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  #1  
Old 09-16-2007, 09:06 PM
Aiman Aiman is offline
CozyRG EJ20 Turbo
 
Join Date: Aug 2005
Location: Rochester, NY (KROC, 7G0)
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Default Waiter's Infinity retract controller.

I am planning on installing the infinity retracts into my CozyIV, and I remember somewhere way back when... maybe in a post on here somewhere, he said that he was considering adding "kneeling" logic to the controller, so that the gear would depressurize the oleo without starting the gear retract sequence. I think he said something about making it easier to board the aircraft or whatnot. Has there been any forward progress on this yet? I'd love to see some sort of controller that could do that...
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  #2  
Old 09-16-2007, 10:02 PM
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Waiter Waiter is offline
LongEZ-RG
 
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Location: Northwestern Ohio
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Default Re: Waiter's Infinity retract controller.

Although the "Kneeling" function is possible, I deemed it to risky to implement on Infinity gear that uses the original scheme to compress the strut, and therefore have disabled this feature.


The original scheme uses "UP" pressure that is ported to the struts to compress them. While the pump is compressing the struts with "UP" pressure, the pump is internally venting the "DOWN" line to the built in reservoir. This is the major factor why a Kneel function cannot be implemented using the original configuration.

ALSO, If the strut valve leaks it could vent high pressure from the compressed struts back into the "UP" lines and cause the main gear to become unlocked or worst, start to retract.

If I were to implement the "Kneel" function, I would place a strut valve on both the "UP" and "DOWN" sides.

This way I could use "DOWN" pressure to compress the struts when I want to perform the "Kneel". and use the "UP" valve for normal retracts.

Now, with than said, I don't think you need to compress the struts for retract when the gear is installed in a Cozy IV. IF this is the case, then take the original valve that is supplied by Infinity, and install it in the "DOWN" line. The block of firmware that performs the "Kneel" is installed in my controller, it just needs to be enabled.

You can review installation drawings diagrams and theory of operation for the Infinity gear at:

http://www.iflyez.com/gear_controller.shtml

and

http://www.iflyez.com/InfinityGear.shtml


Let me know if your serious about this.

Waiter
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Last edited by Waiter : 09-16-2007 at 10:14 PM.
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  #3  
Old 09-16-2007, 11:35 PM
Aiman Aiman is offline
CozyRG EJ20 Turbo
 
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Location: Rochester, NY (KROC, 7G0)
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Default Re: Waiter's Infinity retract controller.

Waiter,

I know that it would be possible to have the retracts in the cozy not compress, but I would like to have them compressed in the retracted position to give me a little bit more fuel capacity.

So, forgive my lack of understanding, but, if I wanted to have a kneeling, 'compressed when retracted' gear that was SAFE, I would need a second set of valves? Could those be ordered at a reasonable cost from Infinity? I am definitely going to use that gear system, and your controller.

Will you be at RR this year? I'm toying with the idea of going.
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  #4  
Old 09-17-2007, 12:01 AM
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TMann TMann is offline
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Default Re: Waiter's Infinity retract controller.

I would suggest getting in touch with JD out at Infinity Aerospace. He is very approachable and you can usually catch him after 2:00 PM PT.

If you plan on getting that retract system, it would be a good Idea to get it on order as soon as you can. It will take some time to get it.
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  #5  
Old 09-17-2007, 07:09 AM
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Waiter Waiter is offline
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Default Re: Waiter's Infinity retract controller.

I don't believe having the struts compress will gain you any significant amount of fuel. I would estimate approximately 1/2 gallon total (both sides).

IMHO ; the added weight, complexity, more failure modes to contend with, etc.. If I didn't need to compress the struts, I wouldn't.

Anyway, to compress the struts on the ground (kneel), this is what needs to happen to do it safely. You need to install the original "Strut Compress Solenoid" even if your not going to compress the struts for retract. You will also need a new valve "Kneel Compress Solenoid". (Same exact valve as the original Strut Compress Solenoid, except plumbed into the DOWN line)

KNEEL - Run the pump in the DOWN mode and energize our newly installed "Kneel strut solenoid" to route down pressure to compress the strut. The UP pressure is internally vented inside the pump when the DOWN pump is running.

UN-KNEEL - Run pump in the DOWN mode and energize the "Compress Strut solenoid" This routes the vented strut pressure to the vented UP line. The UP pressure is internally vented inside the pump when the DOWN pump is running.

THINKING OUT LOUD -

One new twist I just thought about - The pump delivers about 1,200 psi in the UP mode, but only about 600 psi in the DOWN mode.

It internally bypasses at this preset pressure. This may not be enough to compress the strut completely if attempting to compress with 600 psi.

In the original configuration, The only time you need the 1,200 psi is to compress the struts. you only need about 600 psi to actually retract the gear.

SO - If your not going to compress the struts before retracting the gear, you could reverse the lines on the pump so it could deliver 1,200 psi in the DOWN and 600 in the UP. This way you would have enough pressure to do a kneel.

****************************

Nope - I can't make it to RR (I'd sure love to). We're in the middle of fall harvest so we're "Making Hay while the Sun shines". My day starts at about 4am and baring any major problems, I get home about 9pm.

Waiter
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Last edited by Waiter : 09-17-2007 at 07:20 AM.
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  #6  
Old 09-17-2007, 10:26 AM
Aiman Aiman is offline
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Default Re: Waiter's Infinity retract controller.

Waiter,

thinking out loud myself here...
I don't know that you would need to connect the 1,200PSI line to the DOWN line. Wouldn't the weight of the aircraft provide that additional compression force on the strut required to make it kneel fully?
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  #7  
Old 09-17-2007, 10:35 AM
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Waiter Waiter is offline
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Default Re: Waiter's Infinity retract controller.

Yah, good point! It might work out OK.

Waiter
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  #8  
Old 09-17-2007, 10:55 AM
Aiman Aiman is offline
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Location: Rochester, NY (KROC, 7G0)
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Default Re: Waiter's Infinity retract controller.

Ok, read back over your post about fuel savings. Though of another thing...

If it will only save 1/2 gal total of fuel to compress the struts when retracted, thats too insignificant to bother with. sooooo....

Is it possible to have the aircraft kneel (strut compress on ground without retract) AND to retract in flight without compressing them? Also, what amount of complexity would it require to add that level of functionality? Is it all controller logic, and an extra solenoid? or is it a couple of extra solenoids, etc?
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  #9  
Old 09-17-2007, 11:21 AM
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TMann TMann is offline
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Default Re: Waiter's Infinity retract controller.

Quote:
Originally Posted by Aiman View Post
Is it possible to have the aircraft kneel (strut compress on ground without retract) AND to retract in flight without compressing them? Also, what amount of complexity would it require to add that level of functionality? Is it all controller logic, and an extra solenoid? or is it a couple of extra solenoids, etc?
You REALLY need to talk to JD.
He would determine if there is any possibilty of swapping out options. As far as I know (in my application) you get a package of parts that is already defined. I'm building a Long-EZ like Waiter and will have to compress the gear as well due to the narrower fuselage. The Cozy builders can go either way but I believe you get the parts regardless.

Another good source of info would be the Cozygirrrl. They have the Infinity retracts and the application would be closer to what you are doing.

You can catch a lot of info on their install as outlined in chapter 21A on their site.
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  #10  
Old 09-17-2007, 01:46 PM
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Waiter Waiter is offline
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Default Re: Waiter's Infinity retract controller.

Comparing to a standard Cozy IV that doesn't need to compress the struts, it adds back a lot of components that you otherwise wouldn't need. i.e.

1) Hydraulic plumbing to both struts for doing the strut compression.

2) The standard Strut Compress Solenoid to switch the hydraulic flow.

3) Strut compression switches OR a hydraulic pressure switch to detect the struts are compressed.

IN ADDITION, you'll need the following hardware to support "Kneel"

1) An additional Kneel compress solenoid to switch Hydraulic flow. (Exact make and model as the Strut Compress Solenoid, except plumbed into the DOWN pressure line.)

2) Mercury "Tilt" switch. detects the deck angle to determine if its safe to perform the kneel function.

3) And of course, "Waiter's Landing Gear Controller"


AS mentioned by TMann, you need to be talking to JD. Keep in mind that JD does not endorse nor support my gear controller.

Waiter
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