i did think about it for a bit and i came to the conclusion that although aluminum is lighter steel has a higher tensile strength and strength is everything.
i am i kinda basing my project after this one
hortonfilm.weebly.com/montero-sport-project.htmlThose plates that the original bumper supports mount to (circled in red) need to be reinforced. Basically, you need to weld tabs from those plates to the frame rails and reinforce the original welds otherwise, after a few times of using the winch you'll rip the bumper off the frame. This is ABSOLUTELY CRITICAL! A couple of us have already done this - learning the hard way is 'unpleasant' to say the least.
Hope those of you out there with bull bars and winches that haven't done this yet are paying attention.
In case you were thinking of it, that is a really bad 'limb lifter' design. You never ever want sharp corners or edges sticking out from the vehicle. Aside from being dangerous to those outside the vehicle - like your spotters - corners, edges, and other protrusions catch on brush, trees, and rocks. There needs to be a smooth transition from the bumper hoop to the wire to the rack.
Ascetically, the bumper looks decent, but IMHO this is a 'cosmetic' bumper. Fine for the street and better than stock but not suitable for any serious off road use. This is not up to even the durability of an ARB Bull Bar. So, depending on what your uses are going to be, what I'm going to write next may or may not have any relevancy to you.
The louvered lower panel is a good idea. That's a problem with the ARB Bull Bar. Once you install bumper lights like my IPFs you run into air flow issues. Make the louvers a decent size and so that they actually allow air in and put some screen behind that to keep the gravel from smacking your radiator. Do not make them so large that a stick or piece of brush can get through to the radiator or use heavy screen that stuff can't punch through.
The bumper as a whole is not a very strong design. A side or front corner hit is going to fold the 'leg' in and force the entire bumper sideways. Most likely resulting in a tweaked frame. That 16 GA sheet bolted to the top is cosmetic - it adds no strength.
There's a reason ARB designed their bumper as they did. Those angles and creases are not all for show.
There's no provision for a winch - in fact there isn't any room in this design. He didn't say what the actual bumper tube and support thickness is but it looks like 1/4". That's fine, but 2x4 for the supports may be a bit small. Because of the way the Sport bumper is designed you have to remember that the angle creates lot of leverage. It's not like a Jeep where it's a straight pull from the frame rails to the winch to the cable. The further you off-set the winch from the center horizontal center line of the frame rails the more leverage you'll have so the stronger the legs and mounts will have to be.
Obviously, the entire structure will have to be a lot taller to fit an internal 9000 or 9500 winch.
Something to think about ...
Instead of making 'legs' consider making a U shaped plate from 5/16" cold rolled steel that replaces the individual legs. X brace it and make this your winch mount.
Make the actual 'bumper' out of 5/16" and 3/8" T6061 and make it so that it bolts to the U winch mount plate.
This gives you the ability to make the part that needs the most strength - the winch mount/'legs' plate - out of heavy, strong material while not incurring the extra weight of an entire bumper out of steel.
You have a modular setup so you can remove the 'bumper' which is basically just a fascia without removing the winch and you can remove the winch without removing the mount plate. Easily dissembled in pieces for maintenance by one person.
For the aluminum fascia you can box it similar to the ARB style to increase over all strength without adding tons of extra metal. Depending on where you want the strength you can use different thicknesses. 5/16" for the front, corners and side and 3/8" for the top and edges.
This requires a lot more cutting of individual pieces and welding but will result in a strong, relatively light bumper.
The drawbacks of the ARB and others of similar design .... In order to do anything with the winch, the entire bumper has to come off. Stupid design, IMO.
The winch is SO enclosed that it's difficult to get to the controls - a design that necessary since the top is structural. While the push pads are nice from a cosmetic standpoint, they're a liability off road and all but useless any other time. Honestly, how can you push anything when you're 40" off the ground?
It's all steel so it's heavy which is kind of a problem with our Sports. The 3.0L isn't the most powerfull engine especially when you start adding weight like skids, tire carriers, bigger, heavier tires and rims, etc. I haven't weighed everything but I THINK the above design should be a few lbs lighter.
Yes, you're correct, but ... I used to build skid plates for the undercarriage out of 5/16" T6061 and went to 3/8" because 5/16" was over kill. I could drop the entire weight of the front of a Sport on the skid plate and it would barely scrape the aluminum. So, while I would NOT make the winch mount out of aluminum, the actual bumper as I described above would be perfectly fine and stronger in fact that ARB's which is not exactly a weak bumper.
Anyway, just some thoughts.
Edward
www.4x4extremesports.com
It's all steel so it's heavy which is kind of a problem with our Sports. The 3.0L isn't the most powerfull engine especially when you start adding weight like skids, tire carriers, bigger, heavier tires and rims, etc. I haven't weighed everything but I THINK the above design should be a few lbs lighter.
