Building Mariah Gale

[Vance]

Not Anticlimatic!

Not Anticlimatic!

And we Vance... are all looking forward to an explosive culmination.:rapture:

We can only hope the layup is not anticlimactic Leigh.

I never imagined that we were talking about a year long project when we began work on the empennage in December of 2010.

The process has been fun and I feel the result will exceed my ability to imagine.

I love working with these guys.

Mike claims that the body will not take nearly as long.

The wild fantasy is it will at least be ready to display at the Hollister air show at the end of May.

I am flying either The Predator or Mariah Gale in the Hollister air show.

Mike and I both do a lot of traveling the first part of the year so this is probably a stretch.

Things are moving along but there is still a lot to do and money to spend before Mariah Gale flies off her 40 hours.

Thank you, Vance

 

[Friendly]

you don't realize how big that HS is until you see it in the picture with a person standing next to it.
WoW! That is going to be a unique gyro.

 

[Vance]

Mariah Gale has a Big Butt!

Mariah Gale has a Big Butt!

I have to admit to the same reaction Mark.

I have to reaffirm my commitment to large tail surfaces each time I see it or think about how much it will weigh.

Mariah Gale’s vertical stabilizer, rudder and horizontal stabilizer have very close to the same area as The Predator’s with a slightly longer moment arm. Because The Predator is tall and long it doesn’t look too out of proportion.

I feel that Mark was headed in the right direction with such large control surfaces.

I like the horizontal stabilizer on the bottom because the ground effect gives me a little kick when it is time to flair.

I have raised the horizontal stabilizer up a bit with the new keel but it is longer than the one on The Predator so I hope I have not lost that quality.

I prefer an articulated vertical stabilizer/rudder and can only hope it works as well as The Predator’s.

We are making an effort to seal the gap between the vertical stabilizer and the rudder.

We used airfoils to reduce drag and soften a stall.

Most people that see the empennage think it is too large and unnecessarily heavy for a gyroplane.

I am surprised that people on the forum have not been more critical.

We are trying to reduce the drag of The Predator by 30% and in my experience streamlining makes a thing more prone to divergence. The large empennage is our way of trying to stay ahead of that challenge.

We expect the empennage to be 10 pounds heavier than the tube and fabric one on The Predator. That is a 50% increase in weight. The keel will probably be more than ten pounds lighter so it is sort of a push.

That is the goal throughout the project; improve something a little without paying for it.

Horizontal stabilizer width: 74.25” Wide chord: 47” Narrow chord: 39.75”

Vertical stabilizer/rudder height: 50” Wide chord: 47” Narrow chord: 35.4”


Thank you, Vance

 

[Friendly]

Mariah Gale has a Big Butt!
Vance,
I think J Lopez has made that a very accepted profile,:tape:

 

[Resasi]

In Vance's depiction of his long held dream that is taking shape, I personally find Mariah's empennage rather elegant.

I think it appears quite in proportion, and in fact bears a fleeting resemblance to that of another rather fine machine, the Genesis.

And that one, as we all have witnessed, works extremely well.

 

[Vance]

More progress!

More progress!

Thank you Leigh,

I am pleased with how she looks but many who have seen the empennage find it is outside of what they have seen on a gyroplane.

Mike has found that the empennage attracts a lot of attention whenever he is showing someone around and they often offer advice on gyroplane design and what works the best.

The shape of the body will define itself and the doodle is only the vaguest representation of proportions that I use for identifying clearance and the general location of things. I try to keep up with the changes that come with designing on the fly.

I had a very productive and enjoyable visit with Jim.

It doesn’t always happen but sometimes we get so excited we start finishing each other’s sentences and answering questions before they are asked. Eventually we have to just stop and laugh.

Jim seems fully recovered from his sick experience but we lost more than a week.

He has been making little parts and planning out the truss so progress on the keel seemed particularly slow moving.

One of the unasked questions on the keel was the structure for the tail wheel mount.

The two sides are quite a way apart and it is possible to land on the tail wheel much harder than on The Predator because it is in line with the propeller instead of near the back of the vertical stabilizer. Because we are trying to keep the depth down near the propeller to increase ground clearance without increasing height there is not much depth to this section making any cross piece kind of weak.

I agree with Leigh’s suggestion of making a sprung tail wheel which means the mount doesn’t need to be quite as strong.

After we weighed the parts to make the reinforced cross piece strong enough and thought about the additional drag we decided to use two tail wheels, one on each leg of the keel. A place to mount the pivot point presented itself as did the extension stop. At this moment we are planning on using a valve spring but that could change. I am kind of taken with the flat spring on some airplane tail wheels. It eliminates a lot of parts and is simple to make.

The frame is down off the frame table and Jim is using the table to make the legs for the keel and assemble the keel.

Jim had one of the side legs attached to the frame table and was working on the lacing between them. Jim is very focused on keep things square. He tacks the lacing to one side then flips it over and duplicates it and tacks the other making sure that the shape is maintained and everything is square. We have some concern about twist but we don’t know how strong it needs to be. Jim will build it and we will see what we think. At this point we feel that the new keel and suspension will weigh half of what the original design did.

The spherical rod end’s threaded mounts at the front of the keel will allow for some adjustment in the angle of attack of the horizontal stabilizer. Plan B is to go to some shock eye type rubber bushings in case we pick up a resonance. It will lower the resonant frequency of the keel/empennage quite a bit. We can vary it by going to two rubbers or use the rubber mounts on all four. Plan A calls for keeping the resonant frequency above the frequency of the perturbations we imagine.

Jim is going to try to finish up send the rudder horn to Vince by Friday so he will have something to hold in his hand and finish up the bushings for the rudder hinge.

We have had big winds in California and it was mostly a tail wind coming home. I got close to 30 miles to the gallon in my M Roadster on the way back. I had the top down and was running along at 78 miles per hour. I came down interstate 5 instead of state route 101 to take advantage of this. I love my car.

Thank you, Vance

 

[Vance]

We have progress on the plug.

We have progress on the plug.

Mike sent me a couple of pictures and a very short email that read; “smooth as silk.”

He let the pictures do the talking.

We have the finish sanding nearly done on the plug by one of the elves at Corbin’s workshop.

We have the roughed out upper hinge bracket that will be bonded to the vertical stabilizer.

It is not an easy piece to make because it needs to be curved to fit flush in the base on the curved recess for the rudder.

It will have a plastic bushing in it and a pin on the rudder will slide down in it. The whole thing is held in place with the rudder horn at the bottom.


Thank you, Vance

 

[MarkG]

Vance

Can't wait to see this closer to completion! I am a firm believer in the so called "Big Butt" on pusher gyro's too!! If I remember correctly the Preditor's stab has a 6 foot span as well! It works very well in keeping the pointy end forward!!

 

[phantom]

building the mariah gale

building the mariah gale

Looking good Vance, have you thought about using rubber instead of springs on the tail wheel? I have used them off 30 hp Evinrude outboard motors, they are very light weight, the upper side mounts have a two bolt flange on one end and a stud on the other, the metal parts are all aluminum. The front mount is stiffer and has a stud on both ends. These same mounts were used on Johnson and Evinrude engines from late 60's to mid 90' so they are easy to find.

Norm

 

[Vance]

Slip Roll Coupling

Slip Roll Coupling

Thank you Mark, I am glad that I am not the only one who admires a gyroplane with a big butt. You remember correctly; the horizontal stabilizer on The Predator is around six feet wide.

The reason that Mariah Gale has such a large empennage is because she is basically a copy of The Predator. I just finished doing a cursory analysis of the doodle of what we imagine that Mariah Gale will look like at flight attitude for slip roll coupling.

This was based on the recent posts by Doug Riley on another thread called Slip Roll coupling.

If I understand him correctly he feels that the side area above the center of gravity should be slightly greater than below.

I took the doodle and imagined where the center of gravity might be and took the areas times the moment arms and found that I did have slightly more side area above the center of gravity than below. I did the calculations the same way I do them for the center of gravity calculations.

The center of pressure appears to be more than a foot behind and several inches below the center of gravity.

I would not have guessed either of these things.

The Predator has a similar bias with the center of pressure slightly closer to the center of gravity.

If Doug is correct this is why The Predator does not seem to have any slip roll coupling and why I felt so confused when I flew a gyroplane that did.

It appears to me that Mark Givans has a feel for these things and that is why he was able to build such a remarkable gyroplane.

Mariah Gale is basically a larger, less draggy version of The Predator with more fuel capacity, more suspension travel and a bigger front tire.

As we consume the second year of building Mariah Gale I am haunted by my ignorance.

My fears that she won’t fly as well as The Predator visit me late in the night.

I don’t know what I don’t know.

The Doodle is very preliminary and they change so often I have to date them so when we change something on the actual gyroplane I know what my latest fantasy was so I can change the drawing. This particular doodle is Mariah Gale at what we imagine will be flight attitude with the suspension fully extended.

I find when I spend the time to do this sort of preliminary calculations I learn things and become confused on a higher level. I would not have guessed that the fairing on the mast would more than balance the wheel pants and suspension.

The doodle louses resolution when I make it into a jpeg so I can post it. If I left the numbers and lines on it you could not read them.

Thank you, Vance

 

[Vance]

Just what we need.

Just what we need.

Looking good Vance, have you thought about using rubber instead of springs on the tail wheel? I have used them off 30 hp Evinrude outboard motors, they are very light weight, the upper side mounts have a two bolt flange on one end and a stud on the other, the metal parts are all aluminum. The front mount is stiffer and has a stud on both ends. These same mounts were used on Johnson and Evinrude engines from late 60's to mid 90' so they are easy to find.

Norm

Thank you Norm,

That is exactly the kind of input we need.

We have never built a gyroplane before and we appreciate others experience.

I spoke with Jim this morning and we discussed several different tail wheel suspension schemes.

Swing arm and valve spring, swing arm and rubber, leaf spring and forked leaf spring.

Jim sent the rudder horn off to Vince today and the keel in nearly finished. The tail wheels are next and we need to make a decision soon.

Thank you, Vance

 

[MarkG]

Thank you Mark, I am glad that I am not the only one who admires a gyroplane with a big butt. You remember correctly; the horizontal stabilizer on The Predator is around six feet wide.

The reason that Mariah Gale has such a large empennage is because she is basically a copy of The Predator. I just finished doing a cursory analysis of the doodle of what we imagine that Mariah Gale will look like at flight attitude for slip roll coupling.

This was based on the recent posts by Doug Riley on another thread called Slip Roll coupling.

If I understand him correctly he feels that the side area above the center of gravity should be slightly greater than below.

I took the doodle and imagined where the center of gravity might be and took the areas times the moment arms and found that I did have slightly more side area above the center of gravity than below. I did the calculations the same way I do them for the center of gravity calculations.

The center of pressure appears to be more than a foot behind and several inches below the center of gravity.

I would not have guessed either of these things.

The Predator has a similar bias with the center of pressure slightly closer to the center of gravity.

If Doug is correct this is why The Predator does not seem to have any slip roll coupling and why I felt so confused when I flew a gyroplane that did.

It appears to me that Mark Givans has a feel for these things and that is why he was able to build such a remarkable gyroplane.

Mariah Gale is basically a larger, less draggy version of The Predator with more fuel capacity, more suspension travel and a bigger front tire.

As we consume the second year of building Mariah Gale I am haunted by my ignorance.

My fears that she won’t fly as well as The Predator visit me late in the night.

I don’t know what I don’t know.

The Doodle is very preliminary and they change so often I have to date them so when we change something on the actual gyroplane I know what my latest fantasy was so I can change the drawing. This particular doodle is Mariah Gale at what we imagine will be flight attitude with the suspension fully extended.

I find when I spend the time to do this sort of preliminary calculations I learn things and become confused on a higher level. I would not have guessed that the fairing on the mast would more than balance the wheel pants and suspension.

The doodle louses resolution when I make it into a jpeg so I can post it. If I left the numbers and lines on it you could not read them.

Thank you, Vance

Vance

Not sure if you knew it was me by your replied but this is Mark Givans....... You and Ed have a Very Merry Christmas and a Happy and SAFE New Year!!!!

 

[Vance]

I did not handle the transition well.

I did not handle the transition well.

Vance

Not sure if you knew it was me by your replied but this is Mark Givans....... You and Ed have a Very Merry Christmas and a Happy and SAFE New Year!!!!

Sorry Mark, I know who you and I did not make the transition well from addressing you to reporting my investigation. When I spoke of how you have a feeling for center of pressure I was speaking to anyone who was reading the thread. I will try to manage the transition better in future posts.

Merry Christmas and a happy new year to you!

Thank you, Vance

 

[Vance]

Check the hinges and mechanism.

Check the hinges and mechanism.

View attachment 88124I received an email from Vince that it was time for me to inspect the hinges and rudder mechanism on Tuesday so at 5:00 AM Wednesday I was off to Hollister. It was 29 degrees when I left the house and 31 degrees in Hollister.

I was bundled up pretty well with the heater blasting.

The night was clear and the stars were shining bright.

I gave M her head once past Paso Robles. I was making good time until Prunedale when I heard a strange noise and felt a vibration. I pulled into the first driveway with a flat left rear tire.

The tires are so big on the BMW M Roadster and different sizes front to rear so they decided that a spare tire was not practical. They have an electric pump with goo in it that they call the “M mobility System.” I dutifully followed the directions in the manual to no avail.

I very nice fellow, Brian stopped by and observed; “looks like you are having trouble, can I do anything to help?”

I explained the lack of a spare tire and we went into the lumber yard that he had been patronizing and introduced me to the owner who promptly called his friend who came out with his tow truck and tried to fix the tire. I was just telling the tow truck drive about the last time I had fixed a similar tire that had blown up while I was filling it when “POW” the inside side wall exploded. No charge he said and it was back to the lumber yard where the owner called his friend with a tire store. He began the search for my Continental 245/40 ZR17. This is not your typical Prunedale tire. He located one in San Jose and said it would be at his shop by 3:30 and he would come out and pull the wheel off, take it back to his shop, mount the tire and then come back and install it.

Now my only challenge was how to get from Prunedale to Hollister, around 40 miles and Brian immediately offered to give me a lift. It turns out that years ago he had been working on his private pilot’s license when his instructor was killed. Life got in the way and he never finished.

The jack is coming down and I should get on the road so I will post the rest of the pictures and tell of the visit tomorrow evening.

Thank you, Vance

 

[Earthboundmisft]

Vance, a ton of suface area on the tail feathers, versus a tiny focal point under the prop.
What is the Skunkworks gameplan?
I might of missed something, an occasional voyeur.

 

[Vance]

An excellent question Michael.

An excellent question Michael.

We are concerned also and have done a lot of calculating and measuring.

Under the prop the truss is 6.5 inches deep and 14 inches wide consisting of four 7/8 4130 inch tubes .049 wall with lacing. The lacing is not shown in the drawing because we have found that it is best if it defines itself. The truss is 79 inches long and tapers for slightly over half of that until it goes under the propeller.

We feel it is strong enough but we do not know how strong it needs to be.

Our primary concern is low frequency vibration rather than the force that the control surfaces can put on it. At this time we are mounting it with four spherical rod ends that we can change to things similar to the rubbers in shock eyes if we decide we need to lower its natural frequency.

At this time our calculations suggest that the empennage will weigh 31.5 pounds. This is just over ten pounds more that the Predators empennage and we feel Maria Gales keel is stronger vertically by around 30 % in the area under the propeller. We feel that laterally it will be more than twice as strong. The area of bending is around 35% shorter than on The Predator. We feel that the keel will be lighter by around 7 pounds.

When it is built we will test it and add lacing if we are not comfortable how it responds. Worst case we can increase the depth of the section under the propeller at the expense of ride height or ground clearance. We can even add an upper brace if all else fails.

When we do flight testing we will keep an eye on it, probably with a video camera.

What do you and the other forum members think?

Thank you, Vance

 

[Vance]

A very productive day!

A very productive day!

I had a great visit with Vince and Mike today. We went over the two hinges one at a time and worked on the clearance for the rudder travel.

The rudder horn came in the mail from Jim today but I forgot to take a picture of it. We checked the clearance and it is very close. Jim did a nice job on it and sent it complete with hardware. Vince is going to let Jim do the final adjusting and drilling the holes for the cross bolts.

Vince had the preliminary hinge bushings made but we will make new ones when it comes to the actual part.

The upper hinge bracket is now a T but again we will make a new one when we have the actual parts.

We are back to bolting the rudder actuator to the bottom of the rudder because otherwise we lose too much of the part that fits in the gap at the top hinge.

We decided on nut inserts to attach the clear inspection cover over the rudder horns and cables. We feel it will come off a lot so that I can actually touch the cables and pins and lubricate them.

The hinge action is very smooth and precise.

We talked to Nacho who will actually make the mold and decided on the material for the mold. Because we are only making one flying part it does not have to be as strong. The difference is $2.50 per pound for the soft tooling or $12 per pound for production type tooling. Nacho will have the molds done by the second week in January and be ready to make parts. Having them done by the Christmas break just didn’t work out.

Mike again made it clear he is not going into the empennage business.

Vince, Mike and I had a nice lunch and discussed lots of different projects, particularly his latest electric car and the more sophisticated suspension and steering.

When we were finished Mike gave me a ride back to Prunedale and I made the first post as they installed the new tire. She was on the ground a little after 5:00; I thanked Brian for all his help and hit the send button. I was shutting the computer down when I decided to post a couple of pictures. Naturally I posted the wrong ones first.

I am home now and ready for bed. 5:00AM to 9:30PM is a long day for an older fellow.

It is hard to tell from the pictures just how nice the plugs are.

Vince feels that paint just adds weight so he feels that we should just buff out the carbon fiber. I don’t think that will fly with Ed. She wants a paint job with personality that is easy to see in the sky.

The empennage plug is a hard thing to take pictures of because most of the shapes are so soft and it is so smooth.

I found today's progress very exciting.

Thank you, Vance

 

[choppergabor]

Vance that is remarkable! Looks very professional and sturdy. That is a lot of surface you have there. One thing is for sure that baby will be one stable machine! Looks very nice Vance I like it how it came together. Nice job!

 

[i3 roberto]

Vance: I found these crazy picture , Knowing ,your shak art preferences ,:hippie:

 

[Vance]

I feel a stable platform = more maneuverable

I feel a stable platform = more maneuverable

Vance that is remarkable! Looks very professional and sturdy. That is a lot of surface you have there. One thing is for sure that baby will be one stable machine! Looks very nice Vance I like it how it came together. Nice job!

Thank you Gabor,

The Predator has some flight qualities that I wanted to retain in Mariah Gale and I feel that her large horizontal stabilizer is in part responsible for her pitch stability and control precision.

Because we moved the empennage back in relation to the center of gravity for a better streamlined cowl we probably could have made the empennage smaller without giving up any stability.

Because we fear our ignorance we didn’t want to take chances and left is close to the same size with more volume.

I feel that a more stable fuselage to command the rotor from will actually make a more maneuverable gyroplane.

More than a few gyroplane designers have rejected this premise and have warned me she will have truck like handling like some of the gyroplanes I have flown with a lot of horizontal stabilizer volume. I feel the slow response of these gyroplanes comes from other factors. I am hoping she will be as maneuverable and responsive as the Predator. We shall see when she flies.

We will start our flight testing with the angle of attack of the horizontal stabilizer at zero degrees and have provisions to try as much as 4 degrees in either direction.

The Predator has very good yaw stability and very precise rudder control. Tightening up the fabric actually made a noticeable difference. I feel that an airfoil shape may improve it.

The upper tail brace has been a challenge on The Predator although I may have resolved it. Given our rubber mounted flexible mast configuration on Mariah Gale an upper vertical stabilizer would have required more structure and weight. In my opinion the airfoil shape also allows the empennage to be stronger.

We are using both a front and rear spar and wing ribs so the empennage itself should be quite strong.

Because the empennage is in the propeller blast we feel that both the vertical and horizontal stabilizers will be seeing 170kt wind. We feel this makes a reduction in drag in this area important. We feel this empennage will exceed our 30% drag reduction goal.

If Vince had more free time the empennage would have been done some time ago. I feel that the delay has allowed us to make several worthwhile changes in the design of the structure. I don’t have an accounting of his hours but I suspect it is less than you would imagine. Vince works very fast. He is going to deliver the empennage to the mold maker today and the rudder by the end of the week.

Nacho has some other projects in the works and he will be doing this in his spare time.

The airfoil is not the same as a Mooney and has a softer stall and is more progressive in lift vs. angle of attack.

This has been a big project and at this point probably accounts for a third of the work in Mariah Gale.

I feel the quality of Vince’s work has caused us to improve many of the details as we struggle to achieve his level of art throughout the aircraft.

Mike continues to provide inspiration and allows us to learn with less pain.

Thank you, Vance