Author Topic: Canted gear questioning...  (Read 524 times)

Offline Sylvain

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Canted gear questioning...
« on: March 21, 2021, 06:31:06 AM »
Hi Guys.
For those who built and flew the Double Eagle, did you build with the canted gear?
My question is is it really needed? Is the nose so heavy to risk tipping when braking or landing on soft ground?
I just completed both main canted gear legs and started figuring the cross braces and chock build.
Apart from the complexity of the canted geometry, the more I look at it, the more I have doubts about the strength of this geometry compared to a straight non canted gear.
What is your experience with it? I would appreciate any input and opinions on the subject.

Thanks!
Sylvain
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Montreal QC Canada

Offline Tom H

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Re: Canted gear questioning...
« Reply #1 on: March 22, 2021, 06:47:26 AM »
Sylvain, when we were building DE Stubby, it seemed important to install the canted gear, based on reports of nose over incidents.  We did install the canted gear, and it is still on today.

However, after years of flying Stubby, I have come to believe it is not needed.  The canted gear puts more weight on the tailwheel when sitting on the ground.  It is quite a load (somewhere around 40 lbs) to pick the tail up by hand to move the empty airplane, plus it puts a lot of stress on the tailwheel and  spring.  There is even more of a tailwheel load when the airplane is loaded.

The canted gear also shifts the flying CG towards the front, although probably only a small amount.  Stubby has a full featured engine, so we did not need any more weight towards the front.

I may some day modify the gear back to straight.

Hope that helps.
Tom H
Stubby, a BDE
Treehugger, LEU

Offline Sylvain

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Re: Canted gear questioning...
« Reply #2 on: March 22, 2021, 07:50:42 AM »
Hi Tom, thanks a lot for your input! I also read your other posts on the subject. Very informative, I will definitely consider!
For now, both legs are built cantered, still have the chocks and braces to build and rigg. The braces will need a particular geometry to make sute the chocks and landing gear move in the same plane.
I got an answer from John Bolding saying the canted gear is really necessary, waiting for Leonard's answer.
I will continue with the canted gear but since i am at it and I have some time, I might build another set of straight and not cantered gear that I could easily replace an test later.
For me, the fore weight of the canted gear is not an issue, I have a HKS700E ready to install, installed weight is 126 pounds all included. It however needs to spin a larger prop, I will raise the thrust line to about the level of the top of the firewall. The engine itself will renain centered avout the same as for the standard VW installation. I also needed to redesign a slightly higher landing gear than what the plans proposed.

Cheers!
Sylvain.
DE Builder (With HKS 700e)
Montreal QC Canada

Offline Sylvain

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Re: Canted gear questioning...
« Reply #3 on: March 22, 2021, 12:56:42 PM »
Hi again Tom.
The answer from Leonard:

Hi .
The original Double Eagle with an 1835cc engine once at Oshkosh while I was landing down hill fast I applied the brakes pretty hard the tail came up and the prop got a small piece of grass and I let go of the brakes and every thing was ok then as it turns out the go cart type of brakes I used will grab when they get hot they have never given any trouble under normal use  landing and braking hard on level ground a a aeronautical engineer friend was kind enough to design a slanted gear for those that wanted it.  If I were to build another Double Eagle I would build it like the original one.  Leonard

Considering your comment and Leonards one, I guess I will rebuild the gear simply straight.
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Offline rfeenstra

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Re: Canted gear questioning...
« Reply #4 on: March 25, 2021, 04:26:30 PM »
I have never had an issue with the straight gear.  Once you get the CG back a bit where it flies better, there is no tendency to nose over.  Keep up elevator when braking hard!

Offline Sylvain

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Re: Canted gear questioning...
« Reply #5 on: March 25, 2021, 04:38:47 PM »
Thanks! What is the best cg position?
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Offline rfeenstra

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Re: Canted gear questioning...
« Reply #6 on: March 28, 2021, 08:22:01 PM »
As I recall without looking, I'm at about 28% MAC.  I know others are closer to 30%.

 

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