Time to get back into a hobby...

[HAL9000]

Now that life with a new career is settling down for me and I am being introduced to this new concept called "free time"... it's time to get back into a hobby. Years ago, I flew radio controlled helicopters... really enjoyed it... gave it up completely and sold everything with my daughter on her way. I have a little toy one and another electric that actually has collective pitch... but they just aren't the same as the kind I used to own. Well, with no argument from the wife... I'll be saving my pennies for this bad boy;




Rotor span is just under 6 feet, body length just over 5 feet, about 16 pounds, 1.6 cubic inch gas power.

The larger helicopters just fly so much more smoothly and handle the winds a lot better than the little ones do. I'm hoping to purchase by around my birthday, or shortly after [Aug/Sept] and get a little flying in before winter.. but if not, by spring for sure.

I'd really like to go turbine power, but at $7000+ for the kits without radio or gyro systems... I think I'll be holding back on that for a while.

[David M]

Maybe take helicopter flying lessons?...in a real one. I bet it would be fun to get in a simulator at the very least.

[HAL9000]

I'd love to do that David... but I'd be looking at about $45,000 to get my helicopter pilots license.

Interesting story with that though, when I was previously in the hobby, some of the oil pipeline guys would fly by our field to and from work in a helicopter and on the one occassion, landed in our field to check it out. The pilot was amazed that the mechanics were pretty much the same as the real thing and it started out with a joking comment from him of "I bet you could hover a real one".... I jokingly replied, "well, let's try it out". Next thing you know, he had me in the seat giving me a quick run-down of what was what. Granted, he had his hands on the stick the whole time, but I did take it up about 10-15 feet for a hover and set it back down. The "feel" was pretty much the same.

[David M]

That's pretty cool Dave. What a neat experience. I love flying in helicopters and taking flights in them whenever I can. From Long Beach to Avalon, around the SF Bay and under the GG Bridge! and in Hawaii most recently. I wonder what a little simulator time would cost?...just to see if I could learn the coordination....not that I actually ever want to learn to fly one...yes, too expensive, unless someone wants to turn it into their career.

Tell your wife $7000 for a guy hobby is cheap. It's not like you are buying a race car or a sail boat.

[HAL9000]

LOL... I'd love one of those turbine machines, but I'd still rather hold off... they are slowly reducing in price... that and I'm not sure my neighbours are ready for a test run of one of those things yet

[SARGE]

One of my favorite hobbies was building remote controlled boats. I remember laying an old door across 2 sawhorses for the table. Working with all the balsa wood, epoxy, c-clamps and clothespins, the sanding and wet sanding, painting. Always used electric motors instead of gas and had perfect pond with paddle boat if needed. Good old days. Other buds built aircraft

[Xayd]

Speaking of, reminded me of this thing i saw awhile back, definition of excessive...

Very, very, very fast Turbine powered RC Jet - YouTube

[HAL9000]

Approaching 600Kmph with a model excessive? Nah!

[glc]

That's not a model - that's a surveillance UAV!

[David M]

Originally Posted by Xayd Speaking of, reminded me of this thing i saw awhile back, definition of excessive... Very, very, very fast Turbine powered RC Jet - YouTube

Whoah! The sound alone is awesome. I wonder how much thrust it would take to break the speed of sound....if that's even possible with a RC craft?

[HAL9000]

I'm sure it would be possible... the largest model turbine engine that I know of puts out about 52 pounds of thrust... and that one didn't appear to be the largest one. The other advantage on a model is the strength to weight ratio would far exceed that of a full sized plane.

[HAL9000]

I just looked up the specs of the turbine used for that model

32,000 - 125,000 RPM
17oz / min at full power
36 pounds of thrust.

[Xayd]

I dunno, to get up to 750 knots you would need the wings to not buckle (Vne in engineering terms). Then theres the issue of keeping it in range at that speed.

[HAL9000]

Hard to say.. I'm sure somebody will pull it off... I'm sure the strength part, believe it or not, in a model, is the easy part. I have a racing plane in the garage that I have never finished... foam core, plywood joiner, carbon fiber strips internally, balsa sheeting, fiberglass skin... I can put the wingtips on the edges of two chairs and put 300lbs on the center.. it flexes a good 3 inches down in the middle, but holds. As for range, the radios have enough range that it could be done... the problem is maintaining a visual on such a small model moving at such a rate... I would think you would want to get telemetry systems and a camera involved... and the higher end radios have the telemetry capability in them already.

Back to the chopper... I think I'm gonna pull some overtime... I've got the itch bad.

[David M]

I have a technical question, is a chopper limited to half the speed of sound? My thinking is that the rotor cannot exceed the speed of sound, so if the helicopter is going forward at half the speed sound, the rotor tip going into the apparent wind when it reaches 90 degrees to the apparent wind direction would reach the speed of sound, limiting the helicopters speed to half that. Is this correct?

I know the wop-wop sound helicopters sometimes make is from a blade breaking the speed of sound, but I don't imagine they do it this much do they? Wouldn't it cause premature stress cracks or some other type of premature wear?

[HAL9000]

I don't know all the details of it, but there are definitely top speed restricting factors and the physical limitations of the materials being used for the rotor head itself. Not to mention the fact that the rotor head is a gyroscope and gyroscopes tend to react 90' to an applied force. Now depending which way the rotor is turning, uneven left/right lift causes either a pitch up or down of the nose.

[bob]

I know it would be noisy.

[SARGE]

I always heard a chopper was harder to fly than a plane. I can just imagine using radio control. I knew guys who built and flew rc planes while I stuck to boats. Watched a kid lose his plane one day, first trip out. Spent the longest building it as he got the $$. Best I remember he had $700 in it. His radio just died losing all control. He went on to become a Captain with United though.

[HAL9000]

Well... harder to fly is a relative term... it's a different technique and many model plane pilots don't fly properly... meaning they don't know how to properly use their rudder... which is the equivilant of the tail rotor on a helicopter which is a necessity for turning. Now when I flew helicopters, since I had the proper coordination of the the control axis, I found planes easy to fly.

As for crashing... yes, it happens... it's something that if you're going to fly, you have to accept it will eventually happen. Now the new radios these days are pretty sophisticated pieces of equipment and gone are the days where you have to check which frequency everyone is on.

[bob]

Flying is safe and easy. It is the landing you need to learn.

[David M]

There is a setting in Microsoft Flight Simulator so rudder adjustments can be made manually or automatically. I bought a set of rudder pedals so I could learn how to do it manually. It actually gives you a better amount of control and feel....you can do more stuff with the aircraft. I guess if I bought a collective I might be able to flight sim a helicopter....that might be fun. Helicopter crashes wouldn't be expensive, or deadly.

[HAL9000]

Well, flying a plane without rudder is just wrong... especially on take-off. You need the rudder to counter-act torque

[edfair]

Ercoupe?

[HAL9000]

Unless you have counter-rotating props, you have torque that needs to be countered on take-off until there is enough airspeed to make the rudder effective. The Ercoupe has two large rudders that become effective at a lower speed, but there is still torque to correct.

[Xayd]

Originally Posted by David M I have a technical question, is a chopper limited to half the speed of sound? My thinking is that the rotor cannot exceed the speed of sound, so if the helicopter is going forward at half the speed sound, the rotor tip going into the apparent wind when it reaches 90 degrees to the apparent wind direction would reach the speed of sound, limiting the helicopters speed to half that. Is this correct? I know the wop-wop sound helicopters sometimes make is from a blade breaking the speed of sound, but I don't imagine they do it this much do they? Wouldn't it cause premature stress cracks or some other type of premature wear?

Yes but not exactly. Thats why vne is much more critical on a rotor aircraft vs a plane, which has some tolerance above vne. On a plane the only fear is wing stress, on a chopper rotor the lift on the back half of the rotors is minus forward velocity while the front half is increased by forward velocity, so exceeding vne can cause the rear blades to stall, thats the problem.

Its not necessarily the speed of sound.

Figure at hover the rotors are moving at 300 mph for sake of argument. Well if you go forward at 100 the front rotor half are now at 400 effective velocity for lift purposes but the back half are at 200.

Extrapolate that math to 300mph forward velocity. Front lift equals 600, rear lift equals zero, at which point you stall and die.

In short just as going too slow in a plane will make you stall, going too fast in a helo will make you stall.

Thats why the helo speed record is around 220 knots last time I looked.

Originally Posted by edfair Ercoupe?

And yeah as hal said when a plane first starts moving the torque from the engine is jerking you to the left, you have to give it a lot of right rudder on the ground roll otherwise you'll go right off the left side of the runway into the grass. So far I've only put a plane in the grass once, not a bad track record imo . I told that guy the right brake was soft, he insisted it was 'fine', whatever dude, it's your plane...

[Floppyman]

Originally Posted by HAL9000 I'd love to do that David... but I'd be looking at about $45,000 to get my helicopter pilots license. Interesting story with that though, when I was previously in the hobby, some of the oil pipeline guys would fly by our field to and from work in a helicopter and on the one occassion, landed in our field to check it out. The pilot was amazed that the mechanics were pretty much the same as the real thing and it started out with a joking comment from him of "I bet you could hover a real one".... I jokingly replied, "well, let's try it out". Next thing you know, he had me in the seat giving me a quick run-down of what was what. Granted, he had his hands on the stick the whole time, but I did take it up about 10-15 feet for a hover and set it back down. The "feel" was pretty much the same.

$45000!!! Well, looks like I'll be starting with fixed wing aircraft (e.g. PPL) instead and see where to go from there. But it would be a dream to eventually be able to fly a chopper, that's for sure.

[Blaster3]

want a hobby... run for US presidency... seems to work for most canidates.
i prefer fishing (yes i consider it a hobby)... quiet peaceful chalenging, i make my own gear and try many different options to 'live' bait.

[Detonate]

Helicopters did not become practicable until a fellow name Igor Sikorsky figured out how to overcome the problem of the difference in lift between the advancing and retreating blades. I spent six years of my early life as a helicopter crew chief in the Army. Those were the good old days for me.

https://en.wikipedia.org/wiki/Igor_Sikorsky

[HAL9000]

Originally Posted by Blaster3 want a hobby... run for US presidency... seems to work for most canidates. i prefer fishing (yes i consider it a hobby)... quiet peaceful chalenging, i make my own gear and try many different options to 'live' bait.

I somehow don`t think that running for president would work for me... since I`m Canadian

[Detonate]

Originally Posted by HAL9000 I somehow don`t think that running for president would work for me... since I`m Canadian

Well, if a Kenyan can be president why not a Canadian?