Help me build my rear rack

[rob_gendreau]

I posted something about this in Gadgets, but it's more of a mod now. Originally I was gonna build a rack off the bumper or van to hold two 20mm ammo cans on each side. But I decided to look at the hitch receiver instead, since it's unlikely I'll use it for towing now. And I need to avoid the ladder on the driver side (and there's too much weight on that side now.

I discovered my hitch hangs from the frame via bolts on plates welded to the frame, which in turn attach to a bent 2" square tube. It points slightly forward, and although it's seamed tube I can fit a 2" OD tube into it. While playing around with miscellaneous hitch parts I have to get an idea about clearance it dawned on me I could probably use those same parts to build much of it since I don't need them for towing.

So the idea is to put a 2" OD tube into the tube that also contains the regular hitch receiver. It points forward at an angle, but the piece I fit in has a 90 degree weld in it so it points now back and to the outside of the van. That part accommodates in turn another 2" OD tube that is really a hitch ball mount with a couple of inches of drop; I insert and flip it up so that the rise conveniently lifts it at a nice angle around the rear fender, preserving my already crappy angle of departure. Think of it as an "L" with the short line in the receiver structure and the long line pointing back to the right rear corner of the van, and bent upwards. (Pix in next post.)

That gives me a relatively flatish platform of 3/4" steel with a 1" hole in it, that sits right about at the right edge of the rear door. Now I'd run a 2" post up from that about 24", making it angle parallel to the back of the van just outside the right door hinges. Onto that I attach four 4" barrel hinges, with males in the lower positions. I weld the females onto angle iron attached to the ammo cans, and then hang them like doors. They swivel to the outside, and the open rear door doesn't hit the post the cans are mounted on. The cans wouldn't weigh more than 100 lbs altogether (2 x 4" hinges hold 440 lbs).

I haven't decided if I'll weld or bolt the lower pieces together. Drilling a hole in my frame mounted receiver would be a bit of a pain, although it doesn't have to be super tight since the tubes slip together and the bolt only have to keep it from sliding out. I'd probably weld that piece just because it would eliminate some vibration, and I can weld on a part of the receiver tube that isn't critical to the rear hitch structure itself. The other parts I could do either way; I'll probably leave the second piece, the ball mount, boltable so I could remove it altogether if necessary.

I'd also have to mount something on the vertical post so that the cans wouldn't swivel or move up while moving, and make them locking. Maybe something that could use a padlock or locking pin like you use on a trailer tongue.

I'd also have to move the license plate. I'd probably just stick it on the bumper with an LED to the trailer wiring.

Check out the pix in the next post and lemme know what I'm missing.

Rob

[rob_gendreau]

Here's the rear view; I just stuck the cans up on there to show the general layout. I think I'd raise them a couple of inches. I will probably use one vertical post, rising about 24". The cans are about 14" high.



Here's with one.



Here's the right side of the existing trailer hitch mount:



These show how my components fit it:




And here's the parts:



Again, I'd probably lift it a couple of inches; right now they clear the angle of departure by only a couple of inches (they look lower).

I'm also a bit worried about that right taillight. A driver close to me might not be able to see it for turn signal purposes. I've got more trailer parts that I could use to make an additional light if necessary thought.

I could also move the cans more to the center of the van on an arm that would extend left, like a barn door. I like a hinged post design better than the horizontal arm only you see with some tire carriers (more resilient when you get bashed I've found). But I like the idea of just hinges and a vertical post since it's less weight and easy to disassemble.

Thanks for any suggestions.

Rob

[Ford_6L_E350]

With the box you have on there, or something of similar size, I would not worry about the tail light. Just look at some of the SMB's with Aluminess spare carriers that block most of driver's side lights if you want something to worry about. From straight back, the light is totally visible. Anybody close enough to have that light blocked is too close and they couldn't stop in time anyway.

I hope you are using external door hinges. I found some with ball bearing pivots to carry a heavy load and they are weather proof, galvanized hinges aren't as durable. McMaster-Carr pn 1511A22 (Dull Brass finish) is the one I used on some barn doors 15 years ago. Still looking good. Admittedly, you will have to grind through any finish to weld the hinges on. How were you going to finish the hinge and welds?

And welding galvanized requires some precautions - don't breathe the fumes! If you do breath some of it, drink plenty of milk, the calcium will pull the nastys out of your system.

It is an interesting concept. Good luck with it.

Mike

[rob_gendreau]

The ones I'm familiar with are called barrel hinges; McMaster-Carr doesn't carry them big enough. See:
http://www.hardwaresource.com/hinges/SP ... iece+Steel

I prefer steel; easier to weld than stainless. And not as nasty as galvanized (shiny cadmium? ). I'll prime it and probably use Rustoleum rattle can bed liner. Worked great on my last bumper project. Pretty tough. Doesn't exactly match the powder coat on other parts of the van so I may switch to gloss, maybe for the vertical part only.

[witoke]

I think your idea is fine, as in; it will work... But for me it would stick out too much. Have you taken a look at how some bumper vendors make their stand alone tire racks? Angle bolted into the bumper mounts all the way across, the top plate sits on top of the actual bumper on the half of the bumper with the rack and the upright with hinges is attached to that. Its very neat and while I would never suggest you copy someones design, it seems to me you might be able to use the basic idea to get your cans closer to the van body and above the bumper.

Maybe rather than going around the outside of the bumper with the two bent pieces, go straight up through it from the hitch frame? I'm guessing bumpers are free or close too it if you ask around and I know they are really not hard to make holes in. Or maybe around the back of the bumper with some angle?

[rob_gendreau]

The problem with bumper mounts is that they wouldn't fit on a stock bumper without sticking out about as far. A stock bumper has a curved top and is only a couple inches wide, and it's pretty flimsy. You need some major beef to anchor that pivot, even for this weight. The ladder actually extends past the bumper, and although the support I'm proposing curves around the bumper, it still doesn't stick out as far as the rear of the hitch receiver, which is as close in as you can possibly get.

The vertical post that they'll hang off of will only be about 1" off the bumper, and so depending on how the cans hang they'll be very close to the rear door, and only stick out 5" or so. And since they'll be higher than in the photo there's no chance they'll get in the way. In fact they'd stick out less than a door mounted tire. They're only sitting that low so I could get an idea of how it worked.

Going straight up from the hitch receiver tube is a possibility. The problem is opening the doors, and you do get another 4" to hit the ground since that is contact point in the rear. You can open the right door, but the left is wider and hits. I've seen bike mounts as well that pivot there, but again it has to stick out even further and to hold the cans you need to add even more weight.

Rob

[rob_gendreau]

Aargh. Fail.

Turns out I'm rather dyslexic with hinges; good thing I don't hang doors for a living. I have to mount the hinges on the cans on the wide side to avoid the handles. There's some way to use L shaped brackets and what not to essentially change the pivot point, but that introduces more leverage, more failure points, and more weight. And the simplest design actually puts the cans too close to the van. By the time I backed them up it turned out it was probably easier to just use the standard receiver tube in the middle of the van, since the vertical post is now back so far that the right door clears and the left opens enough to access the door hatch and the stuff on that side (just a narrow compartment; you can't enter the van on the left although you can on the right).

So it will be kinda like a swing-around bike rack. I think I can use some creativity and fab a 2" tube for the bottom with a 45 degree cut and a skid plate attached, so that although I'll lose a little bit of rear angle I'll have something I can bang without consequence. I used to use a roller ball anyway but it tended to snag vegetation.

Rob