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• The Aristo Doodlebug
• A Derailment Issue28 May 01
• Power Pickups5 Jun 01
• Scale and Clearance
• Roof Warpage10 Jun 01
• Lighting
• Mounting Kadee Couplers
• Doodlebug Wiring
• Converting the Doodlebug to DCC

The Aristo Doodlebug is a model of a gasoline, distillate or diesel self powered railbus that was common in the early part of the 20th century. Doodlebugs were built for the same reason as the older gas railbuses, to provide passenger service on lightly traveled lines. Later, the Budd RDC replaced the Doodlebugs.

This model is created from a Standard Heavyweight coach, just as some real Doodlebugs were. The car is a combo coach so that it could accommodate small amounts of freight as well.

The rear end of the Doodlebug is a little plainer than the front. The rear end is unchanged from a Standard Heavyweight coach.

The car has full interior detail but no passengers. There is even the customary rest room in the rear. There is an engineer who looks like the twin of the one that drives most other Aristo diesels.

The baggage compartment doors operate, but there is some wiring visible with the doors open. All the extra wiring that is seen in this view is due to the DCC installation as described below.

I have run across photos of ATSF motor cars, M.177, M.180, M.181 and M.182. There have been times when all four were painted similarly to this car. There were other times when the cabs of some of them have been painted with wide diagonal strips similar to the "Zebra Stripe" scheme used on switchers around 1950. All of the ATSF cars have a different roof line than the Aristo model and had a much smaller passenger compartment. The ATSF cars don't have the large grill in the front. I have some color hardcopy photos of both M.181 and M.182 that show that the paint scheme that Aristo used is reasonably accurate for at least one time period (considering the grill differences) and that the colors are close (also considering that the photos may not be true color).

The ATSF cars used a 400 hp Winton distillate engine and an electric drive. Speed was controlled both with motor connection changes and engine speed. Later in life, most of the distillate engines were changed out for straight diesels.

M.181 and M.182 plied the line between Los Angeles and San Bernardino at least between 1929 and 1952. Some more information on M.177 (currently under restoration at Travel Town in Los Angeles) can be found at the SCSRA web site.

Rick Blanchard writes:

Saw a post on LSC about your looking for M.108. All the info is in a book called "The Doodlebugs" by John McCall (Kachina Press). Long out of print but maybe you can locate one through a library exchange program. I have heard of ridiculous prices for the book - hundreds of $$$. I lucked out and got it for $7.50 at a used book store on sale.

The details on the Aristo are god awful compared to the prototypes. Where did they get that front radiator-louver stuff? Roof is rounded on all of ATSF Doodlebugs from day one, not clerestory, etc. Clearly not based on the proto M.108 but may be like a car with some other paint scheme.

Anyway, M.108 was built in January 1928 by EMD as a 72 foot Baggage-Smoker-Coach. 17 windows on the side and eight vents on top. 33" wheels. M.109 is identical and built at the same time.

M.108 was assigned the run from Skeedee to Guthrie via Stillwater in Oklahoma until 1934 when it was assigned to Attica-Belvidere and Shattuck-Etter runs. In 1942 it was on the Brownwood-Menard schedule and moved to Pampa-Clinton in 1943, where it stayed until 1950 and retired. It used trailer car #2384 (also a B-S-C body style). In 1952 it was made into a trailer coach T.105. Scrapped in 1961.

M.109 was used in Texas, Galveston area. Similar fate - trailer T.106 in 1952 and scrapped in 1961.

M.180 was the LA to San Bernardino local and the M.131 was at Fresno-Corcoran. M.181 was backup for both of those cars. Both 131 and 181 had stripes on both ends as they didn't turn the car on the Fresno route. M.181 also did duty in Albuquerque. They both went to Kansas after their tour in So. Cal.

M.177 never ran in So. Cal. It was always a Kansas car. It was donated to Traveltown in Griffith Park fresh from Kansas. Try as I might, I can never remember seeing these out on the rails when I was a kid. I'm sure everywhere they were stationed the locals had an affinity for 'their' car. There were others in the So. Cal. area too. M.190 and M.191, both RDC-1 cars, ran between LA and San Diego.

I found some color photos of M.181 in a book describing the ATSF's involvement in Southern California. At one time, the trucks and pilot were painted silver along the lines of the Warbonnet scheme. I thought that this looked attractive so I painted M.108 along those same lines. I don't know how M.108 was really painted, but I'm willing to suspend disbelief a little for some aesthetics. The couplers and wheels were "rusted" at the same time.

The Doodlebug is powered by a single ball bearing power brick mounted on the front truck. The truck has two traction tires. This new brick is very smooth and quiet, the wheel noise rolling along the rail is louder than the gearing. The friction load in these new bricks is very low, the unit will literally crawl along with no hint of surging or hesitation.

Pulling power of the model is quite good, it pulls better than its prototype ever could. The Aristo car will handle 7 full sized boxcars on a 1.6% grade without wheel slippage. Adding an 8th car caused the Doodlebug to slip. This is about half the load that a regular Aristo diesel can handle which is reasonable since the Doodlebug has half the driving wheels. See my Tractive Effort Tests page for the details on pulling power and current draw. A real Doodlebug was sometimes used with a single trailer car in flat territory. The small engine just wouldn't be able to handle the load of any more than a single trailer. The Aristo Doodlebug handles a single Standard Heavyweight coach with no difficulty at all.

There is a power switch under the Doodlebug. Even though it is labeled "Light" it controls both the motor and the lights. My car came with the switch turned off so I was a little perturbed when it didn't run when I set it on the track. I would probably have known that if I'd read the manual first, but mine didn't come with a manual either.

Even though there are exhaust stacks, there is no smoke generator in the model.

There are operating Aristo knuckle couplers at both ends of the car. However, the uncoupling tab on the front one interferes with the pilot just a little. The coupler doesn't swing side to side freely and it sometimes snaps itself open as it pops over dead center. The rear coupler sticks out too far, as is common with all Aristo heavyweights. This has been fixed during the Kadee coupler installation.

There are truss rods packed with the car, but since it represents a steel car, it shouldn't need them.

The grillwork on the front face of the car can be adjusted to either open or close.

I had no problems with derailments with this car. Even though there were full size ivy stems laying across the track, the car just popped over them and kept on going. It handled rough spots, dried leaves and out of level track without complaint.

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After a month of heavy duty running, the Doodlebug started to derail big time for no obvious reason. There were three spots on the main, always entering a left turn, that it would derail every time. What was odd is that it had run the day before and had no difficulty at all. It is true that these three spots were out of level, but fixing the track didn't fix the problem. Getting down on my hands and knees at one spot revealed that the rear wheel of the power truck on the outside rail was lifting entirely off the track, by at least 1/4". It was clear that some sort of internal interference was at work.

For reasons unknown to me, the right sideframe had become cocked with the front end lifted up. As the Doodlebug was entering a left turn, the front edge of the right sideframe was rubbing on the frame and catching on a mold mark. The truck refused to rotate any further and the forces applied were lifting the rear of the truck. The mold mark isn't very big, maybe only 10 mils high, but it was big enough to catch the sideframe. Some quick work with a file, as shown by the white spots in the photo, fixed the problem entirely. Without any further changes to track, ALL of the derailments ceased.

The truck sideframes are not supposed to be able to rotate so that they could drag at that spot, but the screws that hold it on are set closely together and don't control the rotation of the sideframe very well. Some handling or something had rotated the sideframe so that it could rub on the frame. The end of the sideframes will also just touch the screw tab that attaches the cab floor. I filed a little off the corner there too although it didn't appear that it was actually part of the problem.

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The Doodlebug picks up track power on six wheels, four on the power brick and two on the rear truck. The rear truck has the same wiring scheme as the Streamliner truck or the four wheel heavyweight truck that it is derived from. Only one wheel is insulated from the axle. The insulated wheel does not pick up power. Power is picked up from the uninsulated wheel, through the axle and one wheel bearing.

The bearings can become a little intermittent as they do on the streamliners and heavyweights. This can be improved by wiring BOTH bearings on one axle together. Quickly solder a wire to the side of the unwired bushing. If you heat it too long, you'll melt the plastic journal. Solder the other end of the wire to the lug on the connected bushing of the same axle.

Traction tires do degrade the ability a wheel to pick up power. I did notice a tendency of the car to stall with either truck on a turnout. The stalling wasn't real serious, but it was there. Other than that, the car ran steadily on less than clean track. Perhaps replacement of the traction tires with normal wheels would improve the situation.

After only 6 weeks, the traction tires had become seriously cracked and one had actually broken. I got a new set of wheels WITHOUT traction tires (ART-29130) and changed them out. I immediately noticed an improvement in power pickup on dirty track. I also noticed a loss of traction. On my 1.6% grade, the Doodlebug would pull 7 standard freight cars without wheel slippage with the traction tires, but only 5 cars without the traction tires.

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The Doodlebug is made from a Standard Heavyweight car which represents a 72' car at 1:29 scale. The Doodlebug uses larger wheels than the heavyweights. A Standard Heavyweight uses wheels with a diameter of 1.16". The Doodlebug has 1.375" wheels which represent 40" wheels at 1:29 scale. Few railcars used wheels this large, but Aristo probably used them to match the wheels on the diesel power brick. Since all the truck dimensions are the same and the wheels are 0.2" bigger the car should ride 0.1" higher than a Standard Heavyweight. However, the overall car height comes out to be about the same. It appears that the springs are a little softer and the car settles a little more so that it matches the other cars well. Both the Heavyweight (left) and the Doodlebug (right) have had their Kadee couplers remounted to close the car to car spacing.

Due to the rather extreme length of this model, it probably won't even run on curves of less than 8' diameter. Even an 8' curve is pushing it, bigger curves would be better.

The power brick is recessed up into the car floor to allow the car to sit at a reasonable height without needing further modifications.

The car is about the same length as a Standard Heavyweight, but it is a little wider in one critical spot. There are two marker lamps at the front that hang out the side just a little. On curves, the end of the car hangs out quite a bit making the marker the most critical part in determining right of way width. A marker just clipped a tunnel portal which is rather firmly set in place on the GIRR. Nothing else has touched that portal before so this car is a new benchmark for curve clearance, at least compared to the stuff that I have already. It'll take just a little work with a file and a little touch up paint to adjust the tunnel portal so that the marker will clear.

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Several Doodlebug owners are reporting a problem with the Doodlebug roof. After exposure to some heat, the roof tends to warp and lift at the front. This causes the baggage compartment doors to fall out.

The roof is held down at the rear by screws and at the middle by clips, but nothing holds the front down. Apparently, heating of the roof causes it to warp. This would not have been a problem on the Standard Heavyweights because all the roofs are screwed down at both ends.

There are several potential fixes for this problem. My car doesn't have this problem yet so I have not been able to test any of them. If you try any of these and they work for you, I would appreciate a note and a photo if possible.

1. Glue a piece of styrene on the back of the radiator assembly to hold the front of the roof down. The piece wouldn't have to be very big but it could trap the roof. The roof would have to be slid underneath this piece to get it back on. If the piece were painted black, it wouldn't stand out too much.
2. Glue a block of styrene to the back of the radiator UNDER the roof and drive a screw through the top of the roof down into the block. A small screw would not be extremely obtrusive. There is a panel on the inside of the roof that would have to be partially cut away to clear the block.
3. Drive a screw through the panel at the front of the roof on the INSIDE of the car into the panel in front of it (part of the cab roof). The screw would be a bitch to get to but it wouldn't impact the outside appearance.
4. Maybe a small bulldog clip or spring clamp across the panels on the inside would be enough to hold it down.
5. If the topmost front rivet on the car wall under the front of the roof were drilled out with a small hole on BOTH sides, a 4" piece of music wire could be slid right through and pin the roof down. The end of the wire would not look too much different from the rivet it replaced. The baggage compartment door slide panel may require a small relief to clear the wire. This idea was adapted from a suggestion by Jon D. Miller.
6. A small piece of brass strip bent into an "L" shape could be glued to the front panel of the roof so that the end hooks underneath the similar panel on the back of the cab roof. This would have no external visual impact.
7. If the headlight is rewired back to the roof lighting circuit, the cab and main roof sections can be screwed or glued together to make a single roof section. The the screws at the front will be effective in holding down the roof. This suggestion comes from Dave Goodson.

It's Memorial Day, May 28, 2001 and the weather has finally cleared. The air temperature is about 75 degrees F and its bright and sunny. The Doodlebug has been sitting in the sun for about an hour and I noticed that the roof had warped, not at the front, but in the middle. The roof always had a tendency to bow upward at the middle, but the clips were usually enough to hold it down. The temperature of the black roof got pretty high, easily over 100 degrees F. The center clip will still engage and the roof will stay flat for awhile, then it'll pop back out maybe twice as far as shown in the photo. My roof apparently has different stresses in it than the ones that warp up at the front. The front end of mine is securely down.

I tried the pin fix in the center and this appears to be working. I drilled a #71 hole right between the 3rd and 4th passenger compartment windows at the very top of the car wall on each side. This hole passes through a flange of the roof behind the wall. I then threaded, with some difficulty, a piece of 0.025" music wire through the holes on both sides and clipped it off so that just a little bit sticks out on both sides. The roof is new securely pinned. Another soak in the sun produced no further changes.

I did have some difficulty getting the wire in, it took a few minutes of carefully forming the wire so that I could look through the windows on one side and guide the wire into the hole on the other side. It might be a little easier with a very small pin (such as one used for sewing) pressed into each side but the pin may work itself out or become cocked in the hole.

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The Doodlebug is lit like a Standard Heavyweight. There are four #53 bulbs in sockets inside the car, three in the passenger section and one in the baggage section. As with the Standard Heavyweights, they are much too bright. The heavyweight lighting modifications that decrease the internal lighting intensity will also work on the Doodlebug. These modifications are described on my Aristo Heavyweight Passenger Car Tips page.

The lighting by itself draws about 0.5 amps at 20 volts. After the quick and dirty version of the dimming modification, the total lighting load is about 0.27 amps.

The marker lamps at the front of the car are illuminated and show white. There is also a headlight on the front of the car. The markers appear to be brighter than the headlight. This could be fixed by replacing the incandescent bulb with a white LED however the headlight assembly is rather tightly glued together and access to the bulb is difficult. There is no lighting at all on the rear end of the car.

The roof is held on by two screws under the roof at the back of the car and two clips mid way along the car wall. The screws are easy to access by opening a rear car door for visibility and working through the holes in the car floor with a long slender screwdriver. The baggage doors will fall out when the roof is removed. When it comes time to put the roof back on, the baggage door handles go low and forward.

The rear end of the car was so plain that it needed something. I installed an 8000 mcd red LED (from The LED Light) as a FRED (Flashing Read End Device) even though FRED's weren't in use during the time that this car actually ran. The DCC decoder I installed (see below) had a FRED simulation as one of its function outputs so it drives the LED. This particular LED has a clear lens and a very tight beam so that it didn't show well off angle. I painted the lens with Tamiya X-27 Clear Red to act as a diffuser. The intensity is a little reduced but it was so bright to begin with that it doesn't matter. Now it is actually brighter off angle. Perhaps an LED with a lower peak intensity but a broader beam may be better in this application.

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A Kadee #831 can be mounted directly to the rear coupler mount but it sticks out way too far. The coupler mount can be moved by a number of means, but the one I have used on every heavyweight I own can be applied to the Doodlebug as well. Instructions are on my Aristo Heavyweight Passenger Car Tips page.

The front coupler is a little more involved. A Kadee #831 box can be adapted to the front mount but some modifications are required to the box and perhaps the pilot. The large offset coupler that comes with the #831 needs to be changed out with a medium offset coupler from an #836 kit.

The hole on the #831 coupler box needs to be drilled out to 0.225" and some shims should be glued to the box to space it downward and to provide a bearing surface for the ridges on the coupler mounting post. In my case, a 0.030" shim still left the coupler just a little high. The zero offset coupler from a #837 kit might fit better without the shims but then the post would have to be ground down just a little so that the washer will properly secure the coupler box and prevent it from tilting.

The coupler centering spring must be cut short so that it just fits into a #70 hole drilled into the back of the pocket. The coupler is remounted with the original screw and washer. The spring needs to be bent a little so that it doesn't hang up on the mounting screw. The opening in the pilot is narrow and allows minimal rotation of the coupler pocket. I'm going to try it this way for awhile. If it becomes obvious that more swing is needed, one more row of pilot bars can be clipped out to allow more movement.

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The wiring of the Doodlebug is pretty straightforward. This schematic sort of follows the physical layout if the car is viewed from the bottom. There are three conductor strips embedded in the floor sections. The strip on the engineer's side is the common connection, the center one carries unswitched power to connect the pickups on both trucks. The other strip carries switched power forward to the motor and back to the roof lights. This is the reason that the motor is switched along with the lights. A rather simple wiring change can place the motor on the unswitched circuit if desired. Cut the green motor wire where it enters the wiring bundle and connect it back to the bundle with two black wires.

Since all the necessary wiring is available in the baggage compartment, this is the only loco that I've seen that could have DCC installed without taking anything apart. The wiring can be pulled out a side door, cut and reconnected as desired. If the headlight and markers need to be wired to different circuits, then the cab roof needs to be removed to access the wires to each element separately.

The cab roof comes off with two difficult to see and reach screws way up in the roof line. You'll need a very long #1 cross point screwdriver to reach them. I had to search out an appropriate tool at an industrial tool supplier. It was actually a power screwdriver bit over 6" long. The hole in the floor is large enough to accept a #2 screwdriver, but the screws are too small for a #2. A magnetic screwdriver is HIGHLY recommended for this work. If your screwdriver isn't magnetized already, find a very strong magnet and wipe the bit across it in the same direction several times. The bit will become adequately magnetized to do the job.

The red/black pair on the front truck is the power pickup. The blue/green pair is the motor. The bundle with the largest number of wires is the common connection.

Conversion to R/C would be a piece of cake. There is plenty of room in the baggage compartment for batteries and an RX. With the roof removed, access would be easy. With the appropriately sized battery pack, it might be possible without even taking off the roof.

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Since it looked like it would be easy to do a DCC conversion, I went ahead and did it. I had a few Digitrax DG580L decoders that were out of service because they couldn't handle the load in other locos. The Doodlebug is likely to run light most of the time and it has only one motor, so that this "5 amp" decoder would only have to contend with a 0.5 amp load and it might be able to handle that. As predicted, the installation of the decoder itself didn't require the removal of any mechanical parts of the Doodlebug. All the wiring is done through a baggage compartment door.

I wanted to wire the headlight and markers from the decoder. To do that I actually had to remove the cab roof. Then all the necessary wiring was exposed. I considered converting the headlight to a white LED, but the headlight assembly was rather tightly glued together and I didn't feel like cutting it apart. I did drill out the headlight wiring hole in the roof a little so that the sleeving on the headlight wires would fit in the hole and conceal the red and green ends of the headlight wires.

I just cut the red and green headlight wires from the bundles at the front of the cab and used the old black wires for the markers. I then extended new wires to the decoder from the headlight wires.

This is a pretty straightforward installation. The decoder red and black wires are connected to the dedicated pickup wires. The switched power wire that used to come to the front was cut and insulated as it was no longer needed. The motor was wired directly to the decoder. Since the markers were too bright, I dimmed them with a 100 ohm resistor. The headlight is dimmed in reverse by a 100 ohm resistor. The red LED used for the FRED is wired down through the floor of the vestibule and across the bottom of the car and up into the baggage compartment through an existing slot in the floor.

I also show the modified roof wiring to dim the interior lighting. The changes wire the lamps in series-parallel instead of all being in parallel. The bulbs all run at reduced voltage and will last nearly forever. With DCC, the lights are on at constant intensity all the time unless turned off by the original lighting switch. When the decoder is being programmed, the lights must be turned off to remove their load or the programming operation will likely fail.

As expected with the Digitrax decoder, the unit is a little noisy at low speed. This is due to the low frequency motor controller used by Digitrax. With the exception of the noise, the performance of the unit is quite good even on dirty track.

I had to change out the decoder once as the first one that I picked had apparently been mortally wounded in a previous life (it came out of a Lionel Atlantic) and it didn't work quite right. Once it got going, it would never quite shut off when commanded to stop and the Doodlebug would just drift along for awhile. As can be seen from the lead photo in this section, the shrink wrap had melted around the switching transistors. It would appear that the unit had been heat damaged. A replacement decoder that used to be in an LGB industrial switcher worked as well as could be expected. I expect that after awhile, I'll get tired of the grumbling noise and change out the decoder for a better one.

Even with the light load that the Doodlebug applies to the Digitrax decoder and even with a heat sink attached, it still gets quite warm after extended operation. It is not hot enough to do itself damage, but it runs warmer than other decoders do even while driving significantly heavier loads.

After about a month of listening to the DG580L buzz and growl, I got tired enough of it to change it out to an NCE D408SR silent running decoder. It was an easy change out and all the noise and bother went away. It runs smoother too.