In-Flight reconfiguring Airframe Rotor Disc Control
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Going back to the off set axis gimbal fulcrum which will have about 3 degrees of lateral movement, giving the rotor disc about 5 to 7 degrees of lateral tilt as the hub/disc are a bit higher on the mast above the gimbal fulcrum
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Yep..you are absolutley right.............wrong choice of words. The distance, as you noted, was what I was making reference to. Thanx for pointing that out. Almost stepped on my crank with that one. Equal degrees, moments etc...........greater distance the farther from the fulcrum. Shoulda caught it
Regards,
Dave
Regards,
Dave
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Between 3 and 5 degrees depending on servo adjustments............but I have not measured it just yet. Made servo adjustments to prevent over manipulation or too much tilt. The tethered flight was postponed due to the mast bending from too much torque. I used stainless steel 1/8" round stock and the mast bent right where the cross pin goes through the mast to secure the main rotor gear. Used a thicker CP Grade 5 titanium stock for more strentgh and try not to add additional weight.
Dave
Dave
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Ok I was just curious. You can always change it if you need more. I just wonder how much will be needed for a real machine considering CG range, slope landing capability and amount of rotor flapback during max forward speed plus a margin beyond whatever the max is. Presumably a one man helicopter doesn't need a large CG range and will have a relatively low cruising and max forward speed.
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Yep..........I wanted to start the tilt out a little at a time. Servo arm change outs will give it more range of motion. Another pilot mentioned the same about the speed for a single place with regard to this design. I've only had to deal with the slope terrain stuff when I went to Air Assualt school some years back. Just a few years ago, we had a Chinook pilot hot dogging his bird when I was stationed in Alaska. He was reminded of his slope/rotor blade association "does and don'ts" very vividly. He came in a bit fast and swung the aft portion of the bird around...with a slope in the direction that his aft was going. Yep...you quessed it....rear disc hit the slope. Bird came down and rolled over a few times. Everyone was ok...little roughed up. Kinetic energy and gravity...lol. This platform is the first "baby steps". I'm still tweaking the the small CF frame and a few more mechanical things to do yet. And I still want to scale it up to a gas power. But small steps and it's fun to problem solve.
Dave
Dave
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When Sikorsky first developed the XH-59 the engineers thought that because of the high control moment generated by the extremely stiff rotors they should reduce the amount of cyclic control available to the pilot. However, in certain flow conditions you still need the full cyclic range just to generate the minimum control moment for maintaining aircraft control. Unfortunately they learned this one the hard way by crashing the first prototype when the pilot ran out of cyclic control. Just food for thought...
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Helisphere,
Sorry it's been so long. I read your last post just prior to the 4 day week-end and then went to the field. Back and clean again......4 days in the woodline.
I agree with you and I also believe that alot of testing is needed. This is not an endeavor to get rich, a quick start for a new line of helicopters or to solicit. It's just experimentation, that if proven valid, could be a new platform. Some folks in the respective "industry" are reviewing it. Most recent contact this past week, but I also told them that I did not believe that my platform was the answer for a UAV with regard to "simplified" controls because the concept of mechanical morphing and my theory of CG "flex" are not proven and again it's just a theory. There is emough stress learning the controls of rotorcraft for static airframes. I use the term "industry" loosley for a reason. Some I will not mention.
The HIR platform was intended for sport aviation and civil use such as law enforcement for smaller departments that cannot afford a mutli-million dollar Twin Star, for example, but it's still not ready. I enjoy very much the mechanical problem solving and questioning the norm. As I have said before, I question often where does practical application end and novelty begin. I keep trying until physics and mathematics prove me wrong.
Regards,
Dave
Sorry it's been so long. I read your last post just prior to the 4 day week-end and then went to the field. Back and clean again......4 days in the woodline.
I agree with you and I also believe that alot of testing is needed. This is not an endeavor to get rich, a quick start for a new line of helicopters or to solicit. It's just experimentation, that if proven valid, could be a new platform. Some folks in the respective "industry" are reviewing it. Most recent contact this past week, but I also told them that I did not believe that my platform was the answer for a UAV with regard to "simplified" controls because the concept of mechanical morphing and my theory of CG "flex" are not proven and again it's just a theory. There is emough stress learning the controls of rotorcraft for static airframes. I use the term "industry" loosley for a reason. Some I will not mention.
The HIR platform was intended for sport aviation and civil use such as law enforcement for smaller departments that cannot afford a mutli-million dollar Twin Star, for example, but it's still not ready. I enjoy very much the mechanical problem solving and questioning the norm. As I have said before, I question often where does practical application end and novelty begin. I keep trying until physics and mathematics prove me wrong.
Regards,
Dave
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Fabricated a new rotor hub to fit the blades; no issues with balance. Shortened the titanium rotor mast and mounted the hub to the mast with one of the first rubber grommets (upper) that will allow the hub to teeter flex. The blade bending should negate most of the dissymmetry of lift. Tail rotor mounted and wiring for the motor is "rough in" and not yet soldered. New mast bearing will be 11/64". Now I must re solder a new receiver antenna as some one came into my apartment while I was in the field, went through my stuff, pulled the antenna out of the receiver and went through some of my miliatry records. Seems like I can never win. The Apartment maintenance people were in the apartments changing filters. Should have the bearings mounted next week-end or the week-end after, I think I can solder the antenna this week-end. More to follow.
Dave
Dave
This sort of thing would probably be more suited on rcgroups.com than here, as there are a few physics and aerodynamics traits that would prevent this design from being used on full scale machines.
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Perhaps....., but one patent in the works and DARPA and a few others reviewed it.....said it had merit.....whatever.
Look at Baldwin technologies:
Baldwin Technology Company, LLC
Then again....................... perhaps not. Mechanical morphing rotor control is possible. If not, we'll see. I've never owned an "RC" hobby copter except the one that I cannibalized for parts. Already preparing for the single place full scale. It's only the first of 6 different concepts.
When mathematics and physics prove me wrong.....then I'll stop and find something else that "feeds the mind" in mechanical problem solving. I will not stop if someone makes a suggestion to do so. Most people come up with a good idea and often they listen to others and their dreams fall to the side. Mechanical problem solving is like OCD to me. I lose sleep over it, but it occupies my mind from the memories from Iraq..................and I love it. Thanks for the input though. No one holds the reins on innovation unless you allow them to do so.
Best Regards,
Dave
Look at Baldwin technologies:
Baldwin Technology Company, LLC
Then again....................... perhaps not. Mechanical morphing rotor control is possible. If not, we'll see. I've never owned an "RC" hobby copter except the one that I cannibalized for parts. Already preparing for the single place full scale. It's only the first of 6 different concepts.
When mathematics and physics prove me wrong.....then I'll stop and find something else that "feeds the mind" in mechanical problem solving. I will not stop if someone makes a suggestion to do so. Most people come up with a good idea and often they listen to others and their dreams fall to the side. Mechanical problem solving is like OCD to me. I lose sleep over it, but it occupies my mind from the memories from Iraq..................and I love it. Thanks for the input though. No one holds the reins on innovation unless you allow them to do so.
Best Regards,
Dave
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Lower mast bearing mounted, mast attached, main drive motor mounted. Picture below, airframe is inverted allowing the glue to dry for the lower bearing housing. Still on track for tethered flight tomorrow.
Dave
Dave
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Lower mast bearing housing came loose. Torsional flex developed during tether flight; forward/aft has good transition. Lateral had a tendency to roll over...........shaft collar lock was too close to hub not allowing enough room to teeter. Some of the weight is too high up on the airframe as well. Lowering the motor and widening the lateral foot print of the lower airframe. Changing a few things, re-balance/track and try it again.
Dave
Dave