Need Ideas for Getting the Contour for Cutting aftermarket Roof Rail feet

Suli · Oct 8, 2015

So I've had these sitting in a box for about two months now trying to figure out how I'm going to mod the base feet for these (Perrycraft DynaSport Roof Rack Side Rails)

Well, the Perrycraft bases for permanent mounting are too wide to sit on these raised sections, so I'll need to Dremmel the bases a bit to get a complete flush fitment. See the pics below to get an idea. I need to figure a way of getting a near perfect contour cut into the bottoms of each side's bases (front, middle, rear) and need some ideas on how to do this.

I'll be mounting them like the factory ones with rivnuts through the top sheet metal and sealing the crap out of them.

Here's a test fit:

I'd like to mount them right where the OEM rails sit (see here, http://www.dodgedurango.net/forums/...durango-discussions-2014/20335-anyone-have-top-roof-pics-thier-2014-2015-a.html). So if you have a R/T, it's the raised tracks on the roof to the very left and very right that are not as tall as the other raised sections.

I was thinking laying some wax paper down and taking a clay mold and then let that harden and cut it for a template. Seems messy and not a very good way.

MotorMolarDoc · Oct 8, 2015

Suli said:
So I've had these sitting in a box for about two months now trying to figure out how I'm going to mod the base feet for these (Perrycraft DynaSport Roof Rack Side Rails)

Well, the Perrycraft bases for permanent mounting are too wide to sit on these raised sections, so I'll need to Dremmel the bases a bit to get a complete flush fitment. See the pics below to get an idea. I need to figure a way of getting a near perfect contour cut into the bottoms of each side's bases (front, middle, rear) and need some ideas on how to do this.

I'll be mounting them like the factory ones with rivnuts through the top sheet metal and sealing the crap out of them.

Here's a test fit:

I'd like to mount them right where the OEM rails sit (see here, http://www.dodgedurango.net/forums/...durango-discussions-2014/20335-anyone-have-top-roof-pics-thier-2014-2015-a.html). So if you have a R/T, it's the raised tracks on the roof to the very left and very right that are not as tall as the other raised sections.

I was thinking laying some wax paper down and taking a clay mold and then let that harden and cut it for a template. Seems messy and not a very good way.

Suli, hit up your dentist for some "crown and bridge impression putty" If he doesn't use it, he should be able to have his assistant oder you a small tub. You knead together two putties then mould them to the area you want to duplicate, just like you were going to do with clay. The difference is it will set up super hard, like tire rubber. You will be able to cut/trim it as you wish with NO chance of it disorting. Super accurate. It's what we use to make dental crowns after all. Heck, you may even be able to find it on EBay, although there will be a disclaimer that you must be a licensed dentist to order. FDA doesn't want the public doing self-dentistry I guess. Hope that helps.
STUART

a2t · Oct 8, 2015

you can also use repro rubber, but its very expensive

SlingingBuddha · Oct 8, 2015

If you want I'll do you a solid and trade my '14 limited with roof rack for your '15 R/T lol

boomer775 · Oct 8, 2015

If you don't need it to harden, try play-dough? Just don't eat it afterwards or you'll end up like me

tomk · Oct 8, 2015

you need to find a makerspace with a 3d scanner

Suli · Oct 9, 2015

Thanks guys. I should definitely hit up the makerspace in my area, NOVALabs and see if they can 3d-scan the mounts AND the roof contour locations. I'll just 3d print my own abs mounts!

If they can't help, maybe I'll just look for that dental stuff, sounds like exactly what I need.

a2t · Oct 9, 2015

I think you are going to spend more $ than you should.

What we do in a pinch is actually CAD up a cross section then print it 1:1 (verify scale of course), lay some clear tape over the print out, then carefully trim out and lay up on the car. It works surprisingly well for a 2D cross section and is a quick/dirty way to validate shape before releasing design or spending the money on an SLA.

I would NOT use a rapid prototype piece to attach a roof rack. i would cut from 6061-T651 then anodize. The SLA stuff is not really structural. Its good for lay ups but I wouldnt use it for production. When you bid out an SLA job, it goes to the lowest bidder and who knows what material properties you will end up with.

Suli · Oct 14, 2015

Thanks a2t! Good info. I might also contact Perrycraft and see if they want to make some special ones for the Durangos, since I know most R/T owners are irritated we can't get the factory racks on ours.

a2t · Oct 14, 2015

how are you planning to install the rack into the roof structure ?

i might be able to help cut some prototypes, we have full CNC machining and build a bunch of stuff for VW/Audi. I just bought a 2015 DD RT and I too want a roof rack

Hit me up if you want to collaborate. Paul@GruvenParts.com

Suli · Oct 15, 2015

I'm going to use some zinc coated rivnuts and mount them like the factory ones do. So I'll be using my own hardware, not what comes with the side rails from Perrycraft.

The Perrycraft ones seem to be the best perm-mount setup I could find. Add some mont blonc cross bars, and it has a VERY good weight/load rating.

I'd love to help, but not sure what I'd be able to do up here.

a2t · Oct 15, 2015

so you are pulling the headliner ? whats all involved in that ??

Suli · Oct 16, 2015

Nope! Easy Peasy, I've done them before.

Think of them like a normal rivet, except with threads for a bolt. You use a special tool to install them. They're also sometimes called blind rivets in the aviation industry. You get a special tool to install them.

-Use painters tape/masking tape and tape up the spots to drill
-You simply use a spring loaded punch to mark the spot of where to drill.
-Use the correct size bit for the hole with a drill stop on it (a metal collar that secures to the bit so you don't drill too deep).
-Once your hole is done, remove the shavings and clean the hole (deburring tool is ideal).
-Remove tape
-Use touchup paint on the hole edges and let dry.
-Then on the rivnut, lay a bead of silicone where it will meet the body for extra sealing and insert into hole.
-Then, use the tool that will cinch the collar and the body to the sheet metal.
-Wipe extra silicone away and you're ready to do.
-Some also silicone the bolt when they install it as well.

This is my rivnut tool
https://www.amazon.com/Astro-Pneuma...vet/dp/B004KLVJAA/ref=sr_1_1?ie=UTF8&qid=1444958709&sr=8-1&keywords=rivnut+tool

Here's someone using it on a LandRover

Need Ideas for Getting the Contour for Cutting aftermarket Roof Rail feet

Suli

MotorMolarDoc

a2t

SlingingBuddha

boomer775

tomk

Suli

a2t

Suli

a2t

Suli

a2t

Suli

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