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  #1  
Old 06-16-2005, 03:26 PM
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JonC JonC is offline
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Default ERacer gear on a Long.

I know that it was done with the Berkut, but has there been anyone out there that has put the ERacer gear setup onto a stock Long?

I have not had a chance to look too closely at a Berkut to see how much space it takes up, but it seems that the rear seat would need to be moved forward a bit to do so... If that is the case I think it may just be more worth it to install Infinity style retracts... however I like the idea of gear that does not have to compress in order to retract, it seems in the event of hydraulic loss that Shirl's gear would just drop to overcentre position due to the pogo stick setup, where the Infinity retracts might manage to get stuck in the wheel wells, or not go fully overcentre...

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  #2  
Old 06-16-2005, 04:27 PM
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Quote:
where the Infinity retracts might manage to get stuck in the wheel wells, or not go fully overcentre...
The strut compression line is isolated from the retract (UP) line. These are two seperate lines.

It requires pressure in the UP line to hold the gear up. If you loose the UP pressure, the gear will freefall to the down and locked position.

The same is true for the Strut. It requires pressure to hold the strut compressed. If you loose pressure, the strut will extend.

The controller is monitoring both of these lines, if there is leak, the pump runs to rebuild pressure. If you have a leak in either of these sysytems, your first indication will be that the pump is running continously, when it shouldn't be. (Normally, the pump will cycle once or twice an hour for several seconds)

In order to get the tire to hit the inside of the wheel well, it would require a very fast (i.e. 1 or two seconds) and total loose of hydraulic pressure in both of these systems, simultaniously., two totally unrelated failures that just happened to occur at exactly the same time. But, if you installed the gear according to the plans, and the inboard wall has a slight "slant" to it, the wheel will gravity fall out of the well as the UP pressure bleeds away, even though the tire is hitting the wall.

If you didn't follow the plans and the wall is straight, or even worst, has an inward slant, The DOWN hydraulic pressure is more than enough to pull the gear out of the well, OR, a good shake of the wings will cause it to fall out, OR, the emergency blow down bottle will definantly force it out.

To summerize, In order for the gear to stay stuck in the well, we assume that we had two, sudden and totally unrelated failures that happened at the same time (UP line and compression line), PLUS, we had a failure of the DOWN hydraulic lines, PLUS, the builder didn't install according to plans, PLUS, the shaking din't work, PLUS, the emergency blow down system failed. If all this happens at the same time, YOUR SCREWED.

Waiter

Last edited by Waiter : 06-16-2005 at 04:52 PM.
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  #3  
Old 06-16-2005, 05:40 PM
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Quote:
Originally Posted by Richard Riley
It takes 6-8" out of the back.
That is what I was kinda afraid of... I really like the design of the gear, but I do not want to have to extend the plane in order to get passenger legroom back.

Quote:
If it's available, I'd use Steve Drybread's gear. Goes on the original Long gear mount points, doesn't take up any back seat area. I know someone bought the molds but I don't have any contact information.
I think I have heard of Steve's gear before, but I have never seen any pictures of it around, I'll have to look into that.


Quote:
Originally Posted by Waiter
To summerize, In order for the gear to stay stuck in the well, we assume that we had two, sudden and totally unrelated failures that happened at the same time (UP line and compression line), PLUS, we had a failure of the DOWN hydraulic lines, PLUS, the builder didn't install according to plans, PLUS, the shaking din't work, PLUS, the emergency blow down system failed. If all this happens at the same time, YOUR SCREWED.

Waiter
Interesting... that makes a little bit more sense to me... I've worked on many hydraulic gear systems, but none that did strut compression as well, so it seemed like some voodoo magic or something to me.

Does the infinity gear have any sort of mechanical down lock or does it just rely on the scissors going overcentre? I know quite a few certified airplanes have some sort of latch that holds the system overcentre until you begin the retract operation independant of hydraulic pressure... I like the idea of being down and locked really meaning down and locked.
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Old 06-16-2005, 05:53 PM
rutanfan rutanfan is offline
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I wish that I knew you were considering the Infinity. I would have sent you my promotional video... I’ll have to look and see if I still have it. I know Richard doesn’t care for the Infinity, but I’m seriously impressed with the gear. There’s a scene in the video where Theeringer is doing figure eights. That wide stance has serious ground handling benefits. Plus your c.g. is moved slightly forward, and you can use a larger prop, and less FOD probability.
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  #5  
Old 06-16-2005, 06:42 PM
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Quote:
I like the idea of being down and locked really meaning down and locked.
When the side brace (scissors) goes over center, its not coming back out. Normally, there is also hydraulic pressure (DOWN) that holds it in the over center position. The actuator is rigged in such a way that in DOWN, it pushes against the side brace and hold it firmly in the over center position. When you apply UP pressure to the actuator, it pulls against the side brace to pull it out of over center. The over centered side brace will keep the gear down, even if you loose DOWN pressure.

I like to error on the side of safety, especially when the consequences of a failure are significant. SO, This is a high priority on my computer controller, i.e. the downlock pressure, ALSO (Being ex military) I've manufactured downlocks that I insert into the side braces while parked. This piece of metal prevents the side brace from coming out of overcenter, even if it has RETRACT pressure applied to it.

I understand that the latest version of the gear has a different actuator that incorporates mechanical locks. You need to talk to JD about this as I'm not sure.

Waiter
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  #6  
Old 06-16-2005, 11:46 PM
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Quote:
Originally Posted by Waiter
I like to error on the side of safety, especially when the consequences of a failure are significant. SO, This is a high priority on my computer controller, i.e. the downlock pressure, ALSO (Being ex military) I've manufactured downlocks that I insert into the side braces while parked. This piece of metal prevents the side brace from coming out of overcenter, even if it has RETRACT pressure applied to it.

I understand that the latest version of the gear has a different actuator that incorporates mechanical locks. You need to talk to JD about this as I'm not sure.

Waiter
Yes, looks like JD and I should have a discussion. I just need to decide if I am inclined to spend $5k on having retracts that will gain me maybe 5-10 knots over gear with fairings and pants.

I like the look of a plane with the gear fully retracted, however I am not hellbent on having it... it is more a farmiliarity thing... I only have like 1 hour in a plane with fixed gear (long story), so it is really creepy for me to not see three green lights on pre-landing checks.

Just kinda looking at options while waiting on the first order to arrive.
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  #7  
Old 06-17-2005, 12:24 AM
argoldman argoldman is offline
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Quote:
Originally Posted by JonC
I only have like 1 hour in a plane with fixed gear (long story), so it is really creepy for me to not see three green lights on pre-landing checks.
In the ez types, you are indeed retractable, although only partially (nose gear). If it makes you feel any better, instead of one green light indicating down and locked, use 3 greens in parallel. When the nose wheel is down and locked, you can be assured that the main gear is also.
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