gregh
electronics, computers and scratchbuilding

I bought a PIKO 0-6-0 motor block intending to make a small 2-6-0 tender loco, but somewhere along the line I decided on a 2-6-4 tank similar to a New South Wales Railways 20 class like this:
And this is the almost finished model.
Naturally it is battery powered and radio controlled using Hobbyking 2.4 GHz equipment (see my webpages for more info on this stuff http://www.members.optusnet.com.au/satr/2point4GHz.htm )
So this is a blow-by-blow description of the work.
The first thing to do is to produce a drawing of what it will look like. I am not modelling an exact copy, as it has to fit the small wheels and wheelbase of the PIKO. It also has to have a boiler dia equal to the piece of pipe I have, and have general dimensions of about 140 high, and to have space and access for the batteries and radio control and sound. The PIKO has equally spaced wheels where the prototype has assymetric spacing.
This is how I do the drawing using MS Paint, PhotoEditor and Word. First, in Word, set the page display to View|Print layout so you see the actual page on the screen.
By holding an A4 sheet up to the screen, I have found that if I set my screen size to 70%, it will display as full size on the screen and print the same size as on screen. You may need a different percentage depending on your screen size.
You have to display the Drawing toolbar. I usually rotate the page to landscape view and have to draw at ½ full size to fit the loco across the screen.
Then I open the side view picture in Paint and copy and ?Paste special? into Word.
Then in Word, I draw some simple outline boxes over the picture.
Then ?Group? the boxes and drag down for a separate picture.
I take a photo of the motor block and repeat this procedure to overlay the wheels on the dwg.
Now I adjust the size of the loco pic to give a suitable value for:
the required height (140 cab)
height of running board (45)
boiler dia to suit the pipe I have - 57mm
Motor block location
I wanted to keep the distance from the drivers? centerline to rear end to a max of 140mm to reduce overhang on short curves, so I shortened the side tank and boiler. Because the driver wheel spacing and diameter is smaller than original, this also helps to maintain the correct ?look?. I reduced the front overhang. I use a plastic ruler for measuring on the screen.
Now I group the loco outline and motorblock outline for a completed pic.
Later on I?ll be able to try colours and lettering styles on this pic too.
So now it?s time to start building. I like to start with a ?flat surface? to work with, so I glued 20mm x 20mm aluminium angle to the motor block to make a frame. Everything below this attaches to it. Everything above is attached to the footplate which just sits on it ? no screws.
The footplate is made from 2 thicknesses of 1.5mm styrene with many cutouts for wheel clearance etc.
The motor block does not come with coupling rods so I had to make them from copper clad electronics board. The wheels have strange square-and-round holes for the coupling rods. Luckily I found that these little ?joiners? for garden irrigation pipe were a push-fit into the holes after squaring up a little with a file. They are the right internal size for a 1/8? tap. I superglued them to the wheels.
The steps are soldered up from copper sheet and brass angle ? I?ve found that stuff under the footplate has to be STRONG to take derailment damage. This includes the cowcatcher and buffers too.
... more to follow.......

And this is the almost finished model.

Naturally it is battery powered and radio controlled using Hobbyking 2.4 GHz equipment (see my webpages for more info on this stuff http://www.members.optusnet.com.au/satr/2point4GHz.htm )
So this is a blow-by-blow description of the work.
The first thing to do is to produce a drawing of what it will look like. I am not modelling an exact copy, as it has to fit the small wheels and wheelbase of the PIKO. It also has to have a boiler dia equal to the piece of pipe I have, and have general dimensions of about 140 high, and to have space and access for the batteries and radio control and sound. The PIKO has equally spaced wheels where the prototype has assymetric spacing.
This is how I do the drawing using MS Paint, PhotoEditor and Word. First, in Word, set the page display to View|Print layout so you see the actual page on the screen.
By holding an A4 sheet up to the screen, I have found that if I set my screen size to 70%, it will display as full size on the screen and print the same size as on screen. You may need a different percentage depending on your screen size.
You have to display the Drawing toolbar. I usually rotate the page to landscape view and have to draw at ½ full size to fit the loco across the screen.
Then I open the side view picture in Paint and copy and ?Paste special? into Word.
Then in Word, I draw some simple outline boxes over the picture.

Then ?Group? the boxes and drag down for a separate picture.

I take a photo of the motor block and repeat this procedure to overlay the wheels on the dwg.


Now I adjust the size of the loco pic to give a suitable value for:
the required height (140 cab)
height of running board (45)
boiler dia to suit the pipe I have - 57mm
Motor block location
I wanted to keep the distance from the drivers? centerline to rear end to a max of 140mm to reduce overhang on short curves, so I shortened the side tank and boiler. Because the driver wheel spacing and diameter is smaller than original, this also helps to maintain the correct ?look?. I reduced the front overhang. I use a plastic ruler for measuring on the screen.
Now I group the loco outline and motorblock outline for a completed pic.

Later on I?ll be able to try colours and lettering styles on this pic too.
So now it?s time to start building. I like to start with a ?flat surface? to work with, so I glued 20mm x 20mm aluminium angle to the motor block to make a frame. Everything below this attaches to it. Everything above is attached to the footplate which just sits on it ? no screws.

The footplate is made from 2 thicknesses of 1.5mm styrene with many cutouts for wheel clearance etc.

The motor block does not come with coupling rods so I had to make them from copper clad electronics board. The wheels have strange square-and-round holes for the coupling rods. Luckily I found that these little ?joiners? for garden irrigation pipe were a push-fit into the holes after squaring up a little with a file. They are the right internal size for a 1/8? tap. I superglued them to the wheels.

The steps are soldered up from copper sheet and brass angle ? I?ve found that stuff under the footplate has to be STRONG to take derailment damage. This includes the cowcatcher and buffers too.
... more to follow.......