View Full Version : Working out the Centre Line Thrust Position.
09-01-2004, 10:30 PM
Sorry to show my ignorance but I are helping a friend build a Gyro from scratch, we are not following any plan. Not a flyer myself but one thing that really concerns me is
how do you work out the exact position where the centre line of thrust should be?
Should the gyro be hung tested up from the back by hanging it from the centre of the prop? To see if it hangs level. Yes up on its end, weighted inside as it would be flown of course.
Up to this point I have been unable to get a definite answer from a number of gyro flyers who have looked at what we are making and seem quite impressed with what we have done so far. Most just say try to get the line as close as possible to the centre of your stomach. I want to be much more exact on this as it seems critical towards its overall safety.
09-02-2004, 12:15 AM
If you go to this thread ,
Center of Mass(CoM) by the pic method. ( 1 2 3 )
under "theory of flight" ,you'll get a better understanding of CLT.
09-02-2004, 03:38 AM
Barry, could you post a pic of the project, or direct us to a link where some pics could be viewed? It might help some of the talented designers on this forum to better understand your project. By the way, welcome to this board!
09-05-2004, 01:28 AM
Thanks David for the link, I think we may be making a few changes as you will see in the link and drawing I have shown.
Brian you will see some pictures on this link: http://www.westglass.co.nz/special_products_page_.htm
I think we may have to lower the engine and raise the cabin, as you can see we still have away to go, any suggests are very much appreciated but if all else falls we can just run up and down the runway giving the kiddies rides.
09-05-2004, 01:42 AM
Looks neat,and heavy.Wots the weight so far???
Any idea wot the hang test is likely to be???Looks to be nose heavy in the pic.
09-05-2004, 01:48 AM
Thank you, Barry.
My request for photos was for the benefit of those on this forum that have a working knowledge of aerodynamics whom could help you, such as you requested. I cannot offer any assistance myself, but am confident you will now receive educated responses from experienced people.
09-05-2004, 05:40 PM
That is one nice start to a gyro. Looking at what you have done so far there are a few things that come to mind.
below are a few things I have found that help in achieving CLT, and would suggest that you incorporate them to ease the amount of trial and error that I had to endure. :eek:
1) reverse the gearbox on the engine so that the engine weight is 8" higher.
2) make sure that the fuel is as high as you can arrange it.
3) Use an electric pre rotator, and keep the battery as high as is possible.
4) Use one of the heavier rotor blades systems availible to keep weight up
and also to give a better ride in rough air and ease of landing with the
extra kinetic energy that the heavier rotor blades have.
5) Possibly lifting the cabin 3" to lift the weight of the cabin and occupants
The main points to remember to achieve CLT are to keep as much weight higher up and the propellor thrust line lower down. I have always wanted to keep the entry and exit to the machine user friendly. The above points are just food for thought from my years of playing around with gryoplane geometry to achieve CLT and use friendliness.
Drag also needs to be considered, BUT at the speeds we fly, drag plays a very much smaller part than the CoM (Center of Mass) in the scheme of CLT.
Aussie paul. :)
09-06-2004, 03:39 AM
Good onya Paul. :)
Ps;Your in danger of becom'n a good man. ;)
09-06-2004, 06:39 AM
Birdy, I have very bad news for my livelihood.
Today I recieved a letter from CASA saying that they do not intend to grant me permission to operate from licenced aerodromes including Ballarat!!!!! I am now forced to operate below 500' and not able to use decent airports!!!!
I have been operating from Ballarat for 14 years with CASA approval, and no problems.
It seems that I was "dobbed in" up at the National competitions up your way at Easter by a member or members of the ASRA board for reckless flying!!!!!!!!!
Funny how every single seat gyroplane operated illegally every time they flew but never got "dobbed in".
I reckon that if I had crashed on the way or not made the distance, not word would have been said!!!!! :mad:
I guess I will have to make it all hit the fan now!!!! That is not what I want, but is what I am forced to do, and all because of a personal vendetta by one or more ASRA board members. Does Diabetes and a certain board member ring a bell? This will be very interesting. I have never had to take people to task for discrimination or harrasment before. I think my lawyer can see some potential!!!! :eek:
One can only be pushed around for so long!!!! :eek:
It seems like I have two choices. Fight City Hall, or go fly fixed wing ultralights. I don't need this s**t!!!!!!!!!!!!! :eek:
I have put more time into helping gyro pilots than anyone else in the country, yes, I have been paid for a lot of it, but I have not seen anyone become rich from gyroplane training!!!!!!
Stuff my peers!!!!!
I am very angry tonight as you may have guessed!!!!!!!! Sorry all.
09-06-2004, 10:40 AM
Sorry to hear that Paul. Good luck on getting your privelages back. Give 'em hell!
09-06-2004, 09:05 PM
Hmmmm........I don't know **** bout wot your say'n Paul but to me it sounds like sour grapes. :(
I reckon you'v been piss'n people off for a while and you'v just broken the camels back with your "reckless" fly'n.As stupid as the authorities can be,I don't reckon they could give a toss bout a tin pot gyro instructer,unless he's done something bad enough to warrent grounding.A tin pot gyro instructers scalp is'nt much of a trophey to a egotistical public servant. ;)
As I said,I don't know **** bout the situation,but wot you keep say'n don't add up. :confused:
A full story or stop you bitch'n Paul. ;)
09-07-2004, 07:36 PM
Wait a minute. I only caught a glimpse of the posts about the aussie nationals through this forum but one post I remember is "Birdy's dirt bike of the air." Also, from the nature of chasing cows with aircraft I would hazard a guess that your "feral" flying would appear much more reckless than Paul B. poking around in his heavy RAF, at least to government officials.
So I would guess something else is going on (admittedly from a great distance about a situation I know nothing about!) like perhaps landing at the outback fuel stations causing a stir?
I am sorry to hear of your situation Paul B., I've enjoyed your posts and learned quite a bit from your efforts, tenacity and endurance. (I guess that is why I feel the need to defend him, because as we all know he ain't much to look at, kind of long in the tooth, lop-eared and craggy faced!)
Seriously, Birdy did you see any reckless flying performed by Paul B. at the Australian national gyroplane fly-in at Alice Springs or do you think there is some other motives to the charges against him? darrellwittke
09-08-2004, 12:09 AM
Yeah right Birdy. You know jack ****!!!! That post of yours is not worth replying to.
09-08-2004, 02:34 AM
Darrell.To put it diplomaticaly,I did see a couple of things that I reckon would have raised official eyebrows.
None of it bothered me,but I'm not an official.
I'm not accuseing or defending Paul,how can I??none of us know any deatales.
But I'm not budging from wot I said above,put up or shut up.
You can't expect support or sympathy from anyone if we don't know the FULL story.
So far we'v only heard Pauls side of the coin.
Personaly I hope it's all a missunderstanding and Paul can carry on as before,coz his gyro knowlage can only be of benifit to the gyro scene.
But I'v a feeling I'm go'n to be dissapointed.
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