01/14/06
| NEW FRAME DESIGN FOR HO SCALE DIESEL LOCOMOTIVES |
About a year and a half ago, I started thinking of new ways to design HO scale diesel locomotive frames. It was
not that the manufacturer frames were not good, but they just did not lend themselves to prototype detail work
under the walk way without a lot of cutting. I am sure the ready to run crowd could care less about this, but
those of use (I can probably count all of those people on one hand) that strive for more detail in our models
want more. I am in no way trying to tell people how to model. I just want to offer up some good ideas.
This design can be adapted to just about any model. Not all, but a good many. I would have preferred to use
Kato drive components, but Kato is unreliable with stock and the cost of their parts is just ridiculous. I chose to
use Athearn for two reasons. One, you can actually get parts from them and two, their truck side frames are
hands down the best looking on the market.
My goal was to design a sub frame to fit inside a modeled plastic under frame that was prototype width or darn
near close to it. I also wanted to try and achieve the slung fuel tank look. What you see below is the result. This
frame has provisions for an Atlas motor. I also built into it my patented coupler draft gear box design. This is
actually something the manufacturers could easily design into their existing frames. I am pretty proud of this
design. I love building models, but I also love designing new things.
I think for the most part, people will be afraid to use my parts and ideas because it means you have to actually
"BUILD" a model.
not that the manufacturer frames were not good, but they just did not lend themselves to prototype detail work
under the walk way without a lot of cutting. I am sure the ready to run crowd could care less about this, but
those of use (I can probably count all of those people on one hand) that strive for more detail in our models
want more. I am in no way trying to tell people how to model. I just want to offer up some good ideas.
This design can be adapted to just about any model. Not all, but a good many. I would have preferred to use
Kato drive components, but Kato is unreliable with stock and the cost of their parts is just ridiculous. I chose to
use Athearn for two reasons. One, you can actually get parts from them and two, their truck side frames are
hands down the best looking on the market.
My goal was to design a sub frame to fit inside a modeled plastic under frame that was prototype width or darn
near close to it. I also wanted to try and achieve the slung fuel tank look. What you see below is the result. This
frame has provisions for an Atlas motor. I also built into it my patented coupler draft gear box design. This is
actually something the manufacturers could easily design into their existing frames. I am pretty proud of this
design. I love building models, but I also love designing new things.
I think for the most part, people will be afraid to use my parts and ideas because it means you have to actually
"BUILD" a model.
Above is the overall view of the frame. Disregard the openings between the motor mount area and the bolsters.
I had to build these parts with an adjustable bolster block just to make sure I could get the truck side frames to
clear the step wells. Currently you see the bolsters at the correct prototype spacing. Once I am satisfied with
where the bolster block is located, then I will have the frame cut from brass and build a model with it to see if it
functions the way I have designed it. So far it does.
I had to build these parts with an adjustable bolster block just to make sure I could get the truck side frames to
clear the step wells. Currently you see the bolsters at the correct prototype spacing. Once I am satisfied with
where the bolster block is located, then I will have the frame cut from brass and build a model with it to see if it
functions the way I have designed it. So far it does.
Just the overall top view. You can see where the Atlas motor will sit. What is nice about the Atlas motor is it
comes with a mounting cradle. With this frame, trim the screw lugs flush with the bottom of the cradle and then
set it in the frame. It will fit snuggly inside the motor cavity.
Now there is always gives and takes with designing something. With this design I was not able to put the drive
shaft in line with the worm gear. There is a slight angle from the motor to the worm gear. It is not a lot, but there
is an angle. I am talking about approximately a 5 degree angle.
comes with a mounting cradle. With this frame, trim the screw lugs flush with the bottom of the cradle and then
set it in the frame. It will fit snuggly inside the motor cavity.
Now there is always gives and takes with designing something. With this design I was not able to put the drive
shaft in line with the worm gear. There is a slight angle from the motor to the worm gear. It is not a lot, but there
is an angle. I am talking about approximately a 5 degree angle.
Here you can see the bolster block. But in this photo I wanted to show you my draft gear box mounting design.
See that cut out on the left with the four holes. Well, you glue the draft gear box up under the sill. Then when
you drop the sill on the frame, you put four screws through the frame into the draft gear box. Now essentially
the frame and sill are one piece and you are NOT pulling just off the pilot plate, but rather through the frame.
Pretty slick huh!
The two oblong holes you see in the bolster block are to feed the power wires through.
I'll tell you right now too. This is not an 18" radius curve carpet runner. We are looking at minimum in the mid
30" radius. Due to how narrow the frame is, the truck turning radius has to reduce as well.
See that cut out on the left with the four holes. Well, you glue the draft gear box up under the sill. Then when
you drop the sill on the frame, you put four screws through the frame into the draft gear box. Now essentially
the frame and sill are one piece and you are NOT pulling just off the pilot plate, but rather through the frame.
Pretty slick huh!
The two oblong holes you see in the bolster block are to feed the power wires through.
I'll tell you right now too. This is not an 18" radius curve carpet runner. We are looking at minimum in the mid
30" radius. Due to how narrow the frame is, the truck turning radius has to reduce as well.
Here you see the frame with a Kato sill on it. That is what it was originally designed for although you can build
your own deck and fit it up. I'll probably end up building my own deck and frame from sheet styrene. It is the last
thing I have to challenge myself to do.
your own deck and fit it up. I'll probably end up building my own deck and frame from sheet styrene. It is the last
thing I have to challenge myself to do.
This view is showing you with the bolsters at prototype spacing, the truck frames still sit nicely inside the step
well and they do swivel without interference.
well and they do swivel without interference.
This is an HT-C triple clasp built truck with full inboard and outboard clasps. In order to get this to swivel, I had
to slide the bolster block in on each end by 0.030". In my opinion, I think that is an acceptable compromise. I like
it better than leaving the outboard clasp off.
to slide the bolster block in on each end by 0.030". In my opinion, I think that is an acceptable compromise. I like
it better than leaving the outboard clasp off.