I love the counter-rotation mech by 3 belts: one conventional, one reverse direction with the pulleys to help wrap the other side of another pulley. Never seen that setup. Elegant and simple!!!
Thank you 👍 it seems to work so far and should be efficient, you could possibly do the same thing with chains but it would be running at a higher chain speed than recommended without running in an oil bath.
Hi Ben, congratulations on your first lift off, I was chuffed to bits for you, a great mile stone in the build of your coax machine. I've been following this project from the beginning with great interest, you have made good progress and learned from your mistakes and not given up, I haven't commented before now as I hate & detest typing but now I feel I could be of some help to you, this has gust tuck 25 minuets to type but I will persevere. FIRST I'd like to say your choice of harness, helmet & head board are a must on every test run & please put those stop bolts in the bottom CV housing, Tethers are all so a must at this stage of your testing, I will Come back to this at a later time. Shortening the top mast to 10% of rotor diameter was a very wise & necessary move ( that long slender shaft & the thought of whirl and whip If something went wrong scared me) its also nice to see you testing in that big field with the minimum of on lookers. TEETER STOPS, I've been watching your lift of video again, I think you've got teeter stops in place or there's no wind at all, you will need teeter stops for hover testing but you will need some teeter as you test in winder conditions, I would suggest you limit teeter to 180 mm up and down at the tips this is to stop blade clap on the run up & down. BALANSING the TORQUE, you commented a while ago that you had hit you pitch limit @ 6 deg, I relooked at the video and it seems to me that if you change the lower nylock nut on the pitch horn for some washers you could increase the pitch, I would suggest you set the top rotor to 6 deg and the bottom rotor to 7 deg or to what ever it takes to get zero torque, this would keep your rotors near the most efficient part of the Cl/Cd v A of A curve for a NACA 0012 rotor with a Re number of a tad under 1.5 million. I think you shod do this before you set up your rudders. NOW, you'll soon be come to the hover learning stage but before that I would advise you to sort out the cooling system, you cannot buckets I don't know why it started typing in red? I've got some skid extensions that I would advise you to use till you can hover with confidants with out teethers. I hope you find my comments helpful. There's lots more 'd like to discus but can't do any more typing, I'll send you an email with my phone number & email address if you'd like to get in touch
Love your videos. Its been great to see your progress. For your rudder vanes, would it not be better to mount them on a small tail boom, under the rotor tips? That means your vanes will be under your downwash and will be effective, even while in the hover. Mounting the vanes further back on a tailboom under the downwash will give them more authority on a longer moment arm. Why not make up a leather "CV boot" similar to what you get on your cars gear stick?
Thanks for the comment, the blades are shorter than you think and the vanes are below the outer 1/3 of the of the rotors. I tried it for the first time yesterday and reaction to yaw seems ok for now. Leather for the boots could well be an option, thanks
I don't understand how the surface of the rudders create yaw control in a stationary position when there's no air flow over them. Unless its the down wash from the Co-axil blades?
That's it, just from the downwash. The vane hinges are also tilted. They are inline with the tail boom tubing, that means vane deflection in both vertical and horizontal planes. Should I get to forward flight this should provide some authority in both flight regimes.
Me too. Very surprising how effective it is, it's fairly responsive. Nowhere near as responsive as a tail rotor but plenty good enough for what I'm doing. I did a small workshop test with a small electric fan, it was enough to practise swinging back and fourth.
The Gen h4 is a masterpiece of engineering and it uses differential rotor speed to control yaw. It seems effective from watching the videos but obviously requires making a gearbox with a differential type arrangement. Personally I wanted to simplify the drive and decided that tail directional fins would be my choice instead.
8 degrees is the total. 4 degrees from centre in each direction but I don't know if the travel is suitable for controlled flight. I expect less will be needed but I could be wrong.
Have you got an anti vibration mount in the exhaust system ? You can send me a picture of the failure to my email at btdixey@hotmail.com if you wanted.
Your getting there. Working thru issues is exciting
Thanks for your continued support Bruce. 👍👍
I love the counter-rotation mech by 3 belts: one conventional, one reverse direction with the pulleys to help wrap the other side of another pulley. Never seen that setup. Elegant and simple!!!
Thank you 👍 it seems to work so far and should be efficient, you could possibly do the same thing with chains but it would be running at a higher chain speed than recommended without running in an oil bath.
Thanks for sharing
Finding this build very very interesting and rather like your temporary materials use....wood etc 🤣🤣...why not. Thanks from Rome👍🇬🇧
Thank you. Glad you find it interesting. 👍👍
Hi Ben, congratulations on your first lift off, I was chuffed to bits for you, a great mile stone in the build of your coax machine.
I've been following this project from the beginning with great interest, you have made good progress and learned from your mistakes and not given up,
I haven't commented before now as I hate & detest typing but now I feel I could be of some help to you, this has gust tuck 25 minuets to type but I will persevere.
FIRST I'd like to say your choice of harness, helmet & head board are a must on every test run & please put those stop bolts in the bottom CV housing, Tethers are all so a must at this stage of your testing, I will Come back to this at a later time.
Shortening the top mast to 10% of rotor diameter was a very wise & necessary move ( that long slender shaft & the thought of whirl and whip If something went wrong scared me) its also nice to see you testing in that big field with the minimum of on lookers.
TEETER STOPS, I've been watching your lift of video again, I think you've got teeter stops in place or there's no wind at all,
you will need teeter stops for hover testing but you will need some teeter as you test in winder conditions, I would suggest you limit teeter to 180 mm up and down at the tips this is to stop blade clap on the run up & down.
BALANSING the TORQUE, you commented a while ago that you had hit you pitch limit @ 6 deg, I relooked at the video and it seems to me that if you change the lower nylock nut on the pitch horn for some washers you could increase the pitch, I would suggest you set the top rotor to 6 deg and the bottom rotor to 7 deg or to what ever it takes to get zero torque, this would keep your rotors near the most efficient part of the Cl/Cd v A of A curve for a NACA 0012 rotor with a Re number of a tad under 1.5 million. I think you shod do this before you set up your rudders.
NOW, you'll soon be come to the hover learning stage but before that I would advise you to sort out the cooling system, you cannot buckets
I don't know why it started typing in red?
I've got some skid extensions that I would advise you to use till you can hover with confidants with out teethers.
I hope you find my comments helpful.
There's lots more 'd like to discus but can't do any more typing,
I'll send you an email with my phone number & email address if you'd like to get in touch
Hi and thanks so much for giving your time to type the message you obviously have a lot of knowledge on the subject. Very interesting comments. 👍
Thank you for making this video.
Love your videos. Its been great to see your progress. For your rudder vanes, would it not be better to mount them on a small tail boom, under the rotor tips? That means your vanes will be under your downwash and will be effective, even while in the hover.
Mounting the vanes further back on a tailboom under the downwash will give them more authority on a longer moment arm.
Why not make up a leather "CV boot" similar to what you get on your cars gear stick?
Thanks for the comment, the blades are shorter than you think and the vanes are below the outer 1/3 of the of the rotors. I tried it for the first time yesterday and reaction to yaw seems ok for now. Leather for the boots could well be an option, thanks
I don't understand how the surface of the rudders create yaw control in a stationary position when there's no air flow over them. Unless its the down wash from the Co-axil blades?
That's it, just from the downwash. The vane hinges are also tilted. They are inline with the tail boom tubing, that means vane deflection in both vertical and horizontal planes. Should I get to forward flight this should provide some authority in both flight regimes.
@@Ben-Dixey Pretty nuts 👀you can get that amount of control from the downwash I would have thought it would feel kind of unresponsive.
Me too. Very surprising how effective it is, it's fairly responsive. Nowhere near as responsive as a tail rotor but plenty good enough for what I'm doing.
I did a small workshop test with a small electric fan, it was enough to practise swinging back and fourth.
What about your experience....... Gen h4 coaxial helicopter transmission to yawing control
Is it possible ?
The Gen h4 is a masterpiece of engineering and it uses differential rotor speed to control yaw. It seems effective from watching the videos but obviously requires making a gearbox with a differential type arrangement. Personally I wanted to simplify the drive and decided that tail directional fins would be my choice instead.
@@Ben-Dixey oh yes still I searching the transmission unit diagram of gen h4 to clone the master piece..... but I couldn't able to find.....
@@mohamedshafeelmohamedbilal6364
Found this.
www.e-office.gr.jp/gen/Structure.htm
why a counter rotating helicopter will fly when the upper blades n lower blades are spinning at the same speeds in different directions?
Is the 8 deg is the total travel of the cyclic from left to right like -4 to 0 to +4 OR -8 to centre stick to +8?
8 degrees is the total. 4 degrees from centre in each direction but I don't know if the travel is suitable for controlled flight. I expect less will be needed but I could be wrong.
Sir, I have experienced a broken exhaust 2 times during testing, can you help me with some advice? I only use 1 exhaust
Have you got an anti vibration mount in the exhaust system ? You can send me a picture of the failure to my email at btdixey@hotmail.com if you wanted.
How much total weight of the helicopters without the driver sir?
Hi, The empty weight is 120kg
im waiting your fly😍
Not long now. 👍
👍
How many hp Machine are you using sir.
@@amrinwello6620 it's 60hp.
@@Ben-Dixey ok thank you sir i'm just using a 40pk machine
👍🚁🚁👏👏
Мне кажется мощности двигателя нехватает🤔
The power Seems ok to me now the expansion chambers are working. In the test I wasn't using full throttle.