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General control line discussion => Open Forum => Topic started by: frank williams on March 02, 2020, 06:34:52 PM

Title: Igor's Logarithmic Dimensions
Post by: frank williams on March 02, 2020, 06:34:52 PM

Could someone please fill in the dimensions ... I've misplaced by notes.

Title: Re: Igor's Logarithmic Dimensions
Post by: Tim Wescott on March 02, 2020, 08:12:46 PM

Igor is probably a bit less than 6dBmeter tall, and probably has a mass of around 19dBkg.  Assuming that you take dBmeter as an amplitude ratio, and dBkg as power.

Title: Re: Igor's Logarithmic Dimensions
Post by: frank williams on March 02, 2020, 09:12:17 PM

Thanks Tim

integral of d(cabin) / cabin = log cabin

Title: Re: Igor's Logarithmic Dimensions
Post by: Paul Walker on March 03, 2020, 10:28:35 AM

Quote from: frank williams on March 02, 2020, 09:12:17 PM

Thanks Tim

integral of d(cabin) / cabin = log cabin

Frank.....that integral joke is quite old.....OH.....never mind....😂

Title: Re: Igor's Logarithmic Dimensions
Post by: Brett Buck on March 03, 2020, 11:13:33 AM

Quote from: frank williams on March 02, 2020, 09:12:17 PM

Thanks Tim

integral of d(cabin) / cabin = log cabin

    That bit really killed down at the Mensa clubhouse.

    Brett

Title: Re: Igor's Logarithmic Dimensions
Post by: frank williams on March 03, 2020, 12:29:28 PM

Sorry ... I know its an old one, but I don't do dB ..... if Tim had thrown me a quaternion I could have covered that (as long as it was a left handed one) .......

......So ............. A, B, C, D, E?    also the bellcrank is 100mm, what is the pushhrod arm length?

Thanks

actually its ln rather than log

Title: Re: Igor's Logarithmic Dimensions
Post by: Howard Rush on March 03, 2020, 06:22:11 PM

I’m not answering your question either,  but do you have my control geometry spreadsheet?  It has Igor parameters too.

Title: Re: Igor's Logarithmic Dimensions
Post by: frank williams on March 03, 2020, 06:28:18 PM

No I don't have a copy of it, but I would like to since it probably does have the dimensions in question.

lonestar_77062@yahoo.com

some reviews finds that probably A=24mm, B=22mm, E=20mm, D=?,C=?

Title: Re: Igor's Logarithmic Dimensions
Post by: pmackenzie on March 03, 2020, 08:04:51 PM

Quote from: frank williams on March 02, 2020, 09:12:17 PM

Thanks Tim

integral of d(cabin) / cabin = log cabin

integral of d(cabin) / cabin = natural log cabin :)

FWIW, here are the dimensions I came up with from the paper drawings.  My elevator horn is a slider, but the nominal setting would be 20mm.
Checking in CAD, I get the same throws that Igor lists here:
http://www.netax.sk/hexoft/stunt/the_max_ii.htm

Title: Re: Igor's Logarithmic Dimensions
Post by: frank williams on March 03, 2020, 08:25:39 PM

Thanks Pat
I think thats what I needed.

Title: Re: Igor's Logarithmic Dimensions
Post by: pmackenzie on March 03, 2020, 08:35:07 PM

You might also need the length of the slot in the flap horn that the 10mm OD bearing runs in - 20.6mm.
So flap horn in effect changes length from ~32mm at neutral to ~42mm at full deflection.

Title: Re: Igor's Logarithmic Dimensions
Post by: Brett Buck on March 03, 2020, 08:51:03 PM

Quote from: frank williams on March 03, 2020, 12:29:28 PM

. if Tim had thrown me a quaternion I could have covered that (as long as it was a left handed one) .......

   As I recall, NASA also used the "first element is the magnitude" version, which is not just wrong, it's immoral.  My commercial space colleagues didn't take a stand on that one  - the flight software uses the Correct Lockheed Way (last element normalizes it) and the simulation truth model uses the NASA version. They also use two different rotation definitions - Q⁽⁺⁾ and Q^(-).

     Consistency is for squares, man!

   Brett

Title: Re: Igor's Logarithmic Dimensions
Post by: frank williams on March 03, 2020, 09:33:50 PM

There is an AIAA paper by Yazell from Honeywell titled "Origins of the Unusual Space Shuttle Quaternion Definition".  I grew up with it .... seemed like a logical choice to me.  Station software wound up with a mishmash I think.

Title: Re: Igor's Logarithmic Dimensions
Post by: M Spencer on March 03, 2020, 09:45:28 PM

You could get a similar effect, say. by bellcrank pivot to arm, over the wing ( a Z even )

so the pushrod is over the wing , parrallel . Would need a guide or two .

A cross bar at vertical wire flap horns .

As the control veered from neutral , the horn effective length would increase .

Assumeing you used tube sliders with a pivot on the cross arm .

would be fabricateble with saw hammer & pliers , if you had a vice . For those lacking a machine shop . Be easier with one though .

Title: Re: Igor's Logarithmic Dimensions
Post by: Brent Williams on March 04, 2020, 06:34:15 PM

Quote from: Motorman on March 04, 2020, 05:29:46 PM

Does Igor still sell the kit he mentions on his web site? What's the thickness of the steel and the OD of the ball bearing?


Motorman 8)

1mm steel
10mm bearing