Looking for advice on building rear bumper

[ronsii]

Haha yep, exactly kinda where my head is. I figure if it sucks it was at least a learning experience.

I made a little progress today, and tried to mock up some cardboard for the wings.Attachment 1719628Attachment 1719629

If you want some good cardboard...well sort of... got to the post office... it's free!!!!

and it works for furniture too

[12V71]

If you want some good cardboard...well sort of... got to the post office... it's free!!!!

and it works for furniture too

"Machine parts" deliveries?

[ronsii]

"Machine parts" deliveries?

I use a lot of flatrate boxes when shipping with the PO... most of our product is heavy and I think the breakeven rate on flatrate is 4-5 pounds... so it's a no brainer if you need/want 2- day service also do get quite a few of em' incoming too

[walker]

I’ve already had my learning experiences, I prefer not to repeat them. I was hoping you might gain some knowledge from them, but I suppose you need your own hard knocks.
Best of luck.

[Noidea87]

Cutting these sections with a grinder sucks, but I'm slowly getting them there.

Fit up is tough, it's close but not perfect. With some grinding I can get them to fit cleaner i think. I'm going to tie a section from the bottom of the lower wing back to the main bumper mount, and figure out the shape for the top cap that will go on top of the side wings from the back corner.

I'm thinking that corner face won't support a swing arm without a gusset back down to the frame, maybe it would once it's welded out, but I'm going to try and add a connection there.

[sapperb]

Haha yep, exactly kinda where my head is. I figure if it sucks it was at least a learning experience.

I made a little progress today, and tried to mock up some cardboard for the wings.Attachment 1719628Attachment 1719629

Looks good!!

[evan]

Looks great and grinder is my go to tool for making clean straight cuts. Takes alittle longer than a gofch or plasma but is very straight and true. I use suicide wheels thinnest I can buy and 5"-6" with no gaurd.

Only thing id changd are your recovery points those are not thick enough at least in my opinion
Theres a ton to pic from on ebay. I like the long clevis mounts. I cut the face and run them inside the bumper so both sides are welded

https://rover.ebay.com/rover/0/0/0?m...2F264707628589

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[Noidea87]

Looks great and grinder is my go to tool for making clean straight cuts. Takes alittle longer than a gofch or plasma but is very straight and true. I use suicide wheels thinnest I can buy and 5"-6" with no gaurd.

Only thing id changd are your recovery points those are not thick enough at least in my opinion
Theres a ton to pic from on ebay. I like the long clevis mounts. I cut the face and run them inside the bumper so both sides are welded

https://rover.ebay.com/rover/0/0/0?m...2F264707628589

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I agree on the recovery points. I had planned to weld an extra 1/4" tab onto the outside part that sticks through the bumper so that part is 1/2" thick where the shackle would attach. I had played with the idea of cutting a slot and fitting a larger tab through as well so I may do that like you've described.

[Mr Earl]

The recovery points on my Metal-Tech and US Offroad bumpers are 3/4". I think part of the reason is, you don't want the shackle to turn or flip to one side if that makes sense.

[Noidea87]

Well I was so careful, or thought I was, with watching my heat input so as not to warp anything. But now the passenger side is about 3/16" off when the driver side bolts are in.



Should I slot the holes? Try to heat and bend?

[ronsii]

I'd cut and reweld.... an alternate fix would be to shove a step drill in there and rebore the holes... just make sure to washer em' up good afterwards...

[12V71]

Shove a big tapered punch in there and see if it will line up. Might flex it back where it belongs.

[Noidea87]

I think it pulled out when I was welding the rear plate to the top plate, I wonder if putting some welds on the inside of that joint would pull that side back in? Or make it worse?

....also don't mind that ****ty fit up seen in the picture haha. That plate was there to just cover the gap between the mounts and the side wing under the truck...I got lazy and didn't feel like re-cutting that piece since it's hidden. I've just been filling that gap with weld.

[ronsii]

Shove a big tapered punch in there and see if it will line up. Might flex it back where it belongs.

Oh yeah!!! that's another thing I'd try first grab a couple spud wrenches and go to town!!!!

[M J D]

If it's where you want it, slot the holes, preferably the thinner section. Otherwise like mentioned, taper punch or alignment pry bar.

[Noidea87]

Think I figured out what happened and why this side pulled out. I was very careful welding in small sections and skipping around, but on that front seam I welded from left to right way more than I welded traveling from right to left. What I didn't realize until I watched the video below was that the metal also pulls related to the direction of the weld not just the side the weld is on.

Maybe if I had welded the left side (traveling left to right) then went to the right side (and traveled right to left) and kept alternating like this it wouldn't have pulled so much on that one side? This video is very informative for a newbie like me

I'm wondering now if I weld the back side of the joint in the other direction if it might pull it back some

[evan]

Just by looking at how much the mounting holes are off my mind would tend to think it was off before welding started

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[Noidea87]

Just by looking at how much the mounting holes are off my mind would tend to think it was off before welding started

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I got all 4 bolts in when it was only the front plate and top plate tacked on. After adding the side wings now it's off. I put a big screw driver in and I could bend it to line up barely. The back face plate is bowed in in the middle and touching the rear cross member. So the whole bumper can rock a little side to side. I think if I split the difference and make it so both sides are off slightly maybe I can make both sides holes bigger and make it work.

[evan]

****.

Thats moved damn near half a hole. I usually only see that kinda movement when I'm stick welding big stuff together with lots of heat.

I think I've noticed things move more with flux wire. Though I'm not sure about that maybe the difference in polarity and arc characteristics. Sometimes I think to much. Lol

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[Noidea87]

I should have just left it bolted on, unhooked the battery and welded it up on the truck...dammit.

[ronsii]

****.

Thats moved damn near half a hole. I usually only see that kinda movement when I'm stick welding big stuff together with lots of heat.

I think I've noticed things move more with flux wire. Though I'm not sure about that maybe the difference in polarity and arc characteristics. Sometimes I think to much. Lol

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Yeh... but remember the bumper is 4-5 foot long.... that's a big lever from the other end especially if you're filling half inch gaps here n there not that you were.... but if you were

[ronsii]

I should have just left it bolted on, unhooked the battery and welded it up on the truck...dammit.

No biggie... this is how we learn stuff

[evan]

Ohhh yeah, we for sure learn by doing. I dont do it as often as I used to but accasionaly I burn something then almost right away im wondering why did I just do that.

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[Noidea87]

Haha, well at least everything that's visible looks decent at least these holes are under the truck. I'll make these holes bigger and pry bar this bitch into place. She's going in there one way or another after all this work.

I thought I was so careful with the heat too. I was welding 2 inches and then flipping the whole damn thing over and welding the complete opposite side skipping all around the whole bumper. I got a workout moving this thing around on the bench. If I'd have used 3/16 plate it probably wouldn't have happened but I really didn't want it that heavy.

I definitely got better at cutting straight lines with my angle grinder that's for sure.

[Noidea87]

Went and bought a pry bar alignment tool at home depot,and a step bit. Reamed the holes from 5/8 out to 3/4" and got the bolts to go in. Those frame threads are crusty though so I've ordered a m14x1.5 tap to try and clean them. If that doesn't work I guess I'll drill and tap to 9/16". Hoping I don't have to do that.

Added some gussets to help support the weight of the swing pivot, and some small ones to stiffen the wings, although I don't think they needed them. Cut the cap sections and tacked them on. This flux core is so damn messy i can't wait to use up this spool and get some solid wire and gas. Been wire wheeling the **** out of this thing trying to knock the BB's off