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Another observation at the Nationals was the wealth of aircraft sporting one piece formed fiberglass or Aluminium landing gear like Owen Dulls, Magnis etc.I would value people"s experiences with this hardware as I like the modern look and the inherent mounting simplicity. My sturdy Rosco designed G2244 with it"s 3 point strut gear suits my novitiate status but I question if this design model is as good as these other newer systems with no malignment or opaque disparagement of the original design intended. Perhaps other builders are also interested in the pros and cons of these other systems and perhaps there is room here for discussion by the expert manufacturers on the inherent flaws or benefits of either design and possibly others in my ignorance that I obviously do not know exist.With the unfortunate failure to support an aircraft whilst trailered might be a one off incident (as noted at the Nationals) and this appeared to be a 3 piece unit with one portion only failing, has this been a problem elsewhere?Whilst on this subject I do like the benefit of disk brakes on the Mains only and indeed differential braking as on Sportcopter.Those reflecting on these comments could perhaps consider directing me to suitable Aussie manufacturers and or suppliers of appropriate one piece fiberglass or Aluminium axles and or axle/brake combinations.That is of course if the discussion does not shed adverse light on these landing gear systems.Over to the expertsMike
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Mike,Owen Dull is the only manufacturer of composite landing gear in OZ specificaly for gyro"s that I am aware of at this time but I am sure there would be others that could purpose build for you.Building in composite is not as simple as the conventional metal designs you would have seen and generaly more expensive in my experience. It is also easier to design "light but strong and simple" using alloy.I agree that composite looks good!Adrian
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Hi Adrian.Just a quick question. I love Owen Dull"s machines and think they are up with some of the best gyro"s in the world. A real credit to the man.At the last Nationals I had a look at the fiberglass landing gear. I know there are quiet a few flying, and many flying hours, but am still in 2 minds as to its attachment method. It is simply clamped and nothing else. During taxiing they seem to sway slightly, side to side, and must place a twisting force on the keel.What are your thought
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Thanks Adrian and Sam for your comments.I would be interested also in a reply to Sam"s observations of swaying and possible keel stress.Adrian, Owen, anyone?Would appreciate some comments from those who have used the one and two piece alloy systems also.Do they all invoke keel stress if not used with additional stays fore and or aft and vertically?Mike
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Keel stress,Here is a term I havent heard before!, at least not in the realm of a gyro. Maybe, in battleship designs, keel stress may be a term that is used often, I wouldnt know.The point here is, We are not building battleships. Battleships are heavy, gyros that fly are light. Gyros that are built like battleships dont fly and they dont float, they flogg across the ground like a very expensive Go-cart, leave the earth in ground effect, catch fences trees and unwary wilderbeasts, leaving their builders disenchanted and giving Gyros a bad name.I have been the owner of 3 such machines.
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Guys,I think Mark has covered it well , there is not to much I need to add other than Owens attachment method has been well proven in the mustering environment and I believe he recommends changing the undercart at 1000hrs.Adrian
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Whilst we have this thread going.Sam, I seem to remember something about shocks and there attachments. Wearing more if installed one way rather than the other.Where can I get some rubber donuts to try out? Think I will play with a variable shock now. I noticed my shocks (situated at top of mains down strut) are a little worn/loose.Adrian, what say you re: my shock setup?G"Day Marcus.Mitch
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Thanks,it would appear my extrapolation of Sam"s observation of must place a twisting force on the keel into Keel Stress caused some angst.However Mark did mirror my own observations of other aircraft large and small.....As for Owens maingear design, check out the attachments of the mains on most light aircraft (lots heavier and taller than the humble Gyro) you will discover that there are hardly any with struts braces and the like.Having owned (and flown) my Rosco design Gyro with that well known suspension design for over 4 years, I have often pondered that very statement.It is an admittedly light in weight but cumbersome fore and aft and vertical bracing suspension design.However, I want to modernise in my next project only if it is both advisable in an aviation engineering and or technical sense and Adrian"s comment Owens attachment method has been well proven in the mustering environment confirms my suspicions that this is a sensible avenue to pursue.Still, Owen is not the only builder to use one piece designs and I would like to hear from other builders of Aluminium units like the vertically braced G203 and other alloy designs with brakes.What I would really like to generate is some constructive Pros and Cons of the various designs by a wider range of builders. Comments from a few is a helpfull start, but does not solidify my opinions either way or perhaps that of discerning others reading these lines with similar building aspirations I imagine.Main wheel braking systems was also mentioned and I guess that includes builders of suitable Pedal assemblies incorporating Toe brakes using hydraulic systems that might be inclined to post there experiences with pictures too.Back to the lurking experts for your thoughts,Mike
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Fellers I disagree with one point, most aircraft seem to have un braced undercarage. Most are braced internally. An example used on gyros today in OZ is the Drifter setup. The bracing is small and close coupled to the keel. This is very strong and does give the setup enougth bracing to make it strong and resist any swaying. Sam....
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Sam,I can see what you are driving at, however given the choice between the two, I would still prefer the system constructed by Owen. In the last Photo you posted, the weakness, appears to me, to be in relying on the strength of the downtube to resist all the twisting and bending moments associated with the fulcrum effect rather than the strength of the attachment and bracing itself.In the first picture, my concerns over the effect of a fulcrum are reduced by the depth of the section to resist deflection (horizontally) leaving the attachment as the only question,which ,looking at the picture appears to be fairly wide with a substantial bracket to complete the fixing. In addition, the member that the axle/supension is attached to, is rather short,making it more resistant to deflection, but placing more pressure on the attachment itself. Hence the big plate over the top.I think that your impression of a machine "going from side to side" may have more to do with any machine with some form of suspension rather than being peculiar to one type or another, I noticed the same effect in one of my own machines that had several inches of travel in the mains.Personally, flying off my strip which is pretty rough, I would go for the first picture, there is some suspension effect, it is lower to the ground, it is perhaps less draggy in the air? and in my brain, the main point of failure is at the attachment, rather than where a brace may intersect a member. On a nice paved strip? dont think it really matters, as long as you can flare properly.regards,Mark,
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Hi MarkAll your comments are fair and reasnable. Please dont get me wrong, I like the Owen machine, its just an observation I made at the last Nationals at Lameroo. I belive this forum is a great place to discuss such design topics as this one.
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Sam,Fair comment.Marcus.
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Gday MikeThe stress on the keel is something that has concerned me to as I have been fitting/manufacturing composite suspension with a mate (thanks Keith ) .We have retro fitted a few Rosco"s
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