81 BJ42 - I have to bring it home and pass inspection

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With the heavy OME springs I put in I need more weight in the front so I will have to mount one of my 8274's. Which means I need a bumper. So I have been sketching and designing a simple bumper that will bolt up with no modifications to the frame. Here is what I have so far.
BUMPER.webp

BUMPER 3.webp

BUMPER 2.webp
BUMPER.webp
BUMPER 3.webp
BUMPER 2.webp
 
Nice Design. What program are you using there? How thick will the steel be?

Since my 40 was hit on the outside of the drivers frame rail and the bumper buckled, I've wondered how other bumpers would help and give more protection. Yours look like it would take and impact well.
 
Yeah, I saw your thread about your little mishap. I am using Solidworks 2013, which is about the most prolific design software going right now but it is generally used by professionals rather than the public. It's quite expensive. I don't have it at home, just at work.

I have drawn it all in 1/4" HR plate and made the pieces to suit our tooling at the shop. The recovery points are 1" plate. I will have it all lasered out and then bend it up and take it home to weld.

My major design constraint was to make it bolt-on and not alter the rig because it is all original and I want to keep it that way. On my 45 the angled frame extensions were removed so I put a plate down the outside of the frame rail for more bolts but I'm not cutting the horns off this rig. This causes this bumper to sit 2" further forward than the 45. The winch will also sit 2" forward but I don't mind. It will give more air to the rad then.
 
I like the bends in the bumper.

Do you need more weight because of the ride quality or shackle angle?
 
The OME heavy front springs are designed to run with 100+ lbs of extra weight in the front. With no extra weight the ride would be pretty stiff. The heavy bumper and winch will help.
 
I think your brothers going to want one;)might as well send two down while your at it;p....

Does he have a cruiser, he should hook up with the VI cruiser gang, great bunch of guys:beer:


I like that bumper design alot...


Rob
 
Very cool you can bend the 1/4" steel.

My machine shop that's been helping me with my builds actually told me about Solidworks this week and pretty much said if I can bring anything I want done in on that program it would be a snap for them. Every time I go over there I think how much fun I would have making things in a machine shop. Too bad Solidworks is not for home use...
 
Hansons bumper

FJ40-FRONT.jpg
 
Awl_TEQ said:
With the heavy OME springs I put in I need more weight in the front so I will have to mount one of my 8274's. Which means I need a bumper. So I have been sketching and designing a simple bumper that will bolt up with no modifications to the frame. Here is what I have so far.

Beautiful. I love the simplicity. I made mine simple (though not as schmick) as yours. I am not a fan of the Baja-look of that Hanson.
 
crushers said:
remove a leaf?

Maybe, but I'll see what she's like after some miles and twisting.
 
Diesel Cruiserman said:
I think your brothers going to want one;)might as well send two down while your at it;p....

Does he have a cruiser, he should hook up with the VI cruiser gang, great bunch of guys:beer:

I like that bumper design alot...

Rob

He's got copies of all the pieces from my last bumper build. Not welded, but he's got them. He has a '71 40 on jackstands in mom's garage. It runs and drives but needs some metalwork. But he's in the middle of moving to Edmonton. I know, who wants to move TO Edmonton right? Well, there is a woman involved so he's not thinking clearly.
 
thetoyotaman said:
Very cool you can bend the 1/4" steel.

My machine shop that's been helping me with my builds actually told me about Solidworks this week and pretty much said if I can bring anything I want done in on that program it would be a snap for them. Every time I go over there I think how much fun I would have making things in a machine shop. Too bad Solidworks is not for home use...

We can bend 3/8 depending on the profile.

I've got dozens of things I want to draw up. Just not enough hours in the day.
 
lowenbrau said:
That bumper design is fantastic. I think 1/4" is probably 50% too heavy though. 3/16" with a couple gussets would still kick butt.

Oh, wait! Are you making it out of aluminium?

3/16" would be a fair bit easier to bend tooling wise. You really think 1/4" is too much? Steel.

I made my last one from 24" of 3x5x1/4 wall tube with 3/16 wings on the ends similar to this one.
 
you can always remove a leaf, drive, twist, soften, reinstall if need be.
i wish i could do mock-ups like that, the old pencil and paper and grey matter is all i can work with. if you have any links to free programs to play with ... well ... that would be nice.
 
You can draw it with sketch up for sure. But I don't know what else you can do. That pic above is actually an assembly. Each piece is drawn individually and then they are pulled into an assembly drawing and put together. Also, the pieces are drawn as sheet metal that is bent, not solid representations. So solidworks will flatten them, account for material stretch, and give me the exact flat for each piece.

Bending sheet metal 101:

If you want an angle bracket 1"x1" by 2" long you do not start with a 2" square and bend it down the centerline. If the material is, say, 1/8" thick you will end up with a piece of angle that is 1-1/8" x 1-1/8" by 2" long. The material stretches by approx the material thickness on each side of the bend. At the shop we work with 0.005" tolerance at times so when I say "approx" I mean not quite. When you bend metal it stretches on the outside of the bend and shrinks on the inside. The percentage of shrink vs stretch is different for each material type (steel/ alum/ ss), material thickness, and size of V-die being used. 16ga cold rolled steel, for instance, will have bend allowance of 0.115" when bent 90* on a 0.551 v-die. So to get an angle 1"x1" by 2" you start with a piece 2"-0.115" 2".... IOW. 1.885" x 2". Notice, 16 ga is 0.059 thick so it shrinks by 0.003" (2x0.059-0.115=0.003). Not much, hardly worth the bother to calculate. But the bend allowance for 1/4" is 0.445" so you shrink 0.055" or about 1/16" per bend and if you have three bends on a part yer out 3/16".

Anyway, Solidworks calculates this all for you and gives you a flat that you can then make 1000 pieces from and bend 12 times within a 0.005" tolerance and make your customer smile. And the boss too.
 

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