Recreating Missing ZHP Front Bumper Support Brackets

[///Mark_D]

I posted about this over on E46 fanatics, but thought I'd share here as well since it's ZHP (MTech II) bumper related.

A few months ago I bought a 3.0L swapped E46 touring that had a MTech II bumper installed. It had a few cracks and some damage that needed repairing, including a broken lower support bracket on the right hand side, and completely missing lower support on the left hand side.

For those not familiar, the lower support / adapter brackets are an integrated part of the bumper cover that are the attachment point for the lower inner finder liners, and make up the gap between the bottom of the bumper and the inner fender.

The ZHP bumper is lower to the ground than the standard bumper so the adapters act as spacers to allow the ZHP bumper to mount to the standard inner fenders.







The adapter brackets are melt-welded to the bumper as a subcomponent of the bumper itself, and are not available to buy separately, even though they each have a unique BMW part number.



Left: 51117893127
Right: 51117893128

So at this point I could have just reattached the RH side bracket with some bumper repair adhesive, but I still needed to source a LH side bracket. I searched for a used one from a broken/damaged ZHP bumper, but came up empty handed. So I decided to make my own.

First, I measured and 3D modeled the RH side bracket using CAD software. Then did more measuring and checking to make sure the model matched the physical part. Once I was happy with the RH side, I mirrored it over to create the LH side.



I used Xometry online 3D printing to have the parts made from Polypropylene (PP), which is the same material as the bumper cover. They were printed using HP Multi Jet Fusion for high resolution and strength.

About a week later the parts showed up in the mail.





And then I glued them in placed with LORD Fusor 143 structural bumper adhesive.







I'm working on a few minor improvements to the model files to make the 3D printed parts more accurately match the real parts, and to improve fit and finish. Once the updates are complete I'll be uploading the final model files for anyone to use to print their own.

I printed two sets of each LH and RH side brackets, so the price per unit was reduced vs printing a single part. With shipping cost factored in, each bracket was around $30.

[squashman702]

Nice work! Have you used the bumper adhesive previously? I have a side bracket I've attempted to repair once on my ZHP, and found a better bracket to use instead, so I need a way to adhere that to the bumper skin.

[///Mark_D]

Yeah I've used the LORD Fusor brand adhesive to repair cracks and to reattach the main bumper side bracket in place. So far it's held up well and I'm impressed with how strong and flexible it is. Before using the adhesive there is a surface modifier primer so the adhesive chemically bonds with the plastic.

Check out this Youtube video for more info. Fusor is used by the pros to repair bumpers, create/repair broken mounting tabs, etc.

https://www.youtube.com/watch?v=pwufaE3FQP8

Here are previous repairs that I've done:

[cakM3]

Mark, if you get to the point where you can sell off sets I would be interested. I like this solution. This is good stuff

[///Mark_D]

Thanks! I might do another small run just to confirm fitment with the minor changes I'm making to the CAD models. The other set I ordered the first time around I sold to malapane since he was still looking as well..

Did you need just one side, or both?

When I was looking into 3D printing I checked a bunch of different sites and Xometry was the least expensive. Ordering one piece per side it was like $43 each, but when ordering at least two it dropped to $29 each. They could also print using multi jet fusion (MJF) instead of the more standard FDM, which avoided having to print lots of additional support structures due to the odd shape of the parts.

I should have the models updated in a couple of days and I'll share them here.

[cakM3]

Thanks! I might do another small run just to confirm fitment with the minor changes I'm making to the CAD models. The other set I ordered the first time around I sold to malapane since he was still looking as well..

Did you need just one side, or both?

When I was looking into 3D printing I checked a bunch of different sites and Xometry was the least expensive. Ordering one piece per side it was like $43 each, but when ordering at least two it dropped to $29 each. They could also print using multi jet fusion (MJF) instead of the more standard FDM, which avoided having to print lots of additional support structures due to the odd shape of the parts.

I should have the models updated in a couple of days and I'll share them here.

Mark, hit me up with a message when you're ready

My ZHP is a rescue so it would not surprise me if I need to do this when I take off my front bumper ... there are a lot of cosmetic issues with my car that I have been sorting thru since rescuing it ...

[TXRedDevil]

Amazing skills, Mark! Hell, I can't get my 3D printer to articulate and work lol. I gave up on it months ago out of frustration! Amazing what you can do these days w/ software and outsourcing the work out.

[///Mark_D]

I can still remember back when 3D printing was just becoming a thing, but was super expensive and limited in capability.

It still feels like magic sometimes how much the quality has gone up on the parts and the new printing technologies/materials that are available now.

[///Mark_D]

Hey so I forgot to update this thread, but I made updates to the bumper brackets to improve fit and add a little bit of extra strength to the mounting tab. I've been running the 3D printed parts for a few months now and put on around 4000 miles since then and the parts are holding up without issues.

Updated STL files for both LH and RH brackets can be found on my google drive here:

https://drive.google.com/drive/folde...FRMoxnvf5c1Wjz [drive.google.com]




EDIT:
And is anyone else having issues seeing the images attached in my first post? I'm either not seeing them because of my browser security settings, or the links are all dead.

[slater]

Hey so I forgot to update this thread, but I made updates to the bumper brackets to improve fit and add a little bit of extra strength to the mounting tab. I've been running the 3D printed parts for a few months now and put on around 4000 miles since then and the parts are holding up without issues.

Updated STL files for both LH and RH brackets can be found on my google drive here:

https://drive.google.com/drive/folde...FRMoxnvf5c1Wjz [drive.google.com]




EDIT:
And is anyone else having issues seeing the images attached in my first post? I'm either not seeing them because of my browser security settings, or the links are all dead.

yep, they are visible to me.

and...this is incredible, mark! amazing. i've actually been looking for a good plastic adhesive - i will check out the LORD Fusor stuff you mentioned, as i have to reattach a broken bumper mount on my son's 325Ci.

peter