Author Topic: Current "State of the art" stub axles?  (Read 1113 times)

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Offline Richard48Y

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Current "State of the art" stub axles?
« on: Friday,October 11, 2024, 11:01:49 PM »
Since I am seriously interested in making new billet Europa uprights the question arose as to which axle they should be made to use.

The major options still using Universal Joints appear to be stock, modified Corvair, or custom.
Poking around the web turned up several past efforts, some of which were very nice indeed, but none of which seem to be current.

Grumbleguns was having some made at one point several years ago but I see no mention of them ever actually happening.
PA Motorsport still list a version, maybe they will reply to my inquiry this time?
It also seems that Banks had an uprated version too, but I do not see them on the site. I really like their design.

So my question is, what are the "Best" upgraded axles still using UJ's for the S1/S2 And TC's?

If doing new uprights it only makes sense to me that they should be designed to take the best possible axles.
I am certain that if I make them to take a particular axle the design should not be too hard to alter for CV axle versions as well.

My VMC is not a fancy 5-axis, it is not as fast as newer machines, but it is certainly up to doing this relatively simple and likely low volume job.

I also have a Takamatsu EM-1A "Legend" CNC Lathe that could spit out custom axles but currently no good way to cut splines.
I suppose I could mill splines if I invest in a dividing head, more $$ tooling!
I saw the thread on the old design that used three keys, um, no!

Offline TurboFource

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Re: Current "State of the art" stub axles?
« Reply #1 on: Saturday,October 12, 2024, 04:56:43 AM »
Richard maybe you could use the early VW stub axles etc.as they are readily available and inexpensive. There are cv joint joint adapters available so people could go either way? You would probably need custom length half-shafts.

https://www.driveshaftparts.com/2-2-1339-1
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Offline BDA

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Re: Current "State of the art" stub axles?
« Reply #2 on: Saturday,October 12, 2024, 08:02:50 AM »
I second Turbo's vote for VW. Jmarkusic and Andy Harwood did a write up on using VW sub axles using CV joints (with the required twin link rear suspension) that might be useful to you.

https://www.lotuseuropa.org/LotusForum/index.php?topic=4782.msg51880#msg51880

Offline Richard48Y

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Re: Current "State of the art" stub axles?
« Reply #3 on: Saturday,October 12, 2024, 12:20:14 PM »
Thanks for the links.
At the moment I am still trying to retain the original UJ axle setup.
I've emailed Banks about their upgraded axles.
Also the Motorsports guys.
I'm going to do some more research on pre-made splined UJ couplers.
I can make one-piece axles, or modify something that is reasonably close.
I also like the idea of converting to taper bearings.
This is not going to be quick.
If Banks still offer their upgrade I do not expect to duplicate it.
If they do not offer it anymore I do not require a large volume so may take up doing something similar.
« Last Edit: Saturday,October 12, 2024, 01:08:51 PM by Richard48Y »

Offline gideon

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Re: Current "State of the art" stub axles?
« Reply #4 on: Sunday,October 13, 2024, 11:13:55 AM »
About tapered roller bearings vs ball bearings - my understanding is that with the stock setup the rear wheel bearings take essentially no lateral load, so ball bearings do the job with a bit less overall friction than a tapered bearing pair. 

My suggestion would be to make replacement rear bearing carriers that could be used with the stock setup.  Then, at a later date, you might offer upgraded stub axles for the stock setup.  The problem with using different stub axles is you have to replace the whole stub axle/bearing carrier/hub assembly and that could be a harder sell.

Offline Richard48Y

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Re: Current "State of the art" stub axles?
« Reply #5 on: Sunday,October 13, 2024, 09:14:57 PM »
I have delayed assembly of my rear suspension as I am not thrilled with the original ex-Imp stub axles.
Anything I make will be utilized for my own S2.

Offline Richard48Y

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Re: Current "State of the art" stub axles?
« Reply #6 on: Monday,October 14, 2024, 09:55:37 AM »
This morning I recieved confirmation that Lotus Supplies no longer have their version of the upgrade stub axles.

Offline Lumbes

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Re: Current "State of the art" stub axles?
« Reply #7 on: Tuesday,October 15, 2024, 02:47:31 PM »
I have a TCS and rebuilt the whole rear end with new bearings, stub axles, hubs, studs etc.  All from RDent, nice shiny and new but from my understanding still rather weak and I expect to have a failure after so many years.  Thought I saw uprated stub axles a year or more ago but I never pulled the trigger on them and when time came to order new stub axles I could not find the uprated ones that were being sold by banks / lotus supplies.  Thanks for confirmation that they no longer have them.  This thread will hold my interest and will be checking out what everyone post as recommendations.  For now I would like to keep the set up as close to stock as possible so no twin link system, just interested in a stronger stub axle for when the day comes.  You have the makings of an incredible car, godspeed to your progress.

Offline Richard48Y

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Re: Current "State of the art" stub axles?
« Reply #8 on: Tuesday,October 15, 2024, 08:17:19 PM »
I intend to chase down some of the leads on Thursday.
If no one else wants to do them again, or has an insane price, I will make them myself.
The one-piece axles are not the hard part, the removable inside end is.
Another item to track down the basic core piece of.

Maybe it is just me but it seems key parts are slowly disappearing from the market.
New cast uprights and Renault cast "Gordini" oil pans are gone, will they ever return?
Maybe Lotus Supplies just has to have more turnover than the current market will support?

A large steady market would be great for me too, but not so critical.
If I am making anything for my own car I may as well make several and hope for some return on my time and materials.

Offline Bryan Boyle

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Re: Current "State of the art" stub axles?
« Reply #9 on: Wednesday,October 16, 2024, 04:23:18 PM »
I intend to chase down some of the leads on Thursday.
If no one else wants to do them again, or has an insane price, I will make them myself.
The one-piece axles are not the hard part, the removable inside end is.
Another item to track down the basic core piece of.

Maybe it is just me but it seems key parts are slowly disappearing from the market.
New cast uprights and Renault cast "Gordini" oil pans are gone, will they ever return?
Maybe Lotus Supplies just has to have more turnover than the current market will support?

A large steady market would be great for me too, but not so critical.
If I am making anything for my own car I may as well make several and hope for some return on my time and materials.

Hate to say this, but I think we (the Europanaut collective) are reaching a point of diminishing returns from the point of view of the usual suspects on either side of the big lake in terms of what parts they are willing to stock as measured against the investment to produce (or pay to have them produced) in small quantities. 

Take for example the headlight/wiper switch buttons that Ray sells.  That required copying, tooling, casting, assembly, etc. for how many that he projected he'd sell.  Taking that all into account and dividing by the number produced...that's why the price is what it is, and there is still no guarantee that he'll (or any of the suppliers) will sell all that had to be produced in order to get the minimum quantity that the manufacturer was willing to accept an order for.

Consumables like bushings, rod ends, heims, even some of the more 'exotic' parts, if shared across a number of different manufacturers (which is why I love the Brit system of all manufacturers drawing from a 'parts bin' that was essentially Lucas et al) is easier to get the numbers to justify the production.

In reality...how many Europas do you think still exist, on the road, or in salvageable shape...and if I was a manufacturer...would I want to invest the time, materials, and inventory cost for, maybe 20 or 30 stub axles?  Or rear windows?  Or quarter lights?  Or Corvair stub axle conversions?  For a car model that only had a little over 9K produced in 9 years starting 58 years ago. 

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Offline Richard48Y

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Re: Current "State of the art" stub axles?
« Reply #10 on: Wednesday,October 16, 2024, 04:32:12 PM »
Original axles seem to be a consumable part.
But the upgrade version I am looking at doing seems to last despite abuse.
Of late it seems more Europa's are escaping long term storage and being restored.
So I am confident there is a market for stub axles, a couple of companies are doing "Original" and at least one advertises an upgraded version.
Too bad they do not respond to email.

Not expectig to get rich with this, an supplement to my income would be great but some of these parts are for my own use.
With setup time I may as well make extras.

Offline jbcollier

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Re: Current "State of the art" stub axles?
« Reply #11 on: Wednesday,October 16, 2024, 06:27:27 PM »
The Europa axle came from the Sunbeam Imp.  This axle was also used in formula cars of the day.  There will always be a source for them.  They may well get dearer to purchase though.

I have had a stock set up develop issues.  I then switched to a replacement designed for formula cars.  Worked great but doesn’t have provision for an extra seal (something even Lotus had to add) and the inner bearings fail if driven in the wet.  No big deal on a formula car but a lot of work for an oft driven Europa.

My next set up is the ones offered on ebay and Lotus Supplies (apparently not any longer).  I think using multiple key-ways rather than a spline is not the best but it is easier to machine, and it is so over “specced” that it is bot an issue in practice — the only metric that counts.

Offline Richard48Y

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Re: Current "State of the art" stub axles?
« Reply #12 on: Thursday,October 17, 2024, 03:35:12 PM »
I now have drawings to work from thanks to another member here.
Even if I make changes this saves a lot of time.
I've begun trying to sources the U-Joint end too.

Offline cazman

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Re: Current "State of the art" stub axles?
« Reply #13 on: Thursday,October 17, 2024, 04:30:24 PM »
Would you make the drawings available? The only qualifications I have seen for the serviceability of the axle is visual. It would be nice to make measurements. 
1973 Europa TCS

Offline Richard48Y

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Re: Current "State of the art" stub axles?
« Reply #14 on: Friday,October 18, 2024, 12:19:37 AM »
The drawings I have are not the original.
They are a much stronger alternative.
No way to make them cheap, the billet blanks to start with are now $100.00 each.
That is before any machining or heat treat and does not include the yoke.
In the morning I will make another effort to confirm that no one else is doing the upgrade design.