Small batch aluminium casting of uprights
Discussion
The bespoke cast aluminium uprights on the rear of my track car are acknowledged as being virtually unobtainable nowadays so I was idly wondering about the process involved in having some cast whilst I still have a fully functioning straight pair to use as a pattern. By getting a few done it could help spread the cost and other owners and racers in the future too.
Anybody into this who could offer any insight into the process please. From memory they are around 200mm tall, 150mm wide with a machined centre to accept an interference fit wheel bearing. Wishbones & toe control link bolt to the top & bottom of the upright. I'm near Newbury if anybody knows of any suitable companies to contact for casting & machining.
Thanks!
Anybody into this who could offer any insight into the process please. From memory they are around 200mm tall, 150mm wide with a machined centre to accept an interference fit wheel bearing. Wishbones & toe control link bolt to the top & bottom of the upright. I'm near Newbury if anybody knows of any suitable companies to contact for casting & machining.
Thanks!
See http://website.lineone.net/~g27build/rearsus.htm for a couple of pics.
It shows the rear upright on a late Ginetta G27 with IRS, which is the same as that on the rear of my G20.
Billet uprights could indeed be another option.
It shows the rear upright on a late Ginetta G27 with IRS, which is the same as that on the rear of my G20.
Billet uprights could indeed be another option.
andy43 said:
Strange that it has a massive spacer on the lower wbone mount and then a bolt on add on bracket for the top mount - the upright could be redesigned to eliminate both.
Haha agreed, all good old cottage industry car (lack of) design that could be engineered out. TBH I don't mind the additional upper bolted on bracket - I believe it's included as a deliberate weak link as it deforms & breaks thus saving the upright from damage in a minor shunt. The lower spacer is a straightforward oversight in design - the handbrake cable fowls the toe link end without said spacer. Not an issue on my car though as it doesn't have a handbrake, but if machining from billet I'd tweak the design to incorporate it.foggy said:
See http://website.lineone.net/~g27build/rearsus.htm for a couple of pics.
It shows the rear upright on a late Ginetta G27 with IRS, which is the same as that on the rear of my G20.
Billet uprights could indeed be another option.
I am sure we would have no problem with machining those here. If you are seriously looking to have a small batch made pop me a PM - I own a small machineshop (3/4 axis milling) and it would be nice to work on something new / interesting.It shows the rear upright on a late Ginetta G27 with IRS, which is the same as that on the rear of my G20.
Billet uprights could indeed be another option.
Edited by Rick1.8t on Sunday 5th July 22:21
ferrariF50lover said:
Apologies if this is crassly unhelpful but...
[Long story short]
Enthusiasts prefer the Mk1 Elise for racing as it had steel uprights rather than aluminium, which isn't as stiff.
Have you considered a heavier but stiffer option which might be more readily available?
That's more an issue with the upright design rather than material tbh...[Long story short]
Enthusiasts prefer the Mk1 Elise for racing as it had steel uprights rather than aluminium, which isn't as stiff.
Have you considered a heavier but stiffer option which might be more readily available?
Another vote for billet. Make sure you get the machined faces on the original measured properly using a CMM to avoid any mistakes with the kinematics, or alternatively design in some adjustment as on a racing car you may want to take out some of the bump-steer that Lotus typically engineer into their road cars.
plasticman said:
Where abouts are you Rick(1.8t) ?
West Midlands - CannockFeel free to drop me a PM if you have anything you would like discuss.
In terms of measuring the part, it doesnt have too many features and i doubt original part tolerances are that high - it certainly isnt a problem part and was likely designed for ease of manufacture. CMM would add unnecessary cost imo at this level / complexity but i agree with adding a means of adjustment if required.
Rick1.8t said:
In terms of measuring the part, it doesnt have too many features and i doubt original part tolerances are that high - it certainly isnt a problem part and was likely designed for ease of manufacture. CMM would add unnecessary cost imo at this level / complexity but i agree with adding a means of adjustment if required.
I was thinking more of suspension pickup points and its effect on the kinematics. A 1mm change in the height of the toe link point will make for a significant change in bumpsteer. 1mm in one dimension is pretty easy to measure but on a suspension upright all of the measurements are interdependent in 3 dimensions, which would be hard to get right without a CMM unless there's a simpler alternative I haven't considered.Edited by The Wookie on Monday 6th July 17:18
The Wookie said:
Rick1.8t said:
In terms of measuring the part, it doesnt have too many features and i doubt original part tolerances are that high - it certainly isnt a problem part and was likely designed for ease of manufacture. CMM would add unnecessary cost imo at this level / complexity but i agree with adding a means of adjustment if required.
I was thinking more of suspension pickup points and its effect on the kinematics. A 1mm change in the height of the toe link point will make for a significant change in bumpsteer. 1mm in one dimension is pretty easy to measure but on a suspension upright all of the measurements are interdependent in 3 dimensions, which would be hard to get right without a CMM.Gassing Station | General Gassing | Top of Page | What's New | My Stuff