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General control line discussion => Open Forum => Topic started by: Phil Coopy on May 20, 2006, 02:21:43 PM

Title: Circle Center(Senior Moment)
Post by: Phil Coopy on May 20, 2006, 02:21:43 PM

Are there any competition regs mandating the size of the ring marking the center of the circle.  We are installing a permanent center at our field and want to get it right.

Phil

Title: Re: Circle Center
Post by: Jim Thomerson on May 20, 2006, 04:35:43 PM

Check the AMA rule book, available on line at the AMA website. There are different size center circles for different events.

Title: Re: Circle Center
Post by: rustler on May 21, 2006, 12:45:21 PM

Try not to leave a step down from the centre to the rest of the field. Sounds obvious, but I have seen one or two like this, and some interesting situations when the flying gets a bit hectic!

Title: Re: Circle Center
Post by: Phil Coopy on May 21, 2006, 05:06:52 PM

Been lookin' there but havn't found it yet.  This circle will be for sport and aerobatics.  Does any one know what the center circle size should be?

the other Phil C

Title: Re: Circle Center
Post by: Crist Rigotti on May 21, 2006, 05:27:56 PM

6 to 10 feet in diameter for a stunt circle.  Section 3.1 in the stunt section.
http://www.modelaircraft.org/comp/0506Rulebook/claero.pdf

Title: Re: Circle Center
Post by: Phil Coopy on May 21, 2006, 06:35:12 PM

Thanks, must be going blind....passed over that section a couple of times...oh well grey hair and all that.

Phil

Title: Re: Circle Center(Senior Moment)
Post by: Phil Coopy on May 27, 2006, 11:50:00 AM

So anyway with the above help I compromised on 8 ft for the new circle center at our field.  Figuring Pi times 96in for the circumference, divided by 8in for the bricks I was going to inlay for the circle, came up with 38 bricks.  Went out to the field Tuesday morning, stuck a screwdriver in the center, and measured out 8ft and started to lay bricks..... After about a quarter of the circle I realized I was going to be way short of bricks. (don't stop laffing yet!)  So thinking I figured wrong, I got my calculator out of the car and inputted Pi times twice my 96in radius divided by 8in and came up with a helluva lot more bricks. Approaching my work on the way back from the car I noticed that my circle was going to come out awfully big.....duh!   Went back out Wednesday morning and restarted with 4ft radius.  One of the RC guys walked by and said, "I see you're makin' the circle smaller." I replied, "Yeah, we're not gonna' fly any real big planes here."   Boy, gray hair really does funny things to you.

Phil

Title: Re: Circle Center(Senior Moment)
Post by: john e. holliday on May 30, 2006, 02:16:51 PM

Know what you mean when it comes to figuring number of blocks to make center circle.  Of course mine is not round.  I found some 12 inch round blocks 2 inches thick for mine.  Laid center block down and started laying around it.  I can't remember if it is 5 or 6 sides at the outside edge.  But, it does beat tripping over the grass clods.  Also think it is big enough for pilots circle for racing event I have in my head.  How many remember flying a racing event off of a grass field?  Later,  DOC Holliday