String Alignment

[galaxy]

I couldn’t recall which thread it was, but in one of the self/string alignment threads, I know a few comments were made about how unbelievable it was that strings are more accurate and how unlikely it was that top end race teams use strings to do alignments. Well….

Sponsored

 

[TeeLew]

How about that.

 

[WItoTX]

OP, cool photos!

Someone said using strings was unbelievable? LOL...I took my car in to get a quick alignment done before an event, and the laser system would move as the wind blew. The shop often works on track cars, and they got it pretty close, but after the event I wen't home and put everything on strings, and needless to say, there was some adjustments that had to be made.

What is better, is even the shop said look, it would be fine for normal daily driving, but you will want to run strings to get it exactly where you want it. That is what we do with the track cars we align anyways. Our alignment machine will never get you there.

 

[boB]

It's just geometry/trigonometry and a straight reference line. Taut strings are pretty straight and it isn't difficult to get 1/32" accuracy. With an inexpensive laser I can get to 1/16" and that is good enough.

 

[TeeLew]

It's just geometry/trigonometry and a straight reference line. Taut strings are pretty straight and it isn't difficult to get 1/32" accuracy. With an inexpensive laser I can get to 1/16" and that is good enough.

I can get +/- 2mm by eye. That's not remotely good enough. Before you try to call bullshit, I've done it because it was the only option I had, and it's happened more than once.

Strings are as good as the person using them. The IndyCar guys will work in 0.25mm increments or tighter.

 

[Dana Pants]

Runout of perfectly good wheels is usually at least a mm.

 

[boB]

I can get +/- 2mm by eye. That's not remotely good enough. Before you try to call bullshit, I've done it because it was the only option I had, and it's happened more than once.

Strings are as good as the person using them. The IndyCar guys will work in 0.25mm increments or tighter.

I was not clear, that is 1/16" over my standard measuring distance of 57-1/2" which as we all know from trigonometry is where 1" deflection equals 1 degree. ;) So I am working to 1/16 degree which is about 3x more accurate than Ford's specifications.

As for detecting +/- 2 mm by eye, sounds reasonable, you won't get a bullshit call out of me. If that is over the 19" of the wheel, no, that is not good enough.

 

[TeeLew]

Runout of perfectly good wheels is usually at least a mm.

Which is why you'll notice that most of the IndyCar teams will have a wheelset which is specifically meant for setups and never ran on track. The lip of the wheel will have been machined perfectly flat to eliminate the issue of runout. Let's also be fair, the wheels they use have a little tighter tolerances than most.

 

[TeeLew]

As for detecting +/- 2 mm by eye, sounds reasonable, you won't get a bullshit call out of me. If that is over the 19" of the wheel, no, that is not good enough.

OK, I thought you were +/- 1/16" on the rim.

 

[Buldawg76]

The naked eye can detect 0.015" difference in distances, ask any master machinist.

BD

 

[NeverSatisfied]

I’ve checked my work with lasers and I’m pretty darn accurate with strings on trash bag slip plates

 

[GTP]

Love your DIY string setup. Maybe more closeup photos and how you attached the rear jig?

I was interested in smart strings except for the price.

 

[kz]

Love your DIY string setup. Maybe more closeup photos and how you attached the rear jig?

I was interested in smart strings except for the price.

https://calipergarage.com/products/basic-string-alignment-kit-6tg32

Check this out - not quite Smart Strings but not exactly a DYI setup (almost though) - just makes few things easier.

 

[Roadsign]

I’ve checked my work with lasers and I’m pretty darn accurate with strings on trash bag slip plates

So the trash bags work decent? I've always used abs sheet material.

 

[NeverSatisfied]

you have to be careful they work so well. You can push the car right off them.

Sponsored