at hand)  I've filled the groove with rubber sealant. Works, but you have to be careful not to leave lumps...ask me how I know.
I have a Lionel Reading T-1 sans tires. Runs fine with the sort of train I can run at our club. Requires a little throttle jockeying when starting, which adds to the fun.

I would settle for any reduction in tractive force due to elimination of traction tires. They leave residue on the tracks, I don't enjoy changing them, and I don't like the grooved wheels. However, I have never noticed adverse effects on operation due to traction tires.

MELGAR

Okay, how about we throw in another wrench to the gears of our minds.  So we add weight to our toy trains to make them better pullers.  Does the added weight, which was no intended for by the designer, place the motor and gears in any more danger of wearing prematurely ?

Yes, it's quite likely that with excessive weight and running, other stuff will be overstressed.

Dan Padova posted:

Okay, how about we throw in another wrench to the gears of our minds.  So we add weight to our toy trains to make them better pullers.  Does the added weight, which was no intended for by the designer, place the motor and gears in any more danger of wearing prematurely ?

Of course it does if you add more cars to the train because the weight and traction tires enable them to be pulled. The extra weight, cars and tires increase the tractive force which increases the torque required to turn the driving wheels. This requires the motor to produce additional torque and increases the current (amperage) draw. The extra torque will also result in larger contact and friction forces in the motor and drive gears - and thus more rapid wear. The difference in wear may not be a problem but it will occur. No different than on a full-sized engine and train.

MELGAR

DanssuperO posted:

Hey TED S... you got me thinking why didn't Lionel or any other train manufacture use what we have in our cars (rear end)  a differential to help ?I know cost but would it help? ...daniel

Just trying to envision "Limited slip side rods" on a steam loco.

The steamer just needs a differential on each driver shaft.  Talk about getting expensive!

gunrunnerjohn posted:

The steamer just needs a differential on each driver shaft.  Talk about getting expensive!

And out of quarter !

That would be an interesting problem to solve.  I don't see differentials in our future for steam.

It would be possible in a diesel at some complexity.  "COST"  This problem is what prompted MPC to develop the fast angle wheel for rolling stock.  Even real railroads use a tapered tread on car wheels and the head of the rail is not perfectly flat so the truck rides to the outside of the curve putting the fat larger diameter inside section of the tread on the outside rail and the smaller diameter outside of the tread aligns for the inner rail.

          I could see a fast spinning axle with magnets spinning on each end inside a cup behind each wheel.  The wheels would spin free on the axle propelled by the eddy currents of the spinning magnets "eddy current clutch". Allowing differential between the inside and outside wheel.    WHEW !  You would need a 48 month loan the pay for your next Plymouth switcher.  

    Kidding aside,  Eddy Current Clutches are quite effective in model train drives allowing for very smooth low speed operation.          j