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GWL
10-11-2020, 09:20 AM
First, I had to level the playing field so I used my laser level to set the car horizontal front to back and right to left. I used wood and metal to have a level surface to set the car onto.
https://live.staticflickr.com/65535/50450842967_c3180a54c4_z.jpg (https://flic.kr/p/2jSaKW8)IMG_9304 (https://flic.kr/p/2jSaKW8) by George Ligon (https://www.flickr.com/photos/161275344@N04/), on Flickr

I wanted to set toe-in first, although I know that is not the proper order but my car was scrubbing so much it was hard to roll it in and out of the garage.

Similar to the toe-in plates you can buy, I made my own that would reference to the wheel instead of the tire. I could not rationalize setting toe-in to the tire knowing that 1/32” (1/16” total) is a darn small measurement. A lot of builders do measure to the tire though and that is what those toe plates are made to do. Here is a top view of my plates, referencing to the wheel, see another view in a picture below. I made up small measurement pieces to make sure my plate was square to the wheel, as they are adjustable.
https://live.staticflickr.com/65535/50449974913_b9821b0d0e_z.jpg (https://flic.kr/p/2jS6iTF)IMG_9321 (https://flic.kr/p/2jS6iTF) by George Ligon (https://www.flickr.com/photos/161275344@N04/), on Flickr

I thought I would be using this method, measuring from wheel to wheel as the toe plates are measured, to set my toe-in but soon realized it was going to be difficult to set the wheels square to the chassis. So, I went to the string method and used my new toe plates in combination with the strings.

As I was setting up the strings, my first attempt at doing so, I soon realized how hard it was going to be to set it up accurately and how hard it would be to make this set up repeatable. Just the string alone is 1/16” thick and I needed to measure to half that measurement for toe-in. Making repeated measurements to the chassis, front and back was very time consuming and hard on this old guys back. I wanted to make this process easier and wanted to be able to do it with the body on at a later date. That is when I came up with my chassis string jigs. I am also a woodworker, having taught woodworking and metalworking in high school and have made a bunch of jigs in the past. Following are a few shots of those jigs. I had to adapt one to fit around my fuel lines in the rear. These jigs made the set fast and simple. When setting up you just had to make the strings touch the jigs in the same way front and back and the same way each time I set them up.
https://live.staticflickr.com/65535/50449975288_0f02bb108d_z.jpg (https://flic.kr/p/2jS6j19)IMG_9278 (https://flic.kr/p/2jS6j19) by George Ligon (https://www.flickr.com/photos/161275344@N04/), on Flickr

https://live.staticflickr.com/65535/50450672866_3c78006a02_z.jpg (https://flic.kr/p/2jS9Tnm)IMG_9281 (https://flic.kr/p/2jS9Tnm) by George Ligon (https://www.flickr.com/photos/161275344@N04/), on Flickr

Adapted this jig to avoid the fuel lines
https://live.staticflickr.com/65535/50450672811_67101a03ab_z.jpg (https://flic.kr/p/2jS9Tmp)IMG_9284 (https://flic.kr/p/2jS9Tmp) by George Ligon (https://www.flickr.com/photos/161275344@N04/), on Flickr

I have not seen this anywhere else and maybe I’m missing something because this is the first time I’ve ever done an alignment. Please, if I’m missing something here, let me know.

Here, I’m working on both the front and rear toe-in.
https://live.staticflickr.com/65535/50450672706_0acec50e3c_z.jpg (https://flic.kr/p/2jS9TjA)IMG_9319 (https://flic.kr/p/2jS9TjA) by George Ligon (https://www.flickr.com/photos/161275344@N04/), on Flickr

Another shot of my toe plates using the strings and double checking by measuring wheel to wheel for total toe-in. This is the rear tire of my IRS set up.
https://live.staticflickr.com/65535/50450672241_36655f3228_z.jpg (https://flic.kr/p/2jS9Tbz)IMG_9340 (https://flic.kr/p/2jS9Tbz) by George Ligon (https://www.flickr.com/photos/161275344@N04/), on Flickr

For camber and caster, I used a Longacre set I bought from another forum member several years ago. Turns out the digital level did not work so I had to buy and a newer version and completed the alignment using that set up.

I soon realized that the camber and caster settings work together. So, I’d set camber then caster, then did them again. I’d get closer and closer each time I worked the two until both were within specifications. Note, too the turn plates I used, I got these from Ralph Button and they worked great. They are from Harbor Freight and would let the car settle as they ride on ball bearings and made turning easy, accurate and repeatable. But they are darned heavy and hard to pick up and move around. Thank goodness you don’t have to do it often, if ever again.

This is the end of the journey, for now. The car tracks well up to 40 or 50 for a short distance but I wouldn’t be doing a full road test until I get the body on, which will happen later in the coming week. Depending on how it feels, I may or may not have it checked out at a professional alignment shop.

Please don’t hesitate to respond and critique my process here, as I said, this is my first alignment.

George

mike223
10-11-2020, 02:37 PM
I thought I would be using this method, measuring from wheel to wheel as the toe plates are measured, to set my toe-in but soon realized it was going to be difficult to set the wheels square to the chassis. So, I went to the string method and used my new toe plates in combination with the strings.

As I was setting up the strings, my first attempt at doing so, I soon realized how hard it was going to be to set it up accurately and how hard it would be to make this set up repeatable.




I often say that establishing what exactly "straight" was on the IRS - was the hardest part of my entire assembly (and for the record - I assembled the 393w, went completely through the T56, and put new gears and a TrueTrac differential in the rearend)...

Most of the (would be) useful points on the frame back there are on diagonals.

I finally ended up marking the center of the frame (multiple places front to rear) and worked from there with strings + laser level.


Looks like you did a great job George - far as I know that's exactly what it takes if you want to know it's done "right".

CraigS
10-12-2020, 08:07 AM
You and I have some similar techniques. This is my tool for looking at the rear thrust line. There is an identical scale on the other side so I can use it on both sides of the car. I push it in just behind the front tire till the upright piece hits the round frame tube.
https://live.staticflickr.com/871/41458729111_5b428592af_z.jpg (https://flic.kr/p/26ayPLk)IMG_20170419_160800746 (https://flic.kr/p/26ayPLk) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
I cut a piece of 1x4 so it fits on the wheel lip so I have something to hold the laser against. You can see the dot near the top of the scale.
https://live.staticflickr.com/1750/42669853081_ed36d72996_z.jpg (https://flic.kr/p/281A9J6)IMG_20170419_160647869 (https://flic.kr/p/281A9J6) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
My front tool to wheel adapter is made from a piece of coated shelving.
https://live.staticflickr.com/1755/42572430562_42b43fcc4b.jpg (https://flic.kr/p/27RYQpu)Align tool (https://flic.kr/p/27RYQpu) by craig stuard (https://www.flickr.com/photos/152454123@N04/), on Flickr
Way back when I spent a day w/ a bunch of cobra buddies doing alignments and the guy who set it up used the strings. I hated it like you. To much eyeball measuring just to set the strings and then more to use them. And setting them up again for every adjustment-yuck. I really like your tools as they reduce the string setup by a lot.

emoore924
10-12-2020, 12:23 PM
We use monofilament fishing line at the track when we're setting up the car. Even keep it on a fishing reel :)