Lionel 027 Scout: Why does the flat spring on rear coupler force rear truck upwards, instead of downwards onto the track?

Lionel changed the design of the trailing wheel and drawbar a couple of times over the years.  Can you post a pic?  Maybe a previous owner messed with yours, or you have the wrong parts for your loco.

That being said, on O27 especially the 5121 and 5122 switches, all bets are off.  Backing through the curved leg of a switch, especially when pushing a load might well result in a derailment.

Pix would be helpful as Ted stated. What # Scout engine?

Thanks.  It's a 1949 Lionel Scout 1110.      I'll try to post a picture tomorrow.

The locomotive has a horizontal flat bar, mounted at the very rear, underneath the draw bar..  The drawbar can swing back and forth perpendicularly over this flat bar.   But, mounted on the bottom of the draw bar is a flat spring, which runs underneath the drawbar for the length of the drawbar.   This  flat spring is open, and pushes down on the horizontal flat bar underneath the draw bar.  (It rides on the  flat bar and crosses over it  perpendicularly.)    It exerts spring pressure upward, keeping the draw bar from touching the horizontal flat bar.

Unfortunately,  the rear axle of the engine, which has one wheel on each side,  is also mounted to the underside of the draw bar, further back underneath the engine.  As a matter of fact, the axle is held in place by two tabs of sheet metal, that are actually part of the drawbar itself,  which are bent downward from the drawbar and have a hole through them for the axel to pass through.       As a result, the upward spring pressure on the drawbar also "lifts' the axle and wheels upward as well. 

 So, the rear axle  is kinda "floating" upward, and away from the tracks underneath it.  Although the wheels still touch the tracks, there is no downward pressure pushing them down onto the tracks.  Accordingly, the wheels  often derail  easily when they roll over choppy parts of the track, like when the engine goes over a switch.  The wheels also frequently derail when the engine is backing up. 

It all looks original and untouched to me.  

Thanks,

Mannyrock

That's the wrong trailing truck. Only the 1120 loco had that trailing truck grounding spring. You may remove the spring to work with a 1110.

I'll still try to post a picture.

Strange, but I see no evidence of any modifications to the underside.  The drawbar/truck and spring are all held in place with a single rivet.  The rivet looks totally original.

Maybe I got an abberation in production?  Often, in the firearms world, especially in the years after WWII, when a new model of a gun was brought out, they often blended spare parts from the old model, until those spare parts were all gone, and then they switched over to the newly designed parts.

Thanks,

Mannyrock

Here is a picture of the rear truck, with flat spring pushing it up toward the cab.

Looks like your locomotive was outfitted with the 1120-6 trailing truck assembly at one point.

It is virtually identical to the factory correct 1110-11 trailing truck assembly sans the ground spring.

Thanks for that great information.

I am going to drill the rivet out and remove the flat spring from the underside.

Do you think it would be wise for me to re-install the flat spring, on the top of the draw bar, pushing against the upper tail end of the engine, so that the spring is pushing the truck down?    Do most locomotives have a spring pushing the rear truck down?  Have just a single axle and two wheels, the truck seems awfully light and fluttery.

Thanks,

Mannyrock

I would leave it alone. The spring is for electrical contact. If you are truly opposed to the spring, you can easily obtain the proper 1110-11 part (say from forum sponsor @S AND W). Understand that your locomotive was probably upgraded for the enhanced electrical contact, or it was all that was on hand after the toy suffered an accident damaging the trailing truck.

As for backing up and such over your complex track - I would suggest you are expecting too much from the budget scout line.

It's YOUR loco, and parts aren't expensive.  I would start by ordering the correct part.  Then you can modify the one you have as much as you want.  If it doesn't work out you can use the correct part put it back to stock.  This loco isn't a rare collectible, so anything you do to make it run better is fair game.

I had a 2-4-2 growing up, and as Mr. Moran said, they can be derailment-prone when backing through Lionel O27 switches.  In "real life" sometimes train crews included an extra freight car as a "handle" to reach in, and avoid backing a locomotive into a siding to pick up a car.  If you can find a Marx switch, the type where the whole assembly swivels, it might work better with this particular loco.  My $.02.

Thanks to all.

Mannyrock

Good luck! :-)

He means prewar marx turnouts not the later plastic ones; those are junk imo, for any brand locos.

They need a few pins added to short rails to narrow some gaps as marx used shoes that floated over them vs rollers that drop and bump up. Not hard at all, slip in, eyeball the gap away, crimp, run.

The point style is unusual; actually moves both point ends (vs one) on a center pivot. They are "raw" boxy undecorated covers(often not even a light), and you have to do your own antiderail triggers on plain track. They work well though. There are a few prototypes if that's as, or more important, than running well. (These also work on fat driver trains, few other do)

You might look for a drawbar/truck option where the wheels float free of the drawbar for better tracking as push is applied to the bar.  Also, some tender receivers use a thin slot.  These bind early when "jackknifed".  When backing this keeps the two shafts at less of a jackknifed angle; it compliments pushing.

Bmoran,

I am not sure how the presence of this flat spring could aid at all in electrical contact, since it pushes the wheels upwards and away from the rails carrying the current, not down onto them.  Unless of course the cast iron body can carry an electrical charge up through the body and into the engine, in which case the spring, which is in contact with both the metal truck which houses the wheels touching the track, and the cast iron body of the engine, acts as a separate source for carrying a current to the engine.

But, , , what do I know???

Mannyrock

There are replacement rear truck that are spring loaded on the rear wheels.

I believe I would conduct a small test to see if removing the spring would cause a grounding issue to show itself. Try running just the loco through your switches at the slowest speed it can manage. If the engine does in fact have poor grounding, it will likely stall. Then try the same experiment with the tender hooked on - I would even hook a couple more cars to the tender, just to keep tension on the drawbar. The idea, I believe, was that the tender wheels provided additional outside rail contact that could be conducted through the drawbar to keep things moving over switches. No expense to try it and see if there's any effect on your engine! 

George

Great analysis Geo!

After a little research...I'm always learning sompin' There were 2 issues of the 1110. The early version ('49) did not have the grounding spring on the drawbar. The later version (51' 52') Did have the ground strap. So I guess the spring is correct as issued. So the rear wheels are going to be 'floppy'. If this is derailing too often, like I said in my earlier post, that truck can be replaced with an improved version.

BTW: that side rod in the picture doesn't look correct. Shouldn't have the bend in it.

Is there a chance that the spring should be on the bottom of that crossbar? It would still make contact and it would push the truck down instead of up.