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Author Topic: Brodak Flyer is coming soon.  (Read 980 times)

Offline Paul Smith

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Brodak Flyer is coming soon.
« on: February 13, 2019, 11:47:56 AM »
I got the final proof copy of the 2019 Brodak Fly In flyer.

The completed product should be out soon.

I will be running four speed events and Fun Carrier this year.

Fox 35 Stunt Speed and Perky Speed per the established rules.

The old Sportsman Stunt Speed has been renamed "Two Way Speed" because this year we will be offering two classes, Sportsman and Expert.

Unlike all the other events that use a flying or standing half mile, kilometer or mile, this event is scored by the total of seven laps in each direction.  Sort of like the two-way average for some speed records. 

As in Brodak Foxberg and Clown Racing, Expert class is defined by proven performance, in this case, exceeding 100 MPH in Perky or Fox 35 Speed.

Paul Smith

Offline Skip Chernoff

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Re: Brodak Flyer is coming soon.
« Reply #1 on: February 15, 2019, 03:25:26 PM »
Thanks Paul for handling these events. I've got to find more speed out of my last year's OS MkIII powered Shoestring. I really don't want to build a smaller plane right now as I'm involved with 4 other projects all for Brodaks. Any "speed" secrets you can share for this mill? BTW they do have to be "stock" .....or "Stock Appearing"??? Thanks, PhillySkip

Offline Paul Smith

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Re: Brodak Flyer is coming soon.
« Reply #2 on: February 16, 2019, 06:54:27 AM »
In this speed range (75 to 90 MPH) I don't believe that smaller airplane will make any difference.  In fact (or maybe just in theory) a smaller plane will need a higher angle of attack go slower.

You are free to enlarge the venturi all you want.  But this would be very much considering the need to flip over and get back upside right.  I don't have data on all the world's venturis so I have no basis for setting a limit.

With the Sportsman/Expert split you won't be competing against experts unless you break 100 MPH in another event.

My design, the Medium Clown came in 3rd place last year with a two-way average of 78 with a stock K&B Greenhead.  The airplane is halfway between a Flying Clown & a Super Clown.
Paul Smith

Offline Skip Chernoff

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Re: Brodak Flyer is coming soon.
« Reply #3 on: February 16, 2019, 06:40:27 PM »
With the stock OS venturi I could not get the engine to draw fuel on straight suction. It would probably work fine with a pen bladder or crankcase pressure. I had my machinist pal make me up a much smaller venturi and she ran great both upright and inverted.....she was just not fast enough to run with the more experienced guys. I'm going to try some other props. Was running an 8x8 Cheers,Skip

Offline Paul Smith

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Re: Brodak Flyer is coming soon.
« Reply #4 on: February 17, 2019, 08:42:34 AM »
That's the whole idea of suction and making you go inverted and back upside right.
The forces of nature dictate the venturi size.

Here's what I do with an overize venturi, in the absence of a machine shop.

Take it out of the engine.  Clean it. Fill it with JB Weld.  Redrill to the desired size.

I've done this with everything from 40's to TeeDee .049's.  The TeeDee's that I chocked-down this way worked great in my 1/2A scale planes.
Paul Smith


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