Date   
Re: Sparrow strainer stall

Bruce Crain
 

Did they use the Roncz canard on the Amzoil Racer?  Didn't Burt design that bird?
Bruce


---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Sun, 22 Mar 2020 20:05:32 -0600

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

 

Re: Sparrow strainer stall

Jay Scheevel
 

I think that the Roncz airfoil would probably have been the way to go, but unfortunately, as David said, Burt Rutan did not win that argument. I think, if that airfoil had been used, there would have been no need for the carbon fiber spar.  Maybe the next time Sam replaces his canard, he can use that airfoil 😊

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Saturday, March 21, 2020 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.

 

I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  

Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!

Any speculation Jay?

Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?

"Not a Rock Scientist"  

Bruce Crain



Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

Re: Oil leak - Cylinder Base

Bruce Crain
 

I am sorry I did not explain myself good enough!  None of the thread or locker is to go under the cylinder base bolts or cylinder skirt for the through bolt Jim is talking about!  It is to go inside the hole that the through bolt goes through .  Perhaps an inch or so inside the hole in the case halves!
Bruce 

On Mar 21, 2020, at 11:57 AM, Jim Patillo <logistics_engineering@...> wrote:



Hey Bruce,

I also have an oil leak I’ve been putting off fixing on #2 and #3 cylinders. I think it’s the thru bolts leaking.
I’ve heard that the leak can be stopped by pulling the cylinder away, pushing the thru bolt out a little, wrapping silk thread around the bolt shaft, pushing back in place  and reinstalling the cylinder.

Please let me know what you found and how you repaired it. 


Regards,
Jim
N46JP - Q200

Re: Oil leak - Cylinder Base

Jim Patillo
 

Thanks for the input Bruce and Sam. I will ask on continental engine site. 
Not sure how installing silk thread could change the torque characteristics. Looks like Bruce will be providing an update soon.


Regards,
Jim
N46JP -Q200

Re: Oil leak - Cylinder Base

Sam Hoskins
 

Jim, also try posting on the https://smallcontinentalengines.groups.io/g/main

Silk thread under the through bolts? I dunno. That sounds like the kind of thing that could cause an issue with maintaining proper torque and lead to the loss of a cylinder.

Maybe Harry Fenton will see it and comment. 

On Sat, Mar 21, 2020, 11:57 AM Jim Patillo <Logistics_engineering@...> wrote:

Hey Bruce,

I also have an oil leak I’ve been putting off fixing on #2 and #3 cylinders. I think it’s the thru bolts leaking.
I’ve heard that the leak can be stopped by pulling the cylinder away, pushing the thru bolt out a little, wrapping silk thread around the bolt shaft, pushing back in place  and reinstalling the cylinder.

Please let me know what you found and how you repaired it. 


Regards,
Jim
N46JP - Q200

Re: Sparrow strainer stall

Bruce Crain
 

I like this picture.  I wasn't smart 'nough to understand the others you sent Jay.
 
I am noticing the aft end of the airfoils look different.  It looks like there is negative camber on the aft end of the LS1.  The Epler does away with that negative camber.  Would that negative camber make the aft end want to pull up on the elevator?  Plus would it make the airflow blurble up after the trailing edge of the elevator.  
Not sure about the top of the LS1 airflow going inboard with respect to the 2 airfoils!
Any speculation Jay?
Do we need to design a new airfoil for the canard on the Quickie to make it go faster or slow the stall speed?
"Not a Rock Scientist"  
Bruce Crain


Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 17:54:41 -0600

Re: Oil leak - Cylinder Base

Bruce Crain
 

YepI  That would be correct on the actual through bolt.  I did the silk thread with thread locker or RTV in the thread. 
I did both left and right ends to keep from leaking on either side.  You will need to pull both 2 and 3 cylinders away from the case halves. 
When you start wrapping the thread just keep wrapping it until it starts to fit snugly.  Then do the other end and make them both fit snugly.  I think I wrapped them at the outer ends but not outside the side of the case.  You don't want to let the thread and locker hold the cylinder away from the case half!  Add the thread locker to the thread and push the through bolt into place.  It should be snug enough to keep it in place but not enough to keep it from going into place.  
When you torque the bolt try to keep the ends fairly symmetrical.
 
My leak has been on the left front side of the case.  There are 2 bolts that thread into the case half on the other side.  I thought I might need to check out the cylinder base flat O ring but D and B Engines said the leak never happens with that base o ring.  He said the 2 bolts are the culprit.  I affirm that as I have seen oil coming out of the threads.
I finished remounting the cylinder and torquing the base nuts and installing the new push tube oil return tubes.  I will most likely finish plumbing the rest this week while Honey Lamb is working.  I get lonesome at the hanger so I came home to "entertain her"!  wink_smile
 
I will shout out loud if I can get this 0200 dry!
 
Bruce Crain 
 

---------- Original Message ----------
From: "Jim Patillo" <Logistics_engineering@...>
To: main@Q-List.groups.io
Subject: [Q-List] Oil leak - Cylinder Base
Date: Sat, 21 Mar 2020 09:57:07 -0700

Hey Bruce,

I also have an oil leak I’ve been putting off fixing on #2 and #3 cylinders. I think it’s the thru bolts leaking.
I’ve heard that the leak can be stopped by pulling the cylinder away, pushing the thru bolt out a little, wrapping silk thread around the bolt shaft, pushing back in place  and reinstalling the cylinder.

Please let me know what you found and how you repaired it. 


Regards,
Jim
N46JP - Q200

Oil leak - Cylinder Base

Jim Patillo
 

Hey Bruce,

I also have an oil leak I’ve been putting off fixing on #2 and #3 cylinders. I think it’s the thru bolts leaking.
I’ve heard that the leak can be stopped by pulling the cylinder away, pushing the thru bolt out a little, wrapping silk thread around the bolt shaft, pushing back in place  and reinstalling the cylinder.

Please let me know what you found and how you repaired it. 


Regards,
Jim
N46JP - Q200

Re: Transfer Pump "Clicking"

Corbin
 

Thanks guys!  I’ll check for an air leak but I’m not completely sure where I’d see that.  Any tips?

Corbin

On Mar 21, 2020, at 6:49 AM, Mike Dwyer <q200pilot@...> wrote:


The facet pumps make a hell of a racket when they run dry.  Could you have an air leak somewhere that's leaking air into the pump.  Do you have a squeeze bulb in parralel?  I've had a squeeze bulb go bad and one time at high altitude the facet pump was not keeping up with my fuel needs but when I got down to 3000 feet then it was ok.  If your pump is noisy then I'd look at pulling it.  Some auto parts stores carry them.
Mike Q200 N3QP

On Fri, Mar 20, 2020, 21:10 Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR


--

Corbin 
N33QR

Re: Transfer Pump "Clicking"

Bruce Crain
 

I agree with Mike.  When the tank runs dry the pump gets a lot louder!  Then I start looking for a runway!
Also clean out the fuel filter.  You can not see fiberglass in the filters!
Bruce Crain


On Mar 21, 2020, at 8:32 AM, Martin Skiby <mskiby@...> wrote:

Good thought Mike.  If it’s grabbing air that would definitely cause it cuz yes they make a lot of noise pulling air.  I remember being over the desert thinking I had an hour more in the main tank than I did and hearing that pump on the dry tank!!   Quite sobering.   I added a reliable gauge to the main tank soon after!!!

Good luck Corbin.   It may just be a small leak.  Look for bubbles.

Martin

 


On Mar 21, 2020, at 4:49 AM, Mike Dwyer <q200pilot@...> wrote:


The facet pumps make a hell of a racket when they run dry.  Could you have an air leak somewhere that's leaking air into the pump.  Do you have a squeeze bulb in parralel?  I've had a squeeze bulb go bad and one time at high altitude the facet pump was not keeping up with my fuel needs but when I got down to 3000 feet then it was ok.  If your pump is noisy then I'd look at pulling it.  Some auto parts stores carry them.
Mike Q200 N3QP

On Fri, Mar 20, 2020, 21:10 Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR

Re: Transfer Pump "Clicking"

Martin Skiby
 

Good thought Mike.  If it’s grabbing air that would definitely cause it cuz yes they make a lot of noise pulling air.  I remember being over the desert thinking I had an hour more in the main tank than I did and hearing that pump on the dry tank!!   Quite sobering.   I added a reliable gauge to the main tank soon after!!!

Good luck Corbin.   It may just be a small leak.  Look for bubbles.

Martin

 


On Mar 21, 2020, at 4:49 AM, Mike Dwyer <q200pilot@...> wrote:


The facet pumps make a hell of a racket when they run dry.  Could you have an air leak somewhere that's leaking air into the pump.  Do you have a squeeze bulb in parralel?  I've had a squeeze bulb go bad and one time at high altitude the facet pump was not keeping up with my fuel needs but when I got down to 3000 feet then it was ok.  If your pump is noisy then I'd look at pulling it.  Some auto parts stores carry them.
Mike Q200 N3QP

On Fri, Mar 20, 2020, 21:10 Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR

Re: Transfer Pump "Clicking"

Mike Dwyer
 

The facet pumps make a hell of a racket when they run dry.  Could you have an air leak somewhere that's leaking air into the pump.  Do you have a squeeze bulb in parralel?  I've had a squeeze bulb go bad and one time at high altitude the facet pump was not keeping up with my fuel needs but when I got down to 3000 feet then it was ok.  If your pump is noisy then I'd look at pulling it.  Some auto parts stores carry them.
Mike Q200 N3QP

On Fri, Mar 20, 2020, 21:10 Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR

Re: Transfer Pump "Clicking"

Martin Skiby
 

I’m gonna agree with Jay,  if it makes you think about it then change it out.  

Martin

 


On Mar 20, 2020, at 8:17 PM, Jay Scheevel <jay@...> wrote:


Hi Corbin,
If it makes you think about it, then replace it. Not worth the worry, it won't get better on its own, and they are not that expensive. My two cents.

Cheers,
Jay

Sent from my Verizon Wireless 4G LTE DROID


"Corbin via Groups.Io" <c_geiser@...> wrote:

Mine only makes the clicking sound when the main tank gets low and the pump is running “dry”.

Corbin

> On Mar 20, 2020, at 8:24 PM, Joe Hood <joe.hood@...> wrote:
>


--
Corbin
N33QR




Re: Transfer Pump "Clicking"

Jay Scheevel
 

Hi Corbin,
If it makes you think about it, then replace it. Not worth the worry, it won't get better on its own, and they are not that expensive. My two cents.

Cheers,
Jay

Sent from my Verizon Wireless 4G LTE DROID


"Corbin via Groups.Io" <c_geiser@...> wrote:

Mine only makes the clicking sound when the main tank gets low and the pump is running “dry”.

Corbin

> On Mar 20, 2020, at 8:24 PM, Joe Hood <joe.hood@...> wrote:
>


--
Corbin
N33QR




Re: Transfer Pump "Clicking"

Corbin
 

Mine only makes the clicking sound when the main tank gets low and the pump is running “dry”.

Corbin

On Mar 20, 2020, at 8:24 PM, Joe Hood <joe.hood@...> wrote:
--
Corbin
N33QR

Re: Transfer Pump "Clicking"

Joe Hood
 

Is it supposed to make noise? The one in my Q2 does. Now the Citabria I'm using for a tail-wheel endorsement is quiet (and the 172 is loud).


On Fri, Mar 20, 2020 at 9:10 PM Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR

Transfer Pump "Clicking"

Corbin
 

Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR

Re: Sparrow strainer stall

Jay Scheevel
 

Comparison of shape of Roncz, and LS-1 airfoils. (from Q-talk 97)

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Friday, March 20, 2020 4:30 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Copy that David.

I wonder if the Roncz canard has the elevator top air moving in board at cruise or was it designed out?

I think Mark Shuck was working on a Roncz canard to the Quickie.  I don't know what he was planning to do with the calcs.  Would be interesting to see what he came up with and if it would work on the Quickie.  Need for speed!!

Bruce

 


---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 09:06:05 -0700

Bruce,

 

The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 

 

What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.

 

All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 

 

You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.

 

David J. Gall

 

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

Say Jay I

think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.

 

It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.

Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>

Re: Sparrow strainer stall

Jay Scheevel
 

Comparison model data of Roncz versus a few other airfoils of that vintage.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Friday, March 20, 2020 4:30 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Copy that David.

I wonder if the Roncz canard has the elevator top air moving in board at cruise or was it designed out?

I think Mark Shuck was working on a Roncz canard to the Quickie.  I don't know what he was planning to do with the calcs.  Would be interesting to see what he came up with and if it would work on the Quickie.  Need for speed!!

Bruce

 


---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 09:06:05 -0700

Bruce,

 

The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 

 

What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.

 

All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 

 

You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.

 

David J. Gall

 

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

Say Jay I

think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.

 

It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.

Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>

Re: Sparrow strainer stall

Bruce Crain
 

I don't  have a clue as it has been a looong time ago when I set up the strainers.  They were adjustable at first but the  extra bolt heads sticking out in the wind and also the rough texture of the unfinished stainers made the elevator ride up until I put an upside down flap on both of them to make them ride level in cruise.  When I finally glassed them into place they were more effective without the bolt heads so I sanded off enough of the upside down flap to get back cruise level.  Then I filled and sanded the strainers and again they were more effective so I had to sand off equal amounts of upside down flap on the strainers for cruise pitch.  Then lastly I finished primed and painted them and I ended up sanding all but a very small amount of those upside down flaps.  So I got back to almost plans built for level.  Then the stall showed  up when pushing over to lower the nose.
I probably have the most experience with the strainers in "Quickiedom" but then mine are a bit non standard.
 
I am almost finished with pulling the number 4 cylinder chasing an oil seep.  I looks like the through bolts can leak through the treads on many engines so I am putting an o ring into the 2 through bolts and remounting the cylinder and will let you all know how this plays out.
Stay tuned for the "Old and the restless quest for Quickie perfection"!
 
Bruce Crain 


---------- Original Message ----------
From: "One Sky Dog via Groups.Io" <Oneskydog@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 03:55:32 -0700

Bruce,

 
I found your previous description of stalling the sparrow strainers.
 
What is the angle between the lower elevator surface and the bottom of the sparrow strainer airfoil?
 
Regards,


On Mar 19, 2020, at 7:39 PM, Bruce Crain <jcrain2@...> wrote:

Thanks David, 
For a moment I thought it gave me a bit faster airspeed but the I realized that the air was pretty turbulent and I was having a hard time trimming for straight and level.  I do know that someone said "if you trim the elevator up and compensate level cruise trim with the reflexor you get more airspeed.  I cannot confirm that was the case.  And yes the zig zag did work.  Just made the airplane ride nose high for cruise.
 
Bruce

---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 12:10:51 -0700

 

Bruce,
 
I don’t think the zig-zag tape “created drag” the way you describe it. To me, your description seems like the tape was doing exactly what it was supposed to be doing: keeping the airflow energized and attached. The fact that the now-attached airflow made the elevator “ride up” is exactly what one would expect from an improvement in the air flow over the top of the airfoil; instead of matching the new elevator position with reflexor, you could have accepted the “new normal” and trimmed for it. My bet is that you’ll see similar or identical results with VGs. Was the airplane slower as a result? If so, perhaps that was caused by the nose-high attitude you created when you trimmed the reflexor TE up instead of elevator TE down, and not by “added drag” from the zig-zag tape.
 
The problem with the sparrow strainer being stalled is that the little beastie is too small and/or too close to the elevator hinge line. This could be fixed in any of several ways, including making it bigger or re-contouring the elevator. 
 
I wouldn’t count the zig-zag tape as a failure — according to your description, it was eminently successful!
 
David J. Gall

On Mar 18, 2020, at 6:25 PM, Bruce Crain <jcrain2@...> wrote:

Jon, 
I tried the zig zag tape and did get the stall to go away right up the last test where I finally had all of the zig zag cleaned off.  With the zig zag the stall would not happen on the strainer but it created drag and dragged the strainer up and thus the elevator also.  The elevator would ride up a half inch or so and stay and I would reflex the ailerons up to compensate.
 
I am going to test actual vortex generators next.  Trying to make them small enough so that they don't  create drag and pull the elevator up.  So the zig zag did work but with less than great results for the trim I am used to seeing.
 
Before the next tests I am pulling a cylinder to check for a leak around a cylinder base stud or cylinder base o ring perhaps.
 
Bruce Crain


---------- Original Message ----------
From: "Jon Finley" <jd@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Wed, 18 Mar 2020 11:41:07 -0700

Howdy Jay,

I recently heard a woman admit that there are "degrees of yes" - I was stunned. Of course, I was very familiar with this phenomena but had never heard the other gender actually admit to it. Now you are talking about "degrees of stalled" - please confirm your gender!! 

:-)

Seriously, I know you are correct. I also saw this in my GU canard tuft testing (moving up/forward on the airfoil). 

Bruce; I don't know what to say on your strainers. I struggled to know how to set them (and eventually gave up on them on my GU, since they weren't needed/per-plans (instead, springs take up the load, as I recall)).  I imagine you have already tried reducing their angle of attack - and noted some change in stick force?? 

Jon