heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Also, forgot to mention earlier, but I also designed this top clamp to go over the stock strut bar. The purpose of it is add rigidity to the bottom sheet metal clamp. There will be a torque trying to bend it away from horizontal (or close to) and this clamp should help with that. However, it's totally possible that the final geometry makes this clamp essentially redundant. We'll see.

[0-60motorsports]

Yeah I'm pretty excited about it. Will share all the design files when I'm done in case anyone wants to recreate this on their car.

Awesome Thanks! Wil just have to find someone in the USA to print them for me in the correct material.

[heinzboehmer]

Awesome Thanks! Wil just have to find someone in the USA to print them for me in the correct material.

There's a bunch of online vendors that will do metal 3D printing and ship worldwide. Not sure who I'm gonna go with yet (have yet to decide on materials), but I'll post all that info in this thread.

[0-60motorsports]

There's a bunch of online vendors that will do metal 3D printing and ship worldwide. Not sure who I'm gonna go with yet (have yet to decide on materials), but I'll post all that info in this thread.

Thats good to know. Thanks buddy.

[Obioban]

lol. My workbench right now hears your disassembly plight.



That said... only really added ~5 minutes to disassembly.

[Obioban]

There's a bunch of online vendors that will do metal 3D printing and ship worldwide. Not sure who I'm gonna go with yet (have yet to decide on materials), but I'll post all that info in this thread.

I've had good experience with craftcloud for metal 3D printing.

https://craftcloud3d.com/

[heinzboehmer]

lol. My workbench right now hears your disassembly plight.



That said... only really added ~5 minutes to disassembly.

Ha, there you go!

And yeah, the extra time overhead isn't too bad. I just don't want to deal with the possibility of losing my alignment whenever I go to do something in the engine bay.

I've had good experience with craftcloud for metal 3D printing.
https://craftcloud3d.com/

Nice thank you, I'll check them out.

[heinzboehmer]

Also, was working on recreating the silicone mold in CAD last night and it occurred to me that I might also be able to make the piece that goes under the windshield out of laser cut sheet metal. Would have to add some walls to box in the structurally important sections and have someone weld it up, but it might just work.

I'll likely design both a 3D printable/CNC machinable version and a sheet metal version, then decide which one to go with.

The top clamps for the stock strut bar will definitely need to be 3D printed.

[Mike RT4]

Loving the E86 brace - top "thinking outside the box" work as usual .

[heinzboehmer]

Loving the E86 brace - top "thinking outside the box" work as usual .

Thanks! Looking forward to finishing and installing on the car.

Also, quick update on the design of the windshield attachment point. First, a run down of the space constraints:

1. This feature exists for RHD windshield wiper linkage clearance. Don't need to worry about this for now and the piece can be designed to bond to this surface.
2. This is the same linkage clearance but for LHD cars. The entire marked section is off limits.
3. This part is flat and can be used for extra support (even directly behind the linkage). However, there's not a ton of room between it and the blower motor, so whatever goes in there has to be essentially a thin sheet. Note the (hard to see) grommet. Thin sheet will need to have clearance for this.
4. This white piece sticking down is a grommet that holds the plastic windshield cowl in place. The brace piece must have enough clearance to allow the grommet to work as designed.

While my design will only directly fit into LHD cars, the geometry under the windshield is symmetric side to side, so all that's needed to make a RHD piece is to mirror it.

With the constraints in mind, we come up with this. Note that this design is missing some curved edges that need to be part of the final design. Those will come later once the general fitment is validated:



I think it's pretty clear why the design looks like it does. There really isn't any other geometry that works under there! Space is very limited.

Next step is to print some slivers of the piece and test fit on the car, then move on to the final design.

Speaking of, I still don't have a plan for how to manufacture this, but these options are floating around in my head:

1. Print the thing in some kind of metal and hope it holds up
2. Mill/print the front part and bond a CF/metal plate to the bottom for the flat feature
3. Design it for laser cutting, bending and welding

I think I like (2) the most. Would make it pretty strong and relatively easy to manufacture. I would just need to add some threads to the bottom of the front piece and then bolt + bond the sheet to it. Also, sendcutsend cuts CF sheets, so no need to mess with cutting that stuff in the garage

[heinzboehmer]

Oh! I also designed these things:






They fit over the ends of the E86 braces and tell you exactly where to cut/drill them so that they fit on the E46 chassis. The cuts will shorten the total length of each brace by 53 mm, which is just enough to make them fit.

[George Hill]

Fantastic!

What are your plans for the microfilter housing?

[heinzboehmer]

Fantastic!

What are your plans for the microfilter housing?

Ah great question! Forgot to talk about that. Since the attachment points of the E86 braces will be fully underneath the windshield, the firewall plug will need little modification. Basically just a clearance cut.

Filter housing can also keep its general shape, with some reliefs for the top of the braces. For the first prototype, I plan on cutting some clearances into a stock housing and printing some pieces that I can epoxy in to close up the holes. Trickiest bit will be making sure the gradients on all surfaces point towards one of the two drains, so that water doesn't pool up inside there.

Eventually, I'd like to print a mold for both pieces and remake them out of prepreg carbon using a method like this one:

https://youtu.be/6xj06Am94aQ

Need to get the geometry correct before going crazy with the carbon though

[heinzboehmer]

Also, ran the numbers for the two piece approach (using the current draft design) and the weights are as follows:

• Front "tall" piece
  • ~0.9 kg (1.98 lbs) if made out of 6061 Al
  • ~2.6 kg (5.73 lbs) if made out of 304/316 SS
• Rear "sheet" piece
  • ~0.4 kg (0.88 lbs) if made out of 6061 Al
  • ~1.0 kg (2.20 lbs) if made out of 304/316 SS
  • ~0.2 kg (0.44 lbs) if made out of sendcutsend 3.99 mm thick CF

A lot of these are WAY more than I want, especially since this weight lives high up and in the front of the car.

Design is currently bigger than it will end up being (width wise mostly), so that will shave some weigh off, but the bulk of the weight comes from the front piece being completely solid. Once I figure out the precise angle that each brace will sit at, I can work on hollowing the piece out, while keeping enough material in the load path of the braces. It'll be a fun exercise to find a good tradeoff between weight, strength for the braces and appropriate surface area for bonding the sheet.

Of course, making the front piece out of carbon would dramatically decrease the weight, but I have zero carbon skills, and I absolutely do not trust myself with this as a first project. It would absolutely suck to be grinding the failed pieces out of there in a few months.

If I can make the entire thing weigh less than 1 lb, I'll be happy.

[heinzboehmer]

Initial test fit went well:



Some tweaks needed to get it perfect, but one more iteration should do it.