LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently Tue Oct 21, 2014 11:12 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 20 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Caterham CSR solid model
PostPosted: Thu Nov 03, 2011 11:08 am 
Offline

Joined: Thu Nov 03, 2011 10:45 am
Posts: 8
Hello everyone.

Ive been a long time lurker on this forum and finally decided to register. My names Kevin and im a Mechanical Engineering major at Kettering University. I am project leader/head designer/fabricater for our schools Formula Zero team, which originally started off as a racing series in Europe similar to FSAE except that the cars are hydrogen fuel cell powered vehicles.

Ive been a long time lurker on this forum and was going to hold off until i actually got a chance to start on my locost build, but thought i would share what ive been working on.

For my vehicle design project this past term i went through and modeled a complete CSR frame and body work. The only piece i have not modeled are the suspension arms. I did all of the modeling in nx7.5 and it took me a total of 4 solid days of dawn till rediculous times of the night to finish it. \

Critiques are always welcome.

Image

I can post more screenshots of the bare chassis later tonight.

I also have a few other projects I am working on such as my flat 6 swap impreza L, a 1966 pontiac GTO, and my rb25 swap 240z. Needless to say time and space are at a premium, but as soon as i finish up my Z im starting on the locost build. Ive been dieing to do this for a while now.

Oh and a picture of the FZ kart ive been building for our team for the last year now.

Image

It has a pair of 3.5kW fuel cells, that feed a bank of ultracapacitors, which then feed a pair of 3 phase a/c 18kW electric motors


Top
 Profile  
 
PostPosted: Thu Nov 03, 2011 9:16 pm 
Offline
Always Moore!
User avatar

Joined: Fri Nov 09, 2007 3:40 pm
Posts: 3347
Location: Pittsburgh, PA
Welcome to the board. Slick model Slick. ;)

Are you planning on doing a dimensionally accurate CSR frame? What are your plans for a donor?

Do you guys still have an FSAE team? I remember hearing about their struggles my senior year when Mahle royally screwed them by delivering their engine (and transaxle maybe?) literally days before competition.

_________________
-Andrew
Build Log
Youtube


Top
 Profile  
 
PostPosted: Fri Nov 04, 2011 9:48 am 
Offline

Joined: Thu Nov 03, 2011 10:45 am
Posts: 8
We still do have a FSAE team, and yah Mahle royally screwed them with that motor/transaxle setup. That story is deffinetly true, shame to because they did a beautiful job on that chassis. Although I heard that the transaxle in that car weighed quite a sizeable amount. Lately their last few chassis have been built with a thumper instead.

As for my locost build, im not completely set on a donor yet mostly since I have the urge to design and cnc my own uprights. Although im leaning towards using miata uprights and as far as the motor I'm still weighing a few options. Ide love to build a dimensionally accurate CSR frame, but dont have access to one to confirm the dimensions. I can tell you that the chassis is 1 meter wide at the passenger compartment, making it slightly narrower then a book chassis.


Top
 Profile  
 
PostPosted: Fri Nov 18, 2011 11:34 am 
Offline

Joined: Thu Nov 03, 2011 10:45 am
Posts: 8
I finally made the decision on what motor setup im going to run in the car. I want to run a honda k24 with a t50 mated to it. The reason i went this route is that it is a pretty light motor, but still has good n/a power potential and will make the car very driveable for just going for nice weather cruises along with track days. That gearbox also has a few good gearset options for close ratio sets. I am still going to break out my powertrain calculation spreadsheets and look over the gear ratios before I finalize the gearbox selection.

I finally had a chance to grab another screenshot of the chassis for you guys to check out.

Image

Let me know what you guys think, constructive criticism is always welcome.


Top
 Profile  
 
PostPosted: Sun Nov 20, 2011 1:01 am 
Offline

Joined: Sat Feb 09, 2008 1:05 am
Posts: 678
Location: San Antonio
the toyota t50, out of the mid 80s corollas? I thought those were weak gearboxes, by reputation?

_________________
JSullivan


Top
 Profile  
 
PostPosted: Sun Nov 20, 2011 1:01 pm 
Offline
User avatar

Joined: Fri Sep 30, 2005 1:28 am
Posts: 1206
Location: Sunny-Okanagan, Canada, eh?!
The T50 is not terribly strong. Why not source a W58? Much stronger, and better gearing.

_________________
The Lethal Locost
The Lethal Locost 2 - Even More Lethalerer


Top
 Profile  
 
PostPosted: Sun Nov 20, 2011 1:11 pm 
Offline
User avatar

Joined: Thu Jul 07, 2011 12:17 am
Posts: 115
Location: Sandy, OR
I can't speak of the accuracy of tarradog's CSR model, but it has the appearance of being darn close. There are 10 files combined that create a surprisingly complete car...

http://sketchup.google.com/3dwarehouse/ ... b8eb4d8560

_________________
Regards, Ron


Top
 Profile  
 
PostPosted: Mon Nov 21, 2011 2:27 pm 
Offline

Joined: Thu Nov 03, 2011 10:45 am
Posts: 8
Thats the model i used as the basis for mine, I used the outside dimensions of it then from there created all of the triangulation. Dimensionally it actually seems fairly spot on from what I can tell, although i dont have or know anyone with access to a caterham to confirm them. Someone posted a top down view comparing the normal caterham and the sv model for interior space, and given their dimensions were rough approximations, ide say my model is pretty spot on.

My solid model is currently in native NX7.5 format, but i can probably translate it into a less detailed file format any of you guys want to check it out.

I realize now that the title of my thread is a little missleading, and it seems like im asking for the model. I should probably go back and change it to something a little more along the lines of, my caterham csr inspired chassis design.


Top
 Profile  
 
PostPosted: Mon Nov 21, 2011 2:30 pm 
Offline

Joined: Thu Nov 03, 2011 10:45 am
Posts: 8
Also i believe i read that del long was running a t50 in his d mod car, figured given the low weight of the locost that it would be able to take some abuse. The only thing i have against the w series trans is that the adaptor plate ends up being more complicated and expensive. With the t50 you simply make an adaptor for the k24 bellhousing to the t50 transmission. I made my own toyota 1uz to nissan ka 5 speed adaptor for between the bellhousing and the block and it was a pain. It took a very large piece of ground steel, with a fairly large amount of waste, and quite a few setups given the limits of travel on the mill i was using.


Top
 Profile  
 
PostPosted: Tue Nov 29, 2011 8:01 am 
Offline

Joined: Mon Jan 01, 2007 9:14 pm
Posts: 162
Looking good so far.

I haven't studied your model too closely, but I can tell you that there are some errors/tubes missing up front.

See pics here for example.

http://www.mycaterham.com/174550/180216.html

Best.

T


Top
 Profile  
 
PostPosted: Tue Nov 29, 2011 2:34 pm 
Offline

Joined: Thu Nov 03, 2011 10:45 am
Posts: 8
Yah the model was made on a very tight timeline. I appreciate the input and will make the changes to the front end. I think before i add the extra tubes in im going to lock down my frame side suspension pickup point locations so i can properly triangulate them. I also think if i get some free time im going to try and get the model into a program like grape to get an estimate on the torsional rigidity of it. We attempted to run FEA through nx7.5 but the model is pretty complex and even the most powerful computer i had access to struggled with it. The only way i think i could run a model that size is to run the FEA across a few systems at a time, or with a fairly corse mesh.


Top
 Profile  
 
PostPosted: Wed Nov 30, 2011 8:49 pm 
Offline
User avatar

Joined: Sun Jul 22, 2007 10:58 pm
Posts: 387
Location: Zagreb, Croatia
don't you have the possibility to run beam mesh? that is much faster way of doing FEA on a tube frame..

_________________
Building a single seater middy BEC with GSXR 1000 power :)
build log: http://locostusa.com/forums/viewtopic.php?f=36&t=5899

day job: http://smg.photobucket.com/albums/v723/turbolimac/portfolio/


Top
 Profile  
 
PostPosted: Sat Dec 03, 2011 8:23 am 
Offline
User avatar

Joined: Wed Nov 12, 2008 6:29 am
Posts: 3406
The T50 will go bang unless you go for the best quality front input shaft bearing you can buy or, as smart people do, go to a double row bearing. It's that front bearing that is the boxes weakness.


Top
 Profile  
 
PostPosted: Tue Feb 21, 2012 11:46 am 
Offline

Joined: Wed Jul 23, 2008 2:54 pm
Posts: 250
Location: Carbondale, IL
Might I suggest a 2ZZ+T50 or 2ZZ+W58.

I'm shipping a 2ZZ bellhousing off to Bill Hinsher this week, who is casting bellhousings to suit the ZZ and A series engines to the W-series transmissions. I believe that a W-58 + 2ZZ would be a fantastic combination for a locost.


Top
 Profile  
 
PostPosted: Tue Feb 21, 2012 4:14 pm 
Offline
User avatar

Joined: Thu Feb 08, 2007 11:41 am
Posts: 754
Location: PHX, AZ
Slick wrote:
t50... That gearbox also has a few good gearset options for close ratio sets.... Let me know what you guys think, constructive criticism is always welcome.



Unless your power-band is extremely 'peaky' you may want to hold off on the 'close ratio' transmission gearing. I spend more time than I care to admit wishing my ratio's were wider (stock 1.8L Miata running gear in mine.) The weight of a locost is far less than the donors. If you do the math, the lower weight translates into more effective torque so pairing to short gears isn't necessary. Dumptrucks have a zillion closely spaced gears because they're moving a lot of weight with a short power band. You'll likely be hauling a tiny bit of weight with a wide power band.

- Just food for thought.

-Come to think of it, I wish the gear spacing in my 3-series was wider too… Maybe it's just personal preference.

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 20 posts ]  Go to page 1, 2  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
POWERED_BY