Truck caps/toppers

Find How It's Done, Or Post How You Do It

Truck caps/toppers

Postby explorer2770 on Mon Mar 21, 2016 6:00 pm

I know that a few us want to make truck caps, so here's how I made one for a Dodge Dakota pickup.

Image

First, start by picking the style you want. I like A.R.E. and LEER commercial truck caps for my projects, but there are many smaller companies that make truck caps. Here are some websites that might help.
A.R.E.: http://www.4are.com/
LEER: http://www.leer.com/
Century: http://www.centurycaps.com/

Supplies:
0.040 sheet styrene
0.020 sheet styrene
0.005 sheet styrene (or strip stock)
0.040 quarter round strip
0.030 by 0.040 rectangular strip styrene
Millimeter ruler
Metal Straight edge
square
New X-acto blade
Emory boards
Awe/file
Sand paper (course, medium, fine, 2000 grit)
Dichloromethane based solvent (I'm using Flex-I-File from Hobby Lobby).
& most importantly, Patience

Step 1, Design
Most commercial truck caps have the same shape. The forward and rear bulkheads are trapezode shaped, with rectangular or trapezium sides. Confused, don't be.
The bulkheads looks like this:
Image
and the sides like either or these:
Image
or
Image

These are very easy shapes to cut out, if you know your measurements. To get the measurements, measure your vehicle's bed.

I'm using the Lindberg Dodge Dakota, which has an 8 ft bed, so you will have to adjust your measurements for your vehicles' dimensions

The Dakota's truck bed is 80 mm long and 63 mm wide. The width of the cab roof is 51 mm.

Next, pick the truck cap height. I'm going with 22 mm, you can choose anything from 21, 23, 26, 29, 36, or whatever floats your boat.

Alright, the design is almost done, but you still need to decide on side and rear doors. I'm going with 66 mm side doors, because I want to mount strobes on either side of the doors. You can pick a full length door, a 40 mm door, two 40 mm doors, etc. The rear door is another option. Single or Double? I'm going with single. Side or top hinge? I'm going with top hinge, gives the officer a canopy during the rain events.

Okay, that's most of our design options. Now it is time to cut some plastic.
User avatar
explorer2770
Engineer
 
Posts: 139
Joined: Mon Nov 24, 2014 6:04 pm


Re: Truck caps/toppers

Postby explorer2770 on Mon Mar 21, 2016 6:53 pm

Step 2, Cutting out the pieces.

So, take some 0.040 sheet styrene and cut it to the width of the truck cap. *Note* I want the side pieces to lay over the front and rear bulkhead, so I've made my measures to take up for the thickness of the side pieces.

Image

The trapezoid front bulkhead started off as a rectangle of 0.040 styrene that was 61 mm by 22 mm. Along the top, I went in 6 mm to get the sidewall angle that I wanted. This makes the width at the top 49 mm.

The rear bulkhead was cut out similarly, although you need to add a rectangle the width of the tailgate. So, I cut a piece of 0.040 styrene 61 mm by 44 mm. I cut out a rectangle 2.5 mm by 22 mm from each side on the bottom to fit between the tailgate. I then repeated the cuts mentioned above to give the taper to the top.

The top was a simple rectangle, 82 mm by 49 mm.

The sides, are going to be different. I cut each side pieces out of 0.040 sheet styrene to 84 mm by 23 mm.

Next, came the challenge. I wanted the cap to have a taper that followed the back of the cab. To do this, I cut out a wedge that was only 2 mm wide from one side, this gives the bottom of each side piece an length of 82 mm. This gives the sides that trapezium look. You don't have to do this, just shorten up the sides and roof piece by 2 mm in length.

(I'll get drawings up here in a little bit, my program is being finicky.)

Doors:
The side and rear doors were cut out of 0.020 sheet styrene. The side doors were 16 mm by 66 mm, and the rear door was 4.8 by 3.8.

I also cut out holes for my version of rectangular slam locks, which I used the 0.005 sheet styrene for. You can use Don Mills slam locks or make simple T-handles.
Image

Step 3, Gluing it all together.
Start by dry fitting your pieces together. I use tape.
Image
Image

Once most of the parts look good, use a square block to keep the roof and the rear bulkhead square. Glue with your favorite, I'm using a dichlormethane solvent. Attach the sides with glue, then the front bulkhead.

Step 4. Rounding the edges.
Most of the truck caps have rounded edges on the roof. I accomplished this by using an X-Acto knife blade to scrape off the edge, then used an awe and sand paper to get the curve to shape. This does take patience, so don't rush it.

Here's a mid-progress photo:
Image
User avatar
explorer2770
Engineer
 
Posts: 139
Joined: Mon Nov 24, 2014 6:04 pm


Re: Truck caps/toppers

Postby explorer2770 on Mon Mar 21, 2016 7:16 pm

I forgot to mention that I reinforced the inside edges with some strip stock before I sanded the corners and a cross piece to keep the width uniform for the box. The cross piece has the same measurements as the front bulkhead, just trimmed down 1 mm to make up for the roof thickness and notched to fit over the filler pieces. You can see that here:
Image

Step 5: Adding the details.
Once the edges are rounded, it is time to add the trim pieces. Along the edge of the front and rear bulkhead walls, I glued down a strip of 0.040 half round styrene. This gives that edge a slightly rounded look.
Image

Take your time, let the glue set on a side before you roll over the edge. The glue might cause some excess styrene to bubble up, but you can fix that later.

One that edging is added, trip to length and then gently sand to remove any excess styrene that might have melted out. I use this time to run some 2000 grip sand paper along the front and rear bulkhead. You can use putty at this time, or wait. I chose to wait until I use scratch filling primer.

Next, add the "weather strip" above the side doors. This is 0.030 by 0.040 strip stock cut to width between the rounded edges. I measured so that this trim piece would be at the same height as the windows on the Dakota, so they are mounted 17 mm from the bottom edge of the truck cap sides. I drew a horizontal line at 18 mm from the bottom to use as a guide (see above photo).
Image
Image

Then, mount the doors. I measured in 7 mm from the rear bulkhead trim and used that line to center up the side doors. You can add some 0.030 round styrene to make a hinge, or leave it alone. Your choice.
Image
Image

The rear door was centered and mounted to leave 3 mm space at the boom of the door.
Image

To polish off my version of the slam locks, I cut a small piece of 0.020 styrene to fit inside the hole that I had made. Not Don Mills quality, but a lot cheaper!
User avatar
explorer2770
Engineer
 
Posts: 139
Joined: Mon Nov 24, 2014 6:04 pm


Re: Truck caps/toppers

Postby explorer2770 on Mon Mar 21, 2016 7:17 pm

That's all for now, I'll post pictures once I can paint it.

Let me know if you have questions or need more details.
User avatar
explorer2770
Engineer
 
Posts: 139
Joined: Mon Nov 24, 2014 6:04 pm


Re: Truck caps/toppers

Postby foothill6514 on Mon Mar 21, 2016 8:14 pm

Great tutorial! Very nice work.
User avatar
foothill6514
Firefighter
 
Posts: 95
Joined: Sat Jan 26, 2008 3:20 am
Location: Sacramento, Ca


Re: Truck caps/toppers

Postby EdselDan on Thu Mar 24, 2016 7:34 am

An option here would be to leave the tailgate having both front & rear
be the same size
Also, what about a Window tailgate top
or side windows?

The topper I see here might look more at home on a Utility bed
I see them on those all the time
(When I see a topper on a Utility bed

Most Pickup cappers have windows, and use the trucks tailgate

I have the one from Revell's J10 Jeep Honcho, and from AMT's SnapFast C-1500
Club/Extended cab kit

I do like this and may try it out myself
Dan from DelMarVa
My Photobucket:
http://s145.photobucket.com/albums/r229/EdselDan/Models/
It’s too late for when and how. People we must understand
child labour it has to end. Raise our voices, let’s all shout:
http://pocomokefire.com/
EdselDan
Captain
Captain
 
Posts: 802
Joined: Thu Nov 11, 2010 6:15 am
Location: Between The Atlantic Ocean & The Chesapeake Bay


Re: Truck caps/toppers

Postby GLMFAA1 on Thu Mar 24, 2016 8:10 am

Thanks for the 'how to' The cap reminds me of the 'GEM'' cap I had on my ranger it was a commercial cap that I bought from a locksmith friend, It capped 3 Ford Rangers in it's life
greg
Last edited by GLMFAA1 on Thu Mar 24, 2016 9:52 pm, edited 1 time in total.
Stars at night. You see them due to the light traveling from them. What you see is the stars past. If you are seeing a star that's 6,000 yrs ago. Imagine somebody on that star looking at us. They'd be seeing us as 6,000 yrs ago. Which of those two is now?
User avatar
GLMFAA1
I Live At The Scale Firehouse
 
Posts: 1971
Joined: Wed Jan 30, 2008 11:51 pm
Location: N E Ohio


Re: Truck caps/toppers

Postby Modelmaker on Thu Mar 24, 2016 5:00 pm

Thanks for the how to. it is just the thing I needed. now I can put a cap on any pickup i want to.....Gary
“I won't be wronged, I won't be insulted, and I won't be laid a hand on. I don't do these things to other people, and I require the same from them."
" Bureaucratic Incompetence is the only Universal constant"
Modelmaker
I Live At The Scale Firehouse
 
Posts: 2305
Joined: Mon Jan 05, 2009 10:19 pm
Location: Brookfield , Wi



Return to Tutorials

Who is online

Users browsing this forum: Bing [Bot] and 2 guests