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Old Nov 24, 2004, 04:06 PM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
"The Heat" An autogyro experience.

Hello,

I thought I would share a few photos of my finished electric autogyro. I call it, The Heat. This is not a airplane conversion. it is an all new autogyro design. I will be adding information to this thread as I go and will post updates periodically.

The prop size and power setup is still being worked out. Ground tests have been concluded with two 8 cell AA 2100mah in parallel (4200mah total) with a 11x7 APC E - prop. The engine is an AXI 2820/10 brushless motor by Model Motors. 62 inch rotor span. 58 inches long. Stirable tail wheel and rudder control. This gyro uses a direct control head or gimbal. The hub is a two bearing design. Blades are attached to a polypropylene sheet which acts as its hinge point and allows the blades to adjust themselves in autorotational flight as needed. The blades were balanced both spanwise or lengthwise as well as chordwise. When the blades where hung to adjust the chordwise CG they were perfect and no adjustment was needed. Weight is not final due to final battery pack selection and prop size. As of now with the two 8 AA packs, the autogyro weights, 4lbs 11.3 oz. - 2135 grams. 3 Futaba S3003 standard servos. Jeti esc 40-3p OPTO. HiTec Electron 6 Long Range Receiver.

Most all parts have been punched into Auto-Cad 14. I will be finalizing that soon. I will make the autogyro plans available to others as soon as all aspects of the design have been concluded and flight tests have been completed.

More color will be added as i go.

Blades are from AeroBalsa. I find them to be well worth the money! Very accurate! You can get them at: AeroBalsa.com

The gimbal idea came from Sean ( aka Spindizzy ) From: West Sussex, UNITED KINGDOM. Thanks Sean for the photos you posted of your bird. They were a big help in helping me to design a gimbal for my gyro.

I also have to say thank you to ZB at Esprit models for all of the electric advice he has given over the past year. He really knows his stuff when it comes to electric motors and how to achieve a great setup!

When building the auto gyro I did seek the advice of Paul Johnson at Airfield models. His web site contains a lot of helpful information on how to build a perfect flyer. Paul has some really great advice on all aspects of building. For anyone who is thinking of building a plane or autogyro his website is outstanding! Paul put me touch with a fellow who has the best scroll saw blades I have ever used. If you use a scroll saw and would like to try the best scroll saw blades in the world, contact Mike Moorlach at Mike's Workshop. Thanks Mike for getting those blades out to me so quickly! You and the blades are the best!

UPDATE: 7-29-04

I took the gyro to the flight field today and did some ground rolling with it. I wanted to see how the gyro would come up to auto rotation. The blades would flap up to a 90 degree angle while facing into the wind. I summed this up to not being in full auto-rotation and possibly not enough tip weight. I am going to do some experiments with this tip weight. Sounds logical so I will give it a try. So, after trimming the rotor forward a bit, I tried again, I let the auto-gyro sit facing into the wind ( on the ground ) gave the rotors a spin when a good breeze came along and auto-rotation was reached ( without a doubt they were hummin man! ). I slowly let the auto gyro get some forward motion going. As the gyro started slowly building speed, I could tell it was getting a bit lighter. The front wheels lifted off the ground! I thinking to myself, Go for it John! Go for it! Just as I was committing myself to flight, The gyro fell over on its left side. I walked over to the gyro, looked down at it and yelled, stupid dog! I am sure glad I took the advice of not double bolting the blades! They gave way as they should when they hit the ground. No damage to the blades, I'm sooooo happy! I packed up the bird and headed home to find out how to fix this problem. I know I read about this problem on this forum somewhere but cannot find the solution. If anyone can help with this let me know. After returning home, closer inspection of the gyro has showed a broken vertical stabilizer. No visible blade strikes. I did'nt think there would be, the tips of the blades are 1 1/2 inches from the leading edge of the stabilizer. I am baffled as to how it got broken. Prop bit a little dirt but not damaged. All servos appear to be undamaged and working properly.

UPDATE: 7-30-04

I knew I had read this somewhere:

I just installed a flex hinged hub, and the model wants to roll to the left on launch.... Any idea as to the problem?

If your rotor rotates CCW (left when viewed from the top), one strong possibility is insufficient "up" flap (up flex) allowance in the blades. If you only have perhaps 10 degrees or less originally, increase this to a good 20 degrees and re-test the rotor and model. Note: This assumes you are allowing the rotor to reach full auto-rotational RPM, and are not attempting to "pull" the model off the ground prematurely. Because if the rotor is not up to full rpm for safe launch, it will probably roll into the retreating rotor blade.


The green info came from Jim Baxter's web site in the questions section. So, let's see...... I have plenty of up flap in my blades and I know the blades were in autorotation. Anyone have any other ideas? Maybe some right or forward trim?

UPDATE: 8-5-04

Went to the flight field today. Setup to fly the gyro by hand launching after several recommendations to trim the gyro in the air. It was definitely a handful by myself. But, non the less, I got it done. After concluding all pre flight tests, I picked up the gyro, gave the rotors a push and they got into autorotation right away. I carefully reached down and grabbed my transmitter and began my jog. I jogged with the gyro for about 35 yards taking note of the gyros tendencies. There was no left or right pull noted. At 10 yards I started to feel lift from the rotor as it was speeding up. At about 20 yards the gyro was really light in my hand. At 35 yards the gyro wanted pull from my hand so I let it go. The gyro was now on its flight path straight as could be. The gyro was gaining speed and starting to climb. Five feet. Ten feet. Then, all the sudden, a gust of wind came and the gyro went about 25 feet higher flipped straight over backwards. Like a loop and came down to the ground and hit almost nose in. The rotor was spinning pretty good when the blades hit the ground. I saw one of the blades hit the ground and fly up into the air about thirty feet. It had come completely off the hub. The poly had sheared off clean with the side of the hub. I surveyed the damage after I got home.

One broken prop, one busted poly hinge sheet, one bent control rod and the side of the fuse had a crack from the impact. Not to bad compared to how hard the gryo hit the ground. Everything has been repaired and I'm ready to give it another go.

I'm pushing the batteries forward more to make it a bit more nose heavy.

UPDATE: 8-12-04

Took Gyro to the flight field today with the intentions to ROG this model. Hand launching is not a good option for this model due to it's size. Gave rotor a spin in 15 mph winds. Rotor accelerated with no problem. Started electric motor and gyro began to roll. As the gyro gained speed so did the rotors. Take off was good! Gyro left the ground in a straight flight path and was gaining altitude slowly at half throttle. Gyro was twenty five feet or so off the ground. I tried a little left, gyro turned left, I tried a little right, gyro turned right. No problems noted with stirring. As I was getting ready to make a slow left turn to bring the model back up range, it went nose up, flipped over backwards and landed on the ground on its back (rotors). This all happened within a 50 - 75 yard flight.

Sense I have a pull pull system on my left right servo I am having no problems. Not the case with the forward aft servo. It is a push pull servo hookup. I have come to a conclusion that the control rod is flexing. The forward winds are pushing the rotor backward and the push rod is bending. After surveying the damage, I find forward aft control servo has stripped gears and push rod bent. Push rod is 2-56 type. .070 dia. I have acquired 4-40 type push rod .090 dia. and will install this push rod system and try again.

UPDATE: 8-26-04

The Heat, has left the ground! This update comes with great happiness! It appears, the 4-40 type push rod has done the trick! No more nose up situations taking place. However, this flight did end in a crash. When I put the new gears in the servo which controls up and down, I decreased the reward pitch of the rotor by two degrees. This did not appear to cause any problems other than an increase in takeoff roll. On lift off the gyro started to tilt to the left. I was able to pull it back by giving it some right stick. After leveling off and gaining some altitude, I released the stick and adjusted the right trim. No problem! Houston, we have level flight. At 40 feet altitude and about 60 yards down range. I started a left hand turn to come back up range. No Problem! This was a long slow turn to watch for trouble and to keep the nose from going down. After the turn I decreased the throttle and the gyro started to descend. Increased the throttle and the gyro started to ascend (climb). Level flight is at half throttle. The gyro climbs good at 3/4 throttle. I let the gyro climb to about 60 feet. Once up-range I started another left-hand turn to go back down range and back into the wind. After the turn I decided to attempt landing the gyro. I lowered the power and the gyro started to descend. While in flight I did take note of the orientation of the fuselage from front to rear and looked almost level. A little nose heavy if anything. Which from what I understand is a good thing. Especially during a non powered landing. I decided to complete a landing as the gyro descends under power, allowing the gyro to slowly descend to the ground. Everything was going fine until about 8 feet or so. The gyro caught a terrible cross wind and started to turn left very sharp. I pulled the gyro back but over compensated. The gyro came down pretty hard on the left front wheel of the landing gear and caused the gear to be torn from the fuselage.

So, todays damage list consists of landing gear torn from fuselage. One broken prop and a rotor blade with a crack running the grain of the wood near the blade mounting bolt, on the TE side. Everything else appears to be in good working order.

UPDATE 11-23-04:

Sence the two hurricanes which came through our area, The Heat has not been tested. I have everything ready for a flight in the morning if the wheather holds out. Rain today.
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Old Nov 24, 2004, 04:30 PM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
The Heat Photos

Here are the photos.
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Old Nov 24, 2004, 06:43 PM
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umrk's Avatar
Paducah Barkley, Kentucky, United States
Joined Sep 2003
783 Posts
Looks good!

Would you mind posting a closeup shot of your DC head setup?

Thanks
mike
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Old Nov 24, 2004, 09:27 PM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
The Hub

The Hub.
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Old Nov 24, 2004, 09:39 PM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
The Shaft

The Shaft
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Old Nov 24, 2004, 09:43 PM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
The mounted hub.

The mounted hub.
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Old Nov 24, 2004, 10:06 PM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
I was able to enlarge all the photos for everyone and stay within the file size using a different photo program. Sorry about the small pics!

John
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Old Nov 25, 2004, 06:20 PM
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Northern IL/ Southern WI
Joined Jul 2004
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WOW. Great looking bird. nice paint too.
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Old Nov 26, 2004, 10:11 AM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
The only thing painted is the blades. The rest of the model is Monokote. But, Thanks all the same! I have a new set of blades from Aerobalsa which I am going to be working on as soon as I get a chance. All the testing has put a hurten on my first set.

John
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Old Dec 19, 2004, 05:23 PM
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Rhondas's Avatar
usa
Joined Dec 2004
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I Noticed

Quote:
Originally Posted by iwadmin
The Hub.
your blades have no angle like a delta does it still wind up
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Old Dec 20, 2004, 10:31 AM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
Hi Rhondas,

The rotor spins up to autorotation very quick! There are two ball bearing sets in the hub which makes the rotor spin very easy! The AeroBalsa blades are vantastic. As soon as the Christmas season and all the hussle / bussle pass, I will start up this project again.

John
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Old Dec 21, 2004, 04:27 PM
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Ontario Canada
Joined Aug 2003
538 Posts
John,

Congratulations with your project. So many guys give gyros a quick try, & when they do not succeed, they move on. You deserve lots of credit for your persistence. It took me a full season to learn to fly these deceptively simple machines.

Please add a ply plate on top of the polypro hinge in the tang area. Replace the single bolt with 2 small bolts.This upper plate only needs 1/16 inch or less clearance from the hub to allow enough hinging action.

I personally favour the Delta hinge system for quicker spin up & equal lift at lower rotational speed, but like you, have had good success without it.

Again, congratulations,
Bob G
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Old Dec 22, 2004, 09:18 AM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
Thanks for your reply and input Bob!

I have found that using the single bolt is ample to secure the blades. Duing testing if the blades had made contact with the ground the blades would have shattered at the mounting point. As it is, the blades will just fold up. I had an an up flap stop on the blades in the beginning but removed them as well. What I found during testing of the rotor was when the rotor would pick up speed I would get a terrible bumping. The bumping is from the ply hitting the hub as the blades flap. I let them flap up as much as they want now.

There be some need for them in the smaller models but with a 62" rotor I have not seen the need. I do have the bottom stops still in place though and have no issue with them. I have been working on this project for over a year now. I started with plans from RCM on the Gyro Shtick. After trying to get the gyro CG correct with electric I saw it would not be possible without alterations. So, I fired up autocad and got to work on a redesign. In the design I built in 5 degrees of down thrust to the firewall. I may need to increase this as the gyro had a tendency to nose up and have not been able to do any new testing since all the huricanes down here and now the holidays are eating up all my spare time by "HONEY!!!". Anyway, this appears to be the only change needed in the design, so far. I am going to add a washer at a time to the motor mount until I have it correct, then add the difference to the plans.

Happy Holiday's!

John
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Old Dec 23, 2004, 01:12 AM
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Lnagel's Avatar
Moab, Utah, USA
Joined Apr 2003
5,994 Posts
Very nice John. I enjoyed reading your experiences in getting this aircraft to fly. A commendable effort, it is nice to see that it is all progressing in the right direction.

I don't have any experience with gyros and was just looking at the Gyro Schtik in RCM with thoughts of electifying it. Now I read this If you wouldn't mind, could you tell me what the cg problems are with the Schtik and what alterations you feel are necessary?

Larry
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Old Dec 23, 2004, 09:43 AM
Just one more plane!
JWarren's Avatar
Port Saint Lucie, Florida, United States
Joined Aug 2004
2,537 Posts
Basically Larry,

It came down to power to weight ratio and the fact, I had the motor I am using, already. I wanted rudder control, which added weight to the rear of the model, which ment a stretch on the front of the fuselage was needed. The model started growing from there to fit the AXI motor as well. I am basically down to fine tuning the model and will this thread updated as I go.

Thanks for writing and have a happy holiday!

John
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