Finally spring break is here, and I've got a week with nothing but free time on my hands so I decided I'd finally start work on the front bumper I've been thinking about. I'm a desperately poor, starving mechanical engineering student so I had to improvise a bit on the materials.
About 75% is made out of 1/4 plate I had laying around, the rest was made out of 3 X 1/8 flat stock, the D-ring tabs are 1.25 X .5 cold rolled bar stock. I've still got to make the second D-ring tab and mounting plates and it'll be all done. Total cost to me so far $12.xx
The bottom plate has a recessesed cut out to allow access to the bolts.
I also wanted to try a different approach to mounting the bumper to the frame. Since I dont have a lot of extra plate laying around to reinforce the unibody, I'm mounting the bumper using a friction mode joint. Basicly the mounting plate and the flange on the frame are bolted together tightly. This force creates so much friction that all the forces on the bumper are taken over the entire plate area via friction instead of on the bolt holes.
According to my math, and assuming that the steel used in the Unibody has similar properties to A570 steel, the bumper will be able to withstand a little over 5,000 lbs before slipping. Since the combined max safe working load of the shackles im using is 4,000 lbs I think that it'll be sufficient but what do you guys think?
I'd also be happy to share the math if anyone is interested, it's not very complicated just a couple formulas.
Let me know what you guys think!

 

Nice should look real good when she all painted up

sent from sweet iPhone app

 

Did your knee get sunburnt from welding with it open like that?

Bumper looks good though, should have made the d ring tabs weld through the bumper but it looks like you might have enough weld area to be alright.

 

Haha i didn't get a sunburn but I did end up setting myself on fire with the frayed edge.
I'm hoping that the greater weld area will be enough. I've also ground a groove on the bottom edges to improve weld pen, and I'll be having a friend of mine stick weld them on.

 

I like the mounting option. It is definitly a different kind of mounting. How tight are the bolts? and did you mount them to the stock factory holes??

 

Looks good man. Do you have any pics of the mounts your talking about? Id like to see how they work..

 

x2

 

sic