Mt 03....

mceagle

Gold Member
Joined
Oct 31, 2003
Messages
1,227
Location
Sunshine Coast, Qld, Australia
Aircraft
Eagle Rotorcraft
Total Flight Time
600 hrs
Most MTs seem to have a tendency to want to roll to the left in flight, so need a bit of right-stick pressure in the cruise.
I agree with Chuck, it must be teeter friction. The torque reaction must be compensated for by the pilot but there should be little or no stick pressure required to do this. The stick is not holding the machine against torque - the rotors are doing that. the stick just changes cyclic pitch on the rotors.
In my opinion having an offset roll pivot is only a gimmic, which would lean the airframe the other way in engine idle or engine off conditions. The few in/lbs difference it would make would probably be negligable compared to the many other objects hanging assymetrically on the airframe (inc. the pilot)
 

steveb

Member
Joined
Mar 29, 2004
Messages
138
Location
Popham Airfield, UK
Aircraft
Magni M16 & M24
Total Flight Time
Lots
Huh?

Huh?

OK guys, now I'm confused. If Ernie or Cierva do it then it is to compensate against engine torque, if it's done on an MT then there's a problem with the teeter friction?

I realise that I'm at a disadvantage here because I just own one, whereas you guys have actually seen a picture ...... !:D

In my experience a tendency to turn isn't that unusual - you can trim it out on a VPM by changing the relative length of the two trim springs.
 

bpearson

Senior Member
Joined
Jun 26, 2004
Messages
946
Location
Nottingham
I have not flown one but have been told by the owner of a VPM (early Magni) that had the engine changed to a Rotax that the machine needed roll input on the stick constantly even with the offset roll bolt.

The VPM/Magni has needle bearings for the teeter movement !
 

C. Beaty

Gold Supporter
Joined
Apr 16, 2004
Messages
9,632
Location
Florida
OK guys, now I'm confused. If Ernie or Cierva do it then it is to compensate against engine torque, if it's done on an MT then there's a problem with the teeter friction?

I realise that I'm at a disadvantage here because I just own one, whereas you guys have actually seen a picture ...... !:D

In my experience a tendency to turn isn't that unusual - you can trim it out on a VPM by changing the relative length of the two trim springs.
Cierva offset the rotorhead as an experiment until he worked out differential tailplane incidence. No C-30 had an offset rotorhead. Nor did the similar but larger Kellett KD-1s.

Ernie doesn’t offset the rotorhead. The roll axle in the “U” block is offset perhaps 1/8” with large redrive Subarus where the tall tail doesn’t completely compensate for prop torque, mostly affecting sideward stick force.

Failure to aerodynamically compensate for propeller torque is yet another way to play Russian roulette with a gyro.
 

Gyro_Kai

Senior Member
Joined
Nov 29, 2006
Messages
3,217
Location
near Frankfurt, Germany
Aircraft
MT-03, Calidus (rent)
Total Flight Time
about 150
The MT-03 looks to be a Chinese copy of the ELA-07 except ELA seems to do a better job of keeping the rotor stiff inplane.
I cannot leave this unresponded.
When two German Gyro-maniacs wanted to get an approved gyro in Germany, there was none. Ela and Magni were not interested in the appearantly difficult approval procedure. One of them owned a company that produces ultralight trikes. In their desperation (this is now my poetic strain) they purchased an Ela and copied it, with the changes that the German authorities requested (no I don't know what they were). So the MT-03 was created and is now almost a monopoly. Magni has the M14 and a weight reduced M16 called M14TT approved in Germany but is not really catching up.

Although I only have little more than 10 hours on my clock so far, I know that it does not fly in circles and the roll axis is just where it feels right :)

Kai.
 

C. Beaty

Gold Supporter
Joined
Apr 16, 2004
Messages
9,632
Location
Florida
The expression; “Chinese copy” is merely an idiom that means unimaginative, piece by piece copy, Gyro Kai. I did not mean literally made in China.

The allegorical story goes that General Electric sold a turbo generator to an Asian country but one of the ship’s crew inadvertently kicked over a bucket of red paint during the voyage. When the copies began appearing in that country, the red paint splotch was perfectly duplicated. A “Chinese copy.”
 
Last edited:

Gyro_Kai

Senior Member
Joined
Nov 29, 2006
Messages
3,217
Location
near Frankfurt, Germany
Aircraft
MT-03, Calidus (rent)
Total Flight Time
about 150
Ah, I see. In German we use the term "chinesische Billigkopie" translating as Chinese cheap copy. This refers to car break pads made of card-board etc.

The craftsmanship on the MT-03 is excellent but agreeably un-imaginative.

Kai.
 
Last edited:

Timchick

Tim Chick
Joined
Sep 15, 2004
Messages
10,888
Location
Panama City, Florida
Aircraft
Sport Copter Vortex, 582 Greyhead
Total Flight Time
~30
If it was built by Germans there's nothing cheap about it. They're some of the best engineers & craftsmen in the world. It doesn't matter if they were copying another design, it will be very well built.
 

C. Beaty

Gold Supporter
Joined
Apr 16, 2004
Messages
9,632
Location
Florida
The prototype for all modern European gyros was the JT-5 by Juka Tervamaki of Finland.

Of all the clones, the Spanish ELA 07 has remained nearest to Tervamaki’s concept of propeller thrust line on or slightly below the CG.

If the MT 03 is a Chinese copy of the ELA, there is hardly a better model to copy.

Mr. Tervamaki is a well respected aeronautical engineer who received his introduction to gyroplanes from having worked for Bensen.
 

Vance

Gyroplane CFI
Joined
Oct 30, 2003
Messages
15,593
Location
Nipomo,California
Aircraft
Givens Predator
Total Flight Time
2200+ in rotorcraft
I don’t feel it is right to copy another person’s design without their permission or compensation. Design and innovation takes focus and that often involves considerable effort and pain. This is the reason for the concept of intellectual property.

Not having to do the work of design saves a lot of resources and gives the thief a competitive advantage.

In my opinion, the people who buy these products are participating in this theft.

Patent laws cannot protect intellectual property. Intellectual property is not easily quantified. The designer hopes that people will respect his property long enough for him to profit from his efforts. It is easy for the designer to be consumed in the defense of his property.

Thank you, Vance
 

bpearson

Senior Member
Joined
Jun 26, 2004
Messages
946
Location
Nottingham
The prototype for all modern European gyros was the JT-5 by Juka Tervamaki of Finland.

Of all the clones, the Spanish ELA 07 has remained nearest to Tervamaki’s concept of propeller thrust line on or slightly below the CG.

If the MT 03 is a Chinese copy of the ELA, there is hardly a better model to copy.

Mr. Tervamaki is a well respected aeronautical engineer who received his introduction to gyroplanes from having worked for Bensen.
Are the results of the double hang test that prove this, available Chuck ?
 

C. Beaty

Gold Supporter
Joined
Apr 16, 2004
Messages
9,632
Location
Florida
Are the results of the double hang test that prove this, available Chuck ?
I don’t know, Brian.

In the case of the JT-5, with all the bits and pieces in a pile, Tervamaki was quite capable of weighing each bit and calculating the CG to within a small fraction of an inch.

The easiest method of measuring CG is to weigh the machine at two different angles, compute horizontal CG in each instance and to calculate the crossing point. This demands accurate scales as well as an accurate clinometer since the angles are small. Ordinary bathroom scales aren’t good enough but commercial clinometers such as the “Smart Level” are fine.

I have a spreadsheet that performs the calculations if anyone would like a copy.
 

bpearson

Senior Member
Joined
Jun 26, 2004
Messages
946
Location
Nottingham
I was refering to the ELA Chuck. The MT as far as I know has never had the v c of G tested as this isn't a requirement for sec T, which relies more on flight testing and this it obviously passed.

I would have thought there too many variables such as blade weight and fuel location to be able to determine if the ELA is CLT without doing the tests.
 

Vance

Gyroplane CFI
Joined
Oct 30, 2003
Messages
15,593
Location
Nipomo,California
Aircraft
Givens Predator
Total Flight Time
2200+ in rotorcraft
Hello Mr Beaty,

I would love to have a copy of your spreadsheet.

Thank you, Vance
 

C. Beaty

Gold Supporter
Joined
Apr 16, 2004
Messages
9,632
Location
Florida
Vance, you remind me of one of those characters that attends trade shows pulling a child’s coaster wagon to hold all the literature he collects.

Nontheless, a copy will be on its way as soon as I receive your E-mail address.
 

Vance

Gyroplane CFI
Joined
Oct 30, 2003
Messages
15,593
Location
Nipomo,California
Aircraft
Givens Predator
Total Flight Time
2200+ in rotorcraft
Thank you Chuck.

I appreciate you generosity with your considerable knowledge.

I have spent a lot of time with a weight and balance spread sheet and computer drawings.

I use datum lines and then convert them to the center of gravity. I didn’t do well with pluses and minuses.

I have come within a couple of inches on the things I have built.

Center of gravity is important on a motorcycle.

I suspect that you have a more elegant way to do it.

I do love to collect information, but my laptop is my wagon.

When I am not struggling to rebuild I apply the things I have collected in my wagon.

I am nearly back on track.

Thank you, Vance
 

Vance

Gyroplane CFI
Joined
Oct 30, 2003
Messages
15,593
Location
Nipomo,California
Aircraft
Givens Predator
Total Flight Time
2200+ in rotorcraft
That is very cleaver Chuck.

I will try to make it work before Bensen Days.

I look forward to seeing you.

Thank you again, Vance
 

StanFoster

Newbie
Joined
Nov 16, 2003
Messages
16,880
Location
Paxton, Il
Aircraft
Helicycle N360SF
Total Flight Time
1250
Vance: Hey....cant wait to talk to you at Bensen Days. Keep your dream alive pal. :)


Stan
 

C. Beaty

Gold Supporter
Joined
Apr 16, 2004
Messages
9,632
Location
Florida
That is very cleaver Chuck.

I will try to make it work before Bensen Days.
It works now, Vance. There’s nothing you need to do except plug in numbers and it will spit out the answer in nanoseconds; assuming you have Excel or compatible spread sheet program.

The calculation sequence is locked so there is nothing you can do to hurt it. Any cell not highlighted in yellow can receive whatever entry you like.

The default numbers are simply a check on functionality. The attachment shows the default setting.
 

Attachments

Top