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Picture of Better. Faster. Stronger. Build Your Own Automotive ROOF RACK!

If you've been in the market for an automotive roof rack, you've probably noticed there are already a lot of options. Why take the time to build one yourself?

  • Better! - Since you know how you plan to use the roof rack, you can make it infinitely adjustable to your needs. Using 80/20 extruded aluminum make future changes a snap too!
  • Faster! - OK, maybe this rack isn't going to make your car any faster, but it is super quick to adapt to most any cargo needs! Using an allen key, you can slide and adjust tie-down points or rails in seconds. Add more cross rails, more tie-down points, all in no time.
  • Stronger! - The extruded 80/20 aluminum bars are super strong! Certainly the weak point in my roof rack is the car itself, not the rack.

Step 1: Designing Roof Rail Connection Plates

Picture of Designing Roof Rail Connection Plates
FACTORY-RAILS-1.jpg
plate-iteration.jpg

Not all cars have the same roof layout, so this approach certainly won't work for everyone. This example is for any cars with factory attachment points already available. If you have another roof type, you will have to come up with your own connection method.

On my Chevy Bolt, all the literature I can find about roof racks mentions a 160lb max capacity. Since this comes from multiple 3rd-party rack venders, I'm assuming this is based on the roof limitations. This rack would otherwise hold a lot more, so use your best judgement and research your vehicle. To get started, I discovered the thread size for my car's factory roof rails, which is for a 6mm bolt on the 2017 Chevy Bolt. The bolt holes aren't all in a strait line, but rather follow the contour of the roof. Each pair of holes was measured, and they all turned out to be the same distance apart, 120mm between holes. You can see the process I went through to find a good fit for my Bolt. In the 1st version, I made several sets of holes spaced the right distance apart, and used that to get a sense of the roof angle for the front and rear mounts. The 2nd version then has level mounting points. 3rd version was adjusted for an ideal height to clear the radio antenna. 4th and 5th revisions were for functional testing. I put them in place with my aluminum 80/20 rails to confirm it was a good fit and angle. Also, I knew I wanted to make these out of aluminum, so in versions 4&5 I modified the bracket with the angled fronts so I could condense the set of 4 pieces onto a single 6" x12" plate of 1/4" thick 6061 aluminum. Here's the final design I used for my Chevy Bolt as an Adobe Illustrator file.

BigAndRed1 year ago

Well done instructable, good clear photos. That Aluminium track has many possibility.

For your $200 you could have bought an off the shelf, name brand rack that connect directly to the rails on your car in a few minutes.

Most places in the world that sell ply are standard size sheets of 4'x8' or 1200mm x 2400mm and when tied on properly you dont need the little angle bits on the end of the cross bars.

I have built many roofracks for different cars over the years and have never spent much on them. I regularly carry large loads including awning, kayak, camping gear, jerry cans of fuel and water, spare wheels and all sorts of stuff. Transported an entire bedroom set on the roof of an old Austin Mini once.

Roof racks dont need to be fancy, just simple and strong.

subi and camper trailer 2.jpg
WAC_IDEAWORKS (author)  BigAndRed1 year ago

Lol, not sure if that's a compliment or just a polite opening to a series of criticisms :) Not everyone is into designing and building their own version of products that can be bought off the shelf. I recommend to anyone to go the direction that gives them the most satisfaction. I don't know about you, but I think a lot of people who are here like to make stuff :)

I think that BigAndRed sort of missed the Point. You never claimed that this was the Cheapest, or Most Expeditious/Convenient. Not everyone just wants “Plug & Play”. Some people, like myself, take pride in the (journey) of creating, and making something from ‘scratch’. Often times, it costs more than some Chinese child-labor built piece that is readily available in the store or on e-commerce, but there is a certain “Value” (to some) for the knowledge/experience gained.
1DogRescuer6 months ago
Thank you for an extremely Clear, thorough, well-articulated Instructable. I’ve been doing an entire day’s worth of (research) regarding the application of extruded aluminum for a rack on my Jeep.

I’m wondering if that 3D printed endcap profile could be modified to work in 90* with a smooth outside radius. If so, what sort of money would you need to make 4 ? The idea of me learning the whole CAD design (thing) is a non-starter. I’m 54, and barely competent at the most remedial of computer tasks.

I am NEW here, so no idea if I would be informed of a response Here, so feel free (should you choose) to reach out directly. I’m in California, FWIW.
Regards,
Stan
DogRescuer@iCloud.com
WAC_IDEAWORKS (author)  1DogRescuer3 months ago
I'm not sure exactly what you are envisioning... I could potentially make something for you, but can you sketch it on paper and post the image here so I better understand? Thanks!
Thanks. I ended up using UniStrut. While it is significantly heavier, it was also MUCH Cheaper; and, unfortunately co$t trumps weight savings.

the EndCaps that I was referring to was to make a more streamlined radius for the outer (face) of Corners, Front & Rear.

while i like the instructable and the application, i would suggest that you visit the nearest wrecking yard to see if they have roof racks specific to your car. . . i might be significantly cheaper both in cash and in labor. . .

WAC_IDEAWORKS (author)  phillipnolan1 year ago
Very true, and others have pointed out examples of wrecked cars that had adaptable racks that could be made to fit. In my case, having this new car, and not having had anything “new” in years, I either wanted a store bought new looking rack, or a rack I made new that matched my style.

Half the fun was learning to make something with 80/20 parts! Now I’m making a solar panel mount for a sailboat using a combo of 80/20, extruded tube, and custom aluminum joining plates, similar in heft to the ones I made for this roof rack.
gmcpcs1 year ago

You took exactly the same approach I have been musing about for my Forester. That extruded aluminum was something I wanted to try, as I see it often in restroom stall wall applications. It's not readily findable in a google search though. And, the aluminum will save weight as well. The process you describe to build up the angles is great! Most car roof racks are proprietary, and yeah, you can probably buy a factory rack to work, but where's the fun in that? Are you planning to rooftop camp with this? How's the wind noise?

Thanks for providing the detail plans and very specific applications to your car! I have this saved and voted up in the metalworking contest! Take it easy,

Here is another good resource for linear rail systems https://openbuildspartstore.com/linear-rail/

WAC_IDEAWORKS (author)  mwitherspoon1 year ago

Thanks for posting this! I didn't know this source was out there, and it's a one-day UPS Ground distance from me :)

WAC_IDEAWORKS (author)  gmcpcs1 year ago

I'm not specifically planning to rooftop camp, but mainly because the car's roof doesn't look like it would support that much weight. I weigh about 185, so with a platform up there we're already 40-50 lbs over the roof's rating. The bolt is a sub-compact car. My wife's mini van would be a better contender for rooftop camping. We have an older Thule rack on there and on lot of occasions I've been up there on the roof securing bulky items.

Regarding wind noise, with those pictured 64" cross bars, you do hear it on the highway if the radio is off. Just the rails alone don't make any noise. My plan is to not always leave these extra long bars on there though. It's actually a little dangerous, since the car is so low, and the rack so wide... The bars are at face height. I plan to have a set of short general purpose cross bars in my trunk area that I'd put on as needed for random use.

Be careful Europeans! It's probably illegal to use a non certified roof rack in your country. And in my experience Autobahn Cops will spot this a mile away and pull you right over especially in Germany.

gallagad1 year ago

I like getting 80/20 from McMaster. It comes next day and it's well packaged with reasonable shipping.

Rack looks awesome, nice work!

WAC_IDEAWORKS (author)  gallagad1 year ago

Oh, I didn't know McMaster sold 80/20! I just placed another order yesterday for a solar panel array frame... I'm hoping it's not another 2-3 weeks from the factory again!

dano26641 year ago

How noisy is the rack? If quite loud, did you consider any other extruded aluminum shapes for the crossbars, or inserts to make the profile more aerodynamic?

WAC_IDEAWORKS (author)  dano26641 year ago

The rails don't make any noticeable noise or affect mileage any that I can see. These particular cross bars are pretty large, and I do hear them when I don't have the radio on. I don't plan to leave the wide bars on regularly. I have a piece of aluminum extrusion that was given to me with a rounded profile on one side and square on the other. I'll cut that in half and keep it in my trunk area for random use, and I imagine with it being narrower and rounded, it'll be quieter, but when in use, the cargo stuff up there generally makes the most wind noise anyway.

Lorddrake1 year ago

excellent work.

Quick question, what was the materials cost for the setup you have shown here (support rails crossbars and tie down points)

WAC_IDEAWORKS (author)  Lorddrake1 year ago

Great question... I should have covered that! I bought some 80/20 from Amazon and a second shipment right from 80/20. I didn't end up using every bit of what I bought, so let me total up the actual cost, and add in the aluminum plate, and report back shortly... I'll make a parts list and add it to the instructable.

WAC_IDEAWORKS (author)  WAC_IDEAWORKS1 year ago

OK, Check the instructable now... It's got a complete parts list. The total cost without shipping was $200. Shipping for me was about $33. Let me know if you end up making one. I'd love to see other people's adaptations!

If I can figure out how to mount one to my caravan (it didn't come with any sort of roof rails) I do want to make this for transporting my canoe longer distances

thanks for the parts list and prices

good luck in the contest .. voted

WAC_IDEAWORKS (author)  Lorddrake1 year ago
Just brainstorming your caravan approach... start with some of the manufacturers who make racks specifically for your van, to see how they are attaching. Also, thanks for voting!