Here are some shots of the chassis in it's original configuration. This is for reference when looking a various modifications.
Here are some shots of the floor pans in place along with the frame modifications. The sides were modified to look more like the original 7 and to give me more elbow room when working the steering. The vertical plate was put in place of the 3/4" square tube to allow clearance for the drive shaft. It has a bend in the middle to match the shape of the tunnel and to give it extra strength.
2/6/06 - Pedals
Just finished fabbing up the pedals. I cheated a little on the brake pedal and purchased a Willwood unit. When I did the make/buy analysis, it came out about the same cost wise for a dual MC setup, so I save the time and bought a pre-made unit.
Many using a Willwood pedal have had trouble with the master cylinders interfering with the front frame tube. I really did not like the idea of cutting it up for clearance, so a couple of aluminum spacers were made to get it up high enough to clear the tube. The included hardware was "exactly" long enough to secure it with the spacers. It works out about perfect for my foot.
I wanted to be able to use the stock clutch cable for simplicity and easy to find spares in the future. The clutch pedal pivots a little higher to allow the cable to be pulled from underneath. An anchor/keeper was added to support the shielded end of the cable and keeper for the ferule on the end of the cable was made in the pedal. There are adjustable stops for both ends of the travel. This coupled with the stock adjustment point on the transmission side of the cable will assure that the clutch is always in proper adjustment.
The throttle pedal was kind of tricky to make . It has to clear the cable for the bias adjustment, plus share a common pivot axis with the brake pedal to help the heal-toe action. It is also adjustable at both ends of travel. In addition, the pedal pad itself can be adjusted in and out to get just the right distance between it and the brake pedal. The throttle cable will come in directly from overhead and the end will attach to the "horizontal" part of the gas pedal assembly.
5/3/06 - Curves for Rear Fenders
Most of the locosts that I have seen have a simple 1" wide metal strap that makes the curve between the side rails and the rear shock towers to frame up the fender. I have never been keen on the look of this and the fact that it is flush with the rear fender just does not do it for me. I used 3/4" round tubing to mimic the way that it looks on the real Caterham and made the radius about 1" larger than that of the fender. A wooden form was made to make the curves and fill panels were welded in to cover the back (cockpit side).
5/3/06 - Shifter and Shift Linkage
Another project that has been looming around for a while has been making the shifter and shift linkage. First the linkage at the transmission side. The factory linkage uses a 6mm shank rod end, so a female 6mm rod end was used to connect it to the belcrank. The belcrank is simply a piece of 3/4" OD x 1/2" ID tubing that slips over an axle bolt welded to a bracket with tabs coming out at the right angles relative to each other.
The shifter itself is just a mock up unit for now. I needed to get the mounting holes and blind nuts on the chassis. In addition to this the handle length/ratio needs to be finalized to give the right feel and travel. Eventually all these parts will be made from machined aluminum for an ultra pimpy look. :)
5/21/06 - Harness Mounts
Some mounting anchors were made for the harnesses. The lowers are just bolt through tabs welded securely to the frame rails and floor. The uppers are for the clip on style and use eye bolts. Each eye bolt is mounted in a boss that goes through the upper crossmember of the frame and is welded on both sides.
6/15/06 - Driveshaft
The driveshaft represents the last "task" that needed to be completed before the car comes apart for paint. The driveshaft is a 2-piece unit that I had made up at Driveshaft Specialists. I was referred to them by Chris Fiaccone, who had used them for his BEC driveshaft and was happy with their work. I too had a good experience with them and would recommend them as well. My application was completely custom and is made entirely of new parts.
The sprocket adapter comes from Hawk Machine. They make parts for Dwarf cars along with sprocket adapters for a few configurations. You will also notice that I had to make a "jut out" in the tunnel vertical member. Because of the RX-7 axle being offset to the right by a fair amount, and wanting to keep the U-joint angles as small as possible, I had to compromise a little to make sure the driveshaft had plenty of clearance. It will make for a fun sheet metal project when I go to panel the interior on that side, but it will work out just fine the way I planned it out.
7/4/06 - Final Prep before Painting
The last little bit of work has been done to the chassis prior to painting. All the welds have been ground and next will be a couple of coats of POR-15. I don't think that is going to be all that fun, but it should ensure that the chassis is rust free for a good while.
I added some additional bracing to the nose box and also relocated the lower diagonal tubes in the engine bay to get a little more triangulation up front. Using the bike engine helped make this easier. One more mod that was done was making a drop down loop in the rear lower crossmember to clear the front of the rear end housing.
All the grinding is complete, and all that is left is some clean-up before painting.
7/16/06 - Painting the Frame
Finally! The task I have been dreading is done. The frame now is covered in semi-gloss POR-15. It was not that bad, but I ended up with about 12-14 hours in the whole job. Along the way, I found a neat tool that helped speed up the process and make the finish a little better. Lowes has some disposable paint rollers that have the tray integrated into the packaging. They are only $2 and really help to speed up the painting process.
A few shots of the frame in it's new paint:
1/14/07 - Shifter
The first iteration of the shifter is done. For now it is just a simple steel structure that pivots on an axle bolt. Some time in the future, I plan to make a nice assembly out of aluminum with bushings and less play (which is not much now).
1/20/07 - It's on the Ground!
A big day today...I was able to get the tires mounted on the wheels and naturally, those went right on the car. For the first time in SEVERAL years, the car came off the stand and sat on its own feet. Of course, it had to make it's first trip outside as well.
The roll cage was put back on temporarily so that mounts for the mirrors can be fabricated. Also the exhaust will have a couple of hangers come off of it as well. The finished shape of the car is really starting to become apparent. All the fiberglass goes to the painter in the next couple of days.