Building Hood Sides, Page 2
To get started on building the sides I first need to cut the backing sheet to size, but before that
you want to choose the thickness of your backing sheet. It is suggested that you use 0.020".
As I said before this article is based on building my EJ&E SD38-2 project and the first of these
units is built using the Athearn SD40-2 walkway as a base. Using this walkway I attached strips
along the inside edges as gluing strips. I do not like abutting joints. I prefer overlapping joints.
Doing this made me have to build my backing sheets from 0.015 sheet styrene. So depending
on how you build your model will determine the thickness of your backing sheet.
First step is to cut your backing sheet. The length will be determined by the locomotive you
are building, but the height is the same. The height can be easily found from measuring the
height of the Cannon & Co. long hood end you are using. Using my calipers I measure it to be
1.239". So we have the height, now you need the length. For reference, I used a Kato
SD40-2. Some people may disagree, but Kato in my opinion nailed the hood length and I will
explain why I say this.
I used the web site UTAHRAILS.NET as a prototype reference. This site has hood
measurements of a UP SD40-2 and the SD40-2 and SD38-2 basically use the same hood
dimensions. Look under the heading "Locomotive Notes" and then "SD40-2 and SD40T-2
Measurements". The term end sheet is also known as the pilot face. So taking these
measurements I came up with the hood length to be 5.555". Here are my calculations.
Rear of cab to rear end sheet = 47'-8" (6.575")
Rear of car body to rear end sheet = 5'-9.5" (0.799")
Rear of car body is referring to the end of the long hood point. So now we have to do some
math. Subtract 0.799" from 6.575" and you get 5.775". Now we have to subtract from 5.775"
the depth of the Cannon & Co. long hood end. I measure that to be 0.245". Now from that
0.245" you have to subtract the inner lip running down the mating edge of the long hood end
(see photo at right). The lip sticks up 0.025". So now take 0.025" from 0.245" and you get
0.220". Now we take this 0.22" from the total long hood length of 5.775" and we come
up with 5.555". I took my calipers and run it out to 5.555" and then compared the Kato shell to
this and the Kato shell was dead on from the rear of the cab to the parting line between the
long hood side and the long hood end.
So now you know how I came up with my long hood length dimension. Time to cut and start
building. As I mentioned above, I used 0.015" styrene for the backing sheet. I took a new
sheet of 0.015" and cut a strip off the long side the height of the hood side (1.239"). This strip
is long enough to cut both sides. From the above mentioned length we know how long the
exterior length needs to be, but since this is the backing sheet, the long hood end mating
edge lip will interfere with the real length. Cut the backing sheet 0.025" to 0.030" shorter. The
leading edge of the backing sheet that abuts the rear of the cab will be even with the laminate
sheet that builds the clean air room.
CUTTING TIPS: When cutting sheet styrene,
put your straight edge over the portion that you
want to keep. This will help insure you have a
straight edge cut rather than a beveled edge
cut on your sheet. Also, use firm even pressure
with multiple passes. Do not try to cut it in one
pass and always on important cuts, use a new
knife blade.
I usually cut my sheet a couple thousandths
wider. Maybe 0.001" to 0.002" and lightly sand
it to size. It is very easy to cut your sheet to
narrow if you cut right on the correct
measurement. Test your height cut by fitting
it up to the long hood end. If it is even with the
top and bottom, you are good to go.
NOTE: All your laminate strips and sheets will be cut from 0.020" thick material.
Also one last note before I start. It is very critical for fit up that you make clean 90 degree cuts
in your sheets. I use an adjustable protractor and I square it up with my 1-2-3 blocks. From
that I can achieve the accuracy I want in my cuts.
you want to choose the thickness of your backing sheet. It is suggested that you use 0.020".
As I said before this article is based on building my EJ&E SD38-2 project and the first of these
units is built using the Athearn SD40-2 walkway as a base. Using this walkway I attached strips
along the inside edges as gluing strips. I do not like abutting joints. I prefer overlapping joints.
Doing this made me have to build my backing sheets from 0.015 sheet styrene. So depending
on how you build your model will determine the thickness of your backing sheet.
First step is to cut your backing sheet. The length will be determined by the locomotive you
are building, but the height is the same. The height can be easily found from measuring the
height of the Cannon & Co. long hood end you are using. Using my calipers I measure it to be
1.239". So we have the height, now you need the length. For reference, I used a Kato
SD40-2. Some people may disagree, but Kato in my opinion nailed the hood length and I will
explain why I say this.
I used the web site UTAHRAILS.NET as a prototype reference. This site has hood
measurements of a UP SD40-2 and the SD40-2 and SD38-2 basically use the same hood
dimensions. Look under the heading "Locomotive Notes" and then "SD40-2 and SD40T-2
Measurements". The term end sheet is also known as the pilot face. So taking these
measurements I came up with the hood length to be 5.555". Here are my calculations.
Rear of cab to rear end sheet = 47'-8" (6.575")
Rear of car body to rear end sheet = 5'-9.5" (0.799")
Rear of car body is referring to the end of the long hood point. So now we have to do some
math. Subtract 0.799" from 6.575" and you get 5.775". Now we have to subtract from 5.775"
the depth of the Cannon & Co. long hood end. I measure that to be 0.245". Now from that
0.245" you have to subtract the inner lip running down the mating edge of the long hood end
(see photo at right). The lip sticks up 0.025". So now take 0.025" from 0.245" and you get
0.220". Now we take this 0.22" from the total long hood length of 5.775" and we come
up with 5.555". I took my calipers and run it out to 5.555" and then compared the Kato shell to
this and the Kato shell was dead on from the rear of the cab to the parting line between the
long hood side and the long hood end.
So now you know how I came up with my long hood length dimension. Time to cut and start
building. As I mentioned above, I used 0.015" styrene for the backing sheet. I took a new
sheet of 0.015" and cut a strip off the long side the height of the hood side (1.239"). This strip
is long enough to cut both sides. From the above mentioned length we know how long the
exterior length needs to be, but since this is the backing sheet, the long hood end mating
edge lip will interfere with the real length. Cut the backing sheet 0.025" to 0.030" shorter. The
leading edge of the backing sheet that abuts the rear of the cab will be even with the laminate
sheet that builds the clean air room.
CUTTING TIPS: When cutting sheet styrene,
put your straight edge over the portion that you
want to keep. This will help insure you have a
straight edge cut rather than a beveled edge
cut on your sheet. Also, use firm even pressure
with multiple passes. Do not try to cut it in one
pass and always on important cuts, use a new
knife blade.
I usually cut my sheet a couple thousandths
wider. Maybe 0.001" to 0.002" and lightly sand
it to size. It is very easy to cut your sheet to
narrow if you cut right on the correct
measurement. Test your height cut by fitting
it up to the long hood end. If it is even with the
top and bottom, you are good to go.
NOTE: All your laminate strips and sheets will be cut from 0.020" thick material.
Also one last note before I start. It is very critical for fit up that you make clean 90 degree cuts
in your sheets. I use an adjustable protractor and I square it up with my 1-2-3 blocks. From
that I can achieve the accuracy I want in my cuts.
Now that you have your backing sheet cut, it is time to setup and start adding your laminate
sheets to build up the exterior of the hood. A quick note here. Your hood side will be to short
for the clean air room. Do not worry about that because your laminate sheets for the clean air
room will correct this.
Get out a strip of 0.020" x 0.125" strip styrene. Using my squaring blocks, I put the leading
edge and the bottom edge up against the squaring blocks. The clean air room on the SD40-2
and SD38-2 measures 1.2" from the back of the cab to the start of the engine room. As you
can see in the photo, I slid the strip to 1.2" and then tack glued it in place.
I cut the strip longer than the backing sheet and let more than enough stick out the rear. You
do not want to make the back end of the strip even with the backing sheet.
I am building my sides on a piece of glass. The glass gives you a nice flat surface to work on.
Using the bottom edge of my sides as a reference, I sandwiched the hood side and the bottom
laminate piece between a 1-2-3 block and a brass block. Using my thin steel scale you see in
the above photo, I made sure the bottom edge of the strip was flat on the glass by sliding it
down between the blocks and pushing the strip down to contact the glass. Using the blocks
helps to make sure the bottom edges are flush and squared with each other. I ran a bead of
glue along the seam. Glue a little, slide the sheets out and glue some more. When it was all
done, I glued along the bottom edge.
DO NOT trim the rear edge at this time. You do not want to trim it flush with the backing edge.
sheets to build up the exterior of the hood. A quick note here. Your hood side will be to short
for the clean air room. Do not worry about that because your laminate sheets for the clean air
room will correct this.
Get out a strip of 0.020" x 0.125" strip styrene. Using my squaring blocks, I put the leading
edge and the bottom edge up against the squaring blocks. The clean air room on the SD40-2
and SD38-2 measures 1.2" from the back of the cab to the start of the engine room. As you
can see in the photo, I slid the strip to 1.2" and then tack glued it in place.
I cut the strip longer than the backing sheet and let more than enough stick out the rear. You
do not want to make the back end of the strip even with the backing sheet.
I am building my sides on a piece of glass. The glass gives you a nice flat surface to work on.
Using the bottom edge of my sides as a reference, I sandwiched the hood side and the bottom
laminate piece between a 1-2-3 block and a brass block. Using my thin steel scale you see in
the above photo, I made sure the bottom edge of the strip was flat on the glass by sliding it
down between the blocks and pushing the strip down to contact the glass. Using the blocks
helps to make sure the bottom edges are flush and squared with each other. I ran a bead of
glue along the seam. Glue a little, slide the sheets out and glue some more. When it was all
done, I glued along the bottom edge.
DO NOT trim the rear edge at this time. You do not want to trim it flush with the backing edge.
I used my squaring blocks on the bottom edge and leading edge and then glued the clean air
room sheet in place. The top edge will overlap the backing sheet a bit. This is OK and you
want that.
In the photo at the left you will see me installing the right edge to the blower duct. You can now
really see how useful the squaring blocks are. I glued in a piece of 0.020" x 0.020" strip to
close off the right side and now it is time to build the engine room compartment.
room sheet in place. The top edge will overlap the backing sheet a bit. This is OK and you
want that.
In the photo at the left you will see me installing the right edge to the blower duct. You can now
really see how useful the squaring blocks are. I glued in a piece of 0.020" x 0.020" strip to
close off the right side and now it is time to build the engine room compartment.
Here you can see both clean air rooms are in place. You will notice a small notch in the upper
leading edge corner. This is to fit under the dash 2 cab. Take your time and measure how
much you need to cut out. Best to cut a little at a time, fit and cut again until you have a
perfect fit. You can see here as well how the laminate sheet overlaps the backing sheet.
You will also notice on the blower duct side I had to cut the hood side up from the bottom. This
is because I am using the Athearn walkway and have to make a clearance cut for the blower
duct. If you are using a Kato walkway, you do not need to do this.
You can see I have installed the electrical cabinet door and panel on the right hood side. I
used the KAto shell to help me locate where these needed to go. You only have to make a
cutout in the laminate sheet for the bolted on panel. The door glues flat on the sheet.
The weld line which I still have to create on the left side was done by examining prototype
photos first. Most units will have a zig zag pattern. The unit I am building has an offset pattern
and it is not the same on both sides. It offsets again on the roof. Check your photos first.
leading edge corner. This is to fit under the dash 2 cab. Take your time and measure how
much you need to cut out. Best to cut a little at a time, fit and cut again until you have a
perfect fit. You can see here as well how the laminate sheet overlaps the backing sheet.
You will also notice on the blower duct side I had to cut the hood side up from the bottom. This
is because I am using the Athearn walkway and have to make a clearance cut for the blower
duct. If you are using a Kato walkway, you do not need to do this.
You can see I have installed the electrical cabinet door and panel on the right hood side. I
used the KAto shell to help me locate where these needed to go. You only have to make a
cutout in the laminate sheet for the bolted on panel. The door glues flat on the sheet.
The weld line which I still have to create on the left side was done by examining prototype
photos first. Most units will have a zig zag pattern. The unit I am building has an offset pattern
and it is not the same on both sides. It offsets again on the roof. Check your photos first.
I made the weld bead by first scribing a shallow line in the pattern I wanted. I then took some
Cannon & Co. sprue and melted/ stretched it into thin thread. The scribed lines were used as
a guide to lay in the stretched sprue. I used liquid cement to attach the sprue. I then
repeatedly applied thin layers of glue over the sprue to melt it more. What this does is blend
the sprue into the sheet and also melts it in a pattern that looks like overlapping weld beads.
Gives it a rough look.
Again, look at your prototype photos. Sometimes this weld can be done from the inside which
leaves just a shallow outline on the outside and sometimes they weld from the outside and
grind it all smooth.
Cannon & Co. sprue and melted/ stretched it into thin thread. The scribed lines were used as
a guide to lay in the stretched sprue. I used liquid cement to attach the sprue. I then
repeatedly applied thin layers of glue over the sprue to melt it more. What this does is blend
the sprue into the sheet and also melts it in a pattern that looks like overlapping weld beads.
Gives it a rough look.
Again, look at your prototype photos. Sometimes this weld can be done from the inside which
leaves just a shallow outline on the outside and sometimes they weld from the outside and
grind it all smooth.
I am building the blower duct side. The other side will follow the same build sequence. So my
next step was to cut out the clean air room laminate sheet. Here you need to find out how tall
it is from the walkway to the top of the cab roof because your clean air room top is flush with
the top of the cab roof. I had already built the Cannon & Co. cab, sub-base and nose kits and
had glued them to my walkway so it is easy then to find out the height. Mine measured out to
be 1.291". So from your 0.020" sheet cut a piece that measures 1.2"w x 1.291"h.
Now you need to locate your blower duct on this sheet. Using prototype photos and my Kato
shell I was able to get the location where I wanted it. If you are lucky enough to have actual
dimensions, that is even better. Use your walkway to get the height from the bottom of the
sheet where the bottom edge of the blower duct will sit. It is OK to cut the opening completely
out on three sides. You can rebuild the right edge after you glue this piece on the backing
sheet. You can try cutting it out from the bottom, but the right edge then will be VERY thin and
hard to make an accurate straight cut. What is critical is the leading edge marked "A" and the
top edge marked "B". If the bottom edge is cut to deep, do not worry so much. It will be hidden
at assembly.
next step was to cut out the clean air room laminate sheet. Here you need to find out how tall
it is from the walkway to the top of the cab roof because your clean air room top is flush with
the top of the cab roof. I had already built the Cannon & Co. cab, sub-base and nose kits and
had glued them to my walkway so it is easy then to find out the height. Mine measured out to
be 1.291". So from your 0.020" sheet cut a piece that measures 1.2"w x 1.291"h.
Now you need to locate your blower duct on this sheet. Using prototype photos and my Kato
shell I was able to get the location where I wanted it. If you are lucky enough to have actual
dimensions, that is even better. Use your walkway to get the height from the bottom of the
sheet where the bottom edge of the blower duct will sit. It is OK to cut the opening completely
out on three sides. You can rebuild the right edge after you glue this piece on the backing
sheet. You can try cutting it out from the bottom, but the right edge then will be VERY thin and
hard to make an accurate straight cut. What is critical is the leading edge marked "A" and the
top edge marked "B". If the bottom edge is cut to deep, do not worry so much. It will be hidden
at assembly.
Long hood
end mating
edge lip
end mating
edge lip
B
| No, the table is not curved like this. Nor is the hood side. It is the effect of the lens I was using. |
A