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-   -   Anyone here doing alignments with string? (https://rennlist.com/forums/996-forum/1175173-anyone-here-doing-alignments-with-string.html)

sweet victory 12-27-2019 03:19 AM

Anyone here doing alignments with string?
 
Being able to do an alignment in my home shop is something I've been wanting to learn how to do for a while. Just wondering if there's anyone here who could recommend any specific tools that they found helpful for doing this on their 996/997.

Thanks in advance

jennifer911 12-27-2019 04:37 AM

If you just want to use a string method, here is a very clever technique.
https://www.pelicanparts.com/techart...nment_tips.htm

Also here is an old post on home alignment tips

https://rennlist.com/forums/911-foru...nt-method.html

JTT 12-27-2019 08:33 AM

I've been doing them at home for the last couple of years. First attempt was sort of like Jennifer's post, using jack stands to support strings. Fiddly system.

Next moved to two length of electrical conduit (any straight bar would work, but conduit is cheap and light). I marked notches in the conduit that positioned the strings exactly the same each time and suspend the conduit on jack stands. This at least gave me a parallelogram. In fact, as long as the lines are parallel, they don't even need to be a perfect square, and you can use this program to calculate. https://robrobinette.com/DIYAlignmentCalculator.htm

Problem I ran into was that I couldn't reach the adjustments with the car at static height. So, the next iteration was using tie down straps to suspend the conduit off the front and rear bumper (sort of like a hillbilly Smart String system). This allowed me to lift the car without disturbing the strings. I use large 6x6 blocks (two blocks, glued together for 11" width) under each wheel, with old PVC floor tiles (with grease sandwiched between two) to allow wheel to move without too much resistance when doing camber and toe. The extra 5.5" of ground clearance allows me "just" enough room to reach adjustments. I also switched my strings to a couple of old fishing reels and fluorescent fishing line...makes it easier to manage line.

Still not ideal thought, as I still get tangled in the strings if not careful. I "think" lasers might be the answer and I'll be trying this next. I picked up a couple of cheap laser levels on little tripods that I plan to try next. It will still be fiddly to setup that parallelogram. If anyone has any brilliant ideas of an easy way to do this, I'm all ears.

For camber, I've got a SmartCamber gauge but it doesn't sit well with Porsche lipless wheels. I've also used a magnetic digital angle gauge what sticks onto rotor, but getting it perfectly square to the ground is difficult.

cds72911 12-27-2019 08:58 AM

Do you want to buy a ready made solution, or are you looking for a commercial solution?

Here are smartstrings: https://smart-racing-products.myshop...f-smartstrings

Like JTT said, you can make a homemade version.

I've done some alignment adjustments, and find it works well on the four post lift, since I can get easy access to the adjustments. Like JTT, I used homemade slip plates. I used two ~12"x12"square sheets of HDPE under the tires (stuff that I had around from prior projects), and it was slippery enough by itself that I didn't need grease.

There was a series or articles in the last few months on how to do the procedure either in Total 911 or Panorama. I'm sure there are lots of internet sources too.


Mike Billings 12-27-2019 10:09 AM

The strings are excellent but sometimes you just want to put on some Pink Floyd and use the lasers. It's been my preference for the last 25 years.

Be sure to get laser levels that include the attachment to project a line. Lay the laser levels together on flat surface so they project on a wall and ensure that they are square.

It's best if the laser level can mount flat on the hub or road wheel. When in a hurry, I set a plastic top from a spray can on the wheel and set the laser level on the plastic top. Secure with bungies.

This method uses the door of the car or the door sill as a reference. More exact methods would reference the chassis instead. Stand over the door and look at the laser line on the ground. You should easily see the angle between the door and the line (photo).

One way to measure the angle is set an item on the ground of known width. Let's say I use a 1/2" diameter socket.

My photo is a little off. The hockey puck is there to simply identify the point where the line goes under the door and is no longer visible. So measure from the hockey puck center to the socket center, let's say 25 inches.

A half inch divided by 25 inches is 0.02. On my iPhone calculator, type in 0.02 then hit tan-1. I get 1.1457. That's degrees, not radians. That's the rear toe for that one wheel. Too much! Add the toe for the left and right wheels to get total toe.

Also I use the iPhone to directly measure camber.


https://cimg0.ibsrv.net/gimg/rennlis...fe490e1e93.jpg
https://cimg4.ibsrv.net/gimg/rennlis...95ea57b9dc.jpg


JTT 12-27-2019 03:12 PM

Mike, I'm slow on the uptake today. Where is the second laser placed to create the "zero" toe line?

Mike Billings 12-27-2019 03:52 PM

Well that's a very nice idea. Place a second laser that is aligned withe the chassis to use as a reference.

I didn't do that. I stand by the door and look down, the edge of the door and door sill are the reference.

JTT 12-27-2019 03:55 PM

Oh, from the pic, it looks like a second laser line is visible, fainter though. Must be a reflection?

Mike Billings 12-27-2019 04:14 PM

Yes a reflection. Good idea you have however.

sweet victory 12-27-2019 05:38 PM


Originally Posted by cds72911 (Post 16314531)
Do you want to buy a ready made solution, or are you looking for a commercial solution?

Here are smartstrings: https://smart-racing-products.myshop...f-smartstrings

Like JTT said, you can make a homemade version.

I've done some alignment adjustments, and find it works well on the four post lift, since I can get easy access to the adjustments. Like JTT, I used homemade slip plates. I used two ~12"x12"square sheets of HDPE under the tires (stuff that I had around from prior projects), and it was slippery enough by itself that I didn't need grease.

There was a series or articles in the last few months on how to do the procedure either in Total 911 or Panorama. I'm sure there are lots of internet sources too.


I am looking for a commercial solution. Thank you for the smart strings link!

cds72911 12-27-2019 05:50 PM

I found it: October 19 Panorama, #751, pp. 100-104.


https://cimg5.ibsrv.net/gimg/rennlis...6851fe80b.jpeg
https://cimg6.ibsrv.net/gimg/rennlis...2317d95a6.jpeg
https://cimg9.ibsrv.net/gimg/rennlis...f7c4a78e8.jpeg

Scott at Team Harco 12-27-2019 06:29 PM

OK - I'm in. Good thread so far. Lots of good ideas and solutions.

First off, the 917 is a big winner. A close second is the hockey puck in Arizona.

Sting alignment is very good if you be sure to cover the details. I like the JTT ideas - especially the fluorescent fishing line. I need to work out a "confirmation" system to augment my current one. An old racing friend of mine was selling his alignment gear a few years ago. A Dunlop toe kit and another precision unit for camber and caster.

Verifying all four corners are square to the chassis is an important final check.

https://cimg7.ibsrv.net/gimg/rennlis...4543ce5d85.jpg

https://cimg5.ibsrv.net/gimg/rennlis...93a8c13cfa.jpg

JTT 12-27-2019 09:52 PM

For a commercial system SmartStrings seem to be the deal. I even watched Porsche Cup guys using these in the pits at the Montreal Grand Prix. They use trick wheel stands with them, but in the end, it's all about strings.

That's a cool looking setup Scott! I saw, what I think was one of these, for sale on eBay or somewhere. It was all in a case and hard to sort out how it all went together. So, is that really a little periscope sighting to the opposing mirror?

Scott at Team Harco 12-28-2019 10:32 AM


Originally Posted by JTT (Post 16316198)
For a commercial system SmartStrings seem to be the deal. I even watched Porsche Cup guys using these in the pits at the Montreal Grand Prix. They use trick wheel stands with them, but in the end, it's all about strings.

That's a cool looking setup Scott! I saw, what I think was one of these, for sale on eBay or somewhere. It was all in a case and hard to sort out how it all went together. So, is that really a little periscope sighting to the opposing mirror?

Correct. You calibrate it by placing the two arms together. Look through the periscope and align the gauge so the cross-hairs center in the reflection. Once placed on the vehicle, you look to see what it takes to bring the cross-hairs back to the center. The gauge will read how far off the toe is.

JTT 12-28-2019 10:50 AM

Thats pretty cool! One of the challenges I have with my SmartCamber gauge (similar to the rig you have Scott) is that there is no flat spot or lip to get a consistent reading from on my 5 spoke OEM wheels. It's always a bit of a guesstimate.


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