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Old 02-28-2006, 12:57 PM   #1
spmclaugh
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Default DIY Alignment Method

Hey. I just thought that I would stir up some more discussion on DIY alignment methods. This has been talked about in the "Alignment Thread" (sticky) and a couple others, but I'm interested in some alternative methods.

CAMBER:

I just bought one of these:

http://www.emachinetool.com/tooling/...383&Source=PTC

http://www.smartracingproducts.com/alignment.htm (bottom)

off of eBay (got it for a STEAL), it's the SPI TRONIC Digital Level PRO 360. It measures 0.1 degrees digitally. The upgraded 3600 model measures 0.01 degrees, but I really don't think that's necessary for my purposes (camber measurement). I'm going to get a 16" (maybe a tiny bit less) board/bar with an "L" in it, and mount this on the horizontal part. Then add a couple neodymium magnets to the ends. I'll probably bring out an upright standing mirror so I can see everything while I'm under the car - the ultimate in laziness and convenience.

Before I found this at a cheap price, I was just going to use the "L" board/bar as before, but mount two lasers on the horizontal part: One regular straight-shooting laser, and one of those auto-leveling lasers you see at the hardware stores nowadays. They automatically re-orient the laser to level it, provided the level is already within like 5 degrees of level. Then put a big piece of posterboard 20 feet away, measure the distance between the two dots, and use some basic trig.

The main reason I didn't do that 2nd method was that I don't like the focus and beam width of most contractor-grade lasers, and sometimes they're hard to see in daylight. Not that I don't work at night half the time anyway... but that's another story. I thought about buying two small-ish lab-grade lasers and putting one of them on some kind of balancing rig, but I didn't feel like getting frustrated trying to work out the kinks.

A third method, which I would do if I didn't already buy the digital level, would be to get just one lab-grade laser and place it 20 feet from the car on an adjustable platform. Put a machinist's level (I guess construction grade might work) on the platform too, and adjust the platform until it's level. Then, on the car side, put the "L" brace I described earlier. Except this time, just put a mirror on the horizontal side. The laser beam will travel to the mirror, deflect, and go back towards the laser, making an isosceles triangle. So you can measure HALF the height change in the beam, then right angle trig.

Another cool method, which I already posted in another thread, is what this guy did:
http://www.quadesl.com/miata_alignment.shtml

I'll definitely use the tubing w/ water to level my car before doing camber. If I had the equipment, I'd love to make the camber tool he made. With the equipment *I* have available, if I tried to build that, there's no way I would trust it to 0.01 degrees, like he can.

Also, a traditional "L" arm with a protractor on it, measuring 0 at the top, with a bob+string wouldn't really be so bad. But the "radius" of the protractor should be equal to the string length. It would be easier to just make your own "protractor" by attaching a piece of posterboard in the same plane as the "L" and drawing a circle the same diameter as the length of the string. Then draw tick marks for degrees. I'd do this all on the computer and print it out on a wide format printer. Or, since you only need a range of about 5 degrees, you could just print out the bottom portion of the circle, fit it only regular letter sized paper, and only attach that part of the "circle". You could definitely get 0.1 degrees with a 16" rim.

We don't have adjustable front caster on stock Impreza's, but if anyone has aftermarket kits that let them do it, all these setups would let you figure out caster by calculating camber at 20 degrees (that's the standard, but I guess you could do whatever angle you wanted if you had the calibration data).

TOE AND THRUST ANGLE:

I'm still trying to decide what to do for toe & thrust angle. There are lots of quick tape-measure methods for NET toe, but thrust angle is important to me. I've been trying to build a system similar to the string setup, but using lasers instead of strings. The problem is that if I do it myself with optical grade equipment (mirrors, beam splitters, lenses etc), calibration becomes a pain, and any time savings goes down the drain. If I use contractor grade equipment, which is cheap and readily available, I lose accuracy. There's probably a third choice, professional surveyer grade equipment, but I'm sure the price would hold me back. The issue is that, given you have one line (formed by 2 points on the suspension which you pick), you need to create a 2nd line parallel to that first line. It's really a pretty easy idea conceptually, but doing it quickly and accurately is harder. I could do it quick, or I could do it accurately, but I'm trying to come up with something neat which does both.

The method I am thinking of now is using two "dial indicator holders" with plumb-bobs, and placing them at two points underneath the car which form a line which is parallel to the centerline of the car. Note, contrary to the Miata page I posted earlier, you DO NOT need to ever find the centerline of the car, just something parallel to it. Picking 4 points, then finding the center of each pair, just adds time and introduces more error. Two points will do. Anyway, place those stands with plumb bobs underneath the points you pick. Then take a long finely calibrated ruler (machinist's ?) or a metal/wooden beam with an ruler attached to it. Also get a right-angle laser square. Hook the laser square so that one beam shines down the ruler parallel to it. Either smoke a cigarette and look at the beam, or put semi-transparent targets at the same distance from the ruler along its length. Now move the whole ruler until the SECOND beam goes through both plumb-bob lines. You should be able to tell when it illuminates the lines. If you can't, use a different kind of string/fishing line, or dip the line in some kind of paint. Now you have a long ruler that is perpendicular to the centerline of your car. Now get a regular el-cheapo laser laser. You're not even going to be using the bubble level, just the laser. So don't worry if the bubble is junky. Get one where the length of the level is about the diameter of your rim. Place it horizontally along your rim, with the laser pointing at the long ruler. I think you can see where this is going... You can measure the distance from the laser level to the ruler. You just need to know where the laser would hit the ruler at zero degrees toe. You COULD figure this out by simply measuring the distance from the level to the line underneath the suspension.

But a more accurate way would be to use TWO long rulers at each end of the car. Make sure each of them is perpendicular to the line underneath the car. And get a laser level that has lasers coming out both ends. Or just use a regular one and flip it around as needed. Measure the DIFFERENCE in readings on each ruler. Find half this number, and use standard right angle trig...

Or, don't even use a laser level on the rim. Just use a 2x4. Using a Sharpie market, mark two targets. On the long ruler, put a second 90 degree laser square that can slide along the ruler. Move it back and forth until you hit the first target, then the 2nd. Measure the difference, if any, between the distances on the ruler. This method requires a very fine laser, because near zero toe, the beam would "stretch" along the 2x4 and be hard to read. I would not recommend this method.

As a hybrid method, you could use regular string outside of the car, with the "parallel line" underneath the car being laser-based... There are plenty of accurate string-based tools, like the "Dream Stick" ( http://www.advancedracing.com/dream_...ring_gauge.php ). You could EASILY make this DIY style with plenty of accuracy... But it's pretty cheap anyways.

I'll draw some diagrams and post pics later.
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Old 02-28-2006, 01:29 PM   #2
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Wirelessly posted (Treo 600: Mozilla/4.0 (compatible; MSIE 6.0; Windows 95; PalmSource; Blazer 3.0) 16;160x160)

WOW!
How much time and money have you invested in all of this so far?
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Old 02-28-2006, 01:54 PM   #3
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Quote:
Originally Posted by chrisarella
Wirelessly posted (Treo 600: Mozilla/4.0 (compatible; MSIE 6.0; Windows 95; PalmSource; Blazer 3.0) 16;160x160)

WOW!
How much time and money have you invested in all of this so far?
Got the digital level for $50 shipped. Could have bought a plain old (pen) laser and used the other method. Bought some plastic tubing to use alongside some scrap wood and ripped up phone book to level my car (I don't have a garage or really level area). That's all I need for camber.

Still deciding on what to do for toe and thrust angle, but I bet I can do it cheap too. Never going to an alignment shop again

EDIT: Can't say I've been so frugal on the time part...
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Old 02-28-2006, 02:07 PM   #4
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One quick but not quite as accurate method for toe and thrust:

Start by zeroing out your steering wheel (visually) if you need to (adjust tie rod endlinks on front wheels). Then set toe using the dual tape measure method. Then get a Stanley Single Point Torpedo Laser Kit or similar tripod-mounted laser for under $40 ( http://www.mytoolstore.com/stanley/laserdot.html ).

Make sure your front wheels are straight ahead and have zero toe. If you want to add toe later, you can do it afterwards. Get a 2x4 of length equal to your rim diameter, and two small metal corner braces ("L" braces). Using a small metal drill bit, drill two pinholes, one in each brace, centered and at the same height. Attach the braces to the 2x4. This will be for the front wheel. Build a second setup like this for the rear wheel, but use a 5mm spacer to account for the track width difference.

Get some helpers or neodymium magnets, and hold the 2x4's horizontally against the rims. Shine the laser through the pinholes in the front, then through the rear. If you pick the hole diameter just right, you should be able to see the laser on the edges all around the hole. Or smoke a cigarette, or stick your finger in the beam, whatever. If your 2x4's aren't perfectly horizontal, use a level. The Stanley device has one built in. And your car should already be on a flat surface, which you need to do camber anyways. So everything should line up very easily.
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Old 02-28-2006, 03:17 PM   #5
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I'm not as accurate, so I just maxed out the negative camber and set the toe with two plates and a tape measure.

I am interested in a cheap/quick way to measure camber though, for when the camber plates go back on the car in a month or two. Have you used that water method to level the car? Are there any other simple ways to level it? After it's level, I'll just hang a plumb from the rafters and use trig to figure out the angle.
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Old 02-28-2006, 03:39 PM   #6
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Quote:
Originally Posted by Scooby Freak
I'm not as accurate, so I just maxed out the negative camber and set the toe with two plates and a tape measure.

I am interested in a cheap/quick way to measure camber though, for when the camber plates go back on the car in a month or two. Have you used that water method to level the car? Are there any other simple ways to level it? After it's level, I'll just hang a plumb from the rafters and use trig to figure out the angle.
I'm about to try out the water method (might use some glycol anti-freeze!), I'm just waiting for my digital level / inclinometer to get here. Should be here before the end of the week. I'm sure it'll work, the principle is rock solid, and that guy's page shows a good way to do it. It's really an amazing idea.

As far as other ways to level it, I drew up like 5 different "platforms" I could build to try to adjust level easier. Various things involving wedges, ramps with adjustable height, bottle jacks hooked up home built platforms, etc... In the end, I'm just going to use scrap wood and other things I have lying around (phone book pages) and drive up onto the ramps. Try to avoid jacking your car up to put the shims underneath the tire. If you feel you have to, jump up and down to settle the suspension... but really try not to do that.

The plumb method works fine. You could either use a ruler and trig, or print out a to-scale protracter and read the angle directly. I think the latter method would be both quicker and more accurate. Just make a 10" or so circle in CAD, with big marks every 1 degree, and little tick marks every 1/10 of a degree. Then crop out everything except whatever fits onto a letter sized paper (the bottom portion of the circle), and print it. If you made a 10" circle, use a 10" string + bob (what matters is the distance from the suspension point to wherever you read off the protractor).

sean
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Old 02-28-2006, 10:18 PM   #7
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Hi. Had a little time to draw up and scan some diagrams. They're just hand-drawn, no CAD or anything fancy... Anyways hopefully my writing is legible, here they are:

CAMBER diagrams:







TOE / THRUST ANGLE diagrams:





"Quick Thrust Angle method" diagram:

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Old 02-28-2006, 10:52 PM   #8
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Wow. Thats a lot of work.

1) Build a little metal bracket for your camber gauge
2) Add the toe marks to it like the fancy 3 point toe gauge that you linked to
3) Use jackstands and neon fishing line to string the car
4) Do alignment
5) ????
6) Profit.

I used a bubble $30 camber gauge, tape measure, jackstands and rope to align the car for a full season.

-Tom
who you have insipired to buy the $89 smartool gauge and build his own metal bracket. The $215 smart camber gauge + their bracket was always out of my "I don't really need this but why not" pricepoint.
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Old 02-28-2006, 11:21 PM   #9
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Quote:
Originally Posted by trhoppe
Wow. Thats a lot of work.

1) Build a little metal bracket for your camber gauge
2) Add the toe marks to it like the fancy 3 point toe gauge that you linked to
3) Use jackstands and neon fishing line to string the car
4) Do alignment
5) ????
6) Profit.

I used a bubble $30 camber gauge, tape measure, jackstands and rope to align the car for a full season.

-Tom
who you have insipired to buy the $89 smartool gauge and build his own metal bracket. The $215 smart camber gauge + their bracket was always out of my "I don't really need this but why not" pricepoint.
Hmm, interesting idea. Are you suggesting building one bracket/tool for camber and toe/thrust angle? So that would be like my camber diagram #1 (L brace with digital meter) and toe diagram #3 (the one using regular string / hybrid setup)? Sounds good. If you wanted, you could even make the "arms" for toe and camber perpendicular, so the whole thing would look like an "X", with "shelves" going off three of the four arms. Hard to explain in words, I'm just going to draw something up - let me know if it's what you mean. Will post in a minute.
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Old 02-28-2006, 11:37 PM   #10
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Yea, the X would work too, but would be a pita to adjust for different wheel sizes. I was thinkng the "3 prong" design with just a camber gauge attached. You could flip it, use it to measure camber, then flip it down and do the toe with it. I shall be making one of these. It will take $10 in materials from home depot and a drill.



-Tom
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Old 02-28-2006, 11:38 PM   #11
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Here's the pic I came up with, is this what you had in mind?

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Old 02-28-2006, 11:41 PM   #12
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You wouldn't want to use magnets but use something that would sit on the lip as in my pic above. The magnets might not work right on certain wheels and you would need to worry about wheel placement while the little nubs will sit on the lip just fine. If you have a digital camber gauge, one of these x or 3 prong daddy's, jackstands, and string, you would never have to get another alignment or even worry about being on level ground (camber gauge levels itself).

-Tom
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Old 02-28-2006, 11:42 PM   #13
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Quote:
Originally Posted by trhoppe
Yea, the X would work too, but would be a pita to adjust for different wheel sizes. I was thinkng the "3 prong" design with just a camber gauge attached. You could flip it, use it to measure camber, then flip it down and do the toe with it. I shall be making one of these.

-Tom
You beat me to it! You're right, I didn't notice the digital level mounted near his hand in that picture. Sounds like a good idea! In the end, strings are probably the way to go anyway, the laser-based toe idea(s) probably wouldn't save much time, and there's no point in buying more equipment if it doesn't save time.
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Old 02-28-2006, 11:46 PM   #14
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Just when you do strings, remember to account for the fact that the WRX/STi are slightly wider in the front then the back

-Tom
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Old 03-01-2006, 12:01 AM   #15
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Quote:
Originally Posted by trhoppe
Yea, the X would work too, but would be a pita to adjust for different wheel sizes. I was thinkng the "3 prong" design with just a camber gauge attached. You could flip it, use it to measure camber, then flip it down and do the toe with it. I shall be making one of these. It will take $10 in materials from home depot and a drill.
Sounds good, please post pics as you come along, if you have the ability. Do you plan on making it adjustable, or just for your own wheel? I would think that the adjustability (telescoping arms) would introduce a lot of "play" unless you did it just right, so I'm not going to make mine adjustable. The prongs look pretty simple, just weld some deep "couplers" to the body, and put some bolts in them (I think that's how they did it in the pic). That way you can fine-tune it, instead of having to get it perfect while you're constructing it. You can always weld it permenantly later.

Quote:
Originally Posted by trhoppe
You wouldn't want to use magnets but use something that would sit on the lip as in my pic above. The magnets might not work right on certain wheels and you would need to worry about wheel placement while the little nubs will sit on the lip just fine. If you have a digital camber gauge, one of these x or 3 prong daddy's, jackstands, and string, you would never have to get another alignment or even worry about being on level ground (camber gauge levels itself).
-Tom
Yea, I'm not sure if the alloy rims I have are even magnetic. I would like to have some means of hands-free operation though, maybe I'll think more about it. I could use magnets in addition to the prongs. Just get some "cylinder" neodymium magnets (I already ordered 10 of em) about 1/2" diameter x 1.5" long. Then drill a bunch of holes in the body of the tool. Then stick the magnets through some holes of your choice, and use a big acme-sized office clip (I think they're called "Mauly Clips") to hold the tool onto the magnet. Basically, it's like you're installing a "stud" onto the wheel, and slipping the tool over it, then holding the tool down with some type of clip. You could use a mini version of those Quick-Grips (ie, by Irwin) instead. Home depot sells TINY clips, I'm sure there would be something suitable, spring clamps would probably be fine.
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Old 03-01-2006, 12:04 AM   #16
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I'm very interested in this, but I'm worried that down the road these images will wander off. Any chance you could do a quick write up on webpage when you are through?
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Old 03-01-2006, 12:05 AM   #17
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I won't be doing telescopic, but drilling holes and allowing you to move the nubs by 0.5" increments to fit 15-18" wheels. That will have no play and will be a minimal effort to switch wheel sizes. The $30 camber gauge from racerpartswholesale.com does that right now.

I myself ain't going to worry about hands free operation.

I shall tittywop when I start on this. Won't be for a week or two though.

-Tom
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Old 03-01-2006, 12:27 AM   #18
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Quote:
Originally Posted by trhoppe
I won't be doing telescopic, but drilling holes and allowing you to move the nubs by 0.5" increments to fit 15-18" wheels. That will have no play and will be a minimal effort to switch wheel sizes. The $30 camber gauge from racerpartswholesale.com does that right now.

I myself ain't going to worry about hands free operation.

I shall tittywop when I start on this. Won't be for a week or two though.

-Tom
Good idea! By the way, which brand gauge do you have from racerpartswholesale, the RPW9500 (long arms) or RPW9501 (magnetic)? Has it been pretty easy to use + accurate? I probably would have bought that if I saw how cheap it was, but I'm still happy with my purchase.

Be careful with the thought "camber gauge levels itself" though! Two reasons:

1) Ground is at a constant slope along the entire area in which the car is parked. Here, the angle of inclination that the digital level would read (if placed on the ground) is EQUAL to the angle you would get by putting a piece of wood from one wheel to another and setting the level on the piece of wood. Note the alternative: There could be a "dip" underneath the wood, or multiple hills/valleys (for the mathematically inclined, you want the 2nd derivative / the laplacian of height to be zero everywhere). EVEN in this case, the springs will compress by different amounts, leading to slight innacuracies in your alignment. ie, the car will try to level itself.

2) Ground NOT at a constant slope (the hills and valleys mentioned earlier). Here, unless you got really tricky, you just have to level your car first (ie, using the water + tube method discussed earlier). Your level definitely couldn't compensate for the bumpiness of the ground.

Don't mean to bash the idea, I'd love to have a device which could work on unlevel ground, but just keep this in mind. If you can find a parking lot that is only slightly slanted, and no "bumpiness", you CAN probably get away with the auto-leveling idea without getting much error.

Quote:
Originally Posted by LastResort
I'm very interested in this, but I'm worried that down the road these images will wander off. Any chance you could do a quick write up on webpage when you are through?
Sure, but did you want me to put a writeup on my personal webpage, or were you wanting me to upload the pics to NASIOC? Or do a writeup good enough that the pics aren't necessary? Sorry, not sure what ya meant.

sean
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Old 03-01-2006, 12:30 AM   #19
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I have the RPW9500. I can get it right at 0.1 degree of camber.

I also would be happy with your purchase! I was looking at http://www.speedpartz.com/smarttool.htm as its $90 without the brackets. I couldn't find a deal close to yours on ebay.

-Tom
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Old 03-01-2006, 12:55 AM   #20
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One other thing I was thinking. For toe, using the string method, you need pretty accurate rulers.

If you want to be able to read toe as accurate as 0.1 degrees (which you probably do, toe = pretty important), you need to be able to measure a distance equal to 16" * Sin[0.1 degrees]. This comes out to less than 1/32". The 16" came from my rim diameter (and hence the length of my tool) being 16".

So you probably want your ruler to have graduations in 32nd's or even 64ths. And the rest of the setup can't have any wobble either. The laser level (with two lasers, one at each end) idea starts to sound a little easier, because instead of measuring toe over a 16" length, you can measure it over a length greater than your car's length, ie you amplify the distance you're measuring (using the two long rulers as described earlier)...

Then again, maybe I'm being overly paranoid, lots of pro's use the string setup and consider it a very accurate method. And it's definitely an improvement on the tape measure method, which works fine for a lot of people.
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Old 03-01-2006, 01:17 AM   #21
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EDIT: Nevermind on that last post, but the idea was you can "pick your two points" widthwise rather than lengthwise and use different laser/string methods. But now that I think about it, it isn't THAT much better than the other way.

One thing that would be nice, as far as hybrid laser/strings, would be to pick the points widthwise. Then setup those plumb-bobs on the points you picked. Then get a 3-way laser (they actually are fairly common, believe it or not) and make one of the beams shine through the plumb bob string. The other two should point parallel to the car's lengthwise centerline. You get all that done with just one piece of equipment, which is kind of nice. If the laser is fine enough (it probably is not), you can shine it directly onto your "toe tool" (which we were discussing building). More likely, you'd use these laser lines to setup a string.

Last edited by spmclaugh; 03-01-2006 at 03:57 AM.
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Old 03-01-2006, 05:28 AM   #22
PossumK
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Quote:
Originally Posted by trhoppe
I also would be happy with your purchase! I was looking at http://www.speedpartz.com/smarttool.htm as its $90 without the brackets. I couldn't find a deal close to yours on ebay.
Keep watch on eBay. I got my used SmartTool for just under $50 shipped two weeks ago. I think some people fell asleep when this auction ended.
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Old 03-01-2006, 08:36 AM   #23
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Default More diagrams for toe measurement

Couple more diagrams for measuring toe, if you use width-wise reference points as described earlier:




Turns out you wouldn't even need a 3-laser setup if you do it the way shown in the first pic (using string).

The second pic is about the most accurate way I could ever imagine doing toe (using mirror).

Could make it more accurate, if you REALLY wanted to, by a method which would place the posterboard further back, but it would involve another laser square, and I doubt anyone needs that kind of ridiculous accuracy.
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Old 03-03-2006, 12:21 PM   #24
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Well, my digital inclinometer gauge isn't scheduled to arrive for almost another week, UPS rescheduled the arrival date for some reason (maybe bad weather somewhere?). Anyway, seeing as how I need my car aligned sooner than that, I'm going to make a toe gauge this afternoon out of some threaded rod, small plumbing Tee's, and hollow "pipes", among other things. Going to have a prong coming out in each direction (towards/away from car), on each side of the rod. The prong on the side facing away from the car is hollow. I'm having string come out of this hollow part, with a bob hanging at the end of each string. Then I'm going to use jackstands or some tripods and make a long length of string that just touches the bob-strings. Then do the same thing for the car's centerline, and use some trig. I'm not going to fuss too much with camber, as long as it's fairly moderate and consistent among the wheels. I'll get it more performance tuned when my real equipment comes in. By the way, is anyone else thinking about making these types of alignment tools, who hasn't yet posted??

EDIT: BTW, Hopefully I'll have some pictures later today, though it all depends on if I can get it done while there's still light out...

Also, just got my neodymium magnets. They're UNBELIEVABLY strong on metal, but they don't stick whatsoever to alloy rims. Not even a tiny bit. Maybe on the lugnuts, but haven't tried. I think for hands-free use, I'm just going to use string or small diameter bunjee cord to tie the gauge onto my wheel. Wouldn't be possible for anyone with 100% solid rims, but it works fine for my stock RS rims.

Last edited by spmclaugh; 03-03-2006 at 12:29 PM.
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Old 03-07-2006, 11:22 AM   #25
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Default Pics from laser toe/thrust alignment

Hi. I did my toe/thrust angle alignment using a 90 degree laser setup, but I had to take pictures with my cell phone's camera. Didn't have access to the camera I have used in the past. Anyway, I finally got a way to get the pics off my camera without being charged a ridiculous amount per pic, and I posted them at:

http://www.engr.uconn.edu/~spm01f01/alignment_pics/

Sorry that some of the pics suck, the sun saturated the camera in a few shots, so it's hard to see too much. A couple pics came out good enough though. Let me know if you have any questions. This alignment didn't include camber, because my tool hasn't arrived in the mail yet. But at least I can drive around now without dog-tracking or burning up my tires.

couple example pics:




sean

Last edited by spmclaugh; 03-10-2006 at 07:35 PM.
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