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Re: Sparrow Strainer

Yes, I think you’re right! Just build it like the plans first . . . I’m planning to re-engineer some things so I’m always thinking if I can improve the initial product rather than make it

By Ian Ashdown <ian.ashdown@...> · #53858 ·

Re: Sparrow Strainer

Use the plans version. They work fine for all who have installed them per plans, including me. We are working on the problem of somehow making them better from a drag standpoint. You do not want

By Jay Scheevel · #53857 ·

Re: Sparrow Strainer

This conversation is concerning me. I will be starting to build my Q-200 kit soon-ish and will eventually need to put something on the airplane. The ‘usual sparrow strainers’ look ‘wrong’

By Ian Ashdown <ian.ashdown@...> · #53856 ·

Re: Sparrow Strainer

Chris..does this mean you have a "mini-frankenbird" ?? Grins. Vern

By Frankenbird Vern · #53855 ·

Re: Sparrow Strainer

Chris.. how did you provide for adjustment of the Strainers? Is there a degree limit inherent or what was the design you chose? I am curious because being able to tuft test by camera EACH aircraft

By Frankenbird Vern · #53854 ·

Re: Sparrow Strainer

In the early days Gene Shehan removed the strainers trying to get better CAFE numbers and increased speed. He reported the aircraft was very hard to control in pitch. Also an early Q2 builder Ken

By Greg Z. · #53853 ·

Re: Sparrow strainer stall conundrum

Gurney flaps have been mentioned here before when this 'problem' came up. Has anyone actually tried them?

By Hot Wings · #53852 ·

Re: Sparrow Strainer

I am not smart enough to be in this discussion. The one comment I will make is I make mine adjustable. If I change the angle 2 degrees + or 2 degrees - from plans the way the airplane flies is

By Terry Crouch · #53851 ·

Re: Sparrow Strainer

I will research this, Troy. Thanks for bringing this up. That is a huge difference. The 17.75 inch version is much lower angle, which probably explains the proportional reduction in angle on that

By Jay Scheevel · #53850 ·

Re: Sparrow Strainer

I want to add a note on the sparrow strainers that I haven’t seen mentioned yet. There are (at least) two variations of sparrow strainers in the plans from QAC. Here is the one that you will get in

By Troy Zawlacki · #53849 ·

Re: Sparrow Strainer

Ok, just checked the plans based version and it is more like 40 degrees from the top of the sparrow strainer airfoil and the top of the elevator. That is what mine is, since it is per plans, or at

By Jay Scheevel · #53848 ·

Re: Sparrow Strainer

Thanks Chris, Quick turn around! It sounds like you are about in the same ballpark as I am wrt to angle, so my guess is that your sparrow strainer is also stalled. Sometime when you get back to flying

By Jay Scheevel · #53847 ·

Re: Sparrow Strainer

Jay----------- I found the info you wanted. Easier than putting on the snow shoes. The strainer airfoil is 2 x 10.25 and is upside down. I used balsa and sanded to an airfoil shape and glassed.

By Chris Walterson · #53846 ·

Re: Sparrow Strainer

Thanks Chris. Any chance you could put on your snowshoes and go out to measure the angle difference between the top of the strainer airfoil and the top of the elevator surface. This would give me some

By Jay Scheevel · #53845 ·

Re: Sparrow Strainer

Here are few pics of what I did. These are strainers from Dragonfly plans. I only have two hrs on the airplane, but it did fly hands off with the available trim I had originally set. Lucky. Take

By Chris Walterson · #53844 ·

Re: Sparrow strainer stall conundrum

Problem is, Ben. It is always needed. The elevator will always want to push up (causing the plane to dive), so something needs to keep it in place. If it is not for the sparrow strainer, then you will

By Jay Scheevel · #53843 ·

Re: Sparrow strainer stall conundrum

Anthony, I believe what you are talking about is an elevator slot, similar to a slotted flap? Jay's proposed elevator design is plain-flap style, unlike the R1145MS which does make use of an elevator

By Michael Dunning · #53842 ·

Re: Sparrow strainer stall conundrum

Jay - Keep going! This is great fun. With yarn video and your flow analysis it's clear there is a problem. What about an articulating tab, up only when it's needed? Ben Wilson

By Ben Wilson · #53841 ·

Re: Sparrow strainer stall conundrum

I think you are misunderstanding a concept. The airfoil only changes the direction of the flow, it does not occlude the flow. It doesn’t matter how closely you “tuck in behind” another body. The

By Jay Scheevel · #53840 ·

Re: Sparrow strainer stall conundrum

Ok, thank you. Very hard to believe that an airfoil in free stream would behave similarly to the same airfoil tucked closely behind another body. I'm obviously missing something. I'll go back and

By Anthony P · #53839 ·

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