LocostUSA.com

I don't think you're allowed to keep your workspace that meticulously clean if you're going to continue posting pictures on this forum.

That is some excellent looking work you're doing on this car!

Also would you be able to post the basic SV chassis dimensions as you measured them? Like width across the outside at the main seating area, height from the bottom of the lower rail to the top of the upper rail and to the top of the rear bulkhead, and length from the bottom of the rear bulkhead to the front of the footwell and front of the suspension box? While it's probably been posted before, this has sparked a little curiosity about how the SV compares to the various Locost versions.

I for one would be very interested in looking at any measurements of an actual SV chassis. Others have also expressed interest in the past as some prefer the lines of Caterhams over those of the Locost, especially the set back scuttle and longer hoodline.

I've been getting a few requests for the dimensions of the SV (the guys at Caterham USA refer to it as the "Series Five", not "Ess Vee").

Give me a little while to put it together - I'll try and find a way to put my measurements into a form that's easy to read/post. BTW, don't reference my frame as a copy of the Caterham - it's completely a hodge-podge of everything out there (Caterham/Birkin/Donkervoort/Book/etc), with some of my own ideas thrown in; but it does have the same dimensions and proportions as the SV.

Thanks John! Looking forward to it.

So, it's been a couple of months since I posted anything on the log. With Spring arriving I started doing some house projects, and that quickly turned into a major remodel of the outside of my house, which quickly depleted both the time and cash budget for the Seven - at least for a little while. But I'm happy to be getting the house done - it's something I've been thinking about doing for about seven or eight years now, and it's turning out pretty cool.

Before I stopped working on the Seven, I had taken delivery of all the material I need to fab the control arms and related suspension parts. I had designed the welding jigs for the rear control arms, and just started making the first jig (pictures later).

A couple of weeks ago the wheels that I had ordered a back in February finally showed up. I'm very happy with how they look, and the appear to be very well made - and they're very light. I decided to go with 6-UL's from 949 Racing, 15x7 front, 15x8 rear, with a 7" spare mounted on the rear. Emilio at 949 racing delivers a quality product. I'm anxious to get some sticky rubber mounted up and get this thing on the ground - but it will be a while yet before that happens.

I hope to be back on the control arms in about 6-weeks when the major house project is wrapping up. Until then, here's a couple of pics of the wheels:

Well, the house project is finally wrapping up and I've been able to get back into the shop and get some work done on the car. Since I have the driveshaft now I was able to fabricate the driveshaft hoops and finish up the cross bracing of the tunnel structure. Things are definitely tight in there, but I'm happy with how it all turned out. I got it all welded in place this weekend and then started on the rear control arm construction.

I like those "loops". Using them as structure looks as if it would add something to the stiffness. Can you drill into them and also use it as a mounting place for the E brake? Or would sanctioning bodies frown upon that?

Pre all these stiffness tests everyone can now run on the computer (no Gonzo I'm not talking about [NWS PORN]) I'd have thought it would have added a lot, but now I don't know.

Here's a picture of the upper rear control arm welding jig. Pretty simple - just a piece of 3/4" MDF with holes drilled to accept four blocks that support the pivot points with all-thread. I'm able to tack one side, then flip everything onto the opposite side of the board, and tack the other side before welding.

I'm doing as much welding as I can with everything constrained. I got most of this first one welded tonight, but it's still hot in the fixture as I type. (I guess I could have snapped another pic - I'll get that later).

My plan is to focus on the rear suspension first - weld the control arms, weld in the shock brackets, and fabricate bushings and make sure it all works good with the drive axles in place before moving on to the front suspension.

In my case, I had no choice but to use them as a structure. The passenger side of the rear hoop is bowed out 1/4" just to clear the driveshaft by 1/4", and it is welded to the outside edge of the tunnel. As for mounting brackets to them, I may do that - I'm not too worried about inspections, as it is pretty unlikely that I will actually run slicks at a sanctioned event - I added the hoops mainly as an added safety feature. Not too happy about the couple of added pounds in weight, but I think it's a worthwhile tradeoff.

I didn't perform any FEA on my frame design - I'm just copying the SV Caterham frame design pretty closely, and analyzing my changes in design using common sense. I do think the hoops being crossed braced into the tunnel design helps in stiffness though.

Hey Carguy, wanna share that website address???

Meanwhile, back at the build log...

I agree with you, John, the hoops being part of the structure look as though they'd increase the stiffness of the tunnel, although as a counterpoint, they're square and not triangulated, so perhaps not as much as we might think. Either way, it looks like a well thought out, solidly constructed bit, and should be safer for the squishy organic parts inside the cockpit.

Keep up the good work!

JDK

More progress on control arms. The rears are now finished, and the concept for the jigs worked pretty well. Since the L & R control arms are symmetrical/mirror images of each other, I was able to flip the hardware from one side of the MDF to the other, and do most of the finish welding while keeping the pivot points constrained.

The rear camber/toe adjuster sockets had to be re-bored post welding due to some subtle shrinkage and warping.

Completed adjustment assembly. This allows infinite (fine) adjustment of the toe settings. I found that my miata was very sensitive to rear toe settings, and just 1/32 difference in toe can make a very noticeable change in turn in and stability. This setup probably weighs a bit more than the simpler system that Westfield uses on it's lower control arms, but when I did the math, it seemed like you might have to make a compromise when setting up the alignment if you only have "half turn" increments in adjustment.

Completed rear control arm & upright assemblies, ready for install. I still need to machine the inner pivot bushings before I'll be ready to weld the pivots into the frame.

Spent several hours turning the sleeves for the inner pivot bushings. I had the pivot clevises laser cut and bent - not the cheapest way to go, but they turned out very nice.

I have the front control arm jig's done, and I've started tacking them together. More pics to come soon.