Interested in F1D?

leetx
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Re: Interested in F1D?

Postby leetx » July 2nd, 2015, 10:24 am

F1D plan and construction information are posted here:

https://nffsblog.wordpress.com/2015/06/ ... formation/

Take a look and let me know what you think. All suggestions welcome.

-Kang

leetx
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Re: Interested in F1D?

Postby leetx » July 14th, 2015, 10:26 am

More progress has been made with the construction document, and many more photos have been uploaded. There are also a number of continuing posts on how to fly the F1D.

I believe we will field a full junior team for the 2016 world championship in Romania.

https://nffsblog.wordpress.com/2015/06/ ... formation/

https://nffsblog.wordpress.com/2015/07/06/f1d-basics/

nxtscholar
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Re: Interested in F1D?

Postby nxtscholar » July 15th, 2015, 12:15 am

I'm asking probably already knowing the answer, but what is the age barrier between the F1D junior team and the senior team?

calgoddard
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Re: Interested in F1D?

Postby calgoddard » July 15th, 2015, 11:28 am

Kang -

The plan, instructions and photos you posted are all extremely well done. I can't even begin to imagine how many hours it took to put these together.

Would it help to show the CG on the plan? I assume that if all components are within their designated portion of the weight budget, the location of the CG of the completed F1D will be optimum.

I am surprised to see that this model has 1 - 1.5 degrees of down thrust, but as the current F1D world champion, you would certainly know that this is optimum for this design. I thought I understood from Cezar Banks that indoor duration stick models typically have zero degrees of down thrust. Obviously, I am still learning.

Would it help to show the optimum side thrust on the plan (in relation to the bearing)? I see from your instructions that you twist it into the bearing after the bearing is glued to the motor stick. I assume it is 1 - 3 degrees (to provide some of the left turn).

Congratulations on putting together such a fine tutorial. I have high hopes for your students.

leetx
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Re: Interested in F1D?

Postby leetx » July 15th, 2015, 12:18 pm

nxtscholar,

For the world championship in 2016 (regardless of exact date), a junior competitor must turn 18 in 2016 (regardless of exact date) or later.

calgoddard,

The CG can be flown from 84% to 90%. The students should start at 84%. The CG is achieved using ballast.

Down thrust of 1 deg and left thrust of 3 deg are shown are the plan, but these may not be enough. Each model must be field tested and customized. I believe 1.5 deg down and 3.5 deg left will be necessary.

On this model and on most indoor models, the zero-degree thrust line runs below the vertical center of gravity. Thus, at zero degrees, the thrust creates an upward rotating torque. This upward rotating moment is especially high at launch and causes the model to stall. One part of the solution is to decrease this upward moment by increasing the down thrust. Different fliers do it differently, and many use a motor stick that bend under high tension. In our design, we use 1 deg of down set statically and will use additional down by letting the Ms bend if necessary. In actuality, on this F1D, it takes 4.7 degrees of "down" for the thrust line to run through the vertical CG.

Thanks,

-Kang

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Re: Interested in F1D?

Postby calgoddard » July 15th, 2015, 3:28 pm

Kang - Sorry - you are right. The down thrust and left thrust are shown on the plan in the top view. I missed those details.

Thanks for the explanation re optimum CG, ballasting and down thrust.

leetx
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Re: Interested in F1D?

Postby leetx » July 24th, 2015, 12:49 pm

Wright Stuff student's F1D in flight:

https://www.youtube.com/watch?v=oWyOk38zC8s

calgoddard
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Re: Interested in F1D?

Postby calgoddard » July 27th, 2015, 10:08 am

Marvelous. What an inspiration!

szczur
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Re: Interested in F1D?

Postby szczur » August 24th, 2015, 5:56 am

We are interested.

Cheers,
Don and Joseph

leetx
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Re: Interested in F1D?

Postby leetx » August 27th, 2015, 3:16 pm

Don and Joseph,

Please check out build and trim information here:

https://nffsblog.wordpress.com/2015/06/ ... formation/

Best regards,

-Kang


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