Build thread on the GT-VX2 Explorer.

Nice pics mate, what has changed on the "new improved rotor head"?

Thanks wolfy

Thank you Wolfy, yes they aren’t too bad. As for the ’new improved’, due to the increased weight of the VX2 the rotor head has been beefed up to a double bearing system. The width was increased to allow the use of retaining clips on the teeter bolt hat bushings. The most visible change was the addition of polyurethane-cushioned teeter stops.

IMG_20200722_150450.jpg


Teeter bolt hat bushing held in position with retaining circlip
IMG_20200723_081427.jpg


The rotor head maintains the main features of the single bearing unit, which were the fully contoured hard stops and the built in hydraulic rotor brake & lock.

Thanks a lot,
there is no rush
cheers
jmi
ps: my gyro is nearly finished thank you

The swing on the rudder is + - 30 degrees.
 
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So far we have not really had the opportunity to see Blue with her 25’ Razor Blades mounted.
Denis has sent these that will rectify that situation as she presently sits at Mentone with her sisters
Denis’s Blackie, and the silver machine.

It also allows a closer look at those marvellous new Razor Blade Rotors that Denis has been working so
hard on develop.ing
Blades on!.jpg

A rear view.
Rear View.jpg


Side view top of the mast.
Blades mounted.jpg


Showing her teeter stops from the back...
Teeter Stops A.jpg


...and from the front.
Teeter Stops B.jpg


With the rotors on the back stop, and the gyro on its tailwheel there is still blade/tip clearance from both tall tail and the ground. Any coning
up and clearance immediately increases.
Ground clearance.jpg


These really do show her in all her glory, and, a superb example of how Denis rose to the requests he had received for a 912 powered machine.

The GT-VX2 Explorer is a huge step-up from the shorter range GT-VX1, and most other 2 stroke singles. It has certainly fulfilled a long held desire of mine for a more capable machine that fills a niche for a single seater that could go further, and have the power and ability to carry some basic camping gear as well as the toothbrush in your pocket. :)
 
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Thanks Denis, seems I underestimated a bit.

How does that compare with your rudder JM?
 
Beautiful gyro
 
Thanks Denis, seems I underestimated a bit.

How does that compare with your rudder JM?
Leigh, although the cutout in the HS is 35° each side. The travel of the rubber is limited to ~+-30° each way by the pedal horns to prevent the rudder from slapping against the HSs
Beautiful day at Mentone.... Time to go fly!
 
Could we get a picture of you sitting on the gyro to give us reference for distance to the control panel, for my old eyesight it would be nice to have it as close as possible, even maybe a heads up display in my helmet.
 
Thank you Wolfy, yes they aren’t too bad. As for the ’new improved’, due to the increased weight of the VX2 the rotor head has been beefed up to a double bearing system. The width was increased to allow the use of retaining clips on the teeter bolt hat bushings. The most visible change was the addition of polyurethane-cushioned teeter stops.

View attachment 1147897


Teeter bolt hat bushing held in position with retaining circlip
View attachment 1147898


The rotor head maintains the main features of the single bearing unit, which were the fully contoured hard stops and the built in hydraulic rotor brake & lock.



The swing on the rudder is + - 30 degrees.
That's the teeter stop tops held in with snap rings, not the teeter bolt hat bushings
 
The Cl max of a symmetrical airfoil with infinite aspect ratio is near18 degrees.
An aspect ratio of 4 increases this angle by about Cl / π. A (radians) i.e 4 degrees.
Turning a monobloc rudder beyond 22 degrees appears to me counter productive to stop a yaw.
 
The Cl max of a symmetrical airfoil with infinite aspect ratio is near18 degrees.
An aspect ratio of 4 increases this angle by about Cl / π. A (radians) i.e 4 degrees.
Turning a monobloc rudder beyond 22 degrees appears to me counter productive to stop a yaw.
It is anticipated that most pilots will use only enough rudder to counteract the yaw.

Sadly there have been cases where excessive and aggressive rudder inputs have had tragic results.

This was the case with American Airlines 587 in 2001 where the first officers attempts to stabilise the aircraft with alternating aggressive rudder inputs resulted the force of the airflow against the rudder stressing the aircraft's vertical stabiliser to the point of snapping off. This caused total loss of control and all on board.
 
Nice attention to detail. Love the blue. Has it flown yet?
 
Nice attention to detail. Love the blue. Has it flown yet?

Thank you Greg. Yes the blue has worked very well both for my first, and now for this. No flight yet but certainly looking forward to it.
 
The Cl max of a symmetrical airfoil with infinite aspect ratio is near18 degrees.
An aspect ratio of 4 increases this angle by about Cl / π. A (radians) i.e 4 degrees.
Turning a monobloc rudder beyond 22 degrees appears to me counter productive to stop a yaw.

No reference to AS. I think you are talking about air speeds in excess of 60 MPH, and at 45 MPH this math doesn't hold up.
 
You realize of course that "GT" stands for Greg Taylor. :cool:
 
The transverse force that can be produced by your monoblock surface is given by the formula known to all aerodynamicists:
F = 0.5 ρ * s * v² * cL
If the Reynolds Number is only 800,000, then cL is maximum when the A.o.A is about 18 degrees .
This is what the NACA report n° 610 shows, fig 4, for example:

Sans titre.png

This angle is gived for an infinite aspect ratio.
Whereas the rudder has an aspect ratio of about 4.
l must then add the angle induced under Prandtl's theory discovered in 1911
Induced angle (radians) = cL / π*A Hence 4 degrees for cL = 1.2
So, 22 degrees gives the maximum result and 35 degrees gives clearly less (observe the NACA curve)

Have the laws of aerodynamics been repealed recently?
 
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Yes, when the angle of attack becomes too large, the airflow no longer remains attached to the dorsal wall and lift decreases. Fast or slow speed doesn't change this. Just a matter of angle.
 
Thank you Jean Claude that was most informative.
 
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