Custom Roof Rack - ORNG TACO

Luke, when I saw the above illustration my mind went immediately to stress cracks. Two places: at the bend, and through the bolt slot. How might you service factor those places to plan ahead for the torsional flex forces that will be acting upon them?

 

Because taking someone elses idea and shamelessly copying it is unethical. Regardless of the price of the original.

 

@tonykarter Stress cracks usually form from corrosion first. So the first line of defense is to protect against that with powdercoat/paint. The forming process should not stress that bend enough to create stress cracks, and I trust my metal former/cutter to advise on that. Just a reminder, the material is 5052 Aluminum 3/16" thick, so the corrosion resistance is 'upped' to begin with. Another stress crack driver is weight, and from roof racks I have seen that are similar in construction, I would need to really overload the rack to create a weight-driven crack.

good points again!

 

@Comatose , I agree with it being unethical. Plus, I want my own rack, not someone elses.. so that was actually my main driver for doing this. At the end, I'll have exactly what I want!

 

Oh I wasnt commenting on your design. I've actually never really seen it.

 

Lol how dare you copy a roof rack design. Why can’t you be normal and just import your own pro grille knock off.

Both are the same if you ask me. If anything the rack is less of a knockoff.

 

Yeaaah man! No we are talkin! haha, I couldn't bring myself to get a faux pro grille either

 

I knew you weren't referencing mine, but yeah straight up copying is whack.. and requires no talent to boot!

 

Consider: how many of you have houses filled with Chinese knockoffs of every variety? The hypocrisy on this forum is palpable. Let he who is without sin cast the first stone.

 

Yea, and trust me Luk, I am not critiquing, just trying to play devils advocate for the sake of the best design as possible. It was hard to even ask the questions without seeming rude considering, but I feel like straight forward and honest is always the best policy to help others think. I appreciate that in my job here at the engineering firm. It helps me to grow.

First - ixnay the radius idea, I see that is already being done! Chamfer or stick with the point


I just went back through the whole thread. The design on the first page reminded me why I am still here. The rack is really bad ass. Great job, again.

Yea, recently, I was lazy and didn't remove the snow off the roof. It was a mistake. It turned into a single piece and was sliding back and forth slamming into the light bar at traffic lights. I wasn't sure if I was gonna rip off the shark fin or the light. LOL I guess if you (we) want the best look and the least amount of wind noise and want/need it to be as low as possible to achieve this, then the other side of that sword is you will have to get the snow off and it won't be easy. Naturally you shouldn't (and I suspect you won't) compromise the design for the sake of something as trivial as this. Not everyone gets our shitty weather.

So yea, went back, checked it out, and I guess the side rails not lining up over the oem trim pieces is not that big a deal visually. I was imagining something less natural looking but it's not bad at all. Definitely like the idea of no trim on the sides or wind deflector if it won't ever come in contact with the truck. But, if no one else is doing it and it sets yours apart then it might not be a bad trade-off. I think it would look especially good being black if say parts of the rack were color matched.

As far as that is concerned. I have those Devil Horns (On Fire) on my truck and they are anodized. Anodization and salt do not work well together. I had to send mine back after one winter to be redone. The salt here in Maryland destroyed the luster and really fades them out. The sun has less effect as evidenced by my buds in Texas with the same horns.

I could have avoided that with a clear coat of UV paint or even some Plastidip Glossifyer with the UV stabilizer in it. I'm only bringing this up because color matching might be better with an automotive grade paint or powder coating, not anodization.


Here's what I am talking about

Before (new).



After 1.5 seasons of winter driving on heavily salted roads.



Definitely something to think about from a cost point of view and your general happiness. When I get mine back this time I am putting two or three coats of clear Plastidip on them to protect them better.

Rob

 

That looks tight Luke! I suppose the added length of the cuts at the flange will allow for a easier and less stressful bend in the metal too. Nice! 230 pounds is a lot of weight on a rack. I have seen some RTTs mounted up on the cab (not sure I would want one up there) but I think for your general use, for gear, you will be more than fine

 

Rob,

No worries at all! I am an Industrial Designer so I present concepts all the time that I actually encourage people to critique or flat out destroy for whatever reasons they know (often better than I know) so that the end product is the best it can possibly be. So i totally feel you! I work with mechanical engineers all the time so I can also appreciate the stress/loads/torsional considerations. I didn't know anodizing does not hold up well with salt, but really.. WHAT DOES? haha, I've considered getting color matched paint from www.automotivetouchup.com, I have used them in the past and their paints are great.

I am really thinking that the fairing will be better off with an edge seal that really contacts the roof there. I'm 90% sure I am going to add that. My design is also superior in that it will be able to seal that gap up.

Also, I added those larger hexagonal keyslots to be able to more rapidly tie down whatever is being placed up there. I pick things up all the time so having that was a must.

 

Yeah, I think the relief cut should give it some breathing room for forming the bend. I plan on converting an enclosed trailer into a camper-mobile in the next 2-3 years instead of getting an RTT. I can buy a whole weather-proof trailer for $2-4K vs getting an RTT. So thats the plan for camping in a nutshell. heh

 

@ORNG TACO yeah I'm starting with 1/4 aluminum bc I got it for a super good deal so that will bring its own issues. I will also be using the extruded bars for the cross supports. I plan on using the side pieces with a bend in them for the foot piece. that will be tricky to get into a break to do but I have some options in my buddies shop. seems like getting the curve of the roofline at the front will be tricky along with making the wind deflector match the curve of the windshield. but ill be going to same route of trusty cardboard then refine in cadd. I want to add some sort of handles on the sides for when I want to climb up on the sliders(still need to make those too. lol) to actually use the rack. I want to utilize one piece of aluminum for the spaces and mill out the diameter of the rivnuts in the roof to keep them centered. ill start a thread with my build here soon. I have a few other side projects im finishing up this week before I dive into this.

 

Brandon,

Cool! 1/4" will be super beefy, its gonna kick ass. Yeah, I am not sure how the company I am using will form them in a press but I am not too inclined and don't trust myself because I usually work in plastics.. My boss and I just had that roof curvature conversation.. its definitely the worst part. I have to edit my design even more based on my last cardboard mock up, but that's what its for. For the deflector, I just laid a 2x4 on the front of the windshield and traced the line back against a blank piece of CB to match the angle, stupid and simple! hah.

I'm excited to watch your thread

 

yeah I agree the 1/4" is overkill in terms of support for the rack itself. I have a few guys that I know that have some experience so that might help. I was recommended to take some pvc and a heat gun to make the pvc more flexible to match the curve then when it cools it should be the same as the roof line if I do it right. nice trick with the 2x4 and the cardboard. ill have to keep that in mind.

 

An alternate technique would be to remove the weather stripping piece(s), and place a straight piece of cardboard in the trench, and trace the curve with a pencil lying flat on the roof.. then mark out each point's depth and spacing. Either way its a pita.

 

yeah seems like plenty of ways to do it but getting it to execute properly and look how we want is the "fun" part

 

I’ve done it. Nothing hard, just have to factor in the curvature into the CAD.

 

Cool Cool Cool. I know it's hard sometimes not being face to face and didn't want to come off the wrong way.

I think what I like the most about the design is that you are pulling it off and will actually build it. I don't care who's it looks like. Impersonation is the sincerest form of flattery.

Yea, the holes for tie downs is essential. No need trying to squeeze a ratchet strap hook between the side rails, cross bars and the roof and possibly damaging it.

The edge moulding would definitely help with the wind. I have a light bar up there and it is noisy as hell. Actually, this is the second one. The first one was curved. 42". The new one is also 42" but straight. They are both double row. Oddly the curved bar made more noise. I can't figure that out. Unless it was just that much farther away from the truck due to the curvature and that wider opening caused it to be louder. It actually modulated more too, from the vibrations. It was if I always had a song playing but just the bass on. Low muffled mmm mmm mmm mmm.

I think paint or powder coat is the way to go. Anodizing is very nice but your prep time increases substantially. The pieces need to be polished smooth and near perfect. P/C or Paint & Primer is more forgiving. Yes, P/Cing needs to be done professionally but in the end that finish will look a lot better than the average Joe and a spray can. I can paint well but I am by far an expert. I recently bed lined all my skids. The prep was horrendously long. I will never do that again. Now, the end result is pretty bad ass and will last forever (or until I gouge them very hard on rocks). After doing it though I would pay for P/C if I had to do it again. Of course your cross bars are already black, so doing the side rails in paint or P/C should be too labor intensive or cost that much. It's not like a bumper.

I think your design will be structurally sound and last through anything you can throw at it. Myself I would just have a plano box up there on one side with recovery gear, a waterport, maybe an awning, and later a solar panel.

I can't wait to see it done and on your truck!