New Hub Bar Design Project

[asra]

G"day All,I am embarking on

[davidbuzz]

Can you supply it in a format ( like PDF) that"s not a risk for viruses?

[asra]

No Problems, see attachment for PDF format.Cheers Darren

[adrian_clince]

hi there , didnt we have a guy do this sort of study not to long ago?? im thinking last yearcan anyone confirm that ??cheers adrian

[asra]

Yes, that is partially correct. SteveW also an ADFA student, last year looked at the issues surrounding current hub-bar designs. This project looks to find a replacement composite hub-bar with the intention of negating the problems associated with the Aluminium hub-bars.Cheers Darren.

[davidbuzz]

I would suspect that you will get much of the information you desire from the ASRA registrar, who may be able to supply you anonymous data for the GYRO"s currently in service ( or more info if you want).

[Mark Horan]

Guys,last year, SteveW started something that we should all be pleased to support. Both Steve and Darren are in the army and started out working on Black Hawk Helos. They both made the jump from what they were doing to officer training at ADFA (Australian Defence Force Academy / or military university) Steve started someting that I dont think has ever been done in the history of Gyros, he started to measure the forces that occur on the machines we fly. He spent a good deal of time at my place last year measuring forces on hub bars during pre rotation and looking at how hub bars are put together. All data was plotted on a computer and a good picture was shown as to where the weakness in design exists.

[Brian]

Well said Mark, its very true that our sport is held back because its such a costly business to come up with new deigns out of difernt material eg, hub bars.Also at the end of the day, all these new designs have to be field tested.

[GraemeMonro]

Also at the end of the day, all these new designs have to be field tested.I am not much good at "field testing", but I am pretty good at crash testing.Anyone need any help?Graeme.

[Greg Mitchell]

This project looks to find a replacement composite hub-bar with the intention of negating the problems associated with the Aluminium hub-bars.G"Day Darren,If you have not already done so, I would take a good look at the ArrowCopter and their extensive work in composite constructions.This from their web site...Is the mast of the Arrow-Copter made of steel or composite?The Arrow-Copter is entirely constructed from composite materials. Aluminum inserts have been laminated into the composite material and distribute all forces evenly within the cell (e.g., rotor head, engine mount, etc.). All stucturally relevant parts have undergone a Finite-Element analysis (FEM analysis) for a design MTOM of 600 kg according to the British CAP 643 Section T guidelines. These guidelines also allows for generous safety margins. It is a big advantage of the all composite construction that all parts are structurally joined together to form a single, highly stable airframe and chassis. This is how we manage to achieve maximum structural integrity at minimal weight. ...You can find them here:http://www.arrow-copter.com/home_en.htmlThey will have vast amounts of info, maybe some one will talk to you.This link is to a thread on the US Forum re: ArrowCopterhttp://www.rotaryforum.com/forum/s$%^&*srI would also contact John at Rotortec manufacturers of the Cloud Dancer single and two seater gyroplanes, they have done extensive work with composites also. John is a good bloke and will likely be very helpfull.info@rotortec.comMaybe some of this will save you some time or help to validate any of your own findings. Good luck with your project.Mitch

[Greg Mitchell]

a highly efficient innovative composite rotor make traveling at 120 mph a breeze. Just put the pitch adjustable prop in cruise, listen to the muted sound of the fully enclosed engine, adjust the cabin ventilation and temperature to your comfort and watch the landscape speed by, either by looking out the fully enclosed canopy or by monitoring the 3D moving map display on the EFIS. And once you’re there, your landing will be smooth and easy thanks to the cushioning effect of the lift provided by the wings that also double as a rugged landing gear with more than 8 inches of shock absorbing travel. Performance is more about brains than brawns. It’s comforting to know that the Arrow-Copter has both.The Arrow-Copter’s all carbon fiber composite construction is manufactured using the industry renowned facilities of Carbo Tech Composites. Clean room facilities, autoclave curing, laser cutting, CNC machining, ultrasound testing and more are brought to work in order to turn out uncompromising quality.Ultimately, what we tried to achieve is uncompromising harmony. The kind of harmony you experience when you fly an Arrow-Copter and you feel that the machine is a natural extension of yourself. Everything is right where it ought to be and works just how you expect it to. That’s the hallmark of good design.A design creates emotions. Emotions shape values. Values change the future. We predict that the Arrow-Copter will do no less.

[Greg Mitchell]

Talking to a fellow member yesterday when I rembered the US forum had some info about the ArrowCopters blades being a single unit. Transport was the issue.I believe the whole rotor and hub is a composite construction.

[adrian_clince]

ok i have mixed feelings about this allhub bar design is important , sounds like everyone is in competition .with all the stress on the hub bar and rotor should out last each other ? or its time to get a new set of rotors, and new hub bar. a set of rotors and maintaining the gyro ona regular basis is fit for any man or woman who owns a gyro if you want to go fast fly a fixed wing , the rotor head has a major part in contributing stress on the hub bar. so i dunno. i feel it should be all relitive to how its all made, i fly the aks and they fly well the hub bar seems to be a short hub . maybe therefore should it not take longer to achieve the amount of stress thats been found on other designs ?basically why change with whats ya happy with ?cause it seems to be a hell of a lot of hours spent on something we only check when the rotors come down?dunno im all mixed up :|cheers adrian