britishtrident
|
| posted on 31/5/05 at 05:02 PM |
|
|
quote:
Originally posted by pedromorgan
"The Morgan car has always been built around an ash-frame , and a steel chassis. The new Aero 8 also has an ash frame. This gives unique
strength, flexibility and surprisingly, research showed that the frame made the car safer on impact tests. "
from morgan web site
i think the point is that the ash body framework takes a large portion of the total load.
I cut my teeth on MG T types so know a thing or two ash frames and seperate chassis --- believe me an ash frame can't take impacts
particularly after it has been around a few years.
Every driven a Morgan ? call me Mr Wippy but having driven crawled under and repaired them I can say it ia triumph of shear of the dog headness of
the late Peter Morgan to carry on every single one his fathers mistakes over any semblence of engineering common sense.
If you want to build a Morgan replica the chassis dead simple much simpler than a Locost ust 2 lengths of "Z" section running parrallel
and at the front a crossmember to support the ends of the sliding pillars a bulkhead assembly in the middle and thats it. A Morgan is really just a
big a tunning fork made of "Z" section no other motor manufacturer ever used "Z" section to build a chassis because it has
truly strange deflection properties.
|
|
|
|
|
Wadders
|
| posted on 31/5/05 at 05:13 PM |
|
|
if your going to put a morgan stylee body on, why waste your time building a book spaceframe chassis? why not make life easy for yourself and use 3 x
2 box section to make a ladder frame chassis, which will be plenty strong enough, and allow you to have opening doors, jag suspension all round to
give a comfy ride, Rover v8 upfront. luvverly!
Save the wood for the dash and door tops.
Al.
|
|
|
britishtrident
|
| posted on 31/5/05 at 06:00 PM |
|
|
Plus 4 Plus 8 4//4 trad Morgan chassis
 
Rescued attachment chassis.gif
|
|
|
Wadders
|
| posted on 31/5/05 at 06:08 PM |
|
|
Are you sure thats not a Silver Cross chassis
 
Originally posted by britishtrident
Plus 4 Plus 8 4//4 trad Morgan chassis
|
|
|
craig1410
|
| posted on 31/5/05 at 07:27 PM |
|
|
Oh well that serves me right for being a smart ar$e eh??? 
I just assumed that the fact that sparks fly off the underside of the F1 cars when they scrape across the ground was an indication that the
"plank" was made from a metallic material. I guess it's just the fasteners that scrape on the ground then? Anyway, I still find it
hard to accept that the F1 cars drive around with a big lump of wood strapped to the bottom of the car, surely something more exotic is in order in
the high-tech world of F1... Then again a lump of MDF is quite handy for many things I suppose.
Cheers,
Craig.
|
|
|
Paul_C
|
| posted on 31/5/05 at 09:35 PM |
|
|
Morgans and F1 Skid Plates
An old quote from Motor written by Henry Manney described Morgans at a 1960s Motor Show as a fine collection of early Saxon artefacts. Though I now
quite like Morgans, premature senility.
I believe that the F1 skid plates are Jabroc (densified wood laminate).
|
|
|
Mark Allanson
|
| posted on 31/5/05 at 09:58 PM |
|
|
... the "plank" was made from a metallic material........ In the early 90's they had titanium skid plates.
Rather than strapping a bit of tree under my car, I would like to have spring loaded arms with titanium tips to give the 'mansell spark shower
effect'!!
If you can keep you head, whilst all others around you are losing theirs, you are not fully aware of the situation
|
|
|
craig1410
|
| posted on 31/5/05 at 10:08 PM |
|
|
Thanks for that Mark, I remember fondly watching Mansell, Prost and Senna slugging it out amongst showers of sparks and I couldn't see how such
a shower of sparks could result from the fasteners on the plank alone. I guess they must use different materials today as the sparks seem less
prominent although from the F1 rules I don't think they have to use wood. They seem to be allowed to use other materials provided the density is
within the specified limits.
Anyway, I agree that there are better routes to a stiff chassis than strapping a chunk of oak to your chassis...
Cheers,
Craig.
|
|
|
mcig68
|
| posted on 1/6/05 at 12:03 AM |
|
|
On the same topic but a different problem. Doesn't steel corrode quicker when in contact with oak? Something to do with the acids presesnt in
the wood.
It also tends to deform in an impact into large and very sharp pointy bits. A bit like barbecue skewers!!
|
|
|
kb58
|
| posted on 1/6/05 at 01:39 AM |
|
|
That's what killed so many crewmen back when they used solid (non-exploding) cannon balls. The impack of the ball on the oak planking sent 100s
of "splinters" flying. I put that in quote since most of them were about 12" long!
I got to see a video where they fired a real cannon and a real cannon ball at the oak siding of a simulated ship. They even put dummy crewmen on the
other side.
Amazing damage that...
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
|
|
|
pedromorgan
|
| posted on 1/6/05 at 09:43 AM |
|
|
i dont really want to build a ladder chassis. unless it is precisly manufactured and integrated with the body i think they have appauling crash
worthyness. also i am really after a nice car and not necesserally an easy car.
as for the morgan bashing, they had to be thoroughly crash tested to be type approved in the USA so they cant be that bad. i think they typify an
elegance that virtually no other car has come close to. they are the sort of car you would like to take a posh girl to the theatre in.
going back to the origional question, i hadent seen cymtriks's posts untill now and found them very interesting. i cant remember who pointed
them out but thanks to whoever it was.
i still think an oak plank would be incredibly strong (yes even in tortion) a piece of well seasoned oak is extreamly hard and stiff that is why they
uase if for roofs. it would be impossiable to put a nail into a piece of 2 year old oak withought drilling a pilot hole first.
however i think the benifits would not be as great as cymtriks's findings.
thankyou to all those who posted.
peter
|
|
|
craig1410
|
| posted on 1/6/05 at 11:54 AM |
|
|
Peter,
Yes seasoned oak may be stiff but it's never going to be as stiff, weight for weight, as steel and steel is a lot easier to join together than
wood, especially when you consider awkward compound angles.
Cheers,
Craig.
|
|
|
kb58
|
| posted on 1/6/05 at 02:27 PM |
|
|
It's simply way too heavy for what it does, versus steel and/or aluminum.
Mid-engine Locost - http://www.midlana.com
And the book - http://www.lulu.com/shop/kurt-bilinski/midlana/paperback/product-21330662.html
Kimini - a tube-frame, carbon shell, Honda Prelude VTEC mid-engine Mini: http://www.kimini.com
And its book -
http://www.lulu.com/shop/kurt-bilinski/kimini-how-to-design-and-build-a-mid-engine-sports-car-from-scratch/paperback/product-4858803.html
|
|
|
cymtriks
|
| posted on 1/6/05 at 04:56 PM |
|
|
quote:
Originally posted by Wadders
if your going to put a morgan stylee body on, why waste your time building a book spaceframe chassis? why not make life easy for yourself and use 3 x
2 box section to make a ladder frame chassis
Use 4x2 - 14 gauge, lighter and stiffer.
3 x 2 isn't very good as it's overweight and understiff by comparison to 4x2 in either 3mm or 2mm (14g).
Regarding using an oak plank. Don't.
This just isn't a sensible way to stiffen up the chassis or to use up a nice piece of wood.
My chassis mods ( check the double Y braced frame in the pictures section and read kitcaranalysisV2.doc on locost7.info) will more than double the
stiffness while saving a bit of weight.
The best wood to use for a chassis is plywood. This can be very good as some of it's properties, weight for weight, are as good as some very
exotic materials and it's a fraction of the cost. The problem is joining the sheets together effectively. Possibly the best way to do this is to
use the plywood to reinforce a fiberglass monocoque. This could be a very cheap way to get a very good result.
In fact spruce spars, as used on very early aircraft, are as strong and stiff for their weight as steel but the problem is joining them together, all
sorts of complex plates and gussetts are required as detailed in early aircraft design books, with steel tubes all you need is a saw and a welder.
But don't use an oak plank. It's not a good idea!
|
|
|
fester
|
| posted on 1/6/05 at 05:48 PM |
|
|
quote:
Originally posted by pedromorgan
i dont really want to build a ladder chassis. unless it is precisly manufactured and integrated with the body i think they have appauling crash
worthyness. also i am really after a nice car and not necesserally an easy car.
as for the morgan bashing, they had to be thoroughly crash tested to be type approved in the USA so they cant be that bad. i think they typify an
elegance that virtually no other car has come close to. they are the sort of car you would like to take a posh girl to the theatre in.
going back to the origional question, i hadent seen cymtriks's posts untill now and found them very interesting. i cant remember who pointed
them out but thanks to whoever it was.
i still think an oak plank would be incredibly strong (yes even in tortion) a piece of well seasoned oak is extreamly hard and stiff that is why they
uase if for roofs. it would be impossiable to put a nail into a piece of 2 year old oak withought drilling a pilot hole first.
however i think the benifits would not be as great as cymtriks's findings.
thankyou to all those who posted.
peter
|
|
|
fester
|
| posted on 1/6/05 at 05:57 PM |
|
|
Peter;
your point about Morgan crash testing is taken,but torsional rigidity does not rely upon strength in one plane. Steel box section ladder and space
frames (when correctly designed and triangulated) far surpass wood weight for weight . They also have the added advantage of ductility,so (if you wrap
one around a tree,hope you dont) a large part of the impact will be absorbed by distortion.
|
|
|
Paul_C
|
| posted on 1/6/05 at 08:14 PM |
|
|
Marcos Wood Chassis
Wood has been successfully used in chassis such as various Marcos's and other models designed by Frank Costin (I particularly like the Amigo).
The stiffness to density ratio of wood is comparable to steel and aluminium. I don't know what the crash performance is like but any light
weight car isn't going to be great. I don't believe that the 1 inch box section is all that good. My reservations are based on wood not
liking hot exhausts and heavy point loading like engine and suspension mounts. They would probably benefit from sub frames negating the advantages of
the light material. Also the mechanical properties can be rather variable so if a critical part of the chassis coincides with a defect in the wood
then life could be exciting.
|
|
|
Rorty
|
| posted on 2/6/05 at 04:52 AM |
|
|
quote:
Originally posted by James
This thread's been here for 4 hours and no-one's mentioned Cymtrics yet!
James, are you inferring Cymtrics is a plank? I know some of his notions are a bit off the wall, but that's going a bit far isn't it?
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
|
|
|
Rorty
|
| posted on 2/6/05 at 05:12 AM |
|
|
Morgan (and other wooden chassis) only work because the timber sections are relatively small. It's virtually impossible to 100% seal wood and
inevitably, moisture will get in. That done, a 300mm wide plank of oak will expand and contract across its width by about 6mm. There would be
absolutely no point in using a seasoned plank (unless the car was going to be driven only on dry sunny days), because the first time the car went out
in high humidity, the plank would start to swell.
If the plank were confined within some of the chassis elements (as opposed to being just screwed on), it would have the strength to burst the chassis
apart. Moving timber is very powerful. Have you ever wondered how some of the ancients used to quarry their bloody great blocks of stone? In cold
climates, they would use fire to create cracks and then wait for winter to freeze the water in the cracks to burst the rock apart. In warmer climes,
they would hammer bone-dry wooden wedges into cracks and then pour water onto the dry wood which swelled and broke the stone apart.
The acid in oak (and to a lesser degree, in most other trees) referred to above is tannic acid which reacts with iron when damp, turning it a deep
blue-black (basically,how early ink was made).
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
|
|
|
kreb
|
| posted on 2/6/05 at 06:32 PM |
|
|
I agree that a plank sounds frankly silly, but I have been amazed by the properties of marine plywood sandwiched in Fibreglass. I've built a
kayak using "stitch and glue" construction that's 16 feet long, 40 lbs. and can withstand "aguering" with a 225 lb. lump
aboard (me) Use of this product in place of aluminum might well have aesthetic and strength advantages. Interestingly, I noticed that the LMP has
plywood floors as well.
|
|
|
craig1410
|
| posted on 2/6/05 at 06:42 PM |
|
|
Yes Steve Turner was round at my house last night and mentioned that the LMP uses 6mm marine ply on the floor. He has tried aluminium in the past but
settled upon the plywood as a lightweight, strong, cost effective and easily replaced alternative. He said there are better alternatives but these are
too expensive to be practical in most cases.
Cheers,
Craig.
|
|
|
