NJCB RS-3 Drive Train Improvements.

[Robert]

I'm starting work on my NJCB RS-3 Road Switcher. I am starting this thread to get some advice from those who are very familiar with this type drive train. I sleeved the stock nylon tubes with brass tubing to eliminate the wobbling...I recall Sarge recommending that. The motor is an older Pittman dated 5/1979. It runs fine but is there any worth in swapping it for a new series Pittman such as pictured below. This is a brand new motor I bought from NWSL when they were still available. I've run it as pictured on my rollers and also on a test track using an MRC transformer...in both cases it seems to run decent although a bit noisy. It will become equipped with a sound decoder and run with my DCC system in its finished form.

With that background information and the five photos. I am hoping the few people on this forum who really know this Locomotive well might offer some advice. I'd appreciate this. Thank you.

Robert

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[bob turner]

You are doing everything right. But those look like sintered iron wheels, and they will give you fits. There are three possible solutions (not counting replacing the wheels with steel):
1. Battery/RC
2. Track sliders for pickup (that was my solution - they are not terribly obtrusive)
3. Dedicated pickup car - I do that when I am too lazy to insulate a Diesel model.

[sarge]

To be honest, I usually pull the gear-trains and drop in Weaver/P&D drives on old NJCB. Gets me past the numerous issues the easy way, the iron wheels, odd prop-shafts, and the gearboxes at the wheels which can also be problematic. Pretty much a drop-in conversion that can be had for reasonable money. I need to score a Nick and Jack GP30 and do the same exercise.

Dan D. did several NJCB RS1's in kind, (same drive) after a long discussion here if memory serves, so he is the holder of all our collective expertise expressed in real work if my fecollection holds any water.

[RDSRR]

Let me look at my archives. It seems some info here was lost as I can not see any posts back that far. It would have been 2013.

[Robert]

Appreciate the replies...which generates question naturally.

First what is wrong with sintered iron wheels?

The drive configuration with the exception of those long nylon parts sure looks robust to me...what sort of problems would such an arrangement generate?

Thank you.

Robert

[Rufus T. Firefly]

Let me look at my archives. It seems some info here was lost as I can not see any posts back that far. It would have been 2013.

Been at least 2 purges since 2013. Much has been lost....

[Tom Dempsey]

I believe Dan wrote it up in his magazine.

[E7]

First what is wrong with sintered iron wheels? Robert

They are formed from powdered metal under pressure. I think the problem is they tend to disintegrate.

Rich

[rex desilets]

Sintered iron wheels suck up crud like you wouldn't believe

[bob turner]

Yeah. They are extremely poor at electrical contact with rails.

The plus side is that the rest of the assemblies are from back when they were solid. You can get decades of good performance from the gears and bearings if you lubricate. This is not true of later production gearboxes with steel wheels - they were assembled poorly, and need re-riveting or soldering to avoid looseness and resultant destruction.

[Robert]

The plus side is that the rest of the assemblies are from back when they were solid. You can get decades of good performance from the gears and bearings if you lubricate.

Well that's a relief, thanks Bob. I wasn't up for dumping them for a Weaver replacement especially since they appear to be quite sturdy. For the sintered wheel issue I can get steel wheels from NWSL for example or possibly install wipers if I want to avoid the wheel change over.

Those barbed balls are soldered to the shaft ends on the original motor ... is that going to be a simple soldering iron/torch removal or were they a press fit/solder connection that's going to fight with me I wonder?

Any comments on the possible upgrade to the better motor in my photos? If I went with the newer motor that might be an opportunity to improve on the original coupling perhaps. Open to additional thoughts. For now I have brass work to do on the body.

Thanks again

Robert

[sarge]

The plus side is that the rest of the assemblies are from back when they were solid. You can get decades of good performance from the gears and bearings if you lubricate. This is not true of later production gearboxes with steel wheels - they were assembled poorly, and need re-riveting or soldering to avoid looseness and resultant destruction.

I'll say I sort of agree and don't at the same time.

If noise is an issue, I don't think you are guaranteed a quiet drive with the current A/N style box. Some I've gotten nice and quiet, but some never get that way.

Those look in very good nick, but you must keep brass on steel lubricated. It takes no time for those worm-wheels to get eaten if allowed to go dry.

Many shy away from open boxes needing lubricant (which they most definately do) for picking up ballast and junque, then jamming. Your call.

All in all, I stick with my position. There is not quite enough there for me personally to not just swop them out; about the same effort either way.

As far as the motor, see what you get with the original. Often the older Pitman's are better than one would think. It's like the drive. You might come up a rose or it might be an absolute turd.

It might not be worth the effort to you if the open wet gearbox thing bugs you as much as it bugs me. You have ballast and scenery. If that isn't a showstopper, however, go through Dan's exercise as was recommended. Hopefully you get a rose out of it, but be ready to take a shovel to it. These just aren't consistant enough to say whether this particular one is mechanically worth saving.

[Robert]

A bunch to consider and I am doing so as I do the brass work. I think the NJCB mechanism looks like a nice assembly as it is. I also believe the Weaver system has been well thought out by the many who have work with it. I see P&D sell this drive as a complete kit with many more parts than I would need. Maybe he sells individual parts as well...probably worth a call. I presume his kit would still allow for the use of my ALCO side frames if I went that route...might require either drilling out or a brass bushing for proper axle fitment. I appreciate the good feedback, looking forward to hearing back from Dan D about his setup.

More when I have more.

Robert

[bob turner]

The AN worm wheels are bronze, and rarely wear out on the properly assembled units. The axle bearings are porous bronze. They may be noisier than some, but that is because of the drop-down. I prefer the helical cut gears for that reason.

Bill had the last several batches assembled by an unsupervised trainee - they come apart, and then the worm gear gets eaten. I have no idea how you check for that, but if those steel plates are even slightly loose, beware. They can be fixed, but it requires special tools.

Picking up ballast can be a problem, but it isn't a show stopper on these gears. It can stop an MTH Diesel cold if a rock gets in the spur gears. And early Atwater transmissions had shields soldered on - probably easy to do if this becomes a problem.

Old Pittmans with a "one" in the third slot really should be replaced. Consider Toyota #O hose between motor and shaft, keeping only the horney ball on the transmission end. NWSL makes a really good receptacle - at least they did when their parts were glass-filled.

[bob turner]

And sure - given my druthers, CLW or P&D gearboxes would be my choice too - but the AN units are pretty good, with the exceptions I note above.