I have been looking around for a while, with the plan to build a mid engined BEC style car from scratch and have been debating using 26mm Aluminum / honeycomb panels. They are easy to work, joint’s like wood (tongue and grove) Very strong/light and you can glue it together (see Hexcel composites for details). I have added a PDF of a similar idea. What are ever ones thoughts - has possibilities or a non hoper?

well this fascinates me...I'm about a third of the way through reading the article/paper..........reading it all will take a while!

The centre section of the Stratchcarron uses honeycomb plank construction, as does the Formula Vauxhall Lotus chassis and the clubmans chassis built by Lola designer Ben Bowlby (sbject of an equinox programme on the tv - remember that ?)
This was when everyone else was building spacframes.

hi,

as has been said ther ar a number of cars that are built using this tecneak however the Formula Vauxal Lotus cars are very simple 2 parelel planks with a ally casking at one end and the gear box bolted on the other with two reol hopes in the midle. I can try and fined some pictures if you are intrested.

having read through it a few things come to mind...

1. if you were to build it successfully, what would happen if it had damage to the chassis....would it be start again??

2. is the services of a CNC machine an absolute must for the chassis to be right or could it be done manually in your garage.

3. It states material cost of the chassis honeycomb to be around £560....it won't be a cheap build option.

4. if It all works...can I have one?

Not sure how an engineer type of person would view it but I'd like to know....

If your brave enough for a challenge and not skint...go for it

Alan Staniforth's excellent 'Race and Rally Car Source Book' (Pub: Haynes) shows this material used in building Terrapin monocoque chassis with some detail on the method.

My initially thoughts were just the same but looking round/read i cam up with the following:-

1) The chassis could be made using a router, and careful marking, cutting, and bending - in terms of the accuracy, it should be as easy to build as welding as chassis. Modern epoxy resin is very adaptable.

2) the cost would be more than a steel chassis, but would not need paneling etc, so should only be in the region of £200 - more but not unaffordable.

3) In the event of a crash, the structure would stand up very well, but I’m not too sure if it would be a rebuild or not. You should be able to joint in new sections.

I would be interested in the formula Vauxal. It was also used by most of the F1 cars in the late 70 – They found it quick/easy and very strong in the days before military budgets and technology.

I certainly think it's worth looking into.....have you priced the panels to get the £200 or is that an estimate...

The diagrams in the paper certainly made it look straightforward, but what happens when it comes to attaching suspension etc....I wasn't really understanding how that's tackled....

This is interesting stuff...

I opened a discussion on this before. Didn't get anywhere though.

Fascinating subject!

http://www.locostbuilders.co.uk/viewthread.php?tid=11820

Cheers,

Neil.

I never saw that one....as you say it kinda dries up....

Do a google search on PRB composite.

Wimmera

had a look at PRB and it sounds pretty good..no mention of price though.

I have experience of aluminium honeycomb panels as used in aircraft.
They are light and rigid. However they are always used as structural panels within a structural framework.
Personally I would have serious doubts over the integrity of the joints shown in the PDF and certainly have never come across an instance of major loadpaths being fed directly through this type of material.
As mentioned before, the only method to repair damage is to remove and replace it.

Just my experiences and feelings

Mick

A few years ago (well about 15) I did a Uni project with a fried, where we designed a car using this kind of principle. It was to use a Alfa boxer engine/BMW K100, and was very similar looking to Taydec in looks. The main structure was using a Ali/honeycomb floor, with 2 very deep (aprox 400x400mm box sections down each side. These carried the suspension loads (A frame/trailing link) and air to the rads. Also it only weight in at 380-400 Kg. The main benefit we found, was the in crash - rather than bending/collapsing the structure progressively failed in the local area. As previously stated, in the event a crash, the chassis would be written off, but it should be very quick/easy to build a new one and as an other all % of the investment in a car of this type the martial cost relatively low. With some careful design/though i would think the structure could be made in 2 or 3 major units (front, rear, survival cell) which could dramatically increase safety, and also make repairs possible.
I would think something along the lines of Taydec/Aeon spyder/AGM WLR would lend them self’s to this type of design or even a car like the fisher Fury to replace the floor and side pods with a strong box section structure that would dramatically increase the torsion stiffness with out a big increase in weight but also increase the side impact safety. The main thing is to have a design where you can use deep/wide box sections. Fastening of suspension would need the use of ali top hat/large diameter bobbins to be bonded through the structure to pass the loads to the skins and take care of the compression loads. The use of a hybrid chassis design could be used (space frame rear honey comb front)
The cost would be higher, but should not be too dramatic, but would the advantages make it worth while. As an alternative would it be worth using in a standard 7 stile chassie design, to replace the triangulation, side panels and floor?

This class material has be around for a very long time but the fact it has been used in very few cars in spite of its tremendous stiffness to weight must tell you something. F1 used for a while in the Lotus 79 era but quickly turned away from it when carbon composites came on the scene. I know Charles Barter built a hybrid Davrian Imp with honeycomb structure for hillclimbs back around 1980 but it wasn't as sucessfull has his car with the standard Davrian grp monocoque.

I meet a person in a 'little thief' car park near Shrewsbury today, he was towing a trailer with an aluminium honey comb tub on it. The tub it turnd out was for a Strathcarron sports car. He said they cost about £3000 new, his cost £250 curtesy of good old ebay.

http://www.strathcarron-sports-cars.com/

The strathcarron looks to use a aluminium tub, with steel space frames attached at each end. Pivtured bellow is a Strathcarron tub.
Rescued attachment Strathcarron tub.JPG

davrain/darrian monocoques rule !!!!

extremely repairable , and strong , and durable .

youll have to go some to beat it on material cost aswell

of course im biased

Colibriman, they have a nice little line on one of the sites " PRB will only be supplying this car to those who can prove a competition heritage and who are not fazed by the premium price"

Wimmera

Interesting paper and respect for the effort involved though I don't know how practical the particular configuration shown in the 3D computer model is. Where do you sit and how do you get in ?
Race Tech magazine (www.racetechmag.com) has been featuring a build of a single seater motorcycle engined hillclimb car that uses an aluminium honeycomb tub with a spaceframe rear section holding the engine and transmission.

quote:

---

Originally posted by Volvorsport
davrain/darrian monocoques rule !!!!

extremely repairable , and strong , and durable .

youll have to go some to beat it on material cost aswell

of course im biased

---

Hi There,

An interesting read through this thread..... I manage my farthers company which manufactures Ali Honeycomb panels amongst other composite materials.

The PRB looks like a louts 7 / caterham clone & actualy the caterham does have some honeycomb panels in it. I know, we make them ! They are used mainly for crash impact safty in the sides and in the boot for a weight reduction.

As a side, honeycomb is starting to become common place in a lot of modern road cars. Partialy crushed honeycomb structurs can be acturatly predicted and absorb a large amount of energy, as such they are being used in the head lining around the driver and pasenger for impact absorbtion.

It is true that the F1 uses carbon, but they also use honeycomb in places, typicaly an arimid called Nomex. Its a resin dipped dupoint fiberous paper core, typicaly used for its fire rating as its self extinguishes. The core is laminated into mouldings and vac bagged to produce a shaped lightweight peice. Alas this requires tooling to form the mould and hence is inheriantly expensive for a one off, let alone the material costs.

cya,
Lee

well , if any of you are at brands hatch on sept 17th ill be there showing off my integral kevlar/grp tub .

darrians are built to spec and just plain ole grp and woven roving was plenty durable enough , kevlar/carbon was added in local spots for reinforcement .

i believe one of the aus cars uses an ally honeycomb construction - the closest person to me who uses this ally honeycomb technique is pilbeam in their SR2 car .

The cost of honeycombe looks alarming until you realise that you can buy it ready cut and just slot it together. No cutting to length, no filing of joints to get a good fit, no distortion during welding.

Of course "ready cut" is even more expensive than uncut but when it all arrives it'll be like assembling a flat pack.

I actually discussed this type of chassis with someone who used to supply autoclaves for composite tubs to the racecars business. He was building his own design of spaceframe chassis for a race series and had asked me to do some FE on it. He reckoned that by the time you included your, or an emplyee's time, you were better off with a pre cut flat pack honeycombe chassis.

Interestingly he reckoned that a good spaceframe in this race series had around 3500 ftlbs per degree of stiffness while the honeycombe ones were at about 5000 ftlbs. He didn't tell me this before I did some concept analysis which gave much the same results for spaceframe and honeycombe versions of his car!

The crash resistance is higher but the repair is impossible or very tricky. It's probably new chassis time if you have a crunch.

Try this site for honeycomb ali chassis..........www.rallysportreplicas.co.uk
But don't take it too seriously though it might just be a figment of somebody's wild imagination

Ali Honeycomb get used lots in racing.

I worked for a company called DJ Racecars who buitl their Firecat from Ali Honeycomb panels. There was an article in Car and Car Conversions on it years ago - 99/00 i think. The photos in it show you prety much how it was built.

Mostly made from flat sheets or some bend with glues/rivitted joints. Used machined alloy bulkheads but the rest was honeycomb.

Without any parts bolted to the chassis you can pick up the tub by one end and hold it. Light stuff.

Car was fitted with a standard hibusa engine and was scarily fast So big all round. Much faster than the equivilent radical of the time.

Theres photos of it on their website www.djracecars.com



Jono

[Edited on 28/9/05 by jono_misfit]

there's a fella in Scotland has 2 of their cars.. he does sprints with one.seriously quick but serious money too

yep roy dawson. Quick quick guy

The firehawks are a fair price, but similar money to an equivilent force i think. But then again their carbon composite tubs.

Who ever mentioned Hexel. Good call, took some time to find the right bit of their site, but the bit on honeycomb panels is interesting.

Could anyone please send me a link to the pdf you have been talking about that describes the construction of the honeycomb chassis? Thanks

This discussion is 11 years old, I suspect things have moved on since then

I think you will be lucky. Its an 11 year old conversation and most of the main contributors are not active on here any more.

I would suggest looking through the websites they discuss and see if that brings anything up.

Thanks guys for all the replies. Yes the thread is old but the topic still relevant. If someone has the mentioned pdf please send me a link thats all i want to take a look and maybe run some simulation (eg energy absorption in comparison to a similar spaceframe),study joining methods and bulkhead using the article as a starting point etc.Thanks again

You might find some of the discussion on these threads interesting, if you haven't come across them already:

http://www.ozclubbies.com.au/index.php?/topic/11885-been-playing-around-with-a-new-cheap-clubbie-chassis-concept/

http://www.locostusa.com/forums/viewtopic.php?f=39&t=15283

I am intending on using such board in an upcoming build of a super high MPG car. Specifically I am going to use Cellite 620: http://www.trbls.com/wp-content/uploads/2013/03/Cellite-220-620-Panels-March2013.pdf
£272 + VAT per 8'x4' sheet
You can cut and work this material with normal woodworking tools, jigsaw, bandsaw, circular saw, router etc. Or it can be water-jet cut.
I use Areldite 420 high strength structural epoxy to join it, that stuff is mighty strong, I have made several test joints and tested them to destruction.

Some good articles on building a car with this matirial:
http://www.autospeed.com/cms/article.html?&A=112925
and
http://www.autospeed.com/cms/article.html?&title=Building-an-Ultra-LightWeight-Car-Part-2&A=112926

I am doing things a bit differently, I have decided to delete the side door for example, in order to get a stronger, stiffer chassis.

I design with this in my day job. I don't think it's that hard to use in situations away from my normal work but I'd be wanting to be very careful. It's stiff and strong but it requires careful loading and load path design as it doesn't cope with peel or point loads very well. I actually work with trbls on custom parts all the time. I've designed fastener inserts with 5KN+ pull out load but the problem I have is that failure propagation is often hidden and quiet until it's too late.

I may still use this for chunks of stiffening but I'm not sure I'd make a full chassis from it.

There's a chapter in Tony Pashley's book about such construction. You should be able to have a read here (Contents/Aluminium Honeycomb)


https://books.google.co.uk/books/about/How_to_Build_Motorcycle_engined_Racing_C.html?id=cym6_H4qm8UC

Sad to realise that I have been building my car longer than this thread has been running.


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