Anyone have experience in making a jig?

Chris_Hamilton

Chris_Hamilton

Trying to be the best me, I can be
Like title says just looking for tips to make a "jig" of sorts to help with posistioning replacement panels correctly. I've got a rusty POS 71 Nissan 240Z that the owner abandoned after I looked it over and told him how much rust was in the car and what it would take to fix it. I don't want to scrap the car though and being that I have a rust free 72 240z to take measurements and make patterns off of, I am going to restore it. I hate seeing anything old junked. Anyone have any experience setting up a "jig" (probably not technically the correct term) to help position the replacement panels correctly? I have a pretty good idea of what I think I'm going to do but I would like any advice if any of you have made something similar.
What I'm thinking is, full length of the car, 2 lengths of box tubing, with cross pieces of tubing along the length of the vehicle at various points, and using rod or small tubing attached to the cross pieces to set correct position height etc at various points. Main thing that is tripping me up is setting the reference height. My thinking is get the "jig" level in both planes and get the car level in both planes (car that I'm taking measurement off of) and that will transfer to the other car correctly provided I level the jig and and car when setting it up on the car I'm repairing. Being that I am working off a concrete floor and not a square level frame machine I have to account for the difference in the floor. I think leveling everything before setting up the measurements on the good car and then leveling everything the same way on the repair car will allow the measurements to transfer correctly.
Oh and before anyone asks, yes I will be bracing the car as best I can, before cutting anything.
Hope this isn't too muddled. Anyone have any thoughts?

Edit: To be clear when I say replacement panels I mean structural panels like the inner rockers and frame rails.
 
Here is my first gen Camaro body jig. It picks up the four subframe mounts and the rear frame rails at both ends. The square tube in the side is for an outrigger to pick up
AD8639DF-9A72-4ED2-8876-B3EEE8FC6434.jpeg
B9414112-2F48-47DA-A9A3-385DE3AEBD66.jpeg

the rocker. The square tube at the front is for a frame that extends up and picks up the firewall fender mount holes.

Don
 
Also look up photos of the Celette jig system for ideas. Of course that is a really bulletproof app that's designed to withstand pulling forces, but the general concept might be idea-provoking. You can just about build a car from scratch with a Celette.
 
I'm familar with a Celette as I worked with one for several years doing Mercedes and BMW's. They are really nice when you have all the neccesary fixtures. Slow but nice. :)
I would like to build a table and will someday, when I have space and time, but what I am talking about is essentially like a fixtured jig that will provide reference points and a base as I have nothing good to measure off of when installing the new inner rockers. It will allow me to posistion the panels. Working from the center section out, and both inner and outer rockers on both sides need replacement along with adjacent rust to those panels. I've pretty much worked out how I'm going to do it with the exception of creating a "datum" so that when I place my "jig" under the good car and make reference points (fixtures of a sort) how to ensure that I am able to accurately transfer that when palcing the jig under the car to be repaired. I think if I level the jig in both planes (side to side and front to back) and do the same with the good car, then as long as I do the same with the car being repaired both the jig and the car then the measurements will accurately transfer even if their is a height difference between the two cars. I simply would compensate for the height difference when installing the jig on the repair car. Make sense? I'm also leaving in place the motor and suspension on the repair car until I get the center section done. Measurements off the good car are going to be with the suspension and motor in place as well. Repair car will be braced as best as I can do it before I do any cutting.
Make sense? Thoughts?
 
Based on my limited experience I would not attempt something like that with the engine, running gear, suspension etc on the car. I would take it to a bare shell with doors.

Don
 
Everything is going to change when taking the motor and suspension out. Plus my measurements are going to be off a car with motor and suspension installed. I'm approaching this the same way I would do a heavy collision repair on a unibody. Work from the center section out. I have to get the center section solid first before I attempt to jack it up or remove the suspension and motor. This car is really structurally weakened with the inner rockers being rotten at the front and the rear of the rocker. Doing that on a car with rotten inner rockers and weak ponts at the lower A and B pillars will result in it deforming and twisting. If I had a proper fixtured jig like a Cellete with factory fixtures I could do it that way, but I don't so I have to do it differently. So I have to get the center repaired on the ground as it sits. Right now doors open and close correctly and everything fits decently. I will brace the body completely before cutting and welding in the rockers, so I can lock that in. Once I get the center section strong again then I'll strip it completely and put it on a squared body cart or jig with the center section attached to the body cart. Right now the rockers are so rotten you can't bolt it or weld it to something. It's something that probably should be scrapped but I want to fix it for the experience it will give me. I know I'm crazy...but I'm also stubborn. Got a little bit of Swede in me so it's in the blood.
 
And more....

www.classiczcars.com

240z gets jiggy

Hi Guys. My name is Kent and I am a long time lurker here. I have several 240z project cars - none completed - but lots of ambition ....but that’s a story for a whole different thread probably. I started this car a few years back and, skipping to the point, I recently realized that I needed to ta...
www.classiczcars.com www.classiczcars.com

Don
 
Maybe the first jigs to make are ones that support the car at the suspension. Like if you could take the good car far enough apart to make jigs that go through all the lower control arm mounts.
 
John Long said:
Is it a convertible Chris?
Click to expand...
No Sir. It's a 1971 Datsun/Nissan 240Z. They only came in one configuration.

Thanks to everyone for the help. I'm still noodling it through how to approach it, but I think I know. Been stripping it down the last 4 days and bagggin and tagging all components. Going to be a lot of work, lot of metalshaping as replacement panels are few and far between. Most of the stuff that's out there is made by hand and doesn't really fit well. One reason I'm doing it is for the metal shaping experience I'll get doing it. Should be fun. (at least that's the attitude I'm trying to approach this with:)) I'm planning on doing a detailed build thread and share it with you all. Got my work cut out for me on this one. Only reason I'm doing it is because I have a nearly rust free one as well. (orange one in the background) I'll be able to make patterns for all the panels I need off of it.

Couple of pics:eek:

Doesn't look too bad.
DSCN0654.JPG


Both inner rockers are rotten at the ends......and it's been "repaired" before.:mad:
DSCN0671.JPG



Uh Oh!!!o_O Suprisingly the inner pillar where the door dolts up is still good. Door wasn't sagging, but the rot extends into the lower part of the cowl and even a bit of the firewall.

DSCN0662.JPG
 
When I built my '53 convertible, I left the doors on the car until I had the rockers and quarters installed. That way I could keep an eye on the door gaps and make sure nothing was moving.

On a convertible, without a roof panel to deal with, it was a simple thing to keep the cowl adjusted. As long as the door gaps remained correct, I kmew I was in good shape. I did not cross brace the car until I was ready to take it off the frame and put it on the rotissorie. It really worked out well.
 
3-2-19 628.jpg3-2-19 547.jpgI thought I had a better picture of my support jig but these pics are the best I could find. The frame work is 3x3 tube steel, adjustable cross braces with casters. We had to replace the frame rails and trunk floor on the cuda in these pictures. I was also able to mount the whole rig on my rotisserie too. I've used this rig on many different cars. Each time I make my mounts to match the car. It will flex a little, so I'm careful to keep it on level floor while I'm measuring and welding. ~BOB
 
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