Reality check

Idle chat about any thing Sevens & Clubman cars.

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Mauntinbyka
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Reality check

Post by Mauntinbyka » Fri Jan 20, 2017 7:39 pm

Hi,
I'm after a new set of front upper wishbones. What cost should I expect to have a set made?

Thanks
Terry

Mauntinbyka
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Re: Reality check

Post by Mauntinbyka » Sat Jan 28, 2017 1:14 pm

No thoughts??

The project I've taken on is a Ron Champion rolling frame with standard 711m 1600 cross flow. I really like the idea of keeping the project pure at this stage in the tradition of the original home built cars. My only concession will be that I want the car to look good, ride height, stance, attitude of nose cone, good lines and generally a clean look. Famous last words but caterham and Fraser seem to do a pretty good job of getting these things right.

I've had the car inspected. The upper wishbones have been built in a D shape and the curved tubes show some flattening from the bending process. They are not acceptable so I'll need some replacements. I prefer A shape wishbones which should also be easier to build. The current wishbones are slightly different from usual because they have the usual rod end at the outer end and rose joints at the inner end. Quite a nice touch which will give some adjustment of caster so I think I'll keep that feature.

To build each upper wishbone I'll need a jig, 3 pieces of rod drilled and tapped for the tie rod end and the rose joints, 2 pieces of tube notched for the drilled and threaded rods. Then have it all TIG welded. Has anyone done this or had them made? Any feedback on the work involved or costs would be greatly appreciated.

My preference is to have them made but I need to get an idea of what a reasonable ball park charge might be. Any help out there?
Terry

DMC
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Re: Reality check

Post by DMC » Sat Jan 28, 2017 2:53 pm

Frasers will make them for you but you will be looking at 800-1000. Probably better to make and tack them together yourself and then if you are not up to welding them, pay someone to tig them. Definitely something you want to have a lot of confidence in, so you want them to be right.

If you do decide to make them yourself I would suggest taking the time to make sure the jig is accurate and fit up of the joints are nice and tight, it is harder for a welder to do a mint job on joints with big gaps.

7dreamer
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Re: Reality check

Post by 7dreamer » Sat Jan 28, 2017 10:53 pm

Definitely have a go your self. You will need some tools. A tube notcher is essential a good engineers protractor and square, a bevel will be handy to, A hand drill. I would highly recommend starett constant pitch holesaws they are the best hole saws available. If you get a cheap notcher take your time to set it up and shim it to center. And remember the angle guide is just that a guide. Make your jig out of flat 6mm steel plate Or 19 mm custom wood. Access to a metal lathe is also going to help a lot. I've made my own and my brother suspension components and a bicycle frame with the above tools so.its not impossible and I'm nit a trained fabricator just enthusiastic about building stuff.
Here is the bike I built my 3.5 yr old son
https://m.facebook.com/home.php?refsrc= ... =bookmarks

Mauntinbyka
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Location: Taupo

Re: Reality check

Post by Mauntinbyka » Sun Jan 29, 2017 10:11 pm

Ok thanks guys. Will have a think. Building them myself definitely has some appeal.

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heavyseven
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Re: Reality check

Post by heavyseven » Mon Jan 30, 2017 11:55 am

It's also worth noting, that rose joints on your front wishbones may not pass inspection for racing use. Fine for track days, but from the sounds of it you don't have competitive motor sport in mind anyway.

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techtoys
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Re: Reality check

Post by techtoys » Tue Jan 31, 2017 2:30 pm

Now I'm curious...

Why would they not allow rod ends (rose joints) on the front wishbones on a car designed for racing use? Most of the cars I see, or I race against have them. I couldn't find anything in Schedule A that would be problematic.

I accept that they'd need to be designed properly and maintained in good condition, so that any audit inspection doesn't find them to be worn-out, poorly adjusted, or with insufficient articulation.

I'm not trying to start an argument. Just to learn something.

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nz_climber
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Re: Reality check

Post by nz_climber » Tue Jan 31, 2017 8:23 pm

techtoys wrote:Now I'm curious...

Why would they not allow rod ends (rose joints) on the front wishbones on a car designed for racing use? Most of the cars I see, or I race against have them. I couldn't find anything in Schedule A that would be problematic.

I accept that they'd need to be designed properly and maintained in good condition, so that any audit inspection doesn't find them to be worn-out, poorly adjusted, or with insufficient articulation.

I'm not trying to start an argument. Just to learn something.
I was thinking the same, almost every proper race car i have seen has rod ends in the suspension.

SR Components
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Re: Reality check

Post by SR Components » Tue Jan 31, 2017 8:35 pm

techtoys wrote:Now I'm curious...

Why would they not allow rod ends (rose joints) on the front wishbones on a car designed for racing use? Most of the cars I see, or I race against have them. I couldn't find anything in Schedule A that would be problematic.

I accept that they'd need to be designed properly and maintained in good condition, so that any audit inspection doesn't find them to be worn-out, poorly adjusted, or with insufficient articulation.

I'm not trying to start an argument. Just to learn something.
My understanding is that as long as there is no bending load on a threaded section you are ok.

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heavyseven
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Re: Reality check

Post by heavyseven » Wed Feb 01, 2017 10:55 am

SR Components wrote: My understanding is that as long as there is no bending load on a threaded section you are ok.
That's what it was... I recall it coming up in conversation at the McGregor Motorsport workshop some time ago.
This led to the move away from rosejointed front arms though didn't it Mark?

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