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Vortx Harness mount strengthening
chockymonster - 28/12/06 at 08:39 PM

As you all know, my Vortx failed SVA on the following point.

5.2 A seat belt anchorage or the surrounding vehicle structure is of inadequate strength and likely to fail.
His explanation is
N/S + O/S top seatbelt anchorage points have no triangulation and bracing to spread the load effectively into the chassis.

I looked at Dion and Steve's idea of making the harness posts thicker but didn't think that it would meet the approval of my tester.

Here's our take on beefing up the mounting and offering some further triangulation.
















The only holes drilled are for the central brace, not modifying the roll bar in anyway.


Hellfire - 28/12/06 at 08:50 PM

How come other Vortx haven't been pulled up on this at SVA, or has Marc since changed the design of the mountings? IMO all that extra bracing looks a bit agricultural and unsightly given that it's something you wouldn't wish to remove after SVA.

Can't Marc offer an alternative/neater method to overcome your problem?

Phil

[Edited on 28-12-06 by Hellfire]


graememk - 28/12/06 at 08:59 PM

which sva test cetre was it ?


Hellfire - 28/12/06 at 09:04 PM

quote:
Originally posted by graememk
which sva test cetre was it ?


Southampton I believe.

Phil


amalyos - 28/12/06 at 09:14 PM

Paul,
It looks like a safety strap if it fails, not strengthening to prevent it failing.
I've no doubt that the original posts would be fine as manufactured, so it's more about making it look right, I don't think those straps will convince the SVA.

Steve


TimC - 28/12/06 at 09:18 PM

Erm...

Find out when your tester is off???


[Edited on 28/12/06 by TimC]


Howlor - 28/12/06 at 09:20 PM

Do you have any pics from underneath? I don't think your centre brace will do much to add strength really.

If it was anything like mine the cage is welded onto a flat plate about 4mm thick. I would have suggested the only weak point really is the bolt bending the tube and possibly the tube pulling out of the plate it is welded into, slim chance.

How about getting longer bolts so they go right through and then putting a nut on the back with a large load spreading plate. This would be good enough for rallying therefore should be good enough for the SVA. Mine was done like this as i didn't have the welded threaded tubes.

The only other thing i would suggest is possibly welding say 4 fillets up the length of each tube and welded along the plate. It should look like a missle when looked from above!

Steve


Howlor - 28/12/06 at 09:36 PM

Thinking about it mine also had triangular braces (4 off) welded underneath the plate and onto the uprights that formed the back of the cockpit area. I will try and find some pics.

Steve


stevec - 28/12/06 at 09:42 PM

quote:
Originally posted by Hellfire
quote:
Originally posted by graememk
which sva test cetre was it ?


Southampton I believe.

Phil


That explains a lot, they are a little strict on that sort of thing there.
Personaly I dont think he will like what you have done, He will probably want it fixing like a "Major manufacturer" would do it.
Steve.


chockymonster - 28/12/06 at 09:44 PM

It does look a tad agricultural but I'm against the clock with my covernote expiring on the 9th and having to face faffing around with Reading DVLA who will not inspect the vehicle until I have a MAC certificate.

I want to make up something that is neater but I'm more worried about getting through SVA and then being able to do it at my leisure.

Both Amalyos and Numnuts were pulled up on the same thing at SVA. Something needs to be done to prevent this from happening to other owners as I totally understand where my tester is coming from. The mounts as they stand are insufficient.

I spoke to my tester about drilling all the way through and bracing from the underneath, the issue he had was there was nothing to stop the tube bending forward.


Howlor - 28/12/06 at 09:52 PM

Or just weld 4 fillets up it's length.

Steve


Hellfire - 28/12/06 at 09:54 PM

It's a real PITA when you follow the SVA manual, build a vehicle that would probably pass the test at 99% of test centres across the country and on the day, it all comes down to some jobsworth SVA inspector who probably got refused the leg over the night before, who then expects you to jump through burning hoops to satisfy his exacting requirements, never once questioning his own knowledge/ability to carry out his duties as a competent SVA inspector...........


AAARRGGGHHHH

Phil

Edit: Having read Chockys last post and if the mountings are indeed insufficient, then surely it's down to MNR to put them right?



[Edited on 28-12-06 by Hellfire]


chockymonster - 28/12/06 at 10:15 PM

quote:
Originally posted by chris mason
if the tube was smaller in height this would lower the chance of it bending forward, is it not possible too chop it down a bit?

Chris


Nope, then I fall foul of harness holes on the seats.

Rock and hard place


numnuts - 28/12/06 at 10:19 PM

quote:
Originally posted by chockymonster
It does look a tad agricultural but I'm against the clock with my covernote expiring on the 9th and having to face faffing around with Reading DVLA who will not inspect the vehicle until I have a MAC certificate.

I want to make up something that is neater but I'm more worried about getting through SVA and then being able to do it at my leisure.

Both Amalyos and Numnuts were pulled up on the same thing at SVA. Something needs to be done to prevent this from happening to other owners as I totally understand where my tester is coming from. The mounts as they stand are insufficient.

I spoke to my tester about drilling all the way through and bracing from the underneath, the issue he had was there was nothing to stop the tube bending forward.

I still think that mine and steve solution was a better and neater option. As mine was drilled tapped and large spread washer fitted underneath . with the larger diameter stock fitted over the top there was no way this could then bend forward . sorry but don't think mr SVA man will like that hope all goes well Dion .


RichardK - 28/12/06 at 10:33 PM

Would something like this do the trick?

Image deleted by owner

Or a brace across your roll bar with fully welded threaded inserts at the right hight for your straps.
Just a couple of ideas

Regards

Rich

[Edited on 28/12/06 by RichardK]


marc n - 28/12/06 at 10:53 PM

hi paul
have learnt to drive my new machine now although still on my L plates may be able to make some bolt on brackets in the time scale although we may be cutting it fine ( currently awaiting a software upgrade not due for dispatch till 2nd jan )

quote:

Both Amalyos and Numnuts were pulled up on the same thing at SVA. Something needs to be done to prevent this from happening to other owners as I totally understand where my tester is coming from. The mounts as they stand are insufficient


dont forget that this is only three cars in two years, i have svad 10 myself with no problems at all, dont think they are going to like the straps you have from my experiance of sva, but it would appear that the sva isnt particularly consistent at the best of times so you may be ok Hopefully this issue will no longer occur when i have all the cetification at the end of the year, after a pull test

edit to add

having looked at various other manufacturers cars via build diarys on the net etc our mts are by far the best supported of those i have seen, some are welded to just a 1 inch box section rail with no further supports or rear chassis stays, some have small fillets that are still only mounted to a inch box crossmember with no support to stop the structure moving forward ours are mounted to a 4mm plate which is an integral part of the whole chassis and rollcage structure have a look for yourself,
the main problem i suspect is height of belts / to seat ratio meaning you have kept the full height of the bosses to allow for the runners, the easiest way is to remove the runners to lower the seats to lower the bosses, then bolt with a large load speadng plate underneath as a 12.9 m12 bolt is gonna take some fair bending afterall some 7 types have the harness mount incorporated in the rollbar that has no rear stays often made from thin wall erw and is fixed to the chassis by means of four m10 bolts per side
i know which i would rather have


best regards

marc



[Edited on 28/12/06 by marc n]


chockymonster - 28/12/06 at 11:36 PM

Marc,

We discussed what we were planning with the guy at the centre so all we can do is go on what he suggested after I told him I couldn't bolt anything through the rollbar.

He discounted immediately drilling through and using an M10 bolt all the way through unless I chopped the mount down.

The seats are mounted directly to the floor as the harnesses were not at a decent angle.


chockymonster - 28/12/06 at 11:43 PM

quote:
Originally posted by marc n
dont forget that this is only three cars in two years, i have svad 10 myself with no problems at all, dont think they are going to like the straps you have from my experiance of sva, but it would appear that the sva isnt particularly consistent at the best of times so you may be ok Hopefully this issue will no longer occur when i have all the cetification at the end of the year, after a pull test



Marc,

I understand where you're coming from. My lovely tester did mention other vehicles having mounts welded through 1 inch box section. In his opinion this was preferable because the pulling motion was dissipated more throughout the chassis!


marc n - 29/12/06 at 12:36 AM

quote:

In his opinion this was preferable because the pulling motion was dissipated more throughout the chassis!



words fail me, but unfortunately you are at this testers mercy
quote:

We discussed what we were planning with the guy at the centre so all we can do is go on what he suggested after I told him I couldn't bolt anything through the rollbar.

if he suggested the fix then fingers crossed


quote:

The seats are mounted directly to the floor as the harnesses were not at a decent angle.



im not sure how that has hapened as normally the belt mts are really high when the seat is bolted to the floor

i have found the an sva map i have used at sva previous not sure wether its joao s or not though, i know he has a copy on his pc cause i sent it too him

best regards

marc


DavidM - 29/12/06 at 01:44 AM

If you go with that solution, you'll need to make sure it meets edge radius requirements.

David


marc n - 29/12/06 at 10:48 AM

quote:

If you go with that solution, you'll need to make sure it meets edge radius requirements.



thats why i just dont understand the sva system sometimes, if i went to my sva centre with that setup they would fail it on radius checks and also say it wasnt a permanent solution
one book many variations on understanding it


chockymonster - 29/12/06 at 10:50 AM

quote:
Originally posted by DavidM
If you go with that solution, you'll need to make sure it meets edge radius requirements.

David


It's covered in foam padding now so radius should be ok.


chockymonster - 29/12/06 at 10:58 AM

quote:
Originally posted by marc n

i have found the an sva map i have used at sva previous not sure wether its joao s or not though, i know he has a copy on his pc cause i sent it too him

best regards

marc


Marc,

can you email it across to me?
I'm booked in to do the emissions this afternoon and that would help.

Paul


chockymonster - 29/12/06 at 11:00 AM

quote:
Originally posted by marc n
thats why i just dont understand the sva system sometimes, if i went to my sva centre with that setup they would fail it on radius checks and also say it wasnt a permanent solution
one book many variations on understanding it


Southampton take pictures of every car that passes SVA to keep as a record of how it was when they approved it so they can say "it wasn't like that when we passed it"


Wadders - 29/12/06 at 12:19 PM

Sorry, i can see youv'e put a lot of time into finding a solution, but have to agree it looks like a bodge, and is unlikely to pass. If iv'e got my head around your existing set up correctly (its hard to tell from the photos etc) then something like this might do the trick. pls excuse the drawing its done in word so really its just to give an idea and not to scale or anything.


[img][/img]


bitsilly - 30/12/06 at 03:14 PM

Me and Jon have been discussing our top mountings. I cannot see how they passed as they are a classic cantilever mount. The higher they are the more leverage they have to snap, and this is more lightly the harder the bolts are.
I will add a triangular fillet to a bush running up the mounting bolt, as detailed above, for my own peace of mind as this would greatly spread and change the nature of the loading. However for SVA it would be best to get rid of the cantilever bit IFF the resultantant line of the belt does not run upwards to your shoulder or upwards to part of the seat not designed to take that type of loading. You can put in a seat that is intended to take the seatbelt loading by having the necessary bracing but this is expensive and the chair will have to be examined as a solid part of the chassis! You could also use inertia reel to reduce the number of problem points to one till after SVA!
Gardner Douglas weld in the bolts through their roll bar. On my Cobra I have had to weld on a whole new triangulated frame to pass the SVA.
If I was you I'd bite the bullet and properly triangulate the point with the same bar as the roll over bar. Whatever you do for the SVA, I would not rely just those cantilevers. Good luck.


Winston Todge - 30/12/06 at 05:51 PM

Just my 2 pence worth...

I have Triton seats mounted directly to the chassis and have had to chop down the harness mounts considerably to slot the harnesses through without fouling the holes in the seat... They look much 'stronger' now. Definitely a smaller moment around the welded area.

Anyway good luck Paul. Hope you pass on the retake!

Chris.


bitsilly - 1/1/07 at 08:29 AM

Could you just clarify, is the 'bar' which needs triangulating the cross bar of the chassis or the bar the mounting bolt runs through?
Cheers


chockymonster - 1/1/07 at 07:04 PM

quote:
Originally posted by bitsilly
Could you just clarify, is the 'bar' which needs triangulating the cross bar of the chassis or the bar the mounting bolt runs through?
Cheers


It's not the bar but the mounts that I've been told I need to strengthen


bitsilly - 2/1/07 at 12:03 PM

Looking at the mounting you fabricated and bent around the roll bar (the one you have the other mild bars bolted to).
I had an off road racer fully FIA approved, which had both top harness points bolted to a single bracket like yours. It had to be welded onto the roll over bar and was obviously much beefier. Do away with the other mounts completely, or keep for after SVA.
I can get a link to the SVA guide if it helps (the one the government sells).
These photos don't show much I'm afraid but hey-ho!
http://bus-wad.sihe.ac.uk/gorc4x4/images/trials/res%20Feb%2005/pages/res21.htm
http://bus-wad.sihe.ac.uk/gorc4x4/images/trials/res%20Feb%2005/pages/res34.htm


bitsilly - 2/1/07 at 12:10 PM

Heres the link to the VOSA guide but it charges a contribution of £1.24 now
http://hotrodphotos.co.uk/SVA.htm
Best of luck
Ed


Dillinger1977 - 5/1/07 at 08:54 AM

i might be wrong but ive just been to have a look at the mounts on mine and they seem a bit shorter than some of the ones in photos here. (mine are about 30mm high)
is it my eyes playing tricks, or were they a bit shorter on earlier chassis' Marc?

if so, I might not have as much as an issue as people with higher ones. Also, it looks like i've got the option of shortening them further still if needs be. I'll just see what the inspector says and would advise.


Agriv8 - 5/1/07 at 09:05 AM

Rog I would think yours are on the shorter ones ( same as mine ) they are also attached to the chassis sligtly diferently Shouldnt be any problems unless you are getting SVA'ed at southhampton

regards

Agriv8