Community > Forum > Official Armadillo Aerospace Forum > John, another 6 months have passed and AA still not relevant

John, another 6 months have passed and AA still not relevant

Posted by: Dan Frederiksen - Wed Oct 27, 2010 7:08 pm
Post new topic This topic is locked, you cannot edit posts or make further replies.
 [ 111 posts ] 
Go to page Previous  1 ... 3, 4, 5, 6, 7, 8  Next
John, another 6 months have passed and AA still not relevant 
Author Message
Spaceflight Trainee
Spaceflight Trainee
avatar
Joined: Mon Sep 14, 2009 9:21 am
Posts: 20
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Fri Nov 19, 2010 12:13 pm
The LMP is heavily influenced by the Ferrari F333 SP and the body moulds where sub contracted out however I have built and repaired a number of other compersit plugs, moulds and bodys including structural tubs.

Yes I have experience with vacuum forming transparent thermoplastic as can be seen on the head light covers of the LMP

A small amount of CFD modelling was done. A scale wind tunnel modle was also tested and the car has had extensive track testing with wool tufts. The track testing was the most useful. I dont doubt that the drag could be significantly lowered however the car has to also comply to the appropriate rules.

I have now showen that I have the skills, tools, space, time and inclination to build the free ranger. When do I get the first drawings? So I can get cracking?


Back to top
Profile
Space Station Member
Space Station Member
User avatar
Joined: Wed Jul 30, 2008 9:39 pm
Posts: 266
Location: Denmark
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Fri Nov 19, 2010 1:17 pm
a lot of details would have to be worked out which under your proposal would be unpaid work. as I have many priorities that's not a given that I will do but I'll consider it if you are serious. I trust you are serious, not just trying to make some misguided point?


Back to top
Profile
Spaceflight Trainee
Spaceflight Trainee
avatar
Joined: Mon Sep 14, 2009 9:21 am
Posts: 20
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Fri Nov 19, 2010 1:27 pm
yes I am serios, and you are right I would be doing allot of unpaid work. I'm very surprised that you are not more excited about moving one of your projects forward. if you can get some drawings even just preliminary ones to me I can start planning and mould construction.


Back to top
Profile
Space Station Member
Space Station Member
User avatar
Joined: Wed Jul 30, 2008 9:39 pm
Posts: 266
Location: Denmark
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Fri Nov 19, 2010 3:34 pm
I understand and it is an interesting proposition and I will certainly consider it. but I'm also realistic enough to know it's a lot of work not only completing a vehicle design in every relevant detail before building can begin but also after, and no income may ever materialize. however practical it is that you'll pay for and build the vehicle itself.

it has to be really well thought through before building starts as I assume the moulds will be expensive so we can't just go through several iterations.
for instance the motor I had in mind has to be replaced because it's quite inefficient at the soft loads it will most often encounter. it's only decently efficient at high power level so it would be wasteful to use it. would cripple the design range wise
I originally applied for funding to build a demonstrator with a bit of money for salary so that I could 'survive' in the time I spent on it. however generous your offer is it is an offer to work a long time for free. working a long time for free to better this world is getting old.

I would also want to run my other design by you as that might be more interesting for its broader appeal. the freeranger would be an interesting demonstrator to get people thinking but it is a very eco hardcore vehicle that only few would want to drive. however rational it is, it is made dangerous to drive by all the other cars that are so massively overweight. not that it would buckle but the mass relationship means the experienced acceleration in a frontal crash with a heavier vehicle is mostly yours :) as early as 50km/h frontal collision would approach 100% fatality rate. nasty math when the other vehicle idiotically weighs 20 times more. of course the freeranger is not easy to hit dead on but it is worth considering if commercialization is the goal.


Back to top
Profile
Spaceflight Trainee
Spaceflight Trainee
avatar
Joined: Mon Sep 14, 2009 9:21 am
Posts: 20
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Fri Nov 19, 2010 4:51 pm
There is no way to get round the fact that there is allot of work in in building a vehicle, and yes I would like to avoid having to trash buks, moulds or parts that have 100's of hours of labor in them it the time that makes this type of thing expensive. I dont know if you know this but a hand built car mould is typically quoted at around 1000 hours, obviously the free ranger is smaller and not a paticualy complex shape.

I'm willing to look at other vehicle designs however it is something like the free rager that I think could be a true game changer. Possibly with 3 wheals to enable further stream lining and possibly a moped engin rather than an electric motor in the early version versions.

As for safety I frequently ride a motor bike an that has many of the same limitations in terms of safety and as I have said before my day to day car weighs in at 560kg roof and all so light weight is not that much of a problem.

Eater way lets keep it public and let other contrebute.

So How soon can I have some drawings?


Back to top
Profile
Space Station Member
Space Station Member
User avatar
Joined: Wed Jul 30, 2008 9:39 pm
Posts: 266
Location: Denmark
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Sat Nov 20, 2010 2:37 am
I don't mind keeping it public, I am a true christian and therefore love truth and despise secrets but this forum is simply not an efficient means of communication for a serious effort.
send me an email (it's at my site)

have you used core material? which?
my designs are so far based on structural composites. not just body panels on a tube frame. so will need core materials at some points. I've considered a light weight wood for strong flat areas if nothing else.

one possible motor config would be to use bicycle/scooter hub motors. it probably wont be able to do the ferrari acceleration with motors on the rear wheels but it would probably work well and be an elegant solution that would clean up the engine room a lot so that can be pure cargo or even shorten the vehicle. depending on motor model there might be some reliability issues that need to be tested for prolonged driving on rough road. also the issue of whether hub motors with side mount is even available because the shaft has to be much stronger like that.
for the metal arms I'm thinking chrome moly steel tubes (like 4130 in usa) or other similar high strength steel. have you worked with such?

you can answer these here if you like but send me the email as well.


Back to top
Profile
Spaceflight Trainee
Spaceflight Trainee
avatar
Joined: Mon Sep 14, 2009 9:21 am
Posts: 20
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Sat Nov 20, 2010 10:04 am
Dan it feels like im starting to guide the design now not just construct a free ranger for you from a set of drawings.

Yes I have used core materials remember that any thing can be a core material it is simply a matter of choosing the appropriate material for the job for your designs ply wood, Niplast and foam would probably be good. I notice that there are no internal bulkheads or any other structures showen in your free ranger you also do not show any details of how you will attach the suspension to the tub other than bots this would not be the normal approach.

you might want to take a look at this restoration of a 50/60s Frank Costin designed wooden car it shows a lot of nice intergration i.e. look at how the seats are incorporated in to the ply wood tub.

http://silicon.fastnet.co.uk/specialist ... hp?cid=156

You might also like to have a look for the book 'Flying on Four Wheels' by Dennis Ortenburger it's essentially a technical biography of the work of Frank Costin who designed the wooden car above and a number of aircraft, was one half of MarCos and founded Cosworth I think its safe to say that this chap knows his onions.

You might also like to have a look at the tryaneii a very low CD car from before it was fashionable to make light efferent cars with a moden engin this would get even more impressive numbers
http://home.clara.net/peterfrost/tryaneii.html

no I dont have any experience with cromply tube however in a car as low weight as you are aiming for there is no need CDS tube will do the job adequately. aslong at you remember to aply loads to the tubes correctly i.e. use them in tention or compression.

with all that information im sure you can flesh out the free ranger in a couple of weeks. I look forward to receiving the drawing soon.

PS also sent in email to Dan


Back to top
Profile
Space Station Member
Space Station Member
User avatar
Joined: Wed Jul 30, 2008 9:39 pm
Posts: 266
Location: Denmark
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Sat Nov 20, 2010 11:38 am
I haven't asked you to design a single thing. merely tried to determine your capability. if that was not an issue I would make designs noone on this planet could manufacture.

the tube would not always be used in tension or compression and that's not wrong. haven't you looked at the images on the site? and the short animation of the suspension movement in the log. the arm that holds the wheel.
cold drawn might work if only with a thicker wall or if strengthened at the critical tension point on the mid underside

do you have access to any lightweight wood? like abachi or even balsa. I intend for the flat floor to have core material to be the bulk of the stiffness ot the vehicle. if you have some foam or foam cell core material that isn't eroded by the resin then the sides of the bottom can probably benefit from say 10mm of that.

as for bulheads I'm hunching that integrated fiber glass bulkheads are no good because they will apply purely delamination force. probably just flat sheet fiberglass screwed on with some angle brackets to cover front and rear suspension

and few from the past 'know their onions' or it would already have been done.


Back to top
Profile
Space Walker
Space Walker
User avatar
Joined: Thu Sep 17, 2009 2:25 pm
Posts: 160
Location: Ireland
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Sat Nov 20, 2010 12:12 pm
The Tryane II car is beautiful.

johno


Back to top
Profile
Space Station Commander
Space Station Commander
User avatar
Joined: Mon May 31, 2004 9:47 pm
Posts: 812
Location: Yerushalayim (Jerusalem) - capital of Israel!
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Sat Nov 20, 2010 3:54 pm
Yeah, kind of looks like a Mazda Miata.

_________________
“Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return.”
-Anonymous


Back to top
Profile WWW
Space Station Member
Space Station Member
User avatar
Joined: Wed Jul 30, 2008 9:39 pm
Posts: 266
Location: Denmark
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Sun Nov 21, 2010 3:20 am
I think it's rather hideous frankly.
and the long narrow 3 wheel config is probably very prone to tip over.
and for such an extreme shape, a Cd of 0.24 is unimpressive. a porsche is around 0.28 and the GM EV1 is 0.19.
Ford probe concept is 0.12 iirc and mercedes did a box fish inspired car at 0.095. the fish itself is around 0.04

if you're going to do an extreme shape make sure it's justified

and it appears that a smooth surface is not the most aerodynamic. small overlapping scales with sharp trailing edges and ridges on the scales to guide the flow seems to be quite a bit better. as is uses by sharks.
it is also the phenomenon that make a golf ball twice as good as equivalent smooth ball. a factor 2 is enormous and quite amazing that it works.

a similar surface might actually be of great benefit to rockets cutting through the atmosphere


Back to top
Profile
Space Walker
Space Walker
User avatar
Joined: Thu Sep 17, 2009 2:25 pm
Posts: 160
Location: Ireland
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Sun Nov 21, 2010 12:48 pm
Dan Frederiksen wrote:
I think it's rather hideous frankly.
and the long narrow 3 wheel config is probably very prone to tip over.

Well Dan, at least the potential passengers know that they are getting into a 3 wheeled vehicle before the engine starts. Unlike your design, where they are fooled into thinking they are getting into a stable 4 wheel design, but a few miles down the road it suddenly transmogrifies into a 2 or 3 wheel deathcart.
Dan Frederiksen wrote:
blah Cd blah genius blah Cd blah fish blah Cd blah 2+2=5 blah

So what is the projected Cd of your design? Oh that's right you don't have a projection but your hunch is that it'll be awesome. Why don't you cover your design in sharkskin instead of the current smooth surface? Oh, I forgot that's the fault of the guy who has offered to build it for you, you had to bring the design down to his level.


Back to top
Profile
Spaceflight Trainee
Spaceflight Trainee
avatar
Joined: Mon Sep 14, 2009 9:21 am
Posts: 20
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Sun Nov 21, 2010 4:05 pm
I also like the Tryane II and thing the use of wood is very interesting if you ever get a chance to look at a Costin car or Costin inspired car the integration of components and making evry single part do as much as posible is very interesting.

I'm also very keen on the 3 wheel designs with 2 front wheels it fits well under a teardrop silhouette witch is a very aerodynamically efferent shape. is an inherently stable platform for a vehicle and has 1 less wheel if you drive the rear wheel you can also get rid of the diff all of witch are appealing as they help to drop the mass of the car.

Dan you have not asked me to design any thing however I have just provided links to a cheap low mass construction technique that we can all do in the home and with CNC or just good templates for cutting of the ply will scale to production well and can even be integrated with more moden copersets construction.

Also I would like to say its not that i feel that the designs represent the best that can be done today but thay are a very good effort for the time and seen in that context designs that are 30 to 60 years old from a time when no or very little effort was made in this direction they are very cool.

I guess to some extent Dan is right we can do better to day. So one again I ask Dan get me the drawings do not pull any punches, dont let your creative flare be dulled by my ability to build it. Get me the drawings and I will build it.

Sorry for the slow reply I have spent a very great weakened rebuilding cars.


Back to top
Profile
Space Station Commander
Space Station Commander
User avatar
Joined: Wed Aug 18, 2004 8:47 am
Posts: 521
Location: Science Park, Cambridge, UK
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Mon Nov 22, 2010 9:22 am
Dan Frederiksen wrote:
it's interesting that several companies do LMP racers yet don't do scientifically aerodynamically derived designs. Radical racers for instance don't seem to do it. I assume yours isn't either. it might be possible to halve or even quarter the drag.


Aerodynamics is not yet a completely exact science (which is why F1 teams still use windtunnels rather than computers to design cars - except Virgin I think, and they didn't do that well this year...). A lot of it comes down to experience. The designer of the Radicals has a lot of that. Which is why the current lap record (and second place) round the Nuerburgring is held by a Radical.


Back to top
Profile
Spaceflight Trainee
Spaceflight Trainee
avatar
Joined: Mon Sep 14, 2009 9:21 am
Posts: 20
Post Re: John, another 6 months have passed and AA still not relevant   Posted on: Mon Nov 22, 2010 9:51 am
JamesHughes wrote:
Aerodynamics is not yet a completely exact science (which is why F1 teams still use windtunnels rather than computers to design cars - except Virgin I think, and they didn't do that well this year...). A lot of it comes down to experience. The designer of the Radicals has a lot of that. Which is why the current lap record (and second place) round the Nuerburgring is held by a Radical.


Not forgetting that sports cars have to to comply to rules of there class so could often be significantly more aerodynamically efficient. for example in F1 ground effect, active aro and fans have been baned all of witch would make car much faster.

Also in the given example of a radical its a track day car so needs to have ferly benin handeling with a well balanced set up that will not set the bar so high as to prevent people from learning to drive the car.

@James, what engin do you have in your 7 and how long have you been driving it? have you ever considered a move to any thing else single seater or maybe radical?


Back to top
Profile
Display posts from previous:  Sort by  
Post new topic This topic is locked, you cannot edit posts or make further replies.  [ 111 posts ] 
Go to page Previous  1 ... 3, 4, 5, 6, 7, 8  Next

Who is online 

Users browsing this forum: No registered users and 10 guests


cron
© 2014 The International Space Fellowship, developed by Gabitasoft Interactive. All Rights Reserved.  Privacy Policy | Terms of Use