laser scale pad leveler info wanted

[Josh Pitt]

I just got a set of scales, and want to buy a laser leveler for the pads.

I see 3 systems that I am aware of.
any recommendations on which one to get, or to stay away from?


1) LongAcre Laser Leveling System
http://www.saferacer.com/longacre-la...?productid=484

2)ART Granite & Laser Leveler
http://www.advancedracing.com/laser_scale_leveler.php

3) Intercomp Intercomp Laser Level/Alignment System
http://www.pegasusautoracing.com/pro...asp?RecID=2525

also, if anyone has one of these items that is used and want to sell it, please send me a PM, and let me know what you have, and how much you want for it.

thanks in advance
Josh

[Peter Horvath]

The laser level is kind of cool, Josh, but you're shooting the laser all over the place and trying to find the laser beam across your scale pads.
You're going to lay string across the front pads and across the rear pads to set ride height. So get that bubble level from McMaster that hangs on string, and you're done.
You can use the laser to set front-to-back pad height if you want. I absolutely have to use a laser to set rear ride height but that's it.
Good luck.

[Purple Frog]

I use lasers for some of my construction work. Buyer beware. Some laser levels come with a note that they may vary by +/- 5 degrees. That is way too inaccurate for a race car setup. So read all fine print.

A good quality long level is a great solution. A water level with about 15' of tubing can also be an easy way.

[-pru-]

Received as gift a few years ago, here is what I use in my garage:

Craftsman LaserTrac Level



Looks like Intercomp re-badged the Sears unit and include a few targets.



The only issue I have with the above unit is initial leveling of laser. It has two built in bubble levels (offset 90 degrees) which get you fairly close, but I always check/re-adjust the beam using two down range levels (a 4' bubble and 2' bubble/digital).

I wonder if they sell the targets individually as those look nice. I use various items (usually sockets) marked to a known height as my references. Then again, it's hard to agrue with my investment (i.e $0) or replacement cost (~$40) vs. Intercomp (~$250).

[-pru-]

Some laser levels come with a note that they may vary by +/- 5 degrees. That is way too inaccurate for a race car setup. So read all fine print.

Agree 100%. The long range +/- variance of the Craftsman unit is why I started checking my initial leveling of the laser with down range bubble levels (offset at 90 degrees). In addition, I find the quality of the beam starts to get fuzzy after about 10'... Again, it works well enough to get you close, but it's certainly not up to F1 standards!

[stonebridge20]

Don't waste your time and money on a lazer. Buy a set of water levels. A couple of guys used them to build a bunch of pointy buildings in some desert a really long time ago with pretty good results!
Try www.behrents.com or www.colemanmachine.com

I got my last set from one of them but can't remember which. My first set, I got from Joe Stimola 20+ years ago.

[Rick Kirchner]

biggest problem with a laser is the spot is larger than the quantity you are trying to measure, unless you get something exotic from edmund scientific.

[Paul LeCain]

Lasers aren't close enough if they cost under about $2,000.

I've used water levels, with reasonable success.

My current preference is two machinist levels (about $200). Use a cross level (90 deg.) to set each pad level and a straight machinist bubble across the pads.

I can level a set of pads in under 10 minutes.

[Bruce Allen FSCCA #82]

I use a 6 foot long level, less than $100 from Home Depot. I shim the scales by setting 1/16 inch thick linoleum floor tiles. They are permanently duct taped to my garage floor.

[carnut169]

I picked up 4 decent levels at Home depot, and 2 sets of 1-2-3 blocks. It (scaling) is more about repeatibility than absolute 100% perfection. Mark your levels so you always use them the same way, put the blocks on top of your scale pads and the levels on the blocks. Level the front platform, then the rear. Then, raise the front or back assembly to match the higher of the two. Lastly, put a level diagonally across and it should be level.

I went crazy for a while buying Starrett machinest levels (a 98 and a 199) which was crazy overkill. Also tried the water tube bubble thingy but found the 4 level (could make do with 3) to be the best.

[Josh Pitt]

thanks for all the good input.
I think i will take the $ that i was going to put into lasers, and go for some bubble levels.

[John Robinson II]

You would be better off with a length of alum I-beam, 1 set of 1-2-3 blocks and a machinist level. Everything is a compromise and more importantly repeatability. With a good enough level you will even determine your level bed is not built flat, but as long as it is the same every time it really doesnt matter.
John
PS DO NOT let any one borrow your level beam for ANYTHING!

[disquek]

What are the 1-2-3 blocks for?

Thank you!
-Kyle

[Steve Demeter]

To space the I beam up off the pads the exact same amount on both ends.

Say that your set up has structure between the pads, it might protrude ever so slightly above the pads and make it impossible to get a beam across from one to another. the 123 blocks allow you to raise the beam to make sure it touches nothing but pad.

[Roland V. Johnson]

The same size Craftsman sockets are amazingly consistant in size. They work well as blocks to raise the I beams.

[Peter Horvath]

The same size Craftsman sockets are amazingly consistant in size. They work well as blocks to raise the I beams.

This is what I like about racers. Smart and resourceful.

[Rick Iverson]

Here's what I use. And yes, that reads 0.0005"/ft

[swiftdrivr]

What are 1-2-3 blocks?

[BWC54]

What are 1-2-3 blocks?

Blocks of steel that are machined accurately to 1" X 2" x 3"

[Bruce Allen FSCCA #82]

Here's what I use. And yes, that reads 0.0005"/ft

That is what I need as most of the tracks I race are that level.

[Paul LeCain]

Here's what I use. And yes, that reads 0.0005"/ft

On my car, moving the front pushrod adjuster 1/4 turn moves 12-15 pounds around. The length change in that pushrod with 1/4 turn is .0917". The wheel moves about 40% of that, or about .036". The driver can feel that change.

It seems to me that you want to be as close to flat as you can reasonably get.

I use a similar Starrett machinists level.

[Evl]

On my car, moving the front pushrod adjuster 1/4 turn moves 12-15 pounds around. The length change in that pushrod with 1/4 turn is .0917". The wheel moves about 40% of that, or about .036". The driver can feel that change.

This brings up an interesting point: It seems to me that the smart thing to do would be to not have left and right hand threads of the same TPI on the pushrod, but have both be right hand threads, one coarse, one fine. Then you'd be able to get a lot finer adjustment based on the difference in thread pitches.

[Daryl DeArman]

Alright...I have to ask.

Seeing as how some seem to be extremely concerned about the levelness of their setup platform while I've been in the "repeatability" camp most of my racing career.

How much deflection or compression of the load cells in the scale itself? In other words if a 325# corner weight makes the scale .010" shorter or your lineoleum shims compress or whatever...your platform is no longer level....anyone ever bothered to measure?

[Paul LeCain]

This brings up an interesting point: It seems to me that the smart thing to do would be to not have left and right hand threads of the same TPI on the pushrod, but have both be right hand threads, one coarse, one fine. Then you'd be able to get a lot finer adjustment based on the difference in thread pitches.

That's the way the rear pushrod is - both right hand, one coarse, one fine.

To complicate matters, there's a third one, left handed, along with three jam nuts. Think about it.

[Mike B]

How desirable would a push rod with shims (ala F1) be?

[WhatsThatnoise]

I use a transit (optical)

Like a rifle scope w/ a level

The resolution seems to be +/- 1/64"

Haven't verified the accuracy but it is repeatable.

Then I check 'flatness' w/ a string.

[teamwisconsin]

How desirable would a push rod with shims (ala F1) be?

this seems like a great idea, and for making exact repeatable changes, it is. but its a p.i.t.a. to have to unload the pushrod to get the shims in and out to change the heights while on the pad. and most of our brazed together formula car tube frames aren't really as precise as a modern f1 carbon tub, i feel better off with the adjustability of a turnbuckle on my pushrods.