A scratchbuilt "big" diesel
Posted: Mon Aug 03, 2020 4:04 am
This is a loco build from a few years back.
Despite not being a diesel fan, I decided I would build a ‘larger’ one as they are much easier than a steam loco. I don’t build exact models but like to choose bits from different prototypes. After perusing many photos, I decided I wanted a two hood type, with a small low hood at the front, and a cab that stood higher than the main hood.
I used an Aristo motor block ART29351 from wholesaletrains.com . This is the one used in their L’il Critter. I had another spare set of bogie side frames left over from a previous build. (Aristocraft is no longer a great source of motor blocks)
Planning
My usual method of drawing the plans is to take a side-on pic of the bogie and obtain either a pic or plans of the loco. I then crop the loco pic below the running board and paste both in to LibreOffice Writer. If I adjust the screen “%” (“zoom”) I can draw it to full or half size for an A4 paper size. I shortened the drawing to suit the wheelbase and the total length I wanted. I’ve decided 500mm is the absolute max length for any vehicle on my line, so this one is 480mm.
Then I used Libre Office Draw to outline around the pic to get a simple, full-size drawing, like this. Allows me to decide on colour scheme and lettering style too.
Now the hardest part for me - how to fit everything in and be able to access it, with the minimum number of plugs and sockets. This planning usually takes more time than building it !
I had bought the 2.4 GHz speed controller and receiver, and a 3000 mAh LiPo battery, and the sound card, so I had their sizes. I made sure the hood was wide and high enough to fit them in.
Getting started
Finally I actually started work. First I built the dummy bogie from bits of 25x25mm aluminium angle, some wood and used old plastic Bachmann wheels. They are 3mm smaller diameter than the powered wheels, but who’s going to notice when the side frames are the same level. This shows the top and undersides. The yellow is a bit of scrap steel for weight.
The lugs on top of the bogies were ground off to create a flat bearing for the baseplate to swivel.
Then I cut the baseplate from 1.5mm styrene and glued 10x3mm aluminium bar underneath for strength.
Then I started making all the body pieces, from 1.5mm styrene. It’s amazing how many bits there are. This pics shows most except the cab roof. I’ve learnt from experience that it’s best to put all the detail on BEFORE you assemble it ! (Did I really say that a diesel was easier to build than a steamie?)
I used 0.5mm clear acrylic for windows and build up a sort of frame inside the cab so the acrylic slides in from the top. This allows the windows to be fitted after painting. This pic gives the idea. Here’s the top of the long hood and one of the sides. All the hood and cab sides glue/screw onto the base. All electronics fits in the long hood so all wiring to motor, battery, switch, sound card, charge points, and lights is fixed in place. The only plug/socket is to the speaker which is mounted on the hood roof which is held in place by small magnets. The 2" dia speaker mounts under the circular 'radiator' grill.
to be continued......
Despite not being a diesel fan, I decided I would build a ‘larger’ one as they are much easier than a steam loco. I don’t build exact models but like to choose bits from different prototypes. After perusing many photos, I decided I wanted a two hood type, with a small low hood at the front, and a cab that stood higher than the main hood.
I used an Aristo motor block ART29351 from wholesaletrains.com . This is the one used in their L’il Critter. I had another spare set of bogie side frames left over from a previous build. (Aristocraft is no longer a great source of motor blocks)
Planning
My usual method of drawing the plans is to take a side-on pic of the bogie and obtain either a pic or plans of the loco. I then crop the loco pic below the running board and paste both in to LibreOffice Writer. If I adjust the screen “%” (“zoom”) I can draw it to full or half size for an A4 paper size. I shortened the drawing to suit the wheelbase and the total length I wanted. I’ve decided 500mm is the absolute max length for any vehicle on my line, so this one is 480mm.
Then I used Libre Office Draw to outline around the pic to get a simple, full-size drawing, like this. Allows me to decide on colour scheme and lettering style too.
Now the hardest part for me - how to fit everything in and be able to access it, with the minimum number of plugs and sockets. This planning usually takes more time than building it !
I had bought the 2.4 GHz speed controller and receiver, and a 3000 mAh LiPo battery, and the sound card, so I had their sizes. I made sure the hood was wide and high enough to fit them in.
Getting started
Finally I actually started work. First I built the dummy bogie from bits of 25x25mm aluminium angle, some wood and used old plastic Bachmann wheels. They are 3mm smaller diameter than the powered wheels, but who’s going to notice when the side frames are the same level. This shows the top and undersides. The yellow is a bit of scrap steel for weight.
The lugs on top of the bogies were ground off to create a flat bearing for the baseplate to swivel.
Then I cut the baseplate from 1.5mm styrene and glued 10x3mm aluminium bar underneath for strength.
Then I started making all the body pieces, from 1.5mm styrene. It’s amazing how many bits there are. This pics shows most except the cab roof. I’ve learnt from experience that it’s best to put all the detail on BEFORE you assemble it ! (Did I really say that a diesel was easier to build than a steamie?)
I used 0.5mm clear acrylic for windows and build up a sort of frame inside the cab so the acrylic slides in from the top. This allows the windows to be fitted after painting. This pic gives the idea. Here’s the top of the long hood and one of the sides. All the hood and cab sides glue/screw onto the base. All electronics fits in the long hood so all wiring to motor, battery, switch, sound card, charge points, and lights is fixed in place. The only plug/socket is to the speaker which is mounted on the hood roof which is held in place by small magnets. The 2" dia speaker mounts under the circular 'radiator' grill.
to be continued......