2006-Present Chassis Recap
The chassis is the first thing a locost builder should be thinking about before the build. There are several types of frames that can be build based off of the Lotus Super 7. A purist will go with the original frame, but most no longer build those. The original car is very small and really only designed for one occupant. The most popular design is the +442 designed by McSorley. This design adds 4″ of width, 4″ of length, and 2″ of height to the original frame design. This gives the builder many more options for engines, rear axles, transmission, and also more room when its all built. To get a full overview of the most popular chassis options plus detailed build plans check out McSorley’s website. In my case, I did go for the original chassis. I am a normal guy (5′10″) and actually like a compact driving experience. Also the transmission was not going to work in the larger chassis for me because the shifter would be located far too far forward. If I had to do over again, I would have spent the extra money on the Camaro transmission instead of the S10 tranny. I may still trade it in for one. I made all the measurements and rechecked, my engine and transmission combo would fit in a book (referring to this book: Ron Champion’s “Build Your Own Sports Car for as Little as £250“) frame.
The preferred size of metal to use for building the chassis is 1″x1″ 16swg steel tubing. This size is very common and can be purchased at any metal yard. I purchased around 200ft of it and had some left over. I pretty much stole my metal though. I only paid $168 for all of it. Most pay well over $1 a foot, so be prepared to call around and price it out. Also be aware that this stuff usually comes in 24ft long sticks. No way to just take the pickup truck up there and expect to drive home with it. Most likely it will have to be delivered or in my case have a trailer.
Now that I had my tubing I needed a way to cut it and put it together. To cut it I too the easy way out. I purchased a metal cutting blade from my local hardware store and fitted it to my compound mitre saw. It worked decently for cutting the metal tubing, but when it got time to cut bigger pieces it wasn’t going to work. I ended up getting a Ryobi metal chop-saw later on. I recommend buying a good metal chop saw in the first place. To weld, I ordered a MIG welder from Harbor Freight for around $280. It is not the best welder in the world, but it certainly gets the job done for the small amount of welding I do. Unless you can find a good used Lincoln, Miller, or some other name brand welder for cheap I would just go with something off of Harbor Freight. There is no need to blow over a thousand dollars on a welder just for this project. Don’t forget to check out the tool section of this site to see everything that I used to get the job done.
With the tube in hand and a means of putting it together, the last thing I needed to build was a good, level work table. Some people make tilting, full metal, modular tables that cost 100’s of dollars. I opted for the “scrap wood laying around” table. I had a sheet of MDF from making subwoofer boxes and some left over 2×4’s. I put it all together in about a hour and had a great level surface to make all my chassis measurements on. This is a must!
The actual building of the chassis is as easy as reading dimensions and cutting them out. Just follow the instructions step by step and in roughly 10-12 hours everything should be cut. I tacked my pieces in as I went along. The entire bottom, sides, and top layer are very easy and straight forward. The only part that takes some thinking and adjusting is the front where there is a compound cut to get the nose to sit back a touch. I made a jig for this portion. To cut and tack everything expect to spend a couple of days. I would say it takes 12-15 hours of work before it is mostly put together. Just take it slow and remeasure often. Like the old say, “measure twice, cut once.” Live by that!
Here are some pictures arranged in chronological order (click the picture to view a larger image):
If you have never welded before with a MIG welder, I would make sure you get someone to come over and show you the ropes. Perhaps even take a course at the local community college. I had a mining friend come over and show me how to weld before I tried to tackle the full welding of the chassis. Be sure to buy a welding book and know most of the terminology and some of the science behind welding. There are also a few website out there that have tutorials. Please, don’t just jump into it without becoming knowledgeable on the subject. I would hate to hear of a locost builder being hurt by a weld breaking while they are driving around.
More updates will be coming in the upcoming weeks/months. This is only a recap, I will go into more detail as I get started up with the build again.
Leave a Reply