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I have no experience with GEEZ so I don't know what is used in there. Is there anybody willing to take theirs apart for a quick peek at the parts? Assuming they even come apart...

I would have a hard time believing there is something much different in the GEEZ than in the laptops. Considering the price of high-quality accelerometers, there would be no way to turn a profit considering the price point.

Jim

Jim,

The GEEZ cube is fully potted . . . no takem mine apart.

I'm sure that Byron used readily available "popularly priced" accelerometers. The question may be whether there is a wide range of specs for these things such as "air bag" specs vs. "lap top" specs vs. ???

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Dick Rasmussen

FS 50 2018 Mustang GT

Most definately there is. Also, I would wonder that at the time the GEEZ cube was designed, what was the cost effective solution at that time and how does it compare to what is available and in use today?

My 2 cents is that there is probably a wide range of what is available and I would guess that to get the per part cost down, that the G range and accuracy level of devices that exist in laptops and/or drives is not at the level you would want for motorsports data aquisition. If you have used GEEZ before you will know that a little bit of error can go a long way in how it lays out what it thinks is the path the car took. That URL that Jim provided earlier, I think had accuracy of +/- 5%. That might be great, but without knowing much about what is available today, that seems pretty crappy to me.

However, I could be wrong. I believe it used to be the case the companies such as Intel, AMD, used to have to test and sort their CPU to see which ran at higher speeds. They made them all on the same design/waffer, it is just that they didn't all come out the same. The good ones were labeled at the higher speed. The bad ones a lower speed. I think that in general that is a thing of the past. That at manufacturing quality improved, they all started to test out at the target. So it could be that with modern production techniques and quality control, that these things are getting cheaper and more accurate and that maybe even the ones you find in toaster ovens kick ass.

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Richard Casto
1972 Porsche 914
2013 Honda Fit Sport
2015 Honda Fit EX
http://motorsport.zyyz.com
Money can't buy happiness, but somehow it's more comfortable to cry in a Porsche than a Kia.

I can't speak for GEEZ since I know nothing about it but considering how old the software is, I'm guessing there is room for improvement given more modern equipment (mainly in the area of filtering the raw data).

You guy have me curious about this stuff again. Hopefully I'll be able to find my old notes this evening and I might look at making something useful out of all this stuff. And I should be able to take more than a 30 second glance at some of those data sheets to see if there are any "gotchas" I'm currently missing.

Jim

Jim,

I keep telling myself that if I have time, I would look into this as well. I just never have the time. What I have been wanting to do is not just do the standard 2 axis acceleration acquisition (such as GEEZ), but to try full 6 axis. Specifically with something like this...

http://www.analog.com/en/prod/0%2C2877% ... %2C00.html

In the back of my mind I keep thinking that if you have not just X,Y (maybe Z) motion, but also include rotational (yaw, pitch and roll) that with proper software (which is what I think is really needed) you could really do some great analysis. Maybe even to the point that you could help tune suspension without having to resort to full instrumentation on each corner of the car.

Right now, I believe that products like GEEZ use the X/Y data to calculate pseudo rotational data so that they can show the path of a car and really in my opinion don't do a good job at it (maybe as well as can be expected as you have to deal with pitch and roll of the car and non-level courses).

If you read the GEEZ documentation they sidestep that issue by saying they are not trying to simulate the exact path of the vehicle, but for you to examine the data to learn other things. I generally agree with that, but I also think a bunch of other valuable information is just not there because it can't be extracted just from the existing X/Y data.

Other systems tie in GPS data so that (assume) it makes it easier to overlay data from multiple laps (road racing) as well as have a better idea of instantaneous speed (which GPS does well) vs. a cumulative calculated speed that GEEZ gives (which due to only having X/Y data is not super accurate).

_________________
Richard Casto
1972 Porsche 914
2013 Honda Fit Sport
2015 Honda Fit EX
http://motorsport.zyyz.com
Money can't buy happiness, but somehow it's more comfortable to cry in a Porsche than a Kia.