Easy laser alignment method - Page 2

69 911s · 04-30-2003, 08:14 PM

Sorry guys but you're not getting an accurate alignment this way. If you have ever used an alignment rack (I have) you would have seen that when you remove the locks on the plates that most front wheels move a fair amount because the surface tension binds them into an artificial position. There is a reason that proper alignment requires so much expensive equipment, and it isn't to keep us DIY people from paying a shop for the service. This one truly requires accurate equipment.

logician · 09:05 PM

Hi 69911s,

> Sorry guys but you're not getting an accurate alignment this
> way. If you have ever used an alignment rack (I have) you
> would have seen that when you remove the locks on the
> plates that most front wheels move a fair amount because
> the surface tension binds them into an artificial position.

Actually, we haven't talked so much about how to perform the alignment. What has been mostly discussed his is only how to measure it. I think the methods that have been discussed are very accurate for measurement.

But you rightly point out that the suspension will bind when adjustments are made, and so you have to do something to relieve the pressure when you make an adjustment. Otherwise the measurement will be different after the pressure has been released. Zeke was also getting at that same point in his posting.

> There
> is a reason that proper alignment requires so much expensive
> equipment, and it isn't to keep us DIY people from paying a
> shop for the service. This one truly requires accurate
> equipment.

I don't agree with you that the only way to do alignments is with expensive equipment. Some of the best alignments are done with the inexpensive string method. One of the more clever string techniques that I've seen is the Smart Racing "Smart Strings":

> http://www.smartracingproducts.com/ProdCat/AlSuTool/alsutools.htm

This is a string alignment jig that attaches to your car. Rather than have an expensive alignment stand, all you do to relieve the pressure is roll your car around. Heck, you can drive it around the paddoc and the jig stays aligned! Actually, it seems like driving the car would leave the suspension in a more accurate state than those sliding plate things in an expensive alignment rack.

In the case of the laser method, you do need to roll the car around after you've made an adjustment and recheck it. For DIY, that probably means some iteration compared to using your nice alignment stand. But I think the end result can be just as accurate, maybe more.

-Juan

dickster · 04-30-2003, 11:29 PM

juan

is the string tool clamped to the car? it looks as though it just "hooks" on the pics.

anyone used the smartcamber tool and strings??

i am thinking that all i would need then is corner weight scales. all in around £600. thats not much more than a full shop job.

logician · 05-01-2003, 12:13 AM

Hi Dickster,

> is the string tool clamped to the car? it looks as though it
> just "hooks" on the pics.

I don't know how it is secured. But I have seen Rich Walton driving his Smart Strings rigged race car around the paddoc, so it must be fastened reasonably well.

> anyone used the smartcamber tool and strings??

I can't remember which team it was, but one of the Porsche teams at ALMS last summer was using the Smart Strings setup when I visited their pits.

Regarding Smart Camber, you don't really need the whole tool. All you need is the SmartLevel part. I bought a SmartLevel from SRP, and just put it up against the center cap hole. It's just as accurate, and much simpler.

> i am thinking that all i would need then is corner weight scales.
> all in around £600. thats not much more than a full shop job.

At least around San Francisco, I think the scales plus Smart Strings would be two or three times the cost of a full alignment and corner balance. Alignment, ride height, and corner balance would cost around $500-$600. A set of Longacre scales are around $1000, and the Smart Strings are around $400. Also, in addtion to scales, you really need some ramps to drive up to the scales. I don't think it would be very cost effective. On the other hand, your own setup would provide hours of entertainment... And you would become very popular with your Porsche buddies!

-Juan

dickster · 05-01-2003, 12:35 AM

juan,

the cheap digital scales here are around £850, but i was thinking of the "lever" type (one corner at a time). not as accurate (?) but far cheaper (around £200) and ok for my modest needs!!

btw- full alignment etc here is about £500 (US$750).

logician · 05-01-2003, 01:37 AM

Hi Dickster,

> the cheap digital scales here are around £850, but i was
> thinking of the "lever" type (one corner at a time). not as
> accurate (?) but far cheaper (around £200) and ok for my
> modest needs!!

That's a good point -- you really only need two scales. Time to throw an alignment party for all your friends!

> btw- full alignment etc here is about £500 (US$750).

Yea, that's getting up there.

-Juan

kwikt 911 · kwikt 911's Garage

When I perform my own alignment I have my car sitting on four sets of12"x12" pads of sheet metal with a thin layer of grease between them . Stop Signs work great. Then I roll the car on them, do all my adjusting, and Presto, cheap turn tables.

Kevin
72 911T/E

fredmeister · fredmeister's Garage

Check out Rugles scales for cheap corner weight equipment I don't own a pair yet, but am seriously considering buying them. $420 US and seems pretty accurate providing the set up is done carefully on a very level floor. By some 12 by 2 boards as drive up ramps from the lumber yard and you are all set.
I have the Smart Camber tool and have found that obtaining a repeatable camber measurement very difficult. Don't know if the concrete floor in my garage can effect it +/-0.5 degrees per wheel when I roll the car back and forth about 12 inches or so to take readings from different positions in the garage. Or maybe I wasn't calibrating the gage properly. The instructions are a little confusing if you ask me. I have read them several times and still am a little worried by the variance I found in my readings. My garage floor is not in any way resembling the surface of the moon, in fact it is very flat and level in my opinion.
Anyone else chime in with their experience using the Smart Camber tool?

dickster · 05-01-2003, 11:22 PM

fredmeister

interesting 'cause the sales pitch says you dont need a level surface!

Early_S_Man · 05-02-2003, 01:32 AM

Great work, so far, Juan!!!

I mhave been collecting a few bits to do it myself ... for a couple of years now. A nice eBay steal ($60) military surplus Helium-Neon laser module with twin output beams eliminates the need to set up your two laser 'jig' ... and a 1/4" thick glass 4" x 4" front-surface mirror salvaged from a surplus projection TV lens box ($8.95) ...

Kevin,

Just HOW do you acquire EIGHT stop signs LEGALLY???

KTL · 05-02-2003, 11:12 AM

Quote:

Originally posted by Early_S_Man
Just HOW do you acquire EIGHT stop signs LEGALLY???

Go to your local Public Works dept. and ask them for the old, faded signs they've taken down recently. Do that in a handful of towns and you could round up eight signs in no time!!

The town I work for replaces the signs quite frequently and the old ones are discarded. A whoooooooole lot of employees have all sorts of signage in their personal garages..............