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Macskyver · 08-13-2016, 01:14 AM

Haha, thanks. Yeah, it's glued and screwed... well at least the ribs to bed rail pieces are. The longitudinal piece at the top middle is just glued. I will be using glue and brad nails on the cedar, which I have started cutting up.

I appreciate the confidence but I can't really expect too much overall. I am mostly just hoping to offset the aerodynamic downgrades in the front end. The truck is set up for better off-road capabilities and with that comes maximum approach angle. You can see the entire wheels from the front. I'll take some more pictures of it tomorrow to show you.

As far as how I figured it out... I started by playing with the streamlined body picture overlay thing on this site to get a rough idea of the shape I wanted. Then I took some pictures of the back of the cab to get the profile, which I should have done more carefully in hindsight. I converted the image to a vector graphic so I could import it into CAD, which I use Fusion 360. I scaled the vector graphic based on known dimensions and traced it with a spline to the centerline of the cab outline and then mirrored that so the two sides were perfectly symmetric. I then took measurements of the bed rails and drafted those up. From there, I made an offset plane at the end of the bed rails parallel to the cab profile. On this plane I drafted the back end profile, basically winging it. I knew I wanted it more rounded with a steeper angle coming in from the sides. I also made it as short as I thought would be reasonable for entering and exiting the bed area figuring that I will have a slightly raised platform that holds the mattress. I also wanted to maintain usage of my rear view mirror. From there, I ran a curve from the cab profile to the rear profile. Again, I was sorta winging it, but I made the curve tangent to a line sloping down 1 degree from horizontal at the cab and tangent to a line sloping up 10 degrees from horizontal at the rear profile. I then used the loft command to make a body from the cab profile to the rear profile along that curve. I intersected evenly offset planes with the body to get the rib profiles. There's a bunch more after that, but that was basically the crux of the CAD work.

Oh, and thanks for the welcome. I'll also look into making the pictures smaller as you suggested.

08-13-2016, 01:14 AM	#13 (permalink)
Macskyver EcoModding Lurker Join Date: Aug 2016 Location: Texas Posts: 86 Thanks: 0 Thanked 225 Times in 56 Posts	Haha, thanks. Yeah, it's glued and screwed... well at least the ribs to bed rail pieces are. The longitudinal piece at the top middle is just glued. I will be using glue and brad nails on the cedar, which I have started cutting up. I appreciate the confidence but I can't really expect too much overall. I am mostly just hoping to offset the aerodynamic downgrades in the front end. The truck is set up for better off-road capabilities and with that comes maximum approach angle. You can see the entire wheels from the front. I'll take some more pictures of it tomorrow to show you. As far as how I figured it out... I started by playing with the streamlined body picture overlay thing on this site to get a rough idea of the shape I wanted. Then I took some pictures of the back of the cab to get the profile, which I should have done more carefully in hindsight. I converted the image to a vector graphic so I could import it into CAD, which I use Fusion 360. I scaled the vector graphic based on known dimensions and traced it with a spline to the centerline of the cab outline and then mirrored that so the two sides were perfectly symmetric. I then took measurements of the bed rails and drafted those up. From there, I made an offset plane at the end of the bed rails parallel to the cab profile. On this plane I drafted the back end profile, basically winging it. I knew I wanted it more rounded with a steeper angle coming in from the sides. I also made it as short as I thought would be reasonable for entering and exiting the bed area figuring that I will have a slightly raised platform that holds the mattress. I also wanted to maintain usage of my rear view mirror. From there, I ran a curve from the cab profile to the rear profile. Again, I was sorta winging it, but I made the curve tangent to a line sloping down 1 degree from horizontal at the cab and tangent to a line sloping up 10 degrees from horizontal at the rear profile. I then used the loft command to make a body from the cab profile to the rear profile along that curve. I intersected evenly offset planes with the body to get the rib profiles. There's a bunch more after that, but that was basically the crux of the CAD work. Oh, and thanks for the welcome. I'll also look into making the pictures smaller as you suggested.