Since I moved into a new shop a couple months ago I've had the room to add to my tool/goody collection. I am about to restore my IMSA RX2 after gathering parts for a couple years now and it was time to build chassis jig. I'm going to need to do a complete rear clip on the car after taking stock of every panel that needed to be touched to make the car right.

I had seen a frame jig I liked at the PRI show called a Uni-jig. Problem is they want about $6500 plus shipping. I set out to make my own.

So, since I'm a cheap basterd I'm always looking for materials in strange places. The main frame material is 3x5 3/16" wall(Uni-jig is 3x4) that I got from the back yard of the local Alro Metals. Brown stuff, 60 cents a pound. The H pattern is 12' long and 3' wide on center. The legs are made from some 1.75x .120 wall DOM cage material I had laying around. Inside those legs is 1.5" threaded rod to adjust for uneven floor.

I made little "booties" that go over the rod to hold shopping cart castors that I picked up when my local store put those locking wheels on all their carts to keep them on the property.(free!) I found them in the Grainger catalog, they can handle 350lbs each. These will let me place to project where I want it after I use my lift to put the car on the rack

The frame itself is flat to about 1/4 of the thickness of my laser level's spinning dot. I lined everything up on the top edge of the 'line' the dot makes in its sweep. Probably flat to a few thousandths which will be fine for what I'll be doing on it. Its 2' tall once its off the castors but it can be made taller with the threaded rod legs.

The fixtures to hold the car itself are designed to hold the rocker flanges by clamping them like real frame machines do. The ones I made will be set up for my FC as well. They bolt on so I can change them out. I'll be making some to hold the suspension points as I rebuild the front of the car. They bolt through some 3/8" thick pads I welded on the strategic locations, then drilled and tapped them.

It was a little too cold to finish the painting but when thats done the car goes on it this week.

 

That thing's a beast, nice looking MIG welds.

I would think about gusseting those legs. Sometimes you roll over something unforseen, like a cord or a bolt or a washer, and it either causes the things to flex or vibrate lightly.

Show pics of the car when you get it on there!

 

I had visions of a skateboard hitting a stone and stopping when you mentioned the leg issue.

I was worried about the same thing as I built it. After I had it on the ground I jumped on it and tried to shimmy it back and forth and it moved very little. The legs skidded around more than they flexed. I have some steel that I can add to it later if needed but I was thinking about crawling all over under the car and I didn't want to squeeze through a monkey puzzle to weld.

I'll see how the legs move with the car on it and then decide. It won't be used to keep the project mobile in the shop, just for start and finish moves. If I post a pic with the car mounted on the rack, laying on its side, you know I f*cked up!

 

Good point. You will need to get under the car. It is always something you can add later.

 

Well I got the car up on the rack. I couldn't get to the shop at all in the last week because my daughter came back from my wife's brother's house with MRSA. She gets an extra long winter break and I get to stay at home with her. She's feeling much better and the wife turned me loose this afternoon.

I dropped all the moving parts off the car while it was on the lift and then lowered the chassis onto the jig. Everything fit like a glove(I amaze myself sometimes...).

The next concern was moving the whole thing into place. As I got the lift arms out of the way I leaned on the car and the thing tried to roll away! It moved easier than my race car on Go-Jacks and I can roll it with two fingers.

So I spin it around, roll it into the corner, and then try to figure out how to remove the castors. The jig is too tall for a floor jack alone but with some stuff laying around the shop I got all 6 castors off and didn't let the car fall over.

This is the chassis I had shipped in from Cali. (teddyrx2's car)The front isn't as straight as it looks, its been hit on the pass side and the rail is down about 1/2". On top of that, the entire tunnel and most of the firewall has been cut out. It was a drag racer's project before and I think he had some serious plans for it. I'll be grafting my front end to this chassis and replacing the left rear quarter totally.

 

this is the car......

 

Yes, this is the car from the famous "I sold my car to make things right" thread.

Its going to be mated to my duece that spent its life as a race car. First in IMSA in the RS class and then later in SCCA in B Sedan and GT3.