Railbus Blues

Does anyone know the over the tread diameter of the Bachmann On30 Railbus driving wheels? I noticed that the wheelsets are available on the Bachmann repair parts site for a reasonable price.

The reason for the request is another blast from the past and not a particularly good one. The very first bash that I did in HO (before my interest in On30) was recently unearthed. The body was a variation of a Mack AC railbus that I made out of cardboard salvaged from cereal boxes. The body was reinforced with some thin wood slats cut from tongue depressors, which were cadged from the doctor's office. The body was built to fit around the power unit for an early HO single-truck streetcar.

These units, which just begged to be converted into some kind of rail vehicle, had only one driven axle that was geared to a typical five pole, open frame motor, mounted at an angle. However, the units had small wheels equipped with small diameter axles and this was a problem. As the only readily available larger diameter drive wheels were from Athearn Hi-F rubber band drive locos, homemade bushings were required to fit their larger diameter axle holes to the small axles on the unit.

Having coaxed the open frame motor back to life, I put the now ancient bash on the track and prodded it into operation. Much to my chagrin and my embarrassment, the old bash wobbles just as much as the new one does.

Dang it; before I shuck this mortal coil and go gentle into that good night, I want to bash a model railbus that does not wobble, even if it requires using factory made On30 railbus wheels, hence my interest in the Bachmann ones.

I dug around in the Forum archives and found a set of drawings from 2008 for the BC&G railbus, a possible prototype for the Bachmann model.

On the railbus drawing the wheels appear to be three feet in diameter, which matches the diameter of the original rubber tires on the bash-bait model of the highway postal bus (a bit more serendipity).

Therefore the Bachmann On30 railbus replacement wheel set should work with the bashed railbus, so I ordered a set for just under $14.00, including postage and handling.

All the best to everyone.

Mounting the NWSL Stanton Drive Inside The Bashed Railbus Trailer

This project has been kicking my butt for a while, but by thinking outside of the normal model railroad box, so to speak, a simple solution was devised. The accompanying construction photos show the method that was adopted. To start with, there was an optional coupler pocket molded onto one end of the Drive chassis. As it would be in the way for this application, it was removed, as per the printed instruction sheet that came with the Drive.

The Drive is designed to be mounted by a threaded stud protruding upward from the top between the axles. Unfortunately, the former truck body that is used for the trailer bash has a solid bracing wall molded crossways at the center of the opening where the Drive is supposed to go, preventing the mounting by the use of the threaded stud. Fortunately, the flat tops of the chassis ends of the Drive, located between the axle mounted wheels, are on the same level, just above the wheel flanges, providing an alternative means for mounting the Drive, but one that requires some innovative work.

Adding to the project's degree of difficulty, three ounces of lead weights also need to be installed somehow, somewhere, inside the trailer body, plus there has to be room for a small DCC decoder and the connecting wires. The finished trailer will weigh just under 4.5 ounces, which is enough for good tracking while pushing and pulling the railbus as well as ensuring continuous power pickup.

The solution involves carefully nibbling away much of the irksome center wall with side cutting pliers and using the lead weights as impromptu mounting brackets for the Drive. The weights are the typical flat, half ounce size with double-sided foam sticky tape on the back. To save space the tape is removed by soaking the weights in isopropyl alcohol and attaching them with glue.

Serendipitously, the manufactured length of the weights just happens to be the size needed to secure the Drive at the right height, inside the trailer body. Two sub-assemblies of three weights each are glued into pyramid shapes. When they are centered and glued to the inside end walls of the trailer, they allow the chassis ends of the Drive to support the weighted body.

With careful, but not tedious work, the body is mounted square and level with the running rails with bits of double-sided foam sticky tape on the chassis ends. The tape allows the drive to be removable for either servicing or reassignment to other duties as required; after all, they don't make them anymore.

When the new railbus wheels arrive from Bachmann, decisions will then be made on how to finish the project. To wobble or not to wobble, that is the question.

For whatever reasons, the photos could not be loaded at the same time of the text. I will try later.

Perhaps now it will work. I logged out and then logged back in again.

The first photo is the oddly shaped NWSL Stanton Drive. The second shows the inside of the bashed trailer with the lead weight Drive mounts in place. The third photo is the mounted Drive. Additional detail parts will be added later.

More Railbus Blues

The Bachmann wheelset arrived. The wheels are beautifully done in metal, which means that one of the wheels must be hub insulated from the axle and it is the resulting axle that presents a major problem. What could - and should - be a simple piece of rod is a complex metal turning consisting of five different diameters, none of which lend themselves to railbus bashing.

The axle end for the hub insulated wheel is just 0.03" in diameter with a knurled section that engages the plastic hub. The opposite end is 0.05" to which the other wheel hub is firmly driven on. In between, there are three additional diameters (0.06, 0.07 and 0.10) of varying widths including another section of knurling that engages the hub of the bevel drive gear - one of the plastic gears known for breaking.

If I pull the wheels off to fit a new axle, provided I can find something suitable, I would probably wind up with another wobbly wheelset. Perhaps a bit better looking than my previous attempts at bashing, but wobbly none the less.

Maybe I should just jack the railbus up and put timber cribbing where the rear wheels should be and say that it is under repair. The railbus ain't gonna move that way, but it ain't gonna wobble either and I can finally sleep at night.

Eureka! I have done it!

With pretty much nothing to lose, except my fourteen dollar investment, I bit the bullet and pulled the wheels from the original axle. Those sneaky On30 designers at Bachmann hid some secrets that were not clearly visible until the wheels were off. For example, both of the wheels were insulated from the axle. The parts diagram does show this, once you figure out what you are looking at. Initially, a display of miniature Rorschach inkblots on a drawing that is filled with unspecified part numbers was, as the old saying goes, all Greek to me.

The 0.03" axle ends were there to hold on decorative plastic hub caps and both wheels were attached to the 0.05" axle segments using plastic hubs. This made it a lot easier to modify the complex wheelset assembly into the way things should be, in my humble opinion. It appears that the plastic hubs are the same composition as the notoriously faulty gears. However, as the hubs are under compression between the axle and the axle holes on the metal wheels, there should not be any future problems, but as so many of us have found out, there are no guarantees when it comes to little bits an pieces of Bachmann equipment.

Many years ago, I bought a pack of 1/16" round steel rods from NWSL, so I cut a piece off of one to replace the original Bachmann axle. Since both of the plastic wheel hubs were pressed over knurling on the original 0.05" axle, there was no problem using the slightly larger (0.0625") smooth steel rod for a replacement axle. I slipped some suitably sized brass tubing over the new axle as the wheels were being mounted for a one-piece bearing and the bashed wheel assembly spins nicely.

After a temporary reassembly of the railbus, a trial run was carried out. The re-wheeled bash now glides smoothly around the layout with no wobbles and no wiggles. Now I really can sleep at night, but as it is now (yawn) six in the morning, I'll think I'll wait until tonight to get started.

Connecting The Railbus To The Trailer

Of my previous attempts at building a railbus in On30, this is the first that I consider to be layout worthy. Throughout the project, serendipity always seems to be lurking about and fabricating this connection was no exception. In the finest tradition of rollingstock bashing, it just came together using parts already on hand. Having a collection of parts on hand that goes back some fifty years may have also been a help.

The rear of the railbus and the front of the trailer turned out to be at a suitable height for easy coupling to each other. Although that height is lower than the Kadee standard, a pair of regular couplers could be cobbled up to do the job, but they will be glaringly oversized for this light duty application. In their place, the former loco/tender flat metal drawbar from the previously scrapped AHM engine has been reunited with the recycled, wheel supporting underframe mounted beneath the railbus body.

As they originally worked well together, the drawbar pin was removed from the front of the derelict AHM tender. A simple styrene buffer bar was added to the front of the trailer, ostensibly supported by the slightly too long ends of its recycled dump car underframe and the pin was remounted under its center. This forms a separable and unobtrusive as well as flexible close coupling that is a match for the layout's eighteen-inch radius curves.

Here are some photos of the railbus/trailer hooked together for running on the layout. The discoloration on the side of the trailer is clear adhesive tape to temporarily keep the Stanton Drive from coming loose when the assembly is picked up. Until it is semi-permanently mounted (after painting) - better safe than sorry.

As I mentioned previously, I consider the railbus/trailer combination to be layout worthy. Now, if only I had a worthy layout on which to run them on.

An Unexpected Change For the Railbus

Changing the drive wheels has little physical effect on the railbus, but it did change the look of it. To my mind's eye, the large drive wheels required the installation of a different pilot truck. The tender trucks from the scrapped AHM engine seemed to fill the bill. However, the plastic frames had disintegrated to the point where the trucks fell apart as I was handling them. Fortuitously, as the photo shows, I had an extra truck and that one seems to be OK.

The new pilot truck uses the same mounting point and the same wheel and axle assemblies as the larger old one, but the wheelbase is about a scale foot shorter. When combined with the look of the wheel hiding outside frames, to me the proportions of the railbus are more agreeable.

Lions And Tigers And Bears! Oh My!

Actually, it is just the sounds of cows and sheep. I am referring to what is produced by the Tsunami SoundCar module marketed by SoundTraxx. While working on the railbus, I ruminated on the problem of supplying generic sounds for my model critters (the railroad related ones, not bovine and ovine miniatures).

The module also generates the required railroad sounds (bell, horn, engine exhaust) and for less money than reviving the defunct Whitcomb project, but there are some repercussions for the critters and the railbus. They will be equipped with SoundTraxx 851002 mobile decoders for running on layout DCC. On the plus side, these decoders are rather small and relatively inexpensive and they can be programmed with their own performance parameters. Only the SoundCar generated engine exhaust sounds will be generic.

I bought a SoundCar module from my LHS for about the same price as on eBay, plus I got to take it home and played with it right away. I wired it into the same speaker equipped plastic box that I used for the Whitcomb project. Since the critters and the railbus will only run occasionally, to interrupt the DCC that supplies the SoundCar module, a convenient On/Off switch was included on the front panel of the under-the-layout mounted project box. Sometimes, old technology rules.

Although the Tsunami SoundCar module does not have the panache of a full blown Tsunami2, it gets the job done nonetheless, plus there are considerably fewer of those pesky CVs that need to be programmed. Yes...the aforesaid animal sounds can be turned on and off, along with a number of other sounds.

Questions and comments are always welcome.

All the best to everyone.

SoundTraxx SoundCar Application

As my LHS does not stock the SoundTraxx 851002 mobile decoder that is needed for the railbus trailer, one was ordered off of eBay. It soon arrived and was installed. As usual, there are those pesky CVs to be programmed. As my Dynamis DCC control system requires, on average, twenty-three sequential keystrokes to program a CV, it is an annoying, necessary evil, but the end results are well worth the effort.

As the SoundCar unit and the mobile decoder do not monitor each other or otherwise communicate, a minor compromise will synchronize the automatically generated sounds with the movement of the train. Program CV3 (acceleration rate), CV4 (deceleration rater) and CV61 (braking rate) to corresponding values and they will, seemingly, linkup.

The Soundcar automatic sound functions that were chosen are the clickety-clack rail joint sound (CV131), the flange squeal sound (CV133) and the brake squeal sound (CV139). The usual DCC controller activated sound functions are horn (CVs129 and 115), bell (CVs130, 114 and 227) and the engine exhaust.

That sound is actually a diesel powered generator that is typically found on modern freight and passenger equipment and it can be independently turned on and off with DCC controller function F9. While it features startup and shut down sequences, once it gets going, the sound is a mechanized drone. When its volume is set to a background level (SoundCar CV132), the drone imitates a powered rail vehicle.

The SoundCar and decoder support the SoundTraxx manually set brake simulation (DCC controller function F11). To keep my loco manual controls configured the same, I moved the F11 brake function to the more convenient F7 position (normally the Hyperlight headlight dimmer control that I do not use) by reprogramming CV41 on the SoundCar and the decoder to a value of 128. The actual braking rate (CV61) is set between 127 and 255 on the both of them.

While waiting for the decoder to arrive, the railbus was pushed around the layout by a reanimated relic from my earlier Critt-acious period. It is a long dead Bachmann On30 Davenport that I equipped, during the rebuilding process, with one of the aforesaid mobile decoders. Its operation is now nearly perfect, as is that of the decoder equipped railbus and trailer.

The reason for the trial running was to experiment with various combinations of critter sounds generated by the SoundCar unit. All of the regular layout locos feature onboard sounds that vary as they wander around the layout. As the railbus and critter sounds are coming from a fixed source, directly in front of the layout operator, they are programmed to represent riding on the railroad equipment.

The exhilarating up-close sounds provided by the SoundCar unit pleasantly refresh age-old memories of being in the "railfan seat" next to the equipment operator (or even in the operator's seat) that occurred during the carefree days of my youth, with the critter and the railbus models providing a series of visual references as they silently perambulate around the layout.

nice write up. Thanks for sharing the information.

Bob

It Is Done! (Well...for now)

Although it has taken fifty-plus years, I managed to bash a wobble free railbus with prototype looks, prototype sounds and prototypical operation. While it may yet acquire some minor detail parts, I consider it complete.

As the last major step in its construction, the bash was dismantled to facilitate painting. While not my favorite activity, nonetheless, the painting needed to be done and it kinda-sorta turned out good. The bus roof and the lower section of the bus body, which are both diecast metal, were stripped of their original paint using acetone. Isopropyl alcohol was used to strip the plastic parts of the trailer body and the small, but essential plastic radiator for the bus.

The radiator was molded in black plastic and coated with a garish, glossy gold color, which was loosened by the alcohol soak. A small brush with soft brass bristles was used to remove the gold, leaving the radiator an unobtrusive matte black color, which was the desired goal.

As things turned out, the bus body window section was cast in a yellow plastic, so there was nothing to remove. After everything to be painted was given a bath in detergent water, they were ready to be sprayed with the primer and topcoat.

While a regular grey primer was used on the railbus and trailer bodies, the topcoat was another adventure in the world of spray can paint. As both would be subjected to regular handling, as is all of the layout rolling stock, to keep fingerprints to a minimum a semigloss topcoat was preferred. As a result, the color palette for the railbus seems to have defaulted to the pale yellow and dark brown of the layout structures.

While I liked the original yellow, no suitable replacement was found. A much paler semigloss yellow, nearly the same as the matte paint used on the layout buildings, became a workable compromise. To tone down all that pale yellow, the railbus roof was over sprayed with a coat of flat red primer, which is almost a boxcar brown.

The railbus yellow was a special Krylon paint that was found in a local arts and crafts store. Unlike my past, unhappy experiences with semigloss spray paints, it actually came out of the can with no drips or splatters and it quickly dried to a smooth, hard finish, so it was worth the exorbitant price of nearly ten bucks a can. My only regret with the railbus bash is that the topcoat color was not a deeper, darker yellow, but I can live with that.

All the best to everyone.

Dan, following your ageless rail bus story has been great. For a guy that doesn't love painting, your description of painting your rail bus sounds great. I dislike painting too but I look forward to photos of your finished rail bus. Steve