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Author Topic: Fiorotti accelerometer placement  (Read 1680 times)

Offline Mike Scholtes

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Fiorotti accelerometer placement
« on: July 05, 2022, 09:03:21 PM »
What is regarded as optimal location and orientation for the Fiorotti accelerometer? This will be on bottom of 680 inch full fuselage model. I have seen references that the "wires should be forward." Does this mean the flat bundle of wires exiting the accelerometer should exit towards front of model? Or does it actually matter?
Where should the unit be placed relative to the model's CG, and again does it appear to matter? Or is the CG actually a relevant data point with this accelerometer? Is some other factor more relevant?

Thanks!


 

Offline Ken Culbertson

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Re: Fiorotti accelerometer placement
« Reply #1 on: July 05, 2022, 10:47:11 PM »
I have mine 6" behind the CG near the wing TE wires facing forward.  I am very pleased with the results.

Ken
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Offline Mike Alimov

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Re: Fiorotti accelerometer placement
« Reply #2 on: July 06, 2022, 10:31:01 AM »
Since most people mount the timer somewhere in the nose close to battery compartment, and the sensor is to be mounted on the CG per instructions (and as level as possible), the wires to the sensor naturally point forward. The only placement freedom you are given is to mount the sensor right side up or upside down, which is accounted for in the timer settings.

Offline Fred Underwood

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Re: Fiorotti accelerometer placement
« Reply #3 on: July 06, 2022, 11:30:50 AM »
The wires need to point forward as already noted.  The original instructions suggested that the sensor should be about 25 - 30 mm behind the bellcrank pivot.  Mine is a few inches back because it happened to fit better.  It seems to not matter much.  I have a friend who tried the sensor forward in the battery compartment, and it also works fine.  We exchanged flights and could not detect a difference in timer function.  Even if you mount it forward, wires go toward the nose.  Make sure that the wires are secure directly at the sensor.  Wire motion can affect the sensor.  Also as noted, match the sensor orientation, tape side up or down, to the timer selection.
Fred
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Offline Mike Scholtes

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Re: Fiorotti accelerometer placement
« Reply #4 on: July 06, 2022, 12:23:23 PM »
Thanks everyone! Good point about securing the wires at the sensor, that had not occurred to me as an issue. I don't plan on using a lot of boost from the sensor anyway so it probably will work fine anywhere. As it happens the best and easiest location is just about on the CG ("ready to fly" with battery in place).

Offline dc stunt

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Re: Fiorotti accelerometer placement
« Reply #5 on: July 25, 2022, 05:42:30 AM »
The best place is my opinion is the intersection between Cg and vertical Cg.
I have placed in many places and this location by far is the ultimate location for me.

All the best

Dv
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Offline Ken Culbertson

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Re: Fiorotti accelerometer placement
« Reply #6 on: August 02, 2022, 11:10:45 AM »
I discovered on another thread that my accelerometer position setting on the timer was wrong.  It was set to normal when it should have been set to reverse.  Imagine my disappointment when my Jeti box will not let me change it.  Anybody else having this issue or is there some magic chant you have to use to make it switch.  Plan "B" is to make a bracket that will let me flip it over to the "normal" position.  Also, If I do get it right do I have to do the 10 laps again for G-Force?

Ken
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Offline Fred Underwood

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Re: Fiorotti accelerometer placement
« Reply #7 on: August 02, 2022, 11:51:58 AM »
Go to the reverse/normal choice for the sensor in the Jeti box, then push the timer start switch to toggle back and forth for reverse or normal.
Fred
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Offline Ken Culbertson

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Re: Fiorotti accelerometer placement
« Reply #8 on: August 02, 2022, 12:21:59 PM »
Go to the reverse/normal choice for the sensor in the Jeti box, then push the timer start switch to toggle back and forth for reverse or normal.
So, there was a magic chant after all!  Thanks Fred.  Will switching that make me run ten laps?  Should I consider retrimming the timer from "go" or will my other settings still be valid?  Curious, pressing the start, will that also start the timer?  I would think not since it is being controlled by the Jeti but....

Now for something completely different - I am still having a hard time wrapping what is left of my brain around the sensitivity setting.  I view it as how quickly things will happen and perhaps how fast they will accelerate to a setting once started.  I have a +90 on the Max and a -80 on the Min.  Does increasing the sensitivity determine how quickly I get to those settings or does it do something completely different.

Sorry, I am asking too many questions - Ken
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Offline Fred Underwood

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Re: Fiorotti accelerometer placement
« Reply #9 on: August 02, 2022, 04:11:54 PM »
I finally learned that "chant" though it is on the Fiorotti site.

To calibrate the timer and sensor, it takes about 20 seconds of level flight, or for me, just under 4 laps.  If you have actually always been reversed sensor to timer, then you probably haven't seen the normal flashing light.  Normal flight without new sync from speed change has about 8 - 10 seconds of fast flash and the regular flash for the remainder of the flight until the last 10 seconds of light on.

If you have never had the regular reasonably slow flash through the flight, then it will be a pleasant surprise.  I don't find that light a distraction and then just watch for the 10 second warning light to position for landing. 

You can start over with the timer to learn each actual function, though that may only be a flight for each function since you have been using it.  If you just want to use it, it will probably work fine at about 8 nose up, 8 sensitivity, and 8 G-force.  Max and Min at about 50 delta from set each way.  That is about where I fly and get smooth acceleration changes and still plenty of help.  I don't hear the timer much at those settings unless it really quiet.

Sensitivity is controlled by acceleration and in turns controls the quickness/strength of reaction. High sensitivity may seem desirable, but not needed or desired with the other functions in balance.  Max and Min limit sensitivity, not the other functions.

Hopefully this makes some sense from a non-engineer/nonprogrammer but user.

If you have really been flying with the sensor/timer reversed from need, I can't wait to hear how you like it when you get to fly.
Fred
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Offline Ken Culbertson

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Re: Fiorotti accelerometer placement
« Reply #10 on: August 02, 2022, 04:35:51 PM »
Since everything I have done to balance so far has been backwards (It is amazing how well it works backwards) I am going to just put in 8 8 8 like you suggested and work forward from there.  I had my Delta set at 80 and I think I will leave that alone.  I have gotten used to being able to take a nap while I wait for it to get down from the top of the hourglass! #^

Thanks for the help!  Hope it is useful to others.

Ken
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If it is not broke you are not trying hard enough.
USAF 1968-1974 TAC

Offline Ken Culbertson

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Re: Fiorotti accelerometer placement
« Reply #11 on: August 05, 2022, 11:59:08 AM »
Well the 8 8 8 got me through the first flight.  Little bit slow on the response and a little light overhead.  Moved sensitivity to 12 and G-Force to 10 and Fred, you are right, it only took 2 flights!   Having the pad positioned properly totally cured the inside/outside issues.  5.4 both directions on 63' lines.  Solid overhead in a light but choppy wind - about 10mph.

I have to rely totally on feel to evaluate.  BasAss is so quiet that I can barely hear it.  Lights were different.  I never saw any blinking in the air.  Seemed to stay on steady.  Still not familiar with all of it's noises.  The "grunt" when arming is particularly annoying.  Ramp up for take off is perfect.

Ken 
AMA 15382
If it is not broke you are not trying hard enough.
USAF 1968-1974 TAC

Offline Fred Underwood

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Re: Fiorotti accelerometer placement
« Reply #12 on: August 05, 2022, 12:17:45 PM »
Great to hear that it is working for you.  My 8 8 8 is with 5.3 - 5.35 lap and 67.5 C to C lines.  I may have more force to begin with and need a bit less acceleration.  You can look at your G-force number as a reference.  G-force should change if you change lap time and it recalibrates.

The light should blink regularly/evenly through the flight after the first few seconds of run.  The light should then stay on solid only for the last 10 seconds as warning that the motor will stop, and then the light should go off and stay off when after the motor stops.
Fred
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