I've made more modifications and I'm excited to see what the outcome is in the next coming weeks. What will be achieved in this season of flight trials?
What a project to take on and have watched it become a reality diligently. Yes, I ain't thick, I know it's a complex machine, but I've learned so much, right down to the hard/soft bolt issue. NO; I am not able to make something like this but I love watching and learning, someone who is committed AND the helpful adivsers and experts offering their help.
Excellent video series. Just binged watched them all. As a helicopter/fixed wing mechanic and pilot, I would immediately rethink/redesign the flying boat, and shamelessly copy the Chinese coaxial design. Trust me, you will tire of hover, and soon be tempted to achieve forward flight. There is a reason why all helicopters have a collective pitch control.
@@Ben-Dixey Inadequate strength and rigidity of fuselage/empennage. Complex and fragile cable system to elevator/rudder. Wings are totally inadequate for flight. Again, emulate a working design. Why re-invent the wheel? Last but not least, don't test with a passenger.
Thanks, I've ordered CF53 should be here this week. The only thing I need to check out is the shear strength of case hardened shaft. I'm expect it will be fine though it's only under 125kg of shear force.
I'm so jealous of your genius. I wish I was clever enough to build one. Can't wait for a proper test flight. Keep plugging away at it, you'll be flying in no time. Great video. 👍👍👍
Thank you but I'm certainly no genius, very average I would say. If I can do this then any average person can. 🙂 I'm certainly looking forward to more hovering this summer. 👍
That was mine and I could good go up 4 feet and stay there for maybe 30 seconds then I know go up maybe 10 or 15 or 20 feet up high and make sure the ground don’t same if you are up 1’. I would somehow put springs where your seat has Bolts. Like a car engine on top cylinders
Glad you enjoy it 👍 I'm really looking forward to the next test flight. It has been several months since I last tried to hover, might be a little rusty to begin with. Hopefully the case hardened shaft will turn up this week, then it's just fuel up and wheel out to the field. Weather permitting of course.
Thanks. Yes I could have and it would have saved some weight by doing so. Didn't think of doing that to be honest. Perhaps a future mod when more weight has to be removed. 👍
Practice will give you muscle memory, after that less concentration. I can see that not welding parts gives you an easier time to make alterations as you improve things.
I'm looking forward to being able to relax and enjoy it rather than just be stressed out. 🙂 yes a bolted frame is great when it comes to making changes.👍 welding is lighter but no aircraft I can think of uses a welded fuselage.
mr. Congratulations on the machine, I'm sorry I don't speak your language, I use the translator. I live in Brazil, and I have difficulty in ordering the 6061-t6 aluminum to be extruded, as the minimum amount from the manufacturer is 2 tons at a cost of US 28 per kilo, two questions on the main rotor, are the blades twisted on the leading edge or on the thin plate? In this modification, will you remove that rubber from the cardan that causes destabilization in the alignment?
Hi, the blades are not twisted, they are straight and parallel. A blade with a 6 degree twist would have been more efficient but harder to make. If I removed the rubber drive coupling I might not have had the driveshaft failure. However having a solid mounting may have overstressed the drive belts. I'm not sure but unfortunately the project is on hold for the time being.
Thanks, I need to weigh the machine to find that out, my scales weren't giving consistent readings last time. I need to purchase some better ones. Hoping for around 125kg empty weight.
No, I haven't tried anything more than what it's set to now. I took it out on Thursday for some testing and it was lifting off at around 720 rotor rpm, previously it was 780 rotor rpm. I don't know what pitch is going to be most efficient for lift but I'm expecting perhaps 7 degrees might be, on the top rotor at least maybe 8 on the bottom. It could be even higher and 10 degrees could be optimum. I haven't gone into the calculations on this so don't know.
@@AinamaniEmmanuelSkykingUg Hi, the blades cannot move in pitch. They are fixed pitch and lift is controlled by engine rpm. There is also no swash plate, the rotor tilts like a gyrocopter.
instead of those weights, why don't you put like a roll cage so your better protected if something bad happens or put some more length back on the skids those weights don't do anything .but you can get hung up on the skids so just saying
nice! Im jogging my memory to see if the motor is a 2 stroke or 4 stroke, but a turbo makes things too complicated either way.. Is your pitch maxed out on the rotors? I'd think if the torque isnt the limiting factor that might achieve lift at lower rpm . Have you already restricted your cyclic travel so you physically cannot overcompensate? ( be easier to divert attention when you cannot make huge mistakes ) Theres not much else to cut weight on unless you start a rabbit diet , which while effective becomes deadly after a few months .(-; Once you start losing your faculties, its time to eat some pasta .
Hi, it's a 2 stroke but the engine isn't running at its peak Hp. If I change the gearing and raise the rpm then another 5-10hp could be achieved. This could equate to another 27kg in extra lift. It's an option but I'm hoping not necessary. The pitch is 5.5 degrees on the top rotor and 6.5 degrees on the lower. I believe somewhere around 7 degrees could be max efficiency, I haven't tried more pitch. There isn't a huge amount of weight still to come off it's true but it's surprising when you start looking what can be reduced.
There are different pitch angles because the lower rotor is operating in the downwash of the top rotor. In order for the torque to balance it has to have a higher pitch angle. The lower rotor is exposed to turbulent air but also downward air which reduces its angle of attack compared to the top rotor.
@@Ben-Dixey Your upper rotor pitch is smaller than the lower one. As far as I remember the theory of coaxial propellers, the angle of attack (tilt) of the lower blade should be less than that of the upper one. This is because the lower blades meet the airflow that has changed direction under the action of the upper rotor. This looks like an absurdity, but in the design bureau of Kamov (and not only), they received more lift when the lower rotor had a smaller angle of inclination of the blades than the upper one. If you draw a diagram of oncoming flows on the blades that are moving towards a meeting, then the absurdity turns into truth. If in your design it is not difficult to change the angle of inclination of the blade in relation to the oncoming air flow, then it will not hurt to try.
Notice there is no collective? When the engine fails, both rotor blades will drop to about 50% RPM within less than one second and impact the ground. This "machine " is incapable of handling an engine failure. Its a doomed project.
Thanks to @quadtraxxx for finding me a decent lithium battery! 👍
Very welcome Mr Ben!! 👍👌
@@Ben-Dixey ok how your helicopter control works.
What a project to take on and have watched it become a reality diligently. Yes, I ain't thick, I know it's a complex machine, but I've learned so much, right down to the hard/soft bolt issue. NO; I am not able to make something like this but I love watching and learning, someone who is committed AND the helpful adivsers and experts offering their help.
I'm glad you found the videos of interest. Learning is fun 👍
Glad to see you are back at it👍🐒
😊👍 nice improvement mr, Ben.
Excellent video series. Just binged watched them all. As a helicopter/fixed wing mechanic and pilot, I would immediately rethink/redesign the flying boat, and shamelessly copy the Chinese coaxial design. Trust me, you will tire of hover, and soon be tempted to achieve forward flight. There is a reason why all helicopters have a collective pitch control.
@@yukon4511 Hi and thanks. There are future plans to add collective pitch.
What are your concerns with the flying boat ? Cheers
@@Ben-Dixey Inadequate strength and rigidity of fuselage/empennage. Complex and fragile cable system to elevator/rudder. Wings are
totally inadequate for flight. Again, emulate a working design. Why re-invent the wheel? Last but not least, don't test with a passenger.
@@yukon4511 sounds like I have some convincing to do. 😉
@Ben-Dixey I like you Ben. Stay safe.
@@yukon4511 👍😊 no worries, I will address some of, if not all of those issues raised.
For those roller bearings you need chromed hardened shaft CF53. Something along those lines will do.
Thanks, I've ordered CF53 should be here this week. The only thing I need to check out is the shear strength of case hardened shaft. I'm expect it will be fine though it's only under 125kg of shear force.
Looks like a unicorn now, brilliant.
True, ha! Thanks
Wonderful. Love the persistence.
thank you, unfortunately there has been a set back since this video.
Awesome, you got me motived.
I really wish you happy flights that always equals your happy landings in numbers!
Thanks a lot! 👍
I'm so jealous of your genius. I wish I was clever enough to build one. Can't wait for a proper test flight. Keep plugging away at it, you'll be flying in no time. Great video. 👍👍👍
Thank you but I'm certainly no genius, very average I would say. If I can do this then any average person can. 🙂
I'm certainly looking forward to more hovering this summer. 👍
I also wish to make one,👍😊
That was mine and I could good go up 4 feet and stay there for maybe 30 seconds then I know go up maybe 10 or 15 or 20 feet up high and make sure the ground don’t same if you are up 1’. I would somehow put springs where your seat has Bolts. Like a car engine on top cylinders
always enjoyable to see the upgrades, cant wait till the next flight.
Glad you enjoy it 👍 I'm really looking forward to the next test flight. It has been several months since I last tried to hover, might be a little rusty to begin with. Hopefully the case hardened shaft will turn up this week, then it's just fuel up and wheel out to the field. Weather permitting of course.
Cool video, could you not put that battery on the stalk instead of the weight? Looking forward to the next flight
Thanks. Yes I could have and it would have saved some weight by doing so. Didn't think of doing that to be honest. Perhaps a future mod when more weight has to be removed. 👍
Practice will give you muscle memory, after that less concentration. I can see that not welding parts gives you an easier time to make alterations as you improve things.
I'm looking forward to being able to relax and enjoy it rather than just be stressed out. 🙂 yes a bolted frame is great when it comes to making changes.👍 welding is lighter but no aircraft I can think of uses a welded fuselage.
mr. Congratulations on the machine, I'm sorry I don't speak your language, I use the translator. I live in Brazil, and I have difficulty in ordering the 6061-t6 aluminum to be extruded, as the minimum amount from the manufacturer is 2 tons at a cost of US 28 per kilo, two questions on the main rotor, are the blades twisted on the leading edge or on the thin plate? In this modification, will you remove that rubber from the cardan that causes destabilization in the alignment?
Hi, the blades are not twisted, they are straight and parallel. A blade with a 6 degree twist would have been more efficient but harder to make.
If I removed the rubber drive coupling I might not have had the driveshaft failure. However having a solid mounting may have overstressed the drive belts. I'm not sure but unfortunately the project is on hold for the time being.
Great stuff Ben....what's the empty wieght of the machine in lbs now ?
Thanks, I need to weigh the machine to find that out, my scales weren't giving consistent readings last time. I need to purchase some better ones. Hoping for around 125kg empty weight.
Hi mate - liking watching your journey with the coax build! What pitch angle are the rotors fixed at?
Hi and thanks. The top rotor is 5.5 degrees and the bottom rotor is 6.5 degrees.
@@Ben-Dixey have you tried a greater angle like 10 degrees?
No, I haven't tried anything more than what it's set to now. I took it out on Thursday for some testing and it was lifting off at around 720 rotor rpm, previously it was 780 rotor rpm. I don't know what pitch is going to be most efficient for lift but I'm expecting perhaps 7 degrees might be, on the top rotor at least maybe 8 on the bottom. It could be even higher and 10 degrees could be optimum. I haven't gone into the calculations on this so don't know.
Thanks for creation but now how do put pitch angle or swap plate .
@@AinamaniEmmanuelSkykingUg Hi, the blades cannot move in pitch. They are fixed pitch and lift is controlled by engine rpm. There is also no swash plate, the rotor tilts like a gyrocopter.
Awesome!
👍👍👍👍.
instead of those weights, why don't you put like a roll cage so your better protected if something bad happens or put some more length back on the skids those weights don't do anything .but you can get hung up on the skids so just saying
nice! Im jogging my memory to see if the motor is a 2 stroke or 4 stroke, but a turbo makes things too complicated either way.. Is your pitch maxed out on the rotors? I'd think if the torque isnt the limiting factor that might achieve lift at lower rpm . Have you already restricted your cyclic travel so you physically cannot overcompensate? ( be easier to divert attention when you cannot make huge mistakes )
Theres not much else to cut weight on unless you start a rabbit diet , which while effective becomes deadly after a few months .(-; Once you start losing your faculties, its time to eat some pasta .
Hi, it's a 2 stroke but the engine isn't running at its peak Hp. If I change the gearing and raise the rpm then another 5-10hp could be achieved. This could equate to another 27kg in extra lift. It's an option but I'm hoping not necessary.
The pitch is 5.5 degrees on the top rotor and 6.5 degrees on the lower. I believe somewhere around 7 degrees could be max efficiency, I haven't tried more pitch. There isn't a huge amount of weight still to come off it's true but it's surprising when you start looking what can be reduced.
Why different pitch angles for top and bottom rotor blade😮
There are different pitch angles because the lower rotor is operating in the downwash of the top rotor. In order for the torque to balance it has to have a higher pitch angle. The lower rotor is exposed to turbulent air but also downward air which reduces its angle of attack compared to the top rotor.
Okay, thank you very much.
@@Ben-Dixey Your upper rotor pitch is smaller than the lower one. As far as I remember the theory of coaxial propellers, the angle of attack (tilt) of the lower blade should be less than that of the upper one. This is because the lower blades meet the airflow that has changed direction under the action of the upper rotor.
This looks like an absurdity, but in the design bureau of Kamov (and not only), they received more lift when the lower rotor had a smaller angle of inclination of the blades than the upper one. If you draw a diagram of oncoming flows on the blades that are moving towards a meeting, then the absurdity turns into truth.
If in your design it is not difficult to change the angle of inclination of the blade in relation to the oncoming air flow, then it will not hurt to try.
Notice there is no collective? When the engine fails, both rotor blades will drop to about 50% RPM within less than one second and impact the ground. This "machine " is incapable of handling an engine failure. Its a doomed project.
I can't argue, the hose connector material was a poor choice as was the bullet style connector.
look at the size of that fuse holder! Did they run out of mini blade fuse holders when you ordered? Might save some weight... ;-)
You aren't wrong. 😉 thanks for the battery recommendation that was very helpful.