Badfish740

Spring is here and it's time for some truck projects. Around last Fall I scored a bunch of free steel (angle, box channel, c-channel, all kinds of sizes) and a free stick welder from a machine shop that was moving. I have two 8' lengths of 5" x 2" x 1/4" wall rectangular channel, one of which I'd like to cut down for a rear bumper. It's pretty big (and heavy) but it was free and it'll be pretty darn stout when it's done, so that will be the main part of it. Basically I want to start with something like this, built by TOYOTA1:



The first question is how to cut those angles on the bottom (I don't want the bottom edge to go straight across)? I have a chop saw so I can cut pieces to length, but you can't make a cut that long obviously. How do you guys do it? Just take an angle grinder with a good disc and keep grinding with the edge until you get through the metal? Working with 1/4" that way is going to be a real $*%@! but oh well. Is there a better way that doesn't involve buying a plasma cutter?

I won't be mounting my bumper flush like that one though, because I want to incorporate a swing-out tire/Hi-Lift carrier like this one, built by Snowbear:



His is pretty fancy with room to mount a rear winch and a lot of angles, but I would just mount the main bumper out far enough from the tailgate so that I had plenty of room to weld a big hinge onto one end and a lock for the arm on the other end. Two pull points on either side and a receiver hitch in the middle and it would be good. I have enough steel to pull it off, just need enough time to get going on it. It probably won't happen soon, but I'll start updating with pics once it does.

rustED

iTrader: (2)

I just use my grinder with a skinny wheel. (I wish I owned a chop saw tho!!!) I have built 2 flatbeds, built my front spring hanger when I SASed my 4runner and am now working on my trailer project and I just used the grinder to do all the cutting. I have cut through 1/4" plate and it cuts through faster than you'd think, just let the grinder do all the work and don't force it and your cut off wheels will last longer.

I like the looks of the bumper in the first pic you posted, with the addition of the tire carrier (like you mentioned) that would look sweet, I would like to build something similar for my 4runner. Good luck on your bumper, I look forward to seeing some pics once you get started!

wyoming9

iTrader: (1)

If you feel like taking a ride I am not that far away.

still cleaning the mess up from the storm!! It should have been named after my exwife.

I am trying to figure out just where to mount my spare tire so it is not in the way.

Badfish740

I've been meaning to actually as I'd like to get out that way to check out some of the State Forest roads too, but time isn't something I have lot of these days... If anyone has any ideas on how to make a heavy duty hinge I'm all ears. I'm looking at using a 3/4" bolt for the pin and some bronze bushings to make the action tight but smooth. On the other end I'll use a spring loaded pin to secure the carrier to the bumper.

wyoming9

iTrader: (1)

I just bought a nice Heavy one from McMaster-Carr that I was going to use till I changed my mind. A heavy duty Strap type hinge for like $25.00

I decided I didn`t like the idea of the tire being back there I am now going to mount it to the top center of the headache rack.

highonpottery

iTrader: (1)

in the swingout pic you posted, that guy made his own double-shear hinge instead of a spindle hinge setup (which they sell kits for making swingouts). if you look, he's got a double-shear mounting point and a piece of round stock w/bushings between them. (Google "double shear hinge" and you'll find many examples of how to do this on a bumper) this will definitely work and is much cheaper than a spindle setup. Most people just use a poly bushing, but would be more rigid if you used bronze bushes instead. Not sure how much deflection there would be with either setup, but I'd expect them to be pretty good until you make a REALLY long swingarm or use rubber bushes, etc. this "hinge" is so simple, you could even add it to the face of the rectangle tube you're planning to make the main bumper from, using some 3/8" plate as tabs. to keep with the simple design, make the same type of attachment on the "lock" side and use a pin w/bearing to fasten it closed (look up quick-release pins, there are dozens of different designs) -- and you could technically make it open in either direction by installing a bolt vs pin. if you mount the swingout to the face of the rectangle tube like i just described, you could potentially make the bumper an air tank in the future since it's a good size volume. also think about whether or not you plan to integrate a trailer hitch receiver into the bumper, which may add a degree of difficulty trying to figure out placement so you can still get to the pin. definitely make sure to brace the hell out of the back side of the bumper with triangulated supports for the most rigidity.

as for tools, you really don't need a whole lot. I would have a quality angle grinder(s) with plenty of cutoff wheels to make the long cut and whatever other cuts you need, grinding/sanding disks of your preference to clean up the welds/slag. A sawzall w/metal blades might come in handy for some cuts. Good corded power drill and/or drill press. Beer. No need for plasma cutter or bandsaw on a project like this - but they can make it easier!

stanprophet

Well a 4 1/2 inch angle grinder, with some cutting wheels will make quick work of the 1/4 steel. The hardest part is getting the angles right. I would also suggest some grinding wheels, and some flapper wheels. The flapper wheels are good for pre and post welding preparation.

It is really not that hard, just take your time, and practice the welds on the some scrap, it is much easier to make the welds right the first time then it is to grind them out and redo them. I had one I had to grind out, because I forgot to turn the gas back on. It is a PITA!

If you check my build thread you can see the swing out that I made last week for my round tube bumper. It was a dual shear design with 1 inch bolt and bronze bushings for the hinge. Simple and strong, and I would trust it more than a spindle any day. I can get some part numbers for the tube and bushings and post them if you like.

Really the killer for any swing out design is vibrations that cause metal to metal contact, and potentially metal fatigue that can cause sheering. My swing out was not build as heavy as some of the ones I have seen on the web, but some other design aspects were added to help with vibration and weight distribution near the base of the main structure to keep overall weight torque to a minimum.

Good luck with the build!