Caterham Dimensioned Locost

[STranger 7]

Does anyone know what software was used to generate the McSorley plans.
I'm working with a friend to design a frame that uses MGB parts.
The frame size will be based on the original Series III frame with enhancements based on a Caterham 165. When we are done with the plans, a half dozen frames will be built. Plans include making the molds for the nose and fenders.
I want to post the frame planes, for anyone interested, formatted like the McSorley plans.
Free software if at all possible .
A few pictures for reference,a Cat 165;

042_caterham.jpg

Or this

1_seven.jpg

Ron

[Lonnie-S]

You could e-mail McSorley for the info on what he used, software-wise.

Depending on your skill level using complex software, and how serious you are about 3D design, I'd look at applying for a free, non-commercial license for Autodesk's Fusion 360.

More here ==> https://www.autodesk.com/products/fusion-360/free-trial

There is a significant learning cure for the product (there are a lot of on-line tutorials too), but you have absolutely everything you need available to you, plus some. When doing the molds for the body parts you will also have excellent surfacing tools whose data can be turned into practical output.

On the practical side, there are some MGB-based build logs here. I'd look through those for issues that came up, and how they were solved for those constructors. That could save you a lot of design time and/or rework at construction time.

Good luck. And don't forget to post your progress and results.

Cheers,

EDIT: I didn't recognize your new avatar, Ron. You've worked with SketchUp. It shouldn't be a big step up to Fusion 360.

[STranger 7]

Lonnie,
I will check out the builds of those who have gone before me.
Looking at the Solid Edge 2d program for the plan drawings. It's free.
I just want to put together a pdf of drawings like McSorley did. Sketchup's 3d capabilities takes care of any other needs at this point.
Ron

[STranger 7]

Lots of images gone. Adding this one for what it's worth.

CatConstrc,017,750w.jpg

Ron
From a series 1

lotus-7-series,1.jpg

lotus-7-series-2.jpg

lotus-7-series-3.jpg

lotus-7-series-4.jpg

1960 lotus 7 fifth link.jpg

1960 lotus 7 fifth link,2.jpg

[STranger 7]

For comparison. A series 2 on the left and a Caterham 165 on the right.

1963series2andcat165.jpg

The Series 2 has a Kent crossflow 1600. the weight that the orig frame was supporting can be found here
http://westfield-world.com/engineandtransmission.html
Ron

Alright then. the 165 frame is easily found by Googling Caterham 165 in the images window.
the Prince (and other) series 2 frame drawings can be had here.
viewtopic.php?f=39&t=11691

Engines heaver than the Duratec will require stouter frames.

[Bent Wrench]

Cody, Post some FEA screen shots?

[RichardSIA]

For comparison. A series 2 on the left and a Caterham 165 on the right.

1963series2andcat165.jpg

The Series 2 has a Kent crossflow 1600. the weight that the orig frame was supporting can be found here
http://westfield-world.com/engineandtransmission.html
Ron

Are we sure of that?
Looking at wheels and some other hints it would seem the car on the right is the older one.
Tripped across this old thread while looking for original 7 dimensions as I am about to have some Sprite engines to play with.
Sadly it seems many of the links are now dead.
Was the series of builds ever completed?

[cs3tcr]

Are we sure of that?
Looking at wheels and some other hints it would seem the car on the right is the older one.

The car on the right is the newer Caterham, the car on the left probably didn't leave the factory looking like that but could be a real S2. As for the 1600 crossflow in an S2, only the very last of them were fitted with that motor. They used the pre-crossflow in most (not all) of them. S3's on the other hand primarily had the crossflow, save for 13 (from what I recall) with the Lotus Twincam.

[STranger 7]

True. The crossflow is most often found in the series III. The S2 pre-crossflow weighs about the same. Significantly more than the 948 cc most often found in the S1 7s. I found a screen shot of the missing weights page.

Engine and Transmission Weights.jpg

This is a pic of a 1275 in a Series 1.

A 1275 in a S1.jpg

I have spriget weights somewhere. Also read somewhere or two that the lighter S2 and S3 frames were weaker and more prone to failure. A blend of a S1 frame and a Caterham 165 would be my choice for a Sprite engine and trans.

caterham-seven-165.jpg

Along with a MGB front and rear suspension.

Ron

[Lonnie-S]

That Caterham 165 with the live axle, it looks like it is a slight variation on the "standard" Locost 4-link. Do you have any other details on the rear suspension, Ron? Actually, any information on the chassis would be of interest too.

Cheers,

[STranger 7]

Hey Lonnie,
The 165 frame has the same basic dimensions as the Series 2. Reference the plans from simple sevens site.
The Sprite / Midget engine looks "right" in that size. If you Google " frankfurt-2013-caterham-seven-165-prototype".
you'll find pictures of every angle showing triangulation and front suspension mounts.

cat 165 rear sus,01.jpg

cat 165 rear sus,02.jpg

cat 165 rear sus,03.jpg

cat 165 rear sus,04.jpg

cat 165 rear sus,05.jpg

cat 165 rear sus,06.jpg

CatConstrc,005.jpg

Ron

[Lonnie-S]

Thanks, Ron.

What/where is the "simple sevens" site you mentioned

Cheers,

Lonnie

P.S. For that Frankfort prototype link, the story is still there, but the photos aren't.

[Miatav8,MstrASE,A&P,F]

Thanks for sharing that Ron. Impressive. They avoided a curved upper and didn't add any weight in the form of extra chassis tubes. I think something between the earlier design with the A arm on the right and this but with a few sphericals to replace some of the bushes would probably be ideal.

[STranger 7]

Lonnie,
frankfurt-2013-caterham-seven-165-prototype goes in the image search area,

Google Search.jpg

Here is one of the search result links,
https://www.autoblog.gr/2013/09/10/frankfurt-motor-show-2013-caterham-seven-165-prototype/
This 165 build log is probably where I captured the frame shots.
https://caterham160.blogspot.com/2015/03/day-2-of-build.html
Good source of chassis details.
The SimpleSevens.org site isn't the one with plans. It does have most of the available information about 7s.
http://www.simplesevens.org/
About the avatar, I haven't been able to change it for some time now.
Drawings : The Prince (and other) series 2 frame drawings can be had here.
https://www.locostusa.com/forums/viewtopic.php?f=39&t=11691
Hope this helps. If there are any other questions, please don't hesitate to ask.
Ron

[STranger 7]

One other point concerning using MGB suspension and rear. Depending on engine size,the Sprite rear ratios are the same as the 3.9 Mg rear

Rear End Gear Ratio MG Midget .jpg

The MGB rear is just barely wide enough for an original size frame.
Ron