Home Fabbed Bumper

The pictures shown below display a prototype we were working on about 6 months ago. We have not yet built any frame mounts for it. The bumper is just sitting there unattached. After we finished the body to this bumper, we decided to scap the idea and do something different.













The drawings shown below display the design we came up with after we scapped the first prototype. The problem we ran into with this is that we don't have a laser or press brake. After sending some parts drawings out to various sheet metal shops around, we discovered that they want an arm and a leg to make us one or two of these. We could get bulk for a decent price; however, we would like to finish prototyping it before we were to buy in bulk.













So until we can afford to spend the money to finish prototyping the bumper shown in the drawings, we are going to finish the first bumper.

Basically, we have a few ideas for frame mounts; however, we just want to make the frame mounts very nice the first time we make them. Because we don't really like the bumper, we don't want to fool around with it much.

Our question for you is, "What is the best frame mount design that can be easily fabbed up with small tools (angle grinder, chop saw, sawzall, welder, drill press, ect...)?"

Thank you.

why do you have the dring mounts bolted on? Youd be better off just welding them on.

I only have a 110 Lincoln 130 welder. It won't penetrate as deep as is needed to withstand large forces. This configuration is mechanically grounded through three .180" thick layers of mild steel into the frame. I have to work with what I have. True...I need tools. But don't we all?

I finished the old bumper tonight. I will post pics when I get a chance.

I didn't do anything special with the frame mounts. I just cut, drilled, welded, and repeated until it fit. I used an old tow hook bracket to get the hole pattern.

Thanks for all your posts....Just playing.

Brian

I built mine similar, and just made relief cuts and then welded it back together, ground it smooth, rounded everything with a flap wheel, etc. I did all my cutting with a 4.5" grinder & cut-off wheel. I started out with 4x6 tubing. For the tow hooks, I cut a hole in the bumper face so I could weld them front and rear, then I added gussets on the back side and welded those as well. There are more elegant ways to work within your means instead of bolting them. You could also cut a hole in the face, stick your thick tow hooks through, and have solid round steel dowels that go through holes on the back side so the strength doesn't rely just on the welds. Either way though, the bolts look kind of cool.

What is the best frame mount design that can be easily fabbed up with small tools

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The side plates you have in the cad are really the best deal around from what I have found. Also making a plate that goes between them giving the front cross member a bit more reinforcement is a good idea. IF you sandwich the stock bumper tabs between the inner brace and the outer long braces you have something vary substantial to work off of. 3/16" is good for this but 1/4" is overkill. Given I like overkill but 3/16" will do fine on these items.

With your d-ring tabs I would recommend going all the way through the facial meterial and welding both the front and back. Being that you have a small welder this will work fine. If you still don't fell comfortable, once more I like overkill, Make a plate that goes around the tab again and weld that on also.

JeepZJlover said:

why do you have the dring mounts bolted on? Youd be better off just welding them on.

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Bolting is usually considered more secure (safer) than welding. You definitely don't want those D ring mounts to come off under a hard pull. If welded and designed properly, fine, but not everyone can do that.

Why not just make the frame plates longer and stick out through the face of the bumper, then drill your hole in that? no bolts to come lose, no welds to possibley fail.

Like I said....I am not impressed with this bumper; however, it will work until we can afford to prototype the CAD drawing desgin. Considering we spent under $80 on everything that went into this bumper, I am somewhat happy with its turnout.

You can hate on my frame mounts all you want. I hate on them too. I was thinking that I would make a c-channel bracket or rect tube that connects the cross member, the lip that sticks off of the frame, and the bumper together. I cannot see this breaking.

Thanks for all of your comments.

Two things.



Why are you always saying 'we' and not 'I'? This is a company?


Why'd you cut all around the steering box bolts on the tie-ins? You could have an integrated steering box brace if you'd drilled holes instead of notching it...

Yes...We are starting a new company.

-MADHORSE-

The web-site is in progress....

The reason I did not integrate the steering box bolts into the frame mount design is because the only sheet metal I had available in my garage was 1/4" COLD ROLLED steel. For those of you who have attempted to machine cold rolled steel with a sawzall, angle grinder, and small drill press, you know why I only drilled 4 holes per mount. Basically, I didn't feel it was necessary to the integrity of this design considering my level of sanity.

Also...I do not believe It is going to make much of a difference really. Those grade 8 bolts will not fail given the kinds of loads that this application will deal them. I find it hard to believe that the cold rolled steel is going to deform with ease. If anything, the welds will break that connect the mounts to the bumper.

I will run an analysis using ANSYS on these mounts tomorrow at work. I will post the results.

If you look at the weird gussets I used on the bottom of the bumper (near where the frame mount connects to the bumper body), you will notice that there are octagons laser cut out of them. The gussets were designed to have a 1/2" nut welded into the octagon. You can then slide them into a frame and use them like a nutsert because when a bolt is turned inside the nut (in the frame), the sides of the rectangle catch on the inner frame walls. After running these tests using ANSYS; if I find that there is not enough stuctural support with 4 bolts, I will use some of these frame nutserts to attach a couple more bolts per mount.

I think the extra bolts would help the stearing box not the bumper. I really dont know enough about fab yet so excuse me if im talking out my rear.

Mutant_Xj said:

I think the extra bolts would help the stearing box not the bumper. I really dont know enough about fab yet so excuse me if im talking out my rear.

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Ohh...I was unaware that this was the purpose.

Then I will use the nutsert plates to attach them.

Thanks.

Cable clamps are not D-rings,thats just unsafe!

HaZakated said:

Y

I will run an analysis using ANSYS on these mounts tomorrow at work. I will post the results.

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What sort of parameters are you using to come up with a meaningful simulation? There are many factors that will dictate to accuracy of your results using ansys.

RCP Phx said:

Cable clamps are not D-rings,thats just unsafe!

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Bingo!

Proove it!

Think about a cable clamps application....lol. Did you notice it was grounded into the face of the bumper body.

Your kidding right?Cable clamps dont even have a "load rating" because they dont do any of the work!This is as "ghetto" as yor snorkel!

RCP Phx said:

Your kidding right?Cable clamps dont even have a "load rating" because they dont do any of the work!This is as "ghetto" as yor snorkel!

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I like you RCP. You seem like you have a great personality.

Hey RCP, if you don't want to use cable clamps buddy, by all means, don't. If you don't want to use my snorkel system, by all means, don't. Personally, I like my setup. I can assure you that both the bumper system and the snorkel system will work fine, but if you feel the need to spend $300+, by all means, do so....lol.

I gave the world my designs. Feel free to use them how you would like. I didn't ask to be thanked. If you want to do what I did, by all means, do so or don't.


Thats pretty buddy....lol...Very functional. Did you make that all by yourself. Maybe one day I could be as cool as you are buddy.










All I'm saying is if my designs are so "ghetto", then prove it. Anyone can say, "yor designs are ghetto." I'm saying prove it!

Forget the load ratings.....You seem to be very intelligent....You were given enough information (pictures)... What force will make the cable clamps fail??

At least his bumper has a legit dring mount.
Remind me to never be around you when you attach a strap to those clamps.