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Identifying G-forces?

designerX

Well Known Member
Hello my name is Stan and I’m a recovering utility category spam driver. :)

Admittedly, I yank on my deprived girl (RV-4) like she’s a C-152 because I don’t have experience identifying G-forces (or an instrument to do so.)

While shopping for a g-meter I happened to think that the accelerometer in my phone (Droid Razr) may be just as accurate (without having to saw another hole, wire the device and spend the $$.)

Does anyone have experience flying w/a smart phone G-force app? Anyone happen to have a hard mounted phone and a G-meter in their dash that could run a comparison? Or perhaps a way to verify the device readings?

The attached picture is my setup of Droid Razr w/Otterbox Defender case w/Ram mount typically used for the Garmin Pilot software.

My end goal is to expand my flight envelope w/greater pulls while staying well within the design requirements. Advice on how to get there is greatly appreciated. Thanks in advance.

DSC01796.jpg
 
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I've written a couple of Android applications that use the g-meter. It possibly varies phone to phone, and there is some conversion for orientation that is up to the app developer. So you'd want to test a _particular_ application against your plane to know for sure.

One of my applications was used for lab testing of a vehicle and the readings were within a percent of the expensive instrument we used to use.

But once you've tested phone X with app Y, I'd trust it just as much as the g-meter in my panel.
 
I only have a single experience comparing the G value indicated on a smart phone to other measuring equipment. In that case the reading was quite accurate but it maxed out at about 2 G's (I don't know what model phone it was).
 
belite micro insturments?

might be worth a look at these lightweight instruments from Belite....$99 ain't to bad?

http://www.aircraftspruce.com/catalog/inpages/belite6.php


caution #1; I found some info which sounded like they weren't in this business anymore, so support may be a question.
#2;
something odd going on with their web page to...comes up as a 'threat' risk on my virus scan thingy.
perhaps it's just me.
 
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I only have a single experience comparing the G value indicated on a smart phone to other measuring equipment. In that case the reading was quite accurate but it maxed out at about 2 G's (I don't know what model phone it was).

I've tried a number of different android phones - they went to 6G no prob. (The gui the app developer chose is probably the biggest limit)
 
I tried using the g-meter app for iPhone/iPod on my iPod touch, but gave up pretty quickly; it was too sensitive, i.e. completely undamped, and the result was it constantly oscillated between -1 and +2 g's in relatively smooth air, flying straight and level. Ended up buying a used conventional gauge and mounting it on the center windshield support and am much happier.
 
It ain't free..

but you can always upgrade your Dynon D6 to a D10A, which will provide you with a G-meter, among other cool features.

From Dynon's site:
The EFIS-D6 may be upgraded to the EFIS-D10A for $800. This requires that the EFIS-D6 be returned to Dynon. Some of the functions that are added with the full-featured EFIS-D10A are a full HSI and glideslope with connectivity to GPS and NAV radios, autopilot, networking between Dynon EFIS and EMS products, heading and altitude bugs, checklists, data logging, clock, timers, OAT and GPS derived data, and altitude alerts. See our complete EFIS feature comparison chart for more information on the differences between models.
 
When I was learning aerobatics I got used to the "feel" of 2G with 60 degree banked turns. A 60 degree banked turn at constant speed and constant altitude will require 2G.

Similarly, a 70 degree turn will give you 3G, and 75 4G. It's harder to identify a 75 degree turn accurately, especially considering at 4G it's unlikely you'll be able to maintain speed. But initially it will get you an idea what the G-forces are. And may be enough to "calibrate" your Android.

I find my iPhone to be usable if I have a "damped" G-meter. Good for holding constant G, but not so useful due to the lag for doing actual aerobatics. Turn the damping off, and you have the same problem reported earlier, it bounces around too much.
 
If someone will volunteer to look around the Android market to see if there is a suitable G meter: I'll promise the following. If you can't find such a thing (after a fair amount of looking) - send me a note and I'll write one and upload it ;) (I'll include enough but not too much damping ;-))
 
Mount

Great thread I've been eyeing g meters too but overlooked the iPhone because I thought it would be too inaccurate.

You mention you have a ram mount, what kind exactly and how did you mount it ? Thanks
 
Aircraft G-Meter by Adaptatron seems reasonable

If someone will volunteer to look around the Android market to see if there is a suitable G meter: I'll promise the following. If you can't find such a thing (after a fair amount of looking) - send me a note and I'll write one and upload it ;) (I'll include enough but not too much damping ;-))

Hey Kevin, that's a generous offer and thanks for the info about the mobile phone accelerometers.

I've loaded Aircraft G-Meter by Adaptatron which has a nice simple display and damping for the grand price of $2.99 (it doesn't explain the damping filter value represented by an integer in a textbox.)

Snowflake (Rob) also helped point me in the right direction w/revisiting training of load forces (found a few great articles via google.)

Thanks!
 
I think I'll buy it thanks ! Now I gotta mount my phone. One noob question. Des the phone have to be mounted vertically for the accelerometer to work correctly ? Or could I use this say on iPad with leg strap if nec ?
 
Great thread I've been eyeing g meters too but overlooked the iPhone because I thought it would be too inaccurate.

You mention you have a ram mount, what kind exactly and how did you mount it ? Thanks

I used the following http://www.rammount.com/ items for my install:

(2 count) Diamond Base with 1" Ball (RAM-B-238U) $6.71 each

Double Socket Arm for 1" Ball Bases. (RAM-B-201U) $13.57

As you can see from their website they have many different mount shapes and arm sizes to fit your specific mount location.

The second diamond base is attached to an Otterbox Defender holster using a small aluminum plate cut the same size as the RAM diamond base as pictured below. Since this phone holster remains in the aircraft a second holster was purchased for general use.

DSC01798.jpg


This phone case has no doubt saved my phone from parking lot drops, a treadmill mishap and a trip down stairs. The only complaint is that it turns the thin & small phone into a bulky package.
 
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I think I'll buy it thanks ! Now I gotta mount my phone. One noob question. Des the phone have to be mounted vertically for the accelerometer to work correctly ? Or could I use this say on iPad with leg strap if nec ?

Erik, I *think* this app is currently only available on Android (their website claims an iPhone app is coming soon so you may want to email the developer at http://www.spraguetech.com/ .

With my device it must be positioned at least 45* upright to complete a 5 second 'orienting' process so my specific combination would not work on a kneeboard.
 
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