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SLR Wheel Caps (for Vovchandr)


Rosteri

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Vovchandr has those lovely SLR wheels, but no caps and since they are no longer available, let's figure out how we can make him a set. 

 

Original caps are 2 part, however it is easier to make them as one piece. I have the caps modelled now in 3D by using 6 mm thick aluminium plate as stock and also tried to make them as lightweight as possible:

 

cap1.thumb.png.849658c82c88e927842366f58d5a6ae0.png

 

cap2.thumb.png.9c15cdba9195310a554d4e551dea08ad.png

 

The Super 7 logo was the most work - the easiest would be just to have a circular recess and stick a domed 3D logo sticker, but let's try to do it first with machining. If the caps are painted/powder coated, then one could sand out the logo nicely!

 

The Super 7 has quite small features, so the first operation with a larger endmill leaves areas that remain unmachined:mill1.thumb.png.314d42d90477a9a4c39b626840234223.png:

 

A tiny 1 mm bit should get most of the remaining material out:

 

mill2.thumb.png.375f4636ed552715b0df8755627c61ba.png

 

And perhaps finishing off a chamfer tool (sharp) to follow the lines and clean up any burrs:

 

mill3.thumb.png.8b91b31c0f57e73f95b9a157bc1aa722.png

 

Vovchandr provided me with the dimensions, so next task is to make one and luckily I can testfit it locally first. Once the dimensions are verified, then I'll also post the step file of the 3D model here.

 

 

 

 

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Have I told you that you're my hero yet?

 

were not worthy waynes world GIF

 

I have no idea why but the vast majority of SLR's in the states don't have the center caps. I thought mine were lost over the years but the more and more examples I came across I saw that vast majority didn't have them, pending a few exceptions. I can only assume there were supply issues to begin with in England and US got the short end of the stick on the orders.

Edited by Vovchandr
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71489D9F-4E39-48C3-8703-41EF35851DF0.thumb.jpeg.e6bc6e0b9f8dc8c1f8a690032289f5f2.jpeg
 

D6365CB1-9A5A-40FA-8F5E-93D9078674D4.thumb.jpeg.6512543eda1a858e12212219a135a967.jpeg

 

D4942331-7C93-4829-BDBC-06736B579DAB.thumb.jpeg.210b9c0fb49cf29d0e8a20cc8ed23737.jpeg

 

First test piece turned out ultra light… actually a little too light, as the aluminium I am using is not heat treated. The bead blasting almost went thru… but the logo turned out nice!

 

 

 

Well, I’ll use this piece to check the dimensions next.

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14 minutes ago, Rosteri said:

By the way, what finish will you do? 

 

I will have them painted to match my wheels if thats what you mean.

 

It looks amazing!

 

Question about your recess hole. In the final design will it be just a hole or a concave hall? I know you said you have limited material thickness to work with but it does need some sort of channel in order for the bolt to hold it in place.

 

As you will see when you try it on, the angles of attachment start to do kinky things to the cap. Because of it is mounted on only one point, which is offset from center it's hard to set it up in a way where it doesn't force the opposite side to cantilever out.

 

I can only imagine physics get even more wonky at high RPM rotations of the wheel with the single offset mounting point as well.

 

image.png.6c9279cce9e582edb7a3bf3716a57b31.png

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Plan is to machine a round cylinder on a lathe ( x 4), weld it to the backside and only then chamfer from the front. Is it a 5 or 6 mm bolt btw? Yeah, the whole thing is quite a crappy design.

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On 12/7/2022 at 2:21 PM, Rosteri said:

Plan is to machine a round cylinder on a lathe ( x 4), weld it to the backside and only then chamfer from the front. Is it a 5 or 6 mm bolt btw? Yeah, the whole thing is quite a crappy design.

 

M8

 

 

IMG_20221210_155604133_MP.jpg

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A test fit turned out ok:

 

AD68A668-F122-4AD6-A23C-CF22788244C1.thumb.jpeg.b46afc256b97289abd4b6e71ef115487.jpeg


My friend had two original sets, one out of plastic and the other out of aluminium. The alu version is slightly larger in diameter with 159 mm - apparently there are different versions of the wheel.

 

D01118D7-F8C0-42DD-905E-C18BFDE95089.thumb.jpeg.87c1c06a87b6bedb853ae91001c4a09f.jpeg

 

Also the attachment bolt has some sort of security feature…

 

A00A6F53-ADE6-459A-AF65-BAAC90D8F7A1.thumb.jpeg.4db31490a9d44b079441cefc986a7e41.jpeg

Edited by Rosteri
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Those bigger center caps were offered on the Prisoner wheels and the another wheel type. I was hoping that they would be lazy and just have one mold so rolled the dice to see if they are the same myself. Was willing to bet they were. Alas they are not. 

 

I believe there were two generations of those. Completely fixed one piece metal mold, and a later one where the center '7' plastic plug is removable.

prisoner

 

The Prisoner

 

Racecarsdirect.com - Caterham 7 S3 New Chassis & Parts to Build

 

And this style wheel

 

7x16 5-spoke Caterham rear wheels with 205/45-16 Avon ZZ3 tires | Caterham  seven, Caterham, Mazda

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  • 1 month later...

Thanks, now I know more of SLR center caps than I would have ever dared to dream about…

 

Today I had finally some spare time and commanded the machine to make some chips:

 

0B100D10-279D-4707-A4A5-A759CC44643C.thumb.jpeg.a0131455b01896eeab3e3cc88ca597f1.jpeg

 

C313ECC6-60FE-42A3-BFD6-81B76872BA87.thumb.jpeg.f9c52123dba7eab11787479659d20415.jpeg

 

0FC48C95-1AA7-4A82-BAE5-8B8B3150FB25.thumb.jpeg.1f27d34d78e5527d91c8bf8431beaba8.jpeg

 

 

Edited by Rosteri
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4 hours ago, Rosteri said:

Thanks, now I know more of SLR center caps than I would have ever dared to dream about…

 

Today I had finally some spare time and commanded the machine to make some chips:

 

0B100D10-279D-4707-A4A5-A759CC44643C.thumb.jpeg.a0131455b01896eeab3e3cc88ca597f1.jpeg

 

C313ECC6-60FE-42A3-BFD6-81B76872BA87.thumb.jpeg.f9c52123dba7eab11787479659d20415.jpeg

 

0FC48C95-1AA7-4A82-BAE5-8B8B3150FB25.thumb.jpeg.1f27d34d78e5527d91c8bf8431beaba8.jpeg

 

 

 

You're a magician! :classic_love:

 

And yes, years of knowledge and search have been cooped up in my brains and if I couldn't share it now, the info would never see the light of day. Thank you for entertaining my think tank. 

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65CCA2F8-D936-46CD-958E-87B0A8E2E92E.thumb.jpeg.89e550a005c6ae58afbd9abf38104469.jpeg

 

Mika’s wheels have 22.9mm to the thread start, so if we can hit this, then no more wonky tightening issues. V, you might have to file the bosses down, if they are too long for your wheels or there is a variation.

 

29E60F74-BBFF-41F3-B992-4652D1978B28.thumb.jpeg.bdbb36b1404c21a04f913df774bf8bd8.jpeg


The bosses got an M8 thread first, so welding them on was easy:

 

8704AE91-CCC2-4198-8AC8-AEE9F15746AF.thumb.jpeg.b4f30183992453b86633285c992c1a24.jpeg
 

Which was then drilled out to 8.5 mm and a simple chamfer was added to the front side:

 

8ED24F79-5B37-46BD-A893-C0FAE47CF784.thumb.jpeg.01124c59629503a9a6b952bc3cfdb6e7.jpeg

 

FFF8286D-0551-4947-B103-CF6825238173.thumb.jpeg.62538a53fb3fba78e5a83125c01aad01.jpeg


A bit of sanding and a bead blasting next, then these are ready to go.

 

Edited by Rosteri
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And a fail - a mistake in the 3D file resulted in a very thin wall thickess at the corner. I didn’t do a cross section check on these, since they are not structural… baby, one more time… 

 

97AF1E32-DC09-4C1E-A2EE-0CF2474F52B0.thumb.jpeg.a11533bfe42c12632f23d895c54f8df7.jpeg

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