Building an OTM Tracker from scratch

 The OTM (On Track Maintenance) tracker is manufactured by Brandt in Canada.

 

 

 

 

 

 

(Photos for reference only)

Although they use John Deere components for their MOW equipments, I started with a Kibri Liebherr Excavator model.

The OTM tracker can move on top of railway gondolas and deliver track ties, ballast and rail along the railroad track, where needed. It is quickly transitioned from the highway transport deck to the top of rail maintenance cars within minutes.

Actually there is only one H0 model available, but it proves to be too expensive to ship over to Europe. So I decided to scratch build a more or less believeable representation of such a piece of equipment.

As with every scratchbuilding project, it all starts with a handful of styrene strip and profiles from Evergreen.

First, I started with the moveable frame.

I cut two pieces of #284 H-column, nine feet long, and five pieces of #175 five feet long. I then glued the five .100x.100 square strips between both H-columns, spaced like in the picture below.

Then I cut two strips of #145 to fit diagonally between the center and the outside braces. I sanded and beveled the strip, until they fit correctly. (see picture below)

Next, I modeled the ends of the frame with the hydraulic pistons (simplified)

I need two pieces each of #266 channel and #138 square strip, cut to seven feet length. One square piece is glued to the back of one channel piece. Then I cut four #223 tube two feet long. These are the pistons and glued to the outside edges of the channel assembly. (picture below)

Then I glued the piston assembly to the edge of the frame, like in the above picture with the completed frame.

The next sub-assembly is the moveable pads, which rest on the rim of the gondola.

I cut two #252 square tube pieces 8.5' long (they should loosely fit between the gondola walls).

Then I cut four #153 square strip pieces four feet long and also four #133 strips, one foot long. The small strips are glued to the edge of the square strip, to form the pad.

 

Unfortunately the pads fit very loosely into the tube, so I carved the shaft with my hobby knife, to give them more friction inside the tube. Care must be taken  not to cut or brake the shaft. I know it's not the most elegant solution, but it works. Probably after painting the shafts, there will be some friction also.

Then the pad assembly is glued to the bottom of the frame, like in the picture below. I added round styrene strip for the pistons. I have a sample pack from Slaters, so I don't know the exact size, but 1/32" should fit.

The frame assembly should look like pictured below.

Now on to the lower frame of the tracker platform.

We need two #252 square tube pieces again, and four each #153 and #133 of the same dimensions than for the large frame.

The two #284 H-column pieces are 7 feet in length. They are spaced with two #155 strips of 6.5 feet length. The two pad assemblies are glued to the edges of the #155 strips. 

Two #133 strips are glued crosswise to the square assembly. It will look like on the picture below.

The lower platform and the large frame will look like in the following photo, with the large frame resting on the lower platform. They should barely touch.

As I mentioned above, I did use a Kibri kit #11264 instead of the prototype John Deere Excavator.

For the upper platform, to which excavator is mounted to, I used the chassis from the kit and assembled the part following the instructions. It's only a two-part assembly. The axle suspension will hold the hydraulic pistons. To do this, I cut the lugs, which usually hold the axles, and sanded the underside flat, like seen on the picture below.

I cut two pieces of #175 square strip 6.5 feet long and glued #223 tube pieces at each end of the strip. These represent the four pistons.

Then I glued the two assemblies to the axle mounts on the chassis, like seen in the picture below.

The length of the 'pistons' should be at least match the thickness of the large frame H-columns.

The upper chassis and the lower platform are now glued together with the large frame sandwiched in between. The large frame should move freely between the chassis assembly. Styrene rod is inserted into the round tubes to simulate the pistons.

Now the assembly is ready for the paint booth.

My OTM tracker painted and weathered.

A nice piece of equipment added to my modern fleet.

Next up will be another OTM tracker with a Caterpillar Excavator. 

Stay tuned and thank you for your interest. Comments always welcome.

Building a cheap electric static grass applicator

Standing grass is a very realistic scenic feature on every train layout or diorama. Unless you are really building large layouts professionally, you don't need one of these expensive tools which quickly cost in the 100 Euro range. That's my opinion and the bucks saved can be invested into more models. So, if you want to know how to save money without missing the opportunity of having good looking grass on your layout, keep on reading. I'll show you in a couple of steps how to do it.

There are multiple designs of electric fly swatters, so it doesn't matter which one you choose. The blade will be removed anyway. The electronics inside is always the same. Look for a model where the two halves are screwed together. Otherwise you will destroy the handle.

 

 

The fly-swatter consists of a handle to which the swatter is attached with a couple of screws. When unscrewing the two halves the swatter may be detached from the handle. A small electronic board provides the high voltage needed. I detached the two wires and discarded the swatter.

The biggest problem consisted in finding a plastic sieve with a metal mesh. Any other metal sieve would also work, but then the danger of accidentally touching the sieve and getting an electric shock would be higher.

I shortened and drilled two holes in the handle to fit over the two pins that held the swatter before. This could be different, depending on what swatter you have. A bit of improvisation is advisable. 

 

 I soldered one of the wires to the mesh.

 

 

 

Then I lengthened the other lead with a clamp on one end. This is the ground wire, which will be clamped to a screw or nail inserted into the scenery.

To avoid using batteries, I soldered two wires to the battery contacts to power the unit with a external power pack.

I bought a 3V / 1 Amp power supply for less than 3 Euros and connected it to the wire using a male and female plug.

My power cord is about 2 meters long, which is enough to move around freely.

I attach the ground clamp to a screw, inserted in the center of my workspace, where I want to plant my static grass.

The advantage over an applicator with a pot is that you may reach lower areas easily.

Nevertheless I could not resist to buy one of the cheaper offerings with a large pot and two different styles of mesh. This one makes applying longer static grass easier. Next I will change it to external power also.

The small sieve is ideal for the short 2mm fibers

Here is an example of static grass applied to seaweed for bushes and in tree making.

 

My first attempts with static grass application.

DISCLAIMER: Be aware that this electric device may cause an electric shock. If you build it, you use it under your own responsibility.

Building a switching layout (Part 9) The Yard addition

My switching layout is operational for two years now. I haven't shown it at many shows since, due to time issues. Last autumn I thought that it would be time to attend a couple of shows in France and Germany for the upcoming month. So my first appearance was at the RAMMA Show in Sedan in mid-october 2019. Although I enjoyed operating the layout I found that something was missing to my enjoyment. A neighboring layout almost had the same size as mine, but he had continuous running through an oval with a narrow yard, connected to his layout. My layout only has a short cassette which serves as a drill track for a locomotive and only one (!) car. In fact I only switch the same cars over and over again, except when the big 0-5-0 comes and swaps some cars.

Shortly after the Sedan Show, I headed to my local lumber yard and bought me the required plywood sheets for my new extension of the layout. The days after the show I already made plans how the extension would look like. With measurements on hand, I ordered the sheets cut up, so that I only had to assemble the different segments.

The layout consists of two 90cm (approx. 3 feet) segments, so I build the boxes for the yard to match their size. As I adopted the 90 cm length as a standard for my future show layouts, the yard and future oval will always match whatever layout I would use.

The yard will have a total length of three segments. These will not be needed with my actual switching layout, so I concentrated on only two segments. To save space I used a PECO medium radius 3-way turnout on each side of the yard.

This minimal configuration gives me plenty of storage space to turnover my rolling stock during operations.

I powered the turnouts with surface mounted motors for easy maintenance. Two power the motors I used PECO switches. To install the switches, I had to drill and cut appropriate holes into the baseboard.

 After the wiring was finished, I attached 3mm MDF boards to the sides of the segments. These extend 3cm above the baseboard and prevent rolling stock from falling off the sides. The yard will not be scenicked and its only purpose is to store locomotives and rolling stock on and beside the tracks.

The yard sections rest on a 30 cm deep IVAR shelf from IKEA. The shelf boards give me additional storage space for boxes and stuff needed.

When using the yard as an extension to my switching layout, the original cassettes serves as drill track for a locomotive at the end of the yard. To save space, the 3-way turnouts are located at the edge of the segments, so the cassette is very useful here.

To save on set-up time I installed alignment dowels on all of my segments. To allow multiple configurations I copied the location of the dowels on the cassette to the curve as well as the straight yard sections. Now it's possible to set the layout up in a straight line, as a U or inverted C or as an L, depending on the available space at a show.

With continuous running in mind, I chose to use a 20" radius for the curve. This is tight, I know, but with short switchers and freight cars, the tight radius curve will be no problem.

The new configuration was tested at two shows in December 2019. Some minor issues were corrected and some improvements made and now the layout is ready for the next upcoming shows in 2020 and beyond.

I spent the days between Christmas Dinner and New Year's Eve Dinner to build the third yard segment, which may be inserted in the center of the yard. This, of course in anticipation of the run-around situation for the next show layout.

To avoid tearing up the tracks at the edges of the segments, I always solder the rails to screw heads and cut them later. This makes for a perfect alignment and together with the alignment dowels on the segments I've never had derailment problems.

Stay tuned for more updates.