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Gents,Being tired of having nose wheels collapse on me and seeing it happen to others has bought about this design idea - see image attached.The idea is that the nosewheel is on a swing arm as can be seen pivoting from the bolt at the back, the swing arm is captured so that the failure of a bolt will result in the swing arm being retained. There is an elastomeric [urethane] bush in the front retainer that acts as suspension, the RHS captures the swing arm as well. The amount of travel and suspension dampening can be controlled by the distance between the front and rear bushes and the hardness of the urethane compound.The componentry is to be steel RHS- all engineered to less than 50 MPa stress level, bent where possible and stress relieved through annealing.Steerage is to be through linkages to the front steering yoke - yet to be detailed and the steerage [straight ahead] is to be maintained by springs which are independent of the linkages, the alternate being a lightly loaded detent. The forward rake of the forks is 30ø and this provides a 25mm Trail from the front geometry to the contact patch, I think this should be enough for self alignment under forward travel.The arm will have some torsional stiffness to prevent it from buckling sideways as well.The pin at the back will be in a tube which is not shown as yet.I have seen trailing caster wheels collapse onto the keel of the gyro - as happened with my machine and also John"s machine at Denman when he had his accident a few years back, what happens in this instance is that the nose wheel collapses onto the keel, becoming an instant brake, resulting in the gyro tumbling over the nose wheel. I"d rather have something indestructable up front so that if I"m making the mistake of a nose heavy landing it does the best it can to prevent a pitch over by continuing to roll in lieu of locking up on the keel.I am going to add a brake to the assembly once I can find a suitable one.Can anyone see any likely shortcomings in the arrangement?Nic.
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Hi Nick The new Kruza by GT Gyroplanes in Echuca Vic, uses the same type of design.They have also opted for a fully castering front wheel with toe brake steering.Sam.....
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Nick,
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Eric,That is a very tidy design, I like it. The photo angle makes it a little difficult to determine - how much caster have you got on it? Being a wide tyre does that effect the amount of caster you need to have to stop it from fluttering - I"m sure it works out that with a little more weight on it the caster distance increases.What happens if the shock collapses? Can the tyre lock up on the shock / keel / wheel strut and become an instant brake? That was - apart from the collapse of the spring cross member
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Nic,
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Eric,Do you have brakes on your mains? I cant see one on this wheel so I"m assuming that is where you"ve got them if at all.Does the design flutter at all? You said you"ve only got 15mm af caster in it so it seems pretty fine to me, when the gyro is loaded up with weight what is the caster more likely to be?With the m/c front end I was thinking about it and remembered that Mitch - "Mr Butterly" to you - was expounding Larry"s flying motorcycle - he"s used a motorcycle front end on that machine so I guess it isn"t too much of an issue with respect to inertia and tripping over the front wheel when you try to get it spinning.I agree with the idea of not having much if any forward speed on landing, however, as a novice there were a few times when this might occur - eg, touch and goes if you practice them, and you should. I guess my problem is that I am always expecting the worst to happen at any time - typical engineering philosphy...Cheers,Nick.
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