Chassis mounted, Roof Rack project. (1 Viewer)

[HomerOz]

G'Day Fella's,

I have for some time now, been restricted to what material I'm able to pick up from suppliers.
So I got to thinking over the past couple of months, about how I can improve this situation.
Late last year (2017), I designed, made and installed some New Side Steps for my BJ-73 TLC, and whilst I was doing all this, I had a good look under the vehicle.
I seen that the chassis mounted, body support bracket, adjacent to the rear side step bracket, had two 20mm diameter holes in them.
So I started working out and then measured and made up some go-between brackets, from the two body support brackets (L & RHS), to my newly installed side steps.

Given that a picture is worth 1000 words, I'll let the following images, do the talking.... (apart from the image description)

To be continued.................
Homer

Chassis mounted, body support bracket and rear side step bracket.
Note the lower 20Dia hole in the body support bracket (left) and the two x M8 tapped holes in the side step bracket (Right).

3mm sheet steel, marked out.

2 bracket spacers drilled and cut out and Dummy 1" NB piece of Galvinised water pipe.

Dummy run (and same Dummy 1" NB pipe and 3/4" bolts), prior to Tac welding in place. Note the taper of the chassis bracket.

Ditto, but a view from the rear. D'oh!, that should read "Rear" and "RHS".

 

[HomerOz]

G'Day Again,

Here's some more images, this time on the LHS of the vehicle.


View attachment 1603774

You can see the Tapered "I" Beam washers in place

Note the tapered "I" Beam washers, on the 3/4" UNF "Grade 8" bolts. These washers have a similar taper, to that of the chassis bracket.

The 1" NB water pipe that the flat side brackets are welded to, have tapered ends, to match the taper of the chassis bracket.
They taper from 93mm at the top, to 99mm at the bottom and have to be "timed" into place prior to Tac welding, to match and the inside profile of the chassis bracket and also, the flat side brackets.

I still want to weld a piece of 1" x 1" x 3mm angle iron between the two flat side brackets, to stiffen them up a little. I'll do this, when I remove them and prior to powder coating.

 

[coldtaco]

I know the body doesn’t flex much but do you want to lock the body to/with the frame? At least that is how it looks to me.

 

[HomerOz]

G'Day Fella's,

Yes Cold Taco, I realise that is what I have done and I understand it's not the best way to do this.
Any suggestions would be appreciated.

Regards
Homer

 

[coldtaco]

G'Day Fella's,

Yes Cold Taco, I realise that is what I have done and I understand it's not the best way to do this.
Any suggestions would be appreciated.

Regards
Homer

as long as you are aware of this

 

[coldtaco]

couldnt you just do it like people do rock sliders? Weld/bolt to the frame and skip the body? Or combine them both.

 

[HomerOz]

Thanks for that advice Coldtaco.
The reason I have gone with this design, is I want to mount the forward vertical roof rack, to the rear end of the side step.

I suppose if I don't over tighten the 3/4" UNF bolt (if I just nip it up), this will still allow the chassis to easily rotate or flex some amount around this part of the bracket, during serious 4WDing......... maybe?

D'oh!
Homer

 

[HomerOz]

G'Day Fella's,

I've been thinking a bit for a while now, about how to go about obtaining the required dimensions, for the uprights of this roof rack.

You can see here, where I have painted the edge of a piece of 25x50mm (1" x 2") Steel Rectangular Hollow Section (RHS), and then "Plumbed" (= make it Vertical) it up (both X and Z axis), and then clamped the RHS to my car port.

I had earlier, placed pieces of masking tape, at all the change of direction of the side of the vehicle. I also placed marker pen lines at these locations (x 5), to designate the point where the the direction changes (lets call them Way Points).
From the Top, this is Way Point #3.
I then used my newest Welder square and a tape measure, to take a horizontal measurement (in mm's), from the RHS to the 5 individual Way Points, on the side of the vehicle and placed a corresponding Horizontal line, on the RHS (thats why I painted it White).
I then confirmed these measurements multiple times, and then wrote the horizontal measurement on the RHS and my paper drawing of this.
I also documented the vertical measurement, between each Way Point, on the RHS.

The next day, I marked out all these dimensions, on a piece of appropriately sized heavy cardboard.

Hope that helps

D'oh!
Homer

 

[HomerOz]

G'Day again............

I then got to work with a blade and cut it out.
I then placed the lower section in this image, up against the side of the Battle Cruiser, and it was a good but not perfect match.
Only Good (not Perfect), as there is a considerable convex radius in the side section of the FRP, adjacent to where the window is.

I also then realised, that I will need to make this cardboard template again, as I don't want this roof rack touching the side of the vehicle.
It needs to be 20mm- ish (3/4"), off to the side, of the side of the vehicle profile (for clearance for flex, etc). D'oh!

D'oh!
Homer​

 

[divemedic]

I really feel like your over thinking this. it would be more structurally sound to do as coldtaco recommended. You can run tubing at 90* off the frame to clear the rockers across every section of the truck accept where the downpipe /resonator drops out of the engine bay. if you prefer not to weld to the frame, weld it to u-brackets to bolt to the frame. I feel like your going to cause significant damage to your body work.

 

[HomerOz]

G'Day Fella's,

Thank you for your advice on this Divemedic.
I haven't dismissed what you are suggesting.
I have previously made chassis brackets (I take some images of them later, and post them here).
I was just hoping to go the way I proposed above.

What do you good people think of my 20mm/3/4" roof rack body clearance
Do you think this is to close, or to little clearance?

Regards
Homer

 

[divemedic]

G'Day Fella's,

Thank you for your advice on this Divemedic.
I haven't dismissed what you are suggesting.
I have previously made chassis brackets (I take some images of them later, and post them here).
I was just hoping to go the way I proposed above.

What do you good people think of my 20mm/3/4" roof rack body clearance
Do you think this is to close, or to little clearance?

Regards
Homer

Honestly I think it doesn't matter given the design. If it flexes at all you're gonna get body damage. Either where it mounts or at the mount and whatever takes contact.

 

[HomerOz]

G'Day Fella's,

Thanks for your input divemedic.

D'oh!
Homer

 

[HomerOz]

G'Day Again,

As you can see in the attached image, I have made up full size drawing of what is required for the front upright for this roof rack.
You can see the intermittent line, which basically duplicates the vehicles side profile (at this location) and then the two other lines (inner & outer), which is where the upright will be.
I hope to make a start on this, this week. The spray can is there for size comparison.

D'oh!
Homer

 

[HomerOz]

G'Day again,

I found the time to put some more time into this job.
First off, I needed to finish off the side steps.
This required me plugging up both ends of the steps.
The front was easy, I used some 25 x 3mm (1" x 1/8") flat bar and welded it in place with the Tig.
The rear required a little more, as this is where I want to mount the forward roof rack up-right.
So i cut off two pieces 3" x 5/8" flat bar to 5/8"-16mm length.
I then mounted it in my mill and rebated all but 3mm of it, so it snugly fits inside the side step RHS tube.
I then radiused the top edge and drilled and tapped it for 3 x M10 x 1.5 mm thread, to bolt the R/Rack onto.

Images are worth a thousand words, so FYI.............

D'oh!
Homer

In situation, on the B/Cruiser, prior to "gluing" it all together.

 

[HomerOz]

But wait..................... there's more (not Steak Knives).....

So I unbolted the side steps from the Battle Cruiser and after this was "glued" together and tidied up, and dropped them off at the powder coaters.

D'oh!
Homer

 

[HomerOz]

G'Day Fella's,

I picked up the powder coated item's this arvo (thats Australian for, "this afternoon")..... Mmmmmmmmmmm Donuts!
I squirted some Fish Oil inside the RHS, then sat it in the sun and turned the side steps around, to spread the good oil.
Hope to get them bolted back on, and get started on the roof rack up-rights some time soon.

D'oh!
Homer

 

[HomerOz]

G'Day Fella's,

As above, I installed the side steps in place, a couple of weeks ago.

Once these were in place, I worked out what size piece of Aluminium checker plate (5 Bar), I required.
Luckily, I had a piece that was just right length (at 1065mm), so I marked it out, cut and folded it (70mm x 20mm).
And today, I fitted the two pieces, to the side steps of the Battle Cruiser. Here's some images..........

Avagreatweekendeh!
Homer

 

[350HJ75]

nice one.. the ally wont be going anywhere with that many rivets!

 

[HomerOz]

Thanks for the comment 350HJ75.
Yes I thought about that, at the time I was drilling all the bloody holes on the drill press.
By the way, I deliberately used Sealed Rivets, so no dust and salty water will be getting past the rivets anvil and hole and rusting the step away from the inside.

I also purchased all the material last week, to make the roof racks out of.
I hope to make a start on these some time soon............

D'oh!
Homer