If you could build the perfect grass circle

[Tim Wescott]

My RC club may be moving to a new site.

The guy who's working with the county on the move has identified a good candidate for a flying circle, and asked for my input on what the control line guys would like there.

I kinda babbled on about clearances and stuff, but I realized that -- beyond a nice piece of flat grass -- I didn't know if I was asking for the right stuff.

So --

What size circle do you think is necessary?  I recall Brett Buck talking about 180 feet being ideal.

If we put in a pilot's circle, how big?  Any suggestions on how to make it so that no one ends up stumbling on the edge of it?

Any suggestions on where to locate pits, other than close to the circle?

Getting a paved runway is probably out, but if it is, and if they just want to do a ring, how big should I ask for (both inside and outside)?

In the end we're probably going to get a flat spot with a marker stone in the middle, but I'd like to share "this is the ultimate flying circle" with the guy, just in case the resources are there to get bits of it.

[Doug Moon]

180' would be awesome!  170' will do.

Look at your prevailing winds for the area and put your pits on the side. Not up wind where people will judging or watching, and not down wind so people arent flying on top of those stading in the pits working on their rigs or getting ready.  The pits are out of the way and its safer that way.

[Douglas Ames]

Our circles here at Tulsa Glue Dobbers are, I believe 160' with concrete septic tank lids as centers inlaid flush with the ground. We also groom our circle edge to about 5" with a special mower (Redneck lift kit).

[Steve_Pollock]

Tim, in a separate email I forwarded some drawings Charlie Reeves was kind enough to share with me.  Good luck!  Steve P.

[Tim Wescott]

Stephan, Douglas, Doug -- thank you, these are good suggestions.  Steve's drawings included mention of a hole for a speed pole, which I hadn't considered at all, and setting the pits according to the prevailing wind is a good idea if we can figure it out (the prevailing wind direction in the Willamette Valley is pretty much "different from yesterday", but the proposed site is in it's own side valley and may have some preferred direction; we'll have to check with the locals).

In the event that we end up with a grass field with concrete center (I like the septic tank lid idea!), would it be any use to put up a speed pole?  Or do speed fliers absolutely need concrete to take off?  We'll be doing the mowing, and we currently set the blade height to one step below "scalp" for the circle.

[Steve Helmick]

If you can setup the pits so they are arranged similarly to Salem, Richmond, and Thun Field (handle somewhat near the circle, planes away from the circle, kinda inline), that would be great. Reduces the need to step across other lines and handles. This also keeps planes and people away from the circle, & can allow spectators to get up close to the models, so they can see them, get to understand how they work, and talk to the fliers. Keeping the county from planting a bunch of trees to create turbulence (like Salem and Richmond) would be difficult, but worth a try. If they plant small trees, we have ways...

Although it's a nice thought to make the site "speed friendly", I doubt many would fly speed on grass. I have done it and got away with it, but there is potential for a landing to stick the spinner into the sod and create a tumbling destruction of the plane. But you'd better ask the speed fliers, because there are few sites in the NW that are suitable at this time...Delta Park, Salem and Coquitlam, AFAIK.  Steve

[Tim Wescott]

What you really want is a 180 foot diameter putting green. SMOOTH, firm, green.

Funny, that's exactly how I put it!

[Tim Wescott]

Not sure, as I don't golf, but aren't putting greens (assuming this is the area around a hole) Zoysa grass cut very, very short and rolled smooth??

I don't golf either -- but they're planted with some sort of grass that can tolerate being cut very short, and they're kept very smooth.  I believe that in order to make it work you need to drench the area in fertilizer and herbicide.

In my experience if you just mow real close you get moss and dandelions, and you can take off from that just fine...

[Russell Shaffer]

Tim, look on Flying Lines at the flying sites and check out what the Rice Mill guys have in Vancouver,BC.  Brodak has concrete take off strips and the rest grass I think.  Putting green is great, but I suspect maintenance might be a problem.  My personal preference would be a short take off strip of very smooth concrete set exactly level with a grass area mowed to 1/2 inch height, the grass being planted on a soft bed of peat moss for impact absorption.  Due to the impact absorption, one will also need a narrow slip resistant walk way from the launch area to the circle center. The center also needs to be slip resistant, and for your area, moss and other green stuff, resistant. Don't forget to dome the whole thing.   So on a practical perspective, level, closely mowed ground cover with any kind of decent take off and launching space would be great.  The Vancouver people did good with their paved circle and the rest just mowed green stuff.  Steve is right, speed needs a very nice circle all the way around and it has to be hard - probably not going to happen.

[Peter Germann]

While possibly not being very relevant for you, it might nevertheless be interesting to check what FAI suggests. Attachs are from the current 2013 set of rules for F2B.

Peter Germann

[Bob Reeves]

If you are pressed for room 160 feet can work. As Doug said above all 3 circles in Tulsa are 160 feet. Not quite what is recommended but they have proven to be big enough through many contests and over 100 contestants, helpers and guests walking around. I believe the reason we have been able to get away with it is the six inch tall grass berms around the circles that clearly mark where not to go.

http://stunthanger.com/smf/index.php?topic=19314.0

[M Spencer]

Now this ones obvious . 

You NEED a half a circle , at the top of a 60 degree or vertical bank . Maybe with a waist high fence at the center if youre prone to wander . 

This way you can do authentic carrier landings . And practise underground loops & bunts , and horizontal center vertical eights .

as long as the cliff is always downwind . 

[Phil Krankowski]

Now this ones obvious . 

You NEED a half a circle , at the top of a 60 degree or vertical bank . Maybe with a waist high fence at the center if youre prone to wander . 

This way you can do authentic carrier landings . And practise underground loops & bunts , and horizontal center vertical eights .

as long as the cliff is always downwind . 

Hey!  That's my side yard (but only big enough for 1/2a, 90 ft total diameter circle)  except the low area is typically UPWIND.

Getting underground makes for some interesting crashes!  Otherwise the setup is very effective.

Phil

[Brad LaPointe]

Building and maintaining two grass circles for the last 20 + years has led me to some basic truths .

The field is never smooth enough, the grass is never short ,green or thick enough. Mother nature will both amaze and frustrate you .I'm a farmer so bitching about the weather comes easy .

The Bean Field is located on the "back 40". Formerly parts were used as a motocross track . Most of the circles are on old pit areas or former bean field land .When the circles were new they were very flat . Parts of the circles have "sunk" from decaying plant matter that covered areas where the track used to run .

Both my circles are 180' dia. surrounded/marked by tires like a bike track .I set the pits up so the handle points towards the centre . This prevents a lot of tripping over others lines .Tires are ugly, cheap, easy to move and make good barriers . For the centre we have found a heavy piece of carpet works very well .

We use one circle for combat. It gets ugly by the end of the season . Big divots, fuel "burns" from broken bladders ,lots of debris ,and when it's wet the pit circle looks like football was played on it .

The "stunt" circle gets much better treatment . That is until we use it for sport race . A lot of fuel "burns" occur during racing events .A good rain will help to revive the grass .If it is still brown in the spring I dig up the burned area and reseed it .

Each fall both circles get scuffed with a weighted screen and a bit of top soil added if needed to help smooth things out .For many years I back seeded each fall also. In the spring a good rolling and your ready for another year of grass cutting...errr flying .

Brad LaPointe
MAAC 5418L

[CircuitFlyer]

You might want to look into Geotex fabric for a flying surface.  Numerous RC clubs are using it for runways.  Way cheaper than concrete/asphalt and if you have to move again you could take it with you.  Last spring the RC club that I belong to installed a 200m x 30m runway.  http://www.mmfc.net/  Total cost was about $1800.  It went down in less a day (although we had lots of bodies).  It may be more of a challenge to put it down for a circle (octagon?) but could be done.  It would get beat up if you flew a lot of combat but it can be patched & repaired.  For the pilot circle look into a circle kit or circle pack at your local interlocking concrete paver supplier.  8-10 ft in diameter and would make the field look real posh.

Paul

[john e. holliday]

When I and John Bender put in the center pad at the Knorthern Knights field I got paving stones from Sutherlands that they were closing out.   The stones were only a dollar a piece.  I like the idea of the sewer tank lid.

[john e. holliday]

For those that have small wheels on a grass field, visit your local carpet supplier.   I have a piece long enough for take offs when I forget to mow the grass.