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Aristo Rogers 2-4-2 Tips

Aristo Rogers 2-4-2 Tips

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Aristo RogersThe 2-4-2 Columbia type got its name because one of the first ones manufactured was exhibited at the World's Columbian Exposition at Chicago in 1893. The engine type was generally not very successful and not many were built. The 4-4-0 American and 4-6-0 Ten Wheeler types tracked better at speed due to their 4 wheel leading truck and the 2-6-0 Mogul type was generally bigger and provided better traction in freight service due to more weight and six drivers. The Columbia was just too small to take advantage of the larger firebox that the trailing truck allowed. The real advantage of the trailing truck was realized later in the larger Atlantic, Pacific and Mikado class engines.

The Rogers 2-4-2T did find a home in some eastern elevated and suburban railways. Then engines were small but still handled several wooden coaches. The trailing truck, which did not support an extended firebox, allowed the engine to track well going in reverse which allowed the engines to work well in push-pull service. The engines usually carried their own coal and water to negate the need for a tender. Since the rail lines were usually short, the engines were never far enough away from fuel and water to make a tender necessary.

When the major eastern cities eventually outlawed steam engines on urban lines, the Rogers 2-4-2 engines were put out to pasture and replaced with electric traction.

The Aristo model of the Rogers 2-4-2 has not been manufactured in about 8 years. The original model was a 2-4-2T but apparently so many people added tenders that Aristo decided to forgo the coal bunker and include a switcher type slope back tender with a very basic chuff only sound system.

The model has also been mechanically updated. It has two motors, one for each axle, and two traction tires. The overall detail has been improved in the retooling process. All the grabs and piping are unpainted brass wire. The drivers now have metal tires and plastic centers. Additional weight has been added. Gear and motor noise are imperceptible.

The engine runs very well indeed and its pulling power is very good for an engine this small. See my Tractive Effort Tests Page for the Rogers pulling performance as compared to several other engines.

I've run some other comparisons against an LGB 0-4-0 with a powered tender and the Rogers barely outpulls the LGB engine, even with only 4 drivers vs. the LGB's 8 drivers.



rogers vs shay comparison photoAristo has labeled the box that the Rogers comes in as #1 Gauge, 1/29 scale. However, my eyeballs tell me that this engine is far from 1/29 scale. I don't have any drawings of a prototype Rogers 2-4-2, but setting this engine next to a Bachmann 1/20.3 scale Shay looks reasonable. For example the cab door is 3-3/8" tall, or a little over 8' tall at 1/29 scale. A 1/29 scale Kareem Abdul Jabbar would have no trouble getting into the Rogers cab.

rogers vs pacific comparisonPutting the Rogers next to a 1/29 scale Pacific really shows the difference. This little engine should look like a toy next to a heavy Pacific, but it actually taller and wider. The Rogers would look right at home on a turn-of-the-century narrow gauge layout, but on a more modern 1/29 scale layout, it wouldn't fit well.

The Rogers stands 6-3/4" tall from the railheads and is 4-3/4" wide across the cab roof. The engine and tender are 23-1/2" long from the rear step to the tip of the pilot.

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Power Pickup

When I first got the Rogers, I dropped it onto my track and ran pretty well, but it sputtered some. Since it had rained the day before, the track was covered with splashed grit and the engine didn't like it one bit. One pass with a track cleaning car, and the engine ran well.

The Rogers picks up power from all 8 wheels via carbon brushes. These brushes have lower drag than I usually experience with LGB type contacts.

Running on the same dirty track, the Rogers didn't do quite as well as a Bachmann Shay (which has outstanding power pickup reliability) but it did well enough.

After extended running, the engines wheels got dirty and needed cleaning. This is a common problem with Aristo steam engines. There is something about the wheel material that seems to attract dirt and makes wheel cleaning a common chore. The pony trucks really do pick up significant power. Just cleaning them and leaving the drivers dirty will result in a significant improvement.

As of late 2000, Aristo has released replacement drivers for the Rogers made of a new material. If this is the same stuff that the new 0-4-0 wheels are made of, then there will be an improvement in power pickup reliability. The improvement that the drivers can provide is somewhat tempered by the traction tire on the rear set. Since the crankpins are of different length, a second front set cannot be substituted for the rear set.

Before I changed out the wheels, I ran the Rogers a bit and it was showing definite signs of needing the wheels cleaned, even with the tender wheels being used for power pickup too. After I changed the wheels, and without cleaning any of the others, the engine ran much better even with the tender disconnected. I ran it for about half an hour and the power pickup didn't seem to be degrading. I'll need to put many more hours on it before I'll really know how much better it is. With the old wheels, a half hour of running was enough to get it to start sputtering.

Replacing the drivers is a fairly straightforward task. Remove the crankpin screws and remove the connecting rod. The wheels may have to be rotated some to get access to the screws. It is easiest to do the work if the crankpins are at their lowest point. Then remove the wheel screws, lockwashers and the indexing washers. Use a flat blade screwdriver to gently pry off the wheels making sure that you don't lose the carbon brushes behind the wheels. Then press the new wheels in place with the crankpins in the same position. The wheel with the longer crankpin and traction tire goes to the rear. Before you press the new wheel home, make sure that the carbon brush is in place, it may have popped out when the old wheel was removed. Note that there two slots next to the axle hole, these have to line up with the slot in the axle. The indexing washer has a ridge that goes into these slots and locks the wheel to the axle. Your new wheels should come with a split ring lockwasher, use it even if there wasn't one under the old screw head. As you tighten the axle screws rock the wheel slightly to be sure that the indexing washer seats properly. The new wheels may also come with a replacement axle, you won't need it.

The wheel spacing of both the pony trucks and the drivers are such that several of them can sit on the plastic frogs of cascaded turnouts or crossings. Add this to some dirt on the remaining wheels that are sitting on the track and the traction tires on the rear drivers which limit their effectiveness in picking up power, and the engine can stall in some places. This seems to only be a problem with tight radius turnouts.

Since the tender also picks up power on all 8 wheels for the sound system, I wired it across to the engine following the technique show in my Power Connector Tips page. After this was done, much of the power pickup troubles went away. However, the tender wheels get dirty too and eventually, they all need cleaning. Maybe someday, Aristo will release replacement wheels for the tender in the new material, maybe even with ball bearing pickups.

The connector wires are easy to attach to the tender, simply solder them to the lugs that are behind each journal box. On the engine, its a little more difficult. The power pickups on the rear pony truck are the likely places to connect the wires. However, the brass bushings for the brushes are encased in a plastic holder and soldering directly to the exposed surfaces of the bushings would surely result in a melted brush holder. Instead, I cut the wires about 1/2" away from the pickups and stripped both ends of each wire about 1/16" I then soldered the ends back together along with the wire leading to the power connector.

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Tracking and Derailments

The leading and trailing trucks are sprung and I initially experienced no problems with derailments on 4' radius curves. The drivers do not rock with respect to each other as with some other Aristo steamers and this probably is the reason that the engine doesn't hop and chatter when the drivers are slipping as the Pacific and 0-4-0 do.

When I brought the engine to the GIRR Mountain Division and ran it on 2' radius curves, it had some minor tracking problems. On curves, the inside wheel on both the leading and trailing trucks tended to lift off the rail. The leading truck would lift going forward, the trailing truck would lift in reverse. Sometimes the springs would fully extended and sometimes they would bind and not fully extend. The wheel lifting appears to be a result of the fact that the trucks don't actually guide the engine through curves. When the body of the engine cocks to the outside upon entering a curve it puts a lot of pressure on the outside pony truck wheel. As a result, the inside wheel is lifted a little until the whole engine settles itself into the turn.

This didn't actually cause any derailments but it is clearly a precursor to one, especially if the track is not level. The problem is due to the travel limit of the pony trucks. They are allowed to swing just far enough to deal with 2' radius curves when the engine body is lined up on the track centerline. When the engine body is cocked with respect to the track centerline, the pony trucks can hit their travel limit stops. This tends to force the engine back into line, but it also causes the inside wheel to lift.

rogers front truck modifications I've gouged on my Rogers a little and fixed this problem. The front pony truck is fairly easy to fix. Remove two screws that hold on the cover to the truck pivot and lift out the truck a little. Use a fine file or a small motor tool cutter to remove some plastic at the ends of the curved slot as shown in the photo. Trim the truck until the truck can actually touch the cylinder head. You may also have to remove a small amount of plastic from the frame where the truck edge touches it. This shows as a white spot on the photo.

The rear truck is a little more difficult to remove. One of the cover screws is obscured by the mount for the power pickups. Remove the screw that holds the pickup assembly in place and carefully remove it. Be sure to restrain the carbon brushes as the internal spring will push them out when they get free of the wheel. Then gently pry out the mounting bracket for the brush assembly. The sides of the mounting bracket have tabs on them that if pressed inwards from the bottom will release and the mounting bracket can be pulled out. Then remove the truck and do the same slot widening as with the front truck. You may also have to trim some plastic from the upper rear outside corner of the truck itself so that it can clear the screws that mount the cab steps.

A different kind of tracking problem occurred because of another typical Aristo problem. The screws that hold on the drivers got very loose which allowed the drivers to spin on their axles at times, especially in those same tight turns. This caused the drivers to on each side to rotate with respect to one another and the siderods would bind. The result is that the engine would grind to a halt in tight turns. After the driver mounting screws were tightened and the driver quartering rechecked, this problem went away.

The drivers are indexed by a ridge on the back of the washer under the driver mounting screw. When the screw gets loose, the driver will no longer be locked in position with respect to the axle. Aristo has sent me some split ring lock washers to put under the screw head. These seem to be working in keeping the screws in place. If this doesn't work in the long run, a little Purple LocTite 222 on the screws will definitely hold them in place. Don't use anything stronger than 222 or you will never get the screws back out if you should need to.

The pony truck wheels on my unit seem to be just a bit under gauge. This didn't seem to cause a problem until they ran through the LGB 1200 turnouts where I had shimmed the guard rail to solve derailment problems with wheels that were slightly over gauge. On the turnouts with the thicker shims (40 mils) the under gauge pony trucks would bind between the shim and the wing rail next to the frog. This would cause the pony truck to squeeze upward and derail. Turnouts that had been treated with a thinner shim (20 mil) worked better so I have been replacing the thicker shims with the thinner ones.

stock tender spacingI noticed another problem with the Rogers. It doesn't like to push heavy loads on 2' radius track. The drawbar in the engine is mounted on the rear pony truck. When coupled to a slopeback tender, the force applied to the rear pony truck while pushing a heavy load would tend to derail it on a curve. This photo shows that the spacing between the tender and the engine is fairly tight during pushing but the drawbar still takes up the entire load. However, if the spacing could be reduced just a little, the frame members on the engine and tender would touch and take up part of the load. I considered body mounting the drawbar, but after playing with the drawbar position with the rear truck derailed so that it could be centered, it became obvious that the width the loop on the tender was not wide enough and the engine would probably derail the tender truck. Further, body mounting the drawbar would be a nonreversible modification and if it didn't work out, I would be stuck buying a new pony truck.

modified engine drawbarMoving the engine drawbar was quite easy and completely reversible so I decided to try it to see if it worked. A new screw hole is drilled in front of the original one and the drawbar is simply attached to the new hole.

closer tender spacingIn the depth of a 2' radius curve where the side forces on the pony truck would be the highest, the frames of the engine and tender touch and take up the load. The drawbar actually fully unloads at this point. This seemed to fix the derailment problem. The forces on the pony truck are still pretty high when the engine is coming into or out of the curve and the frames are not touching but it doesn't seem to derail. Maybe the drawbar could be pulled forward as far as it would go and it might work even better.

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Sound Tender

The Slope back tender that comes with the Rogers appears to be identical to the tender that is supplied as an option to the 0-4-0 switcher. The tender comes with a sound system installed. This system has been much derided, but under the right conditions it isn't too bad.

The system chuffs fairly well but that's all it does. The sound system relies on the Aristo PWC system to work properly. Without PWC, the sound system doesn't get enough voltage off the track to work and can howl, growl, or screech terribly at low speed. On pulse power packs (such as MRC packs) it will hum and buzz. With PWC, it may occasionally make awful sounds but only at very slow speed. Unlike the Pacific's Long Tender, there is no provision for connection of a battery to allow the pack to work without PWC.

The volume control for the chuff is accessed by lifting the coal load from the rear. The water hatch slides back to unlatch the coal load.

The chuff trigger is a Hall effect device mounted above a tender axle. A doughnut shaped magnet rides against a rubber roller on the axle. The Hall effect device is mounted next to the magnet. If the chuff isn't working right, make sure that the rubber roller is clean and that the Hall effect device is RIGHT NEXT to the magnet. Even when it is working, the chuff rate is about half of the prototypical rate of 4 chuffs/turn.

After the rubber roller gets old and hardens up some it doesn't provide enough friction to turn the magnet reliably. After much fussing and fiddling, I finally tried to renew the roller surface with a coating of contact cement, AND IT WORKED! Pull the wheelset with the roller from the truck by flexing the truck sideframe slightly and then paint a layer of contact cement on the roller. Rubber cement would probably work too. Let it dry for about an hour and reinstall the wheelset. I do not know how long this patch will last, but even if it fails after awhile, it would be easy enough to do it again.

I have subsequently done an installation of a Soundtraxx Sierra in this slopeback tender. This sound quality of the Sierra is much better than the built in system, but then again, it costs a lot more too.

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The Rogers comes with a smoke system. The system is similar to other Aristo steamer smoke systems in that it puffs smoke in time with the drivers, but at only one puff per driver turn. As is typical with Aristo smoke, the system doesn't generate large quantities of smoke, but it does smoke for quite a while on the 6 to 7 drop recommend charge.

The smoke switch is behind the smokebox door (like Bachmann engines) but it is not labeled so it is easy to forget if the switch is in the on or off position. Also even the though the smoke generator has its own switch, the smoke won't work unless the motor is on too.

The smoke unit plugs onto the smoke box so replacing a burnt out generator should take about 3 seconds.

The instructions say to pour smoke fluid in the opening at the top of the stack. However, the hole is so small, the first drop plugs up the little hole. The top cap can be easily pulled off to reveal the smoke element so that it is much easier to load fluid.

The smoke unit in mine eventually shorted out due to a damaged plug it was replaced a Sue the unit. Sue the makes LGB smoke units which are identical. A 16 volt unit works well as this engine usually runs fairly slowly.

smoke unitsThe center unit in the photo is the stock Aristo unit. It can be removed from the stack by pushing it out of the bottom of the stack. The Sue the unit is slightly larger in diameter than the Aristo unit so the stack has to be modified for it to fit. Run a 3/8" drill bit through the stack to ream it out and the Sue the element will just fit. A 3.5 mm mono phono plug can be wired to the smoke element so that the assembly will still plug into the engine although a pair of needle nose pliers is necessary to insert the plug before the stack is pressed home.

The hole in the stack cap also can be opened up. A 1/8" hole seems to work fine.

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Mounting Other Couplers

kadee coupler mountA Kadee #831 coupler can be mounted directly in place of the supplied Aristo knuckle coupler, however the rear step must be cut to clear the coupler box. Cutting right next to the step supports will provide enough clearance for running on 8' diameter curves. To accommodate 4' diameter curves, more of the step and the inside two step supports would have to be removed and new step supports fabricated from strip styrene.

An LGB knuckle coupler mounts more easily and with no modifications to the tender required, although some modification to the coupler is necessary. The mounting groove in the coupler is slightly too narrow to fit over the coupler mounting tang. I find that a quick pass with a 1/4" motor tool cutter tool will widen the slot in the coupler to allow it to mount with the original screw in the original hole. The small cross piece on the coupler shank, the part with the LGB logo on it, also needs to be ground down to about 1/3 its standard thickness or it will ride on the rear step and hold the rear wheelset slightly off the track. After these modifications are made to the coupler, the coupler height comes out just right.

Mounting a coupler on the engine pilot is not practical. The overhang on curves would be too large to allow a coupler to work properly. The pilot does have a drawbar attached.

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Instruction Manuals

Aristo instruction manuals are typically cryptic. The Rogers manual is better than most, but it could still use improvement. I did find some problems with the instructions.

Marker Lights. The manual indicates that there are LEDs used for classification lights. I couldn't find any on the PRR unit that I had. Lewis Polk informs me that some road names have LED markers and some do not. The PRR configuration has flag standards instead marker lamps.

Tender Instructions. My engine didn't come packed with any instructions for the tender at all.

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©1998-2000 George Schreyer
Created May 5, 1998
Last Updated Dec 27, 2000