It's gotta be low. And it's gotta look like it's an original frame. Now, a nice reproduction frame would save a lot of time figuring out what shape it should be, not to mention hours of sawing, grinding, and welding, but we're not scared of a bit of hard work. And since the front and rear rails need to be kicked up it would be a waste to cut up all that nice expensive metal - about five hundred of our English Pounds-worth - when thirty quid's-worth of steel tube would do fine.
Original Model A Ford chassis are quite simple in their design, being basically 4" x 2" section pressed channels, tapered at each end, to about 2-1/4" at the rear, with the front frame horns curving down to 2" high. Original chassis are available - about £200 for the last one we saw - but by the time the results of 70 years of use and abuse have been cleaned up and repaired, and then the whole thing boxed to stiffen it up, it is simpler to start from scratch.
(2004 Update: With the current popularity of 'traditional' hot rods, original chassis prices have been climbing, so £200 would be a good buy these days!)
Using rectangular-section tubing effectively replicates a boxed-in channel, so that is the basis of the main rails. We are using 100mm x 50mm steel box, with a 3mm wall-thickness, as it is the nearest standard industry size to the original design. To keep track of what we're doing, like the kick-ups needed to keep the truck as low as possible, the chassis is being drawn up on a cheapo 2D CAD system. As well as being easy to change if necessary, this also helps when calculating the various cut lengths required. We are using some street rod chassis plans for reference during the build-up, so hopefully they are fairly accurate. While we're preparing the main rails, actual hole positions aren't needed, so they can be confirmed later.
|Page 1 shows what a few hours - actually a LOT of hours - with a hacksaw, MIG-welder, and angle-grinder can do . . .|
|Page 2 continues the framerail fabrication with more hard labour . . .|
As mentioned in the introduction to the pickup, by early 2001 we appeared to be building two Model A's. Why? Well, the chassis plans we have are for a stock-type chassis, but we want the truck to sit low. Rather than just channel the body over the chassis by about 8 inches we want to channel it by four inches, then kick up the front and back sections. Because we're starting from scratch, we don't really know how much of a change we'll have to make. Instead of building the chassis, changing it, then changing it again (been there, done that!), we will build the first set of rails into a stock-style one. Then we'll sit the cab over it, and work out how the motor sits at the front, and where to put the bed at the back.
That means that we will have to repeat all that hacksawing and welding again, but, what the hell, it's good exercise! Better get on with it before the summer though (English summers might be wet, but they can be warm). What we'll do with the 'spare' chassis is uncertain yet, but there's a 396 Chevy about here somewhere, and, you never know, we might find a '30 coupe bodyshell to stick on it.
|Page 3 shows how we got the rear crossmember and a '40 Ford leaf spring ready to hold the back up . . .|
|. . . while Page 4 involves, surprisingly, more sawing, filing, and welding on the front crossmember.|
|Page 5 follows the comparatively easy build-up of the front crossmember for the second chassis.|
|But first, on Page 6, we tweak the rails and crossmembers to get the right sizes and shapes . . .|
|. . . before, on Page 7 we roll out the chassis jig and get welding.|
That's the end of Chapter 1: we've got our basic repro frame ready. In Chapter 2, see how we get on with the second chassis.