Lightweight Chassis Improvements

[Guest zoomzoom]

Hi

I got new h/t zinc plated bolts from my local factor (orbitial fastners) after getting the kit as i did'nt like the robin hood bolts, some were too short to allow 2 threads to pass the nylock and they werent zinc plated.

Also all washers etc are plated as well.

[Mat-Moo]

I was thinking about this chassis etc. might be a lot of work, but how about building a 1" square tube chassis to fit just inside the current ally structure. Then the seatbelts etc. at least would have some good fixing points, be easier if your kit is new than someone who has already built it, and might require the assistance of mr.gingerfix?

[Guest zoomzoom]

Hi

I've thought about metal corrosion before and was luckly enought to speak to a senior engineer at the bmw degolfing plant in germany last year. At this plant they make the bmw 5 series (e60/61 type) and this car has an alloy front end which is joined to the rest of the car by bonding and riveting.

I explaned. in general terms construction of the l/w and asked him his advise on the matter of bonding/joints and corrision. His opinion was (and he said that it was his opinion and not to be considered a fact) that using plated bolts was ok given the use I said I was going to put the car to i.e. summer use, fun use and not as a everyday car.Also if I wanted to I could use washers under the bolts or maybe look to replace the bolts every year and maybe have an closed electrial system (not using the chassis as an earth return).

Well this made me think that for my use galvanic corrosion would'nt be too much of an issue.

 

 

P.S. this guy also thought that building a car like a 7 type was mad!!

 

Oh and it was the day after the night before at the october beer fest so could be all wrong

 

Marcus

[peter_m7uk]

But zinc and zinc-aluminium alloys are often used as corrosion protection.

They both form oxide layers which prevent any further corrosion, so there

may be a small amount initially which will stop once the oxide layer is formed...

 

Pete

[Guest ScotMac]

But zinc and zinc-aluminium alloys are often used as corrosion protection.

They both form oxide layers which prevent any further corrosion, so there

may be a small amount initially which will stop once the oxide layer is formed...

 

Pete

 

From what i have read, that is true...except where there is some continuous abrasion, in which case the oxide is scrubbed off, and you can get deep corrosion.

 

-sm

[Guest Battery Bill]

As long as you use a good quality "Jointing Compound" and use it on the Bolts, Washers, Nuts, Rivets and anywhere that the differrent metals touch each other you will not get "Dissimilar metal corrosion" or any other type of corrosion on the joins.

Aeroplanes all use mixtures of metals on them but they are built using "lots of Jointing compound"

 

[Jon Bradbury]

I've already begun the replacement of screws in the rear box sections with M6 high tensile bolts.

I got them from Namrick in Hove and they're zinc plated.

 

Pete, if you need any more get them from The Nut House in Worthing (Dominion Road, opposite Wickes). Namrick are very expensive!

 

And you can pop in for a cuppa when you're passing..

[Guest chris brown]

As long as you use a good quality "Jointing Compound" and use it on the Bolts, Washers, Nuts, Rivets and anywhere that the differrent metals touch each other you will not get "Dissimilar metal corrosion" or any other type of corrosion on the joins.

Aeroplanes all use mixtures of metals on them but they are built using "lots of Jointing compound"

 

As Bill says use a jointing compound and use it on everything it has to be a good quality one and defiantly not silicone based Sikaflex is aboutf the best IMHO

[Guest mark kingston]

i have spoken to trevor and had a very good idea who the sva inspector who failed it was and trevor confirmed i was right.

i had my 2B tested by this guy back when the 2b's first came out and had similar problems over seat belt mounting points.

Back then i contacted richard stuart who agreed to back and fund an appeal and after a few phone calls between my self, richard and the inspector and the vosa his decision was reveresed and that was that.

the guy clearly did not like robnhoods and told me i was going to be their all day for the test before he had even set sight of the car and he meant it.. my SVA test toke 7 1/2 hours.

I was fortunate that on my retest i had another inspector and the was no sign of the original guy.

My conclusion is that i personally feel that it probably didn't matter how good or bad the lightweight had been built this guy would have had a downer on it because it was a robinhood before he even set his eyes on it, and as he had also not seen this paticular kit before he would have had a field day.

I just feel sorry for trevor and feel that perhaps it has all got blown out of proportion on the VOSA side of things.

I wonder how many other kit car manufactures have provided seat belt pull test figures to the VOSA???

as the EXMO model had no chassis and was a monoque constuction i am left wondering where that paticular model stands re the seat belt mountings and sva.

I know that this model is no longer in prodution but the is still a fair few being built and laying around that have yet to be sva'd.

I am left wondering how can the VOSA ask for seat belt pull test figures for the light weight but choose to not ask for them for all other kit cars being tested.

I hope i the long run that some solution can be found and that this whole mess can be put behind us.

[Guest Battery Bill]

Mark

 

Back then i contacted richard stuart who agreed to back and fund an appeal and after a few phone calls between my self, richard and the inspector and the vosa his decision was reveresed and that was that.

 

 

like I have said before "Thats the difference between the original Robin Hood owner, and the current "business Owners""

 

Still the current Lightweight owners are still not on their own they have the support of the best club in the planet!!!!

[peter_m7uk]

Mark,

 

I'm very interested that you said the EXMO was a monocoque as well...

 

Anyone got any pictures of the EXMO chassis under construction???

 

Pete

[Shandylegs]

Pete

 

Most of the models prior to the 2B were of a monococque design. I was involved in building and SVAing a series 7 last year. If you take a common sense approach to areas such as seat belt mountings etc.. there is no problem getting these cars through an SVA.

 

If required I can forward any pictures required (If I have them)

 

Thanks

Duncan

[Longboarder]

Exmo and series three were all welded stainless monocoque which came ready constructed from the factory so considerably stronger than an ally chassis but still have some fatigue problems. Extra strengthening bars/plates were needed under the floor to reinforce the seat belt mounts and prevent pull through failures.

 

Nigel

[Guest gdc]

please see my posting on sva section

 

ta graham

[Peter Bell]

Exmo and series three were all welded stainless monocoque

Don't forget series 2, 1, and Cortina Nigel, there must be loads of them in total.

Peter