Custom Roof Rack Mounts

[Matt]

Started discussing this in the Home Grown Solutions thread and figured i'd start my own so that doesn't get taken over with my posts.

Basically, I hate how the OEM cross rails are so high above the roof. When mounting cargo baskets up there on top of them it makes the basket look too "detached" from the vehicle... and in Sal's case, he had to drop his down to get in his garage.

What I've decided to do is make my own cross tail stantions out of 6061 Aluminum. Below is a quick 2 minute sketch I made to just get an idea of where I wanted to go with it.



Next step is to start modeling the concept. Once I have a working 3D model I can start thinking about other ideas such as making it lockable. I have a few ideas for that... but I also like keeping it simple. In the end, I'll determine my "locking" method based on which roof rack I end up getting and how I attach the rack to the cross rails. That's another thread though

UPDATE:

CLICK HERE TO JUMP TO POST #51 <---- Starting to make my stanchions here

[Matt]

This morning I was able to escape from my [almost] 2 year old to grab some quick measurements. So i started my model with the factory rails... which, btw, are a PITA to measure. Especially since I couldnt find my protractor and I left my micrometer at work. So with some fancy level and scale work, plus some basic geometry, i think I got them pretty close (close enough to at least work on the design anyway).

[Doc in AZ]

Wow, and I thought I over engineered stuff. If you have access to a mill and can make that then you should be able to make something that flows with the rig better than a block and square tube. If you are going to pay a shop to build it you might find something off the shelf that is more cost effective. My rates for machine work are $ 125 an hour, those blocks would cost more than the rack its self. And if you have a decent roof rack you wont need cross bars, it can go directly to the stanchion and you can keep the profile even lower... jmho

[Holaday07 4.7]

Wow, I just wing stuff, that looks great man.

[Matt]

I have my own lathe/mill/drill machine and a pretty good supply of tools in my shop.. I also have access to a pretty solid machine shop where I help high school kids build robots to compete in competitions. So i'm well covered there; just need to buy the material and find the time.

I was actually thinking about mounting the roof rack directly to the stanchions, but the rack would have to be about 52" at the front stanchion and 49.5" at the rear stanchions and it gets a bit more complicated.

Also, by making these "low pro" stanchions for my Thule load bars, I have some more options down the road if I ever take this rack off (not sure why the hell id ever do such a thing though..)

Man... but now my mind is working a million miles a minute now... I bet you could easily weld on 6 mounting tabs that would simply bolt to thru bolt with my stanchions (like the load bars would) and eliminate the need for the load bars altogether. They would have to be gusseted pretty good in the fronts since a 48" wide rack would be cantilevered on the front 4 mounts... it'll rest right on the rear two.

Doc, a quick question. When we say "48 inches wide", is that 48" to the outside of the tube? Or is that 48" on-center (which would make the outside dimension a total of 49" if you're using 1" tube)? That'll help me determine what kind of interference I'll have with the rear most mounts...

[Matt]

Ok guys... just put my son down for a nap so I have a few more minutes to work on this.

I just took a few more quick measurements because the top of the roof line is very important. So I threw a profile in there to simulate the height of the roof in relation to the rack. Obviously the roof profile is not that drastic, i'm trying to keep the model compressed so its easier to visualize... the max roof height is obviously more than 3" away from the rails.





Next up is a quick & dirty of the cheapest/easiest load bar mounting idea.

[Matt]

Ok haven't had as much time as I thought.... while my son is napping great, my 3 week old daughter has decided to give her lungs a workout this afternoon.

I didn't have time to mess around with the rendering to make it look a bit more "realistic" either. I tried a few quick presets but it made the surfaces way too reflective and even a bit harder to see what was going on.

Also did not put the lower clamping plate on or the nut. I figure this gets the point across enough... i'd make a lower clamping plate out of 1/8" thick steel and put a good nut/washer on it and probably call it good. Still debating whether I want to put a 0.1" platform on the one side of that plate so that the washer and nut sit a bit more flush. That's something I can figure out later though and will be pretty consistent regardless of which design i go with. As I started measuring and modeling I came up with some "better" designs... but "better" also means more $$ in materials and almost twice as much machining. As it sits now, I can probably make all 6 of these mounts for about $100 in materials (that includes bolts and hardware).

After I get my rack and see how the rack will mount to the crossbars, I even have the ability to cut down the groove where the load bar sits to bring it a bit closer. Although, as it sits right now, there'll be a little more than 1/2" clearance with the very top of the roof.

[Matt]

Quick note....

While driving to my parents house to take the kids swimming I was thinking about Docs suggestion to mount directly to my stanchions..... I like it. The front most mounts will have the mounting bolts only about 2-2.5" away from the edge of the rack, and with my stanchion design there really wont be much cantilever action at all. If anything the problem would be with the rear most mounts if the edge of the rack interferes with the bolt head... but the bolts might end up being just off the edge of the rack.

When we get home tonight I'm going to make a quick model of what I think would need to be welded on the rack. Basically just 6 L-brackets that are 2" wide and have some gussets for stability.

[Matt]

I'll be shooting these to Doc in an Email in a few minutes... but if he can weld 6 brackets like this onto the rack (or something similar that he thinks would do the job) then this may be the best idea for a nice clean & custom rack setup.

For the model I used rough dimensions for the front-most mounts. Here, the center of the cross rails are roughly 52" apart. So with a 48" wide rack the bolt would be about 2" from the edge.

I'm happy I modeled this... with my custom stanchions the rack will be plenty supported. The middle and rear mounts will be almost completely supported on the stanchions as well since the rails taper as you get further back.

[IamJEEP]

I like this kind of thinkng! Awesome work, Matt.......I was actually going to do something similar when i make a custom rack. Why make a rack when I allready have one, you ask? Well, for the fun of it. I like projects like this, just don't have the skills you have will the cad drawings. Keep it up, im subscribed.