Since it hasn’t been shown what this frame is being built off of, I figured it’d be good to give a peak at the final rendering that all dimensions are following:
Well, after about half a tank of gas, I completed the rear subframe. On the top of my list of lessons learned on a big, crucial welding project is drilling pressure relief holes in any tubes that will be fully welded up. In this case, I ended up with around 10 holes that I’ll leave for now. There will be plenty more welding to be completed on this subframe with the addition of the suspension and motor mounts.
And now for the eye candy:
I was able to make a trip to the metal supply shop here in town this past weekend. On my single item list was 10 feet of 1″ 0.063 wall tubing. The entire frame calls for somewhere around 20 feet total, but most of that will be used for the suspension A-arms and isn’t necessary to have on hand now anyways. Also, final decisions haven’t been made as to what wall thickness to use for those parts.
I was pretty impressed how these tubes turned out. Not much gap here and shouldn’t be a problem to weld up nicely. It’s really starting to come together; it almost looks like pieces of a car….well, a open wheel tube frame car, anyways…
I have a feeling I’m going to be using the phrase “getting there” a lot, mainly just to hear someone say it and keep myself motivated.
Here’s a pic of what is here so far, the front and rear subframes, upside down. I’m trying to come up with a completion percentage but can’t really do it. I’d like to say more than 10% of the work is done, but I know that’s not correct. It’s practically 50% if you envision wheels, an engine, bodywork, seats, and a steering wheel, and then flip the whole thing right-side up.
Here are a few more pics of the actual construction of the rear subframe. A lot of tight fits here!
In some ways the rear sub-frame should be easier than the front, and in some ways harder. We are using left over tubing from the 24′ sticks we had to buy for the roll bending. The jig won’t be quite as self-explanatory, because we have to deal with the upper side tubes of the sub-frame being 2″ diameter here, instead of 1.5″.
You can tell from this picture what is being done. We’re going to construct the sides of the sub-frame first, dealing with the difference of tubing diameter by offsetting those tubes over the edge of the actual table using sections of 2×4’s with milled flat sides for accuracy. All of the 2×4 pieces are being offset from the edge of the table by using plate aluminum of the correct thickness, and locking them into place before screwing them down by using a few sturdy clamps. It’s turning out very well so far.
There are a few decisions to be made on the overall dimensions of the sub-frame. For one, we’re dealing with a different motor here. Not only is it a different make of motor meaning the dimensions won’t be the same, but the intake and exhaust are on opposite sites on our motor choice when compared to the ‘real’ Atom. We are going to attempt to get all of the dimensions close enough to keep the half-shafts as straight as possible both from a bird’s eye view, as well as a ground level view. This could be tricky…
I know this doesn’t look like much, but it’s a pretty crucial section of the car. The front subframe is constructed fully of 1.5″ x 0.65″ tubing and the same tubing will be used for a majority of the rest of the car. At this point, we have the tubes all coped and they fit very tightly. This will really help when welding it up as there won’t be any gap to fill.
Here it is, all complete. This is going to be our flat surface to build a majority of the frame of the car on. It’s a 12′ x 4′ table that’s constructed in a very stout way. No idea how much it weighs, but the two of us can lift it up and move it around a bit. We plan to shim the legs up from the ground to make it completely flat when we have it in the final resting place.