So it is 2013 and looked nice today so decided to maiden my Spitfire but it COLD!!!
I forgot my heated Tx glove at home :( and ended up with frozen fingers but the goal was achieved and the Spit flew relatively nice - It was hunting quite a bit and am not sure it is due to the cross wind or the torque from the prop (I did not change the angle of the motor).
Where was this?
I thought about flying today, but the minus 10 temperature outside made me stay inside.
Bob,
Congratulations on a successful maiden! Hope all your fingers are still functioning!
I have an HK Spit too and I'm really interested in what you describe as "hunting"...I'm reading that as unsteady pitch.... am I on the right track?
I have to fess up on a related item. Somewhere on this thread, I think I said the CG on my model was 75mm from root LE. I think my memory failed me...I'll try to get down to the basement and check and get back to you.
Quote from: thehaze on January 01, 2013, 07:18:03 PM
Where was this?
I thought about flying today, but the minus 10 temperature outside made me stay inside.
Happy New Year guys!
It was GORGEOUS today (Jan 1, 2013). Winds moderate NW 13-17 kmh, but at times near calm. And -13 to -11 is a spring day in Winnipeg, especially in full sun! The cold dry snow cover on the field is light and fluffy and perfect for skis. I rigged up a pair of DuBro aluminum skis for my Sportster and flew it yesterday and today at ROGO. It was wonderful. It performed exactly as planned and the slight increase in weight did not impede aerobatic performance at all. I used rubber bands from the ski tips to the tops of the struts to provide nose up tension at the front of the skis (to bring the skis level after take-off), and string guys from the ski tails to the wing mounting bolts to limit the nose up rotation of the skis after takeoff (see photos). I did not bother with a tail ski. A little extra power is all that is needed to manoeuver on the ground during taxiing, and the tail comes up quickly during the take-off glide. Winter flying is fantastic, especially on a sunny day! No heated TX glove; regular gloves were just fine.
Cheers! Hope to see more ice pilots soon.
Andy Hoffer
Quote from: Wingnutz on January 01, 2013, 09:18:11 PM
Bob,
Congratulations on a successful maiden! Hope all your fingers are still functioning!
I have an HK Spit too and I'm really interested in what you describe as "hunting"...I'm reading that as unsteady pitch.... am I on the right track?
I have to fess up on a related item. Somewhere on this thread, I think I said the CG on my model was 75mm from root LE. I think my memory failed me...I'll try to get down to the basement and check and get back to you.
Hi Bill,
I have a separate thread for the Spit on the forum but my CG was about 75mm and when I flew it - it was a bit windy but nothing too crazy. the "hunting" was yaw - left and right, even though not too much it was still there and a bit strange but I didn't try to fix it or investigate too much as it was called and I just wanted to see the plane fly :)
As for pitch I did noticed that when powering up from about 60% to 80% or 100% the plane pitched up a bit but it was steady and controllable at all times.
I will double check the CG and post it on the second thread.
If you want more details please post them on the second thread - that way we can keep everything in one place.
Bobby
Correct me if I am wrong. My understanding is that a plane to pitch up on throttle is normal in the case of warbirds?
I generally set my planes up at 50% throttle at level flight. But it was told to me that it is normal for it to pitch up at full throttle and drop at lower.
On the flip side.. depending on airframe.. some don't follow these rules.
Quote from: Gregor77 on January 02, 2013, 09:27:05 AM
Correct me if I am wrong. My understanding is that a plane to pitch up on throttle is normal in the case of warbirds?
I generally set my planes up at 50% throttle at level flight. But it was told to me that it is normal for it to pitch up at full throttle and drop at lower.
On the flip side.. depending on airframe.. some don't follow these rules.
That is my understanding too. Adding power increases the downlift on the stab, pulling the tail down and pitching the nose up. Andy
It was GORGEOUS today (Jan 1, 2013). Winds moderate NW 13-17 kmh, but at times near calm. And -13 to -11 is a spring day in Winnipeg, especially in full sun! The cold dry snow cover on the field is light and fluffy and perfect for skis. I rigged up a pair of DuBro aluminum skis for my Sportster and flew it yesterday and today at ROGO. It was wonderful. It performed exactly as planned and the slight increase in weight did not impede aerobatic performance at all. I used rubber bands from the ski tips to the tops of the struts to provide nose up tension at the front of the skis (to bring the skis level after take-off), and string guys from the ski tails to the wing mounting bolts to limit the nose up rotation of the skis after takeoff (see photos). I did not bother with a tail ski. A little extra power is all that is needed to manoeuver on the ground during taxiing, and the tail comes up quickly during the take-off glide. Winter flying is fantastic, especially on a sunny day! No heated TX glove; regular gloves were just fine.
Cheers! Hope to see more ice pilots soon.
Andy,
Share your enthusiasm for flying a ski-equipped model...not so much enthusiasm for Winnipeg winters!
Mother Nature provides the ultimate in smooth runways after a snowfall if you can get to the park/flying field before people walk all over it. Will join you at ROGO as soon as my new knee is up to it. Hope there's still some snow left!
Andy Hoffer
[/quote]
If this is normal I will just add a add a mix to the throttle.
You could try moving the CG back a bit to decrease the amount of pitching up as speed increases.
You can check for CG by rolling inverted. Nose heavy will require more down elevator to maintain level flight.
Pat MacKenzie
If its not freezing I will test it again over the weekend and I will make sure the heated transmitter glove goes in the car first, the only problem is that I will need someone to throw it.
Many planes pitch up under power, especially flying upwind, this is normal. I'm surprised it doesn't happen with your Sundowner?
Anyway the spitfire flew well but did get tossed around a bit by the wind which was 15-20K. Your model is 3 or 4 pounds. A full scale small aircraft which weighs 2000lbs cannot fly safely in winds much over 45K. I think we're doing pretty good.. ;D
Quote from: Bobmic on January 02, 2013, 08:39:42 PM
If its not freezing I will test it again over the weekend and I will make sure the heated transmitter glove goes in the car first, the only problem is that I will need someone to throw it.
I hear Greg is available.... :)
Quote from: thehaze on January 03, 2013, 11:22:52 AM
Quote from: Bobmic on January 02, 2013, 08:39:42 PM
If its not freezing I will test it again over the weekend and I will make sure the heated transmitter glove goes in the car first, the only problem is that I will need someone to throw it.
I hear Greg is available.... :)
hee hee the black widow is only free this Sunday... but i think I'll sit on the side lines and watch
Quote from: battlestu on January 03, 2013, 11:36:10 AM
Quote from: thehaze on January 03, 2013, 11:22:52 AM
Quote from: Bobmic on January 02, 2013, 08:39:42 PM
If its not freezing I will test it again over the weekend and I will make sure the heated transmitter glove goes in the car first, the only problem is that I will need someone to throw it.
I hear Greg is available.... :)
hee hee the black widow is only free this Sunday... but i think I'll sit on the side lines and watch
I though the deal was that he is only smashing your planes ....:)
Can't get anything by you... ;D
Quote from: flying saucer on January 03, 2013, 12:06:04 AM
Many planes pitch up under power, especially flying upwind, this is normal. I'm surprised it doesn't happen with your Sundowner?
Once a plane has left the ground wind direction is irrelevant to how it flies. It only affects ground speed, and hence our perception of its airspeed.
I would agree, however I have noticed my models tend to climb slightly when flying upwind at a given throttle setting, when flying downwind they fly level or lose altitude slightly. Although most of my planes don't fly "perfect", I have become used to utilizing the sticks to fly around bad habits and strange tendencies.
Oh man, I had this exact same discussion with a fellow flyer in 1995! ;D
I was of the same opinion as Jeff and I was too determined to accept anything else because I Knew (and still know) I could see a difference. Here's my current opinion on the subject:
I agree that in theory (and reality) the aircraft knows nothing about wind (besides gusts) when in the moving mass of air. What I think is causing the effect that we are talking about is the fact that we, the pilots are standing on the ground and therefore that is our frame of reference. I believe that when flying into a head wind, we observe the craft slowing down and tend to hold a bit more power to try to maintain a comfortable ground speed. When the plane is flying down wind, we subconciously tend to want to slow the plane a bit and will hold less power. This is my only explanation for what I observe. Oh, and when turning from one wind direction to another, we want to see a nice smooth radius, not one where the plane is drifting downwind (as it would while moving with the air mass), so we do the same thing by compensating with power, whether we know it or not.
What do you guys think of my pet theory? ;D
Robert
Sounds about right to me. ;D
Have enjoyed the various twists and turns this thread has taken so until my new knee lets me get back to flying, thought I'd post on the joys of being an Ice Pilot...
In response to Andy's post showing a mechanism for pushing the ski into a positive AofA without actually going vertical once the model lifts off, I re-installed the skis on my trusty Apprentice and have included pics of the wheel collars and spring arrangement used to achieve the above. My variation took several sessions to evolve but seems to work well with the Apprentice's three pound weight.
Also some photos of Ice Pilot Ken Ross flying his truly all-weather F-18 pusher in February 2012...yes, there were a few days last winter with snow! These were taken with my dumb phone last Feb so hardly photo award quality! Get out there...enjoy winter!
That method of ski positioning is amazing. Very well thought out and minimum parts. Nice show I must say.
If you run the end of the wire through a tube glued to the ski it will both hold the tips up and also stop them from going too high.
This is on my brothers old Easybuilt Turbo Porter.
How old? First flew at Miliken Park, brushed 550 and 6 cell NiMh.
Very efficient setup that would cruise around for 15 minutes.
A lot of fun to fly off fresh snow, just skimming it so only the tails of the skis are touching.
Pat MacKenzie
Very neat idea Pat! Gotta try that this winter!
Today (late afternoon) was very interesting for ski "flying", and very different from my earlier post. The snow is now saturated, wet and heavy, as opposed to the nice light fluffy stuff of just a day ago. I could taxi fine, but as soon as I started my takeoff run, the ski created a bow wave at the tip, effectively providing a packed snow chock in front of each ski which resulted in a nose over. No amount of finesse could get the plane airborne. :(
Re control of ski angle of attack after takeoff, I am intrigued by the elegance of the designs used by Bill and Pat. I had used the approach evident in most of the full scale ski planes I found by Googling "ski plane images", all of which show bungees attached to the ski tips and travel-limiting guy wires on the ski tails. The original DuBro skis I used had torsion springs attached to the struts, but I thought rubber bands and string would achieve the desired performance with less weight.
Now we just have to wait for some more real snow.
Andy Hoffer
Floats worked great! :D
Quote from: pmackenzie on January 06, 2013, 02:38:09 PM
If you run the end of the wire through a tube glued to the ski it will both hold the tips up and also stop them from going too high.
Pat MacKenzie
Hi Pat,
I understand the section of the wire that goes into the tube but how do you attache the spring wire to the landing gear axle. The Du-Bro method wraps around the axle and the spring is only pushing the ski while a mechanical stop is used to limit the travel down lower than parallel to the wing.
Now I have a second question:
I was at AJ on Saturday and bought a set of skis for my Toledo Special, he also had plastic floats that should fit this plane and do not cost like a new one as the H9 (they were something like $50 less then double the price of the skis).
I am not sure what is involved in taking off and landing of water etc. but what do you guys think - should I keep the skis or swap them for the floats as I am sure they can also work on snow even if they will not look as nice or efficient...:)
Thank you
Hey Simon, Nice plane !
Next time you have to put more effort in the photos and lay on the ground level with the plane as Andy does - we will have better appreciation on the scale and beauty of your plane.
Hey guys. Fair weather flyer here (a feel a little reluctant to post in the Ice Pilots thread :))
But, like they say... opinions are like A$$H*les... everyone's got one ;D
First, I don't think most people here would get the Milikan Park time frame reference, Pat. To clarify, I think you're talking 1990ish... right?
And in my very humble opinion, Bobby, floats are a good way to go, especially considering what Andy was talking about. My opinion is that ski's are great (and cool) when the snow conditions are ideal. Soft and fluffy, but not too deep with the fluffy stuff. The ski's have a pretty modest contact patch for the weight of the plane (unless we're talking about a light foamy. Floats distribute the load better, have a large bow to "ski" up onto the snow, have a longer bow to prevent nose over, and generally a wider stance for lateral stability. And of course, then you'd be set for float flying in the Spring ;)
Quote from: piker on January 07, 2013, 09:55:58 AM
Hey guys. Fair weather flyer here (a feel a little reluctant to post in the Ice Pilots thread :))
But, like they say... opinions are like A$$H*les... everyone's got one ;D
First, I don't think most people here would get the Milikan Park time frame reference, Pat. To clarify, I think you're talking 1990ish... right?
And in my very humble opinion, Bobby, floats are a good way to go, especially considering what Andy was talking about. My opinion is that ski's are great (and cool) when the snow conditions are ideal. Soft and fluffy, but not too deep with the fluffy stuff. The ski's have a pretty modest contact patch for the weight of the plane (unless we're talking about a light foamy. Floats distribute the load better, have a large bow to "ski" up onto the snow, have a longer bow to prevent nose over, and generally a wider stance for lateral stability. And of course, then you'd be set for float flying in the Spring ;)
Especially when the snow melts at TEMAC !! :)
ANdy
Quote from: piker on January 07, 2013, 09:55:58 AM
Hey guys. Fair weather flyer here (a feel a little reluctant to post in the Ice Pilots thread :))
But, like they say... opinions are like A$$H*les... everyone's got one ;D
First, I don't think most people here would get the Milikan Park time frame reference, Pat. To clarify, I think you're talking 1990ish... right?
And in my very humble opinion, Bobby, floats are a good way to go, especially considering what Andy was talking about. My opinion is that ski's are great (and cool) when the snow conditions are ideal. Soft and fluffy, but not too deep with the fluffy stuff. The ski's have a pretty modest contact patch for the weight of the plane (unless we're talking about a light foamy. Floats distribute the load better, have a large bow to "ski" up onto the snow, have a longer bow to prevent nose over, and generally a wider stance for lateral stability. And of course, then you'd be set for float flying in the Spring ;)
I must admit, the fun of flying with skis has given me a terrible itch to try float flying this summer!
Andy
Before Rogo, and before 14th avenue, there was Milliken Park. :) I think everyone in TO who was flying electrics back in the day used that park.
It was less built up at the time, just a flat open field.
It was a great place to fly, till Toronto R/C club moved in a couple of blocks to the west and had us booted out. >:(
Late 80's to early 90's
We probably would have gotten the boot anyway because shortly after they continued to build up the park infrastructure.
But it still hurt that Toronto R/C (or at least some member) got us kicked out. Water under the bridge now.
(Those who know their history will know that Toronto R/C used the same park for many years, till the housing development encroached on it and got them booted.
They flew first on the South west corner near Middlefield, then when the houses got too close they moved over to the East side of the park over by McCowan.
Only at that location for about a year I think till more houses were built.)
A bit hard to see in the picture but the spring is soldered to the wheel collar. Ski angle is set by simply tightening the collar in the desired position.