DIY Alignment with Iphone

[sik68]

It just dawned on me that I am always carrying around an alignment tool in my pocket.

As long as you have faith in the Iphone/Ipod Touch accelerometer accuracy (I do....this thing is damn sensitive) you can use it as your camber/caster gauge. Apparently I'm not the first to realize this. There's an App, although it's pretty janky just to lay it up against the hub like they show. I think I'll make a jig like they recommend to reference my wheel better.
http://18000rpm.com/ialign_for_iphone_and_itouch/ialign.html

Now we can all deftly steal each other's alignment settings while pretending to take pictures of wheels.

https://static1.pt-content.com/images/pt/2010/04/P1030102-1.jpg

EDIT: This sounded like an advertisement...but it's not. You don't even need the app, just the angles from the accelerometer that thousands of apps will give you.

[wmhjr]

Personally, I would not trust the accelerometer from any consumer device like the iPhone or the Blackberry storm for anything of an accuracy nature. just me.

[JohnUlaszek]

Personally, I would not trust the accelerometer from any consumer device like the iPhone or the Blackberry storm for anything of an accuracy nature. just me.

Based on what data?

[wmhjr]

Based on what data?

Based on business experience of attempting to use that technology for line of business applications. We found too much variability in the measurements. Who knows? Just our experience. YMMV.

[JohnUlaszek]

Based on business experience of attempting to use that technology for line of business applications. We found too much variability in the measurements. Who knows? Just our experience. YMMV.

Can you share specific data regarding the Iphone? Accuracy, precision, etc?

I would like to see how it compares to a "Smart Level".

[sik68]

Can you share specific data regarding the Iphone? Accuracy, precision, etc?

I would like to see how it compares to a "Smart Level".

Today is no argument day in this here Suspension forum!:machine:

:) I'll try it a couple ways and post how it goes.

[JohnUlaszek]

Today is no argument day!:machine:

:) I'll try it a couple ways and post how it goes.


Was it a precision problem or an accuracy problem?

Plenty of people use the "Smart Level" to do alignments which is based on the same accelerometer technology. I already have an Iphone, but if it's not as good it would be good to know how "good" it is or isn't.

[parsonsj]

I did all of my DIY alignments with my Craftsman digital level. After the first alignment, I took it to an alignment shop to check my work, and it was within .1 degrees. As a bonus, they scratched the paint on my fender. :crying:

After that calibration, me, my smart level, and my Stanley tape measure did the rest of them.

jp

[silver69camaro]

Only one way to find out. Try it out, and see if you can borrow a digital level from sombody.

Or, take a distance from the top of the rim to a vertical line. For example, if the rim edge is 3/16" from vertical, that's about 0.5 degrees.

[wmhjr]

Can you share specific data regarding the Iphone? Accuracy, precision, etc?

I would like to see how it compares to a "Smart Level".

I can try to get the data for you. I was not involved in the actual test - only the project brief and the outcome, but I know the engineers that actually did the testing. Might take a week or so if you really want but I'm not sure of the details. My understanding was that the iPhone applets they used resulted in a lack of consistency over time when measuring against the same test artificts. It's also possible that their acceptable amount of tolerance was lower than what is needed here. I honestly don't know. It was just enough to steer me away from anything other than consumer type use of these devices.

[Rod]

Today is no argument day in this here Suspension forum!:machine:

:) I'll try it a couple ways and post how it goes.

if there were no arguments!! some would not be happy!!:rolleyes: measure away man! measure away!!

[parsonsj]

I'd love to see the data, if it's not too much trouble.

thanks!

[lthawk]

Iphone is pretty cool. have you ever downloaded any pics from photo buckett app on your iPhone 2 pt. thanks I'm new here

[wmhjr]

I'd love to see the data, if it's not too much trouble.

thanks!

I'll see what I can do. I'd actually kind of like to see it myself. Can't promise anything but if it's possible I'll pm you. Should know within the next week or two.

[parsonsj]

Cool!

[wmhjr]

John -

Good news and bad news.

The good news first. I had a conference call with the Engineering Mgr concerning this about something else sooner than expected. I brought this request up.

The bad news. I mistakenly mentioned that I wanted the data for somebody interested in iPhone apps using this technology. The first question that he popped out with was "Do we have a master agreement and NDA (non disclosure agreement) with whoever wants the data?". I should have been smarter and not mentioned it wasn't for me - even though this isn't for a commercial purpose. It seems as though since we've been purchased by a larger company (we were about $1.4B or so in revenues - new owners about $37B) there is far more focus on IP security. Bottom line, he's not keen on giving me data. I'll see what transpires but I'm not optimistic. Knowing this is purely to satisfy curiosity I should have framed the request differently. Sorry :(

[sik68]

Followup:

I rigged up my home-made camber/caster gauge using an adjustable shelving bracket.

https://static1.pt-content.com/images/pt/2010/04/IMG_0902-1.jpg

I tested it using my Ipod touch, which gives readouts to 0.1 deg and is calibrated to the surface your wheel is on. I found it to be very accurate/sensitive to any changes, but I would not recommend it for actual alignments. The backside is just too rounded to provide consistency because your grip on the device greatly affects the measurement. It is a great device for quick at-the-track measurements though!

https://static1.pt-content.com/images/pt/2010/04/IMG_0982-1.jpg

[Rod]

why not use a ipod mounting bracket?
https://static1.pt-content.com/images/noimg.gif
the touch is fairly accurate I guess its relative to the soft ware here its use for a military app
https://static1.pt-content.com/images/noimg.gif
and are tough also
https://static1.pt-content.com/images/noimg.gif