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drmike
drmike New Reader
11/22/10 8:39 a.m.

I've been working on my own splitter design for my MINI Cooper S, so it was interesting to see that a splitter was just added to the GRM MINI.

I thought I'd share my design here, as it's fairly simple to make and does not require the links or turnbuckles seen on other designs.

(BTW my image-fu is weak so please excuse me if the image sizes annoy)

Ingredients:

Aluminum 6061-T6511

Carbon Fiber, Bidirectional (BID)

Carbon Fiber, Unidirectional (UNI)

Epoxy, West or Proset

Rohacell foam, 4lb/cu.ft., 0.38 inch thick

1/4-28 Stainless steel threaded rod, 60ksi UTS

-6 Aluminum tubing, 6061-T6

Step 1: Cut the foam to a pleasing shape:

Step 2: Add carbon fiber. Three plies top and bottom. The middle ply on top should use the UNI with the fibers oriented front to back.

Step 3: Vacuum bag wet layup for 24 hours. Keep layup at about 75 degrees F.

Step 4: Trim the part, and add aluminum mounting hardware.

Step 5: Mount the splitter using the threaded rod and the tubing. Check for structural integrity by applying approximately 185 pounds of weight to the front edge of the splitter. Bounce up and down a bit to check for deflection.

Step 6: Trim off lower lip of nose panel and install panel on car.

That's it! Here's a picture of the finished product:

After all of this, I found that I CAN get into my driveway without scraping the splitter on the ground. Nice.

triumph5
triumph5 HalfDork
11/22/10 8:47 a.m.

Very nice job! I take it you're more than a little familiar with vacuum bagging?

Production run posibilities? (I do not own a MINI, would like to, just thinking.)

Grtechguy
Grtechguy SuperDork
11/22/10 8:48 a.m.

Very nice

mndsm
mndsm Dork
11/22/10 8:57 a.m.

I'd buy one of those for mine, that's for sure.

Matt B
Matt B HalfDork
11/22/10 9:00 a.m.

Dern, that's a lot nicer than the alumalite concoction I was thinking up. Great job.

TJ
TJ SuperDork
11/22/10 9:43 a.m.

I hate that most picture hosting sites are blocked at work when I see a thread like this. I have to wait all day to go home and look at the pics. The suspense is a killer.

triumph5
triumph5 HalfDork
11/22/10 9:52 a.m.
TJ wrote: I hate that most picture hosting sites are blocked at work when I see a thread like this. I have to wait all day to go home and look at the pics. The suspense is a killer.

drmike is STANDING on the splitter and it's not deflecting. Hope that helps with the suspense. It looks as if Pratt & Miller made it.

Tom Heath
Tom Heath Webmaster
11/22/10 10:10 a.m.

This is my favorite new reader post of the week. Way to go Dr. Mike!

93celicaGT2
93celicaGT2 SuperDork
11/22/10 10:12 a.m.

That is MEGA awesome.

drmike
drmike New Reader
11/22/10 12:56 p.m.

Thanks everyone! This was a fun project.

I'd call my level of composite expertise as one step above a kid with an "easy-bake oven."

I have no plans to make these things for sale... yet... I'm not set up to make composites other than for tinkering. I guess if enough people were interested I could look into it.

triumph5
triumph5 HalfDork
11/22/10 1:00 p.m.

From your pics, I'd say that's the Viking Brand "easy bake oven."

Pumpkin Escobar
Pumpkin Escobar SuperDork
11/22/10 3:40 p.m.

where do you get your vacuum bagging materials (bung, fittings, bagging, etc)? Have you ever used Soller Composites? Thats a really great build - can you give us some pointers for drawing up the template?

Cone_Junky
Cone_Junky Reader
11/22/10 4:17 p.m.

I came into this thread thinking it would be something for me to make. Unfortunately looks like to many steps for me to berkeley up. Time for some ply...

I have to give credit for an excellent piece of GRM hardware. Looks like an expensive, professional splitter.

triumph5
triumph5 HalfDork
11/22/10 4:21 p.m.

It looks like it should be written up and put in The Magazine, with tips on working with the stuff, where to buy it, quick tips on handling it, pulling and holding down a vacuum....stuff we could use.

Tom Heath
Tom Heath Webmaster
11/22/10 4:40 p.m.
triumph5 wrote: It looks like it should be written up and put in The Magazine, with tips on working with the stuff, where to buy it, quick tips on handling it, pulling and holding down a vacuum....stuff we could use.

You're right; it's been a while since we've done a DIY carbon story. The last one was around 2000; I'll look up the specific issue shortly.

Good thing Per is doing a sports racer body in CF over the winter. Stay tuned, faithful readers.

SillyImportRacer
SillyImportRacer Reader
11/22/10 5:48 p.m.

Very nice.

TJ
TJ SuperDork
11/22/10 6:41 p.m.

Very nice.

drmike
drmike New Reader
11/22/10 6:46 p.m.
Pumpkin Escobar wrote: where do you get your vacuum bagging materials (bung, fittings, bagging, etc)? Have you ever used Soller Composites? Thats a really great build - can you give us some pointers for drawing up the template?

Most of my stuff comes from either Fibre Glast or Revchem. I haven't used Soller, although I do have a folder of bookmarks for several suppliers, and I'll add them to the list.

The template started as a big piece of corrugated cardboard. I cut and chopped it until I had something like what I wanted. I then took a few measurements of this and put the drawing into a CAD package. The leading edge, for example, became one half of an ellipse. Then, I printed out a full-sized drawing of the part (almost, anyway - my plotter isn't really big enough) and pasted that to a fresh piece of cardboard. Finally, I cut the cardboard out along the drawing, and held this back up to the car to make sure the fit was correct. I used this template to trace out the pattern on the foam. You can see the cardboard piece on the table in one of the pictures. The same piece of cardboard was also used to transfer the front four mounting holes to the carbon part (the rear two mounts were tack-welded in place while bolted to the carbon piece so that they would line up perfectly).

heyduard
heyduard New Reader
11/23/10 11:19 p.m.

nice! notice any benefit yet?

Mikey52_1
Mikey52_1 HalfDork
11/23/10 11:49 p.m.

Well, your image-fu may not be good...I dunno, looked fine to me!...but dayam! The splitter-fu, and its associate carbonfiber-fu is excellent! That splitter is at least as good as any of the mega-dollar splitters there might be in a certain genre of mags...good job!

Luke
Luke SuperDork
11/24/10 12:05 a.m.

Awesome. That looks excellent, very professional-like.

Here's a boring question...are you faced with any legality issues running that thing on the street? I was thinking along the lines of pedestrian safety bullE36 M3. (Obviously that would differ from region to region, etc...)

LainfordExpress
LainfordExpress New Reader
11/24/10 5:12 a.m.

Looks great!

Platinum90
Platinum90 SuperDork
11/24/10 7:11 a.m.

Wow. That is much nicer than anything I could make.

I would also appreciate an article on working carbon. I plan to make several carbon parts for the heavy supra, and knowing how would certainly help.

Or at least post the 2000 article to the site. (Btw, weren't there plans for an article archive? How is that progressing?)

drmike
drmike New Reader
11/24/10 7:58 a.m.

Yeah, there's a lot of jokes at work about how much I must hate pedestrians to want to chop their feet off! That, and squirrel decapitation jokes. The splitter doesn't violate any laws that I'm aware of. California seems obsessed with anti-smog laws. Heck, they don't even have safety inspections here.

Judging by seat-of-the-pants, the splitter has a very small benefit at about 65 mph, growing to a grin-causing amount of extra stick at 90 mph. The next time I'm at the track, I should compare lap times with the splitter on and off the car.

njansenv
njansenv HalfDork
11/24/10 8:08 a.m.

One concern I'd have (at least around here) is less about whether it's "legal" (it's not illegal....), and more about "if I hit a pedestrian, will I get sued for making changes to the car that increased the extent of the injuries". Just a thought.

VERY, VERY cool build though...and it reminds me that I need to work on a CF project sometime.

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