EIII Restoration
05-13-2013, 04:19 AM
#202
Thread Starter
RE: EIII Restoration
ORIGINAL: Nieuport nut
I agree with the possible need for downthrust. How hard will it be to add? (I hate giving up on an airframe.)
Martin
I agree with the possible need for downthrust. How hard will it be to add? (I hate giving up on an airframe.)
Martin
What makes determining the problem more difficult is trying to separate out the effects of CG, the hyper-sensitive elevator, and engine thrust. On previous flights I felt like it was starting to fly reasonably. But it felt completely different on this last flight. Straight and level flight was nearly impossible.
05-14-2013, 04:47 AM
#204
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RE: EIII Restoration
I had a similar problem recently, (needing to put down thrust in a 45 degree mounted engine) and did it with a disk of ply. I cut a disk the same size as the mount and used a sanding belt to taper it from 1/8" to 1/32". After it was tapered, I cut the centre disk out for the fuel lines, drilled the mounting holes and then fuel proofed it. The sanded away laminations show where the top is so that I put in only downthrust.
Martin
Martin
05-15-2013, 04:23 AM
#205
Thread Starter
RE: EIII Restoration
But is engine thrust actually the problem? Here are what seem to be the facts:
1. The model seems to want to climb.
2. However, it requires a long talk-off run.
3. It sinks quickly at idle (or power off).
4. The model is EXTREMELY sensitive on the full-flying elevator (even with 50% expo).
1. The model seems to want to climb.
2. However, it requires a long talk-off run.
3. It sinks quickly at idle (or power off).
4. The model is EXTREMELY sensitive on the full-flying elevator (even with 50% expo).
05-15-2013, 08:21 AM
#206
RE: EIII Restoration
Except for pattern types of planes down thrust is almost always a good thing in a tractor plane. You will always have a penalty with a small flying stab at the size you are playing with. The laws of physics demand that; if not why would someone make them bigger if a smaller one worked? The takeoff run being long could be related to the small stab. Until it has the authority to lift the wing's angle of attack. Tail being low in the grass does not help as the grass is a n aerodynamic shield spoiling the air on the stab.
Sinks with power off, consideration is going to have to be attitude of the airplane. If power off it nose dives, relative up thrust could have the plane so out of trim with no power, you think you have a rock with all the up you need to keep it flying. If the plane has a normal glide angle but drops like a rock, then it is just drag at work. An extreme trim change is either the incidences or CG and they are both inter related. The question is what can you tolerate? My Bellanca CF was bashed from a Sig Kadet SR kit. Redid the fuselage and tail to scale; the wing only took tips to make it scale except for the cord which was about an inch too wide. With the shortened fuselage and much smaller tail but with much more elevator surface on the tail, completely unflyable in any kind of wind. First 4 flights were crashes, minor damage. I could not dial out enough control; all it did was dart any direction I put controls too. To get it to fly at any reasonable way, I had to remove the wing struts which were spoiling the air on the stab and make a bigger stab/elevator. Lots of CG changes. That at least tamed it, but it sucks to fly. Decommissioned. Probably give it to a friend; know a restraunt that wants a hanging model? I had too many built in errors that stacked the wrong way. So is scale. It is a good size plane too. At 1/6 it has a 80 something wingspan.
Sinks with power off, consideration is going to have to be attitude of the airplane. If power off it nose dives, relative up thrust could have the plane so out of trim with no power, you think you have a rock with all the up you need to keep it flying. If the plane has a normal glide angle but drops like a rock, then it is just drag at work. An extreme trim change is either the incidences or CG and they are both inter related. The question is what can you tolerate? My Bellanca CF was bashed from a Sig Kadet SR kit. Redid the fuselage and tail to scale; the wing only took tips to make it scale except for the cord which was about an inch too wide. With the shortened fuselage and much smaller tail but with much more elevator surface on the tail, completely unflyable in any kind of wind. First 4 flights were crashes, minor damage. I could not dial out enough control; all it did was dart any direction I put controls too. To get it to fly at any reasonable way, I had to remove the wing struts which were spoiling the air on the stab and make a bigger stab/elevator. Lots of CG changes. That at least tamed it, but it sucks to fly. Decommissioned. Probably give it to a friend; know a restraunt that wants a hanging model? I had too many built in errors that stacked the wrong way. So is scale. It is a good size plane too. At 1/6 it has a 80 something wingspan.
05-16-2013, 07:05 AM
#207
Thread Starter
RE: EIII Restoration
Went back to the old (reasonably trustworthy) incidence meter. First, I propped up the tail so that the top longeron at the cockpit is level, which on the original EIII (and the Nieto drawings I used) results in a line running straight through the shaft of the Gnome rotary to the pointed tip of the fuselage. I take this to be the fuselage centerline.
In this position the engine shows -2 degrees of down thrust and the wing sits at +1 degree. The elevator, in it's "neutral" position (radio on), is at -2 degree at the moment. None of this sounds quite right.
In this position the engine shows -2 degrees of down thrust and the wing sits at +1 degree. The elevator, in it's "neutral" position (radio on), is at -2 degree at the moment. None of this sounds quite right.
05-16-2013, 08:29 AM
#208
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RE: EIII Restoration
Hi!
-2 degrees on the stab is no good! Set it at 0 degrees to ther wing. The wing could be anything around 0-+2 to the fuselage centerline!
At this position the engine should be pointing slightly down.
Try to reduce elevator trow as much as possible and at the same time move the CofG backwards...byt not too far back. Sounds as if the plane is nose heavy.
-2 degrees on the stab is no good! Set it at 0 degrees to ther wing. The wing could be anything around 0-+2 to the fuselage centerline!
At this position the engine should be pointing slightly down.
Try to reduce elevator trow as much as possible and at the same time move the CofG backwards...byt not too far back. Sounds as if the plane is nose heavy.
05-16-2013, 09:46 AM
#209
RE: EIII Restoration
Actually, sounds right for a free flight job...but Jaka is right, reduce the wing/tailplane to closer to , say, one degree. Contrary to Jaka, extreme elevator sensitivity sounds like a balance at the rearmost position, move it forward. Loose the expo, only makes the pitch reaction seem poor for a start, then way too much at the ends of the travel. then try again.
Evan, WB #12
Evan, WB #12
05-16-2013, 11:21 AM
#210
RE: EIII Restoration
I have been following this thread for the past few days. The plane is too nice to be relegated to the status of a hangar queen. My first hunch upon reviewing the symptoms is that the stabilator (flying stab) is too small for the plane. I whole heartly agree with what TFF wrote.
The fact that the stabilator is set at -2 degrees might be an indication that the stab is too small: it needs significant deflection in order to generate the downward force needed for level flight. Since the plane has a relatively long tail moment I would be tempted to shift the CG back a little and see how it flies.
Regarding the pitch sensitivity it could be an issue with the amount of travel available. In general, a stabilator is more effective than a normal stab and elevator and hence it needs less movement to achieve the same result. Most airfoils stall at about +/- 15 degrees for the angle of attack, so I would use that as a guide to set the travel for the stabilator. In some of the photos, you can see it deflected significantly during landing; I wonder if you can reach a point at which the stab stalls and you no longer have the power to raise the nose. This could also be confused with the main wing stalling. Maybe blipping the power during the approach would help smooth things out a little.
If you get really desperate, I would pose the question on the Pattern forum and see what those guys suggest. They certainly know how to trim an airplane properly.
Good luck and don't give up on the nice looking plane.
Teo
The fact that the stabilator is set at -2 degrees might be an indication that the stab is too small: it needs significant deflection in order to generate the downward force needed for level flight. Since the plane has a relatively long tail moment I would be tempted to shift the CG back a little and see how it flies.
Regarding the pitch sensitivity it could be an issue with the amount of travel available. In general, a stabilator is more effective than a normal stab and elevator and hence it needs less movement to achieve the same result. Most airfoils stall at about +/- 15 degrees for the angle of attack, so I would use that as a guide to set the travel for the stabilator. In some of the photos, you can see it deflected significantly during landing; I wonder if you can reach a point at which the stab stalls and you no longer have the power to raise the nose. This could also be confused with the main wing stalling. Maybe blipping the power during the approach would help smooth things out a little.
If you get really desperate, I would pose the question on the Pattern forum and see what those guys suggest. They certainly know how to trim an airplane properly.
Good luck and don't give up on the nice looking plane.
Teo
05-16-2013, 01:22 PM
#211
Thread Starter
RE: EIII Restoration
Thanks for all the input...even if it doesn't all agree. It gives me ideas to think about. I believe I initially set the model up with zero degrees on the elevator relative to the centerline. But then modified it with the radio bit by bit to it's current position. I can't say this was a completely clear and rational decision...more like dealing with the panic of the moment during flight.
I think the CG is as far back as I dare put it. It's a bit over 30% MAC now...and to be honest, I'd be more comfortable with it being in the 28% range.
I think the CG is as far back as I dare put it. It's a bit over 30% MAC now...and to be honest, I'd be more comfortable with it being in the 28% range.
05-16-2013, 01:29 PM
#212
Thread Starter
RE: EIII Restoration
ORIGINAL: viva_peru
Good luck and don't give up on the nice looking plane.
Good luck and don't give up on the nice looking plane.
05-16-2013, 02:45 PM
#213
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RE: EIII Restoration
Ahh... I think you have it - too rearward a cg for a small stab. As painful as it is to add, perhaps more noseweight is in order. As Teo noted, a +3 degree wing stab decalage is probably too much.
Martin
Martin
05-16-2013, 03:44 PM
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RE: EIII Restoration
Abu,
To figure out what the plane (engine thrust) is doing, set down and think of what happens when you are flying at 1/2 to full throttle. If you have too much positive (or in this case, not enough negative) thrust, when then engine is running at the upper end of your throttle range eg. 1/2 to full throttle, it is pulling the nose of your plane up. What do you do to compensate? You put in down elevator trim on your radio. Now that you've got the down trim in, what happens when you cut the throttle and the engine is no longer pulling the nose up. Bing, I know the light just went off above your head. The down trim in the elevator (stabalator) causes the nose to drop dramatically.
Now for the caveat. This only applies when the C of G is in the correct location. I can assure you that the CG of this plane should be no where near 30%. Get the CG back to 25-28%. Put the weight back in.
I've not followed this thread like all your others so I'm not sure what airfoil the plane has. I'm going to assume it's not a symmetrical airfoil. If it's a semi or flat airfoil, when you get the CG right you will find that you will have a slight amount of negative trim in the stabalator. This is due to the fact that as we measure incidence on these type of wings we are not reading the true incidence. A flat bottom airfoil particularly always gives us positive incidence when we think we have it set to zero. As an example, this is one of the reason our trainers always have a bit of down trim in them.
Viva was right about the throws on a stabalator. When you have the CG and engine thrust right you will probably find that you only need 10-12 degrees of travel. Also, a stabalator does not need to have as much area as a regular stab/elevator. It's much more effective than a stab/elevator. BUT, in our models and more specifically, in a model of this size, it still needs to be bigger than scale. It does sound to me that it's probably close to minimum size needed to fly the plane.
It's nice to know that all those years of pattern flying have some value. If only I had gotten more trophies as recognition. [&o] 
Later
Bob
To figure out what the plane (engine thrust) is doing, set down and think of what happens when you are flying at 1/2 to full throttle. If you have too much positive (or in this case, not enough negative) thrust, when then engine is running at the upper end of your throttle range eg. 1/2 to full throttle, it is pulling the nose of your plane up. What do you do to compensate? You put in down elevator trim on your radio. Now that you've got the down trim in, what happens when you cut the throttle and the engine is no longer pulling the nose up. Bing, I know the light just went off above your head. The down trim in the elevator (stabalator) causes the nose to drop dramatically.
Now for the caveat. This only applies when the C of G is in the correct location. I can assure you that the CG of this plane should be no where near 30%. Get the CG back to 25-28%. Put the weight back in.
I've not followed this thread like all your others so I'm not sure what airfoil the plane has. I'm going to assume it's not a symmetrical airfoil. If it's a semi or flat airfoil, when you get the CG right you will find that you will have a slight amount of negative trim in the stabalator. This is due to the fact that as we measure incidence on these type of wings we are not reading the true incidence. A flat bottom airfoil particularly always gives us positive incidence when we think we have it set to zero. As an example, this is one of the reason our trainers always have a bit of down trim in them.
Viva was right about the throws on a stabalator. When you have the CG and engine thrust right you will probably find that you only need 10-12 degrees of travel. Also, a stabalator does not need to have as much area as a regular stab/elevator. It's much more effective than a stab/elevator. BUT, in our models and more specifically, in a model of this size, it still needs to be bigger than scale. It does sound to me that it's probably close to minimum size needed to fly the plane.
It's nice to know that all those years of pattern flying have some value.
If only I had gotten more trophies as recognition. [&o] Later
Bob
05-16-2013, 05:38 PM
#215
RE: EIII Restoration
I think that a -2 degree incidence (leading edge low) on the stabilator means that he is probably flying with quite a bit of up trim. In normal trim, most planes fly with the stab and elevator generating a downward force. For the stabilator to do that, it would need negative incidence relative to the wing. The 3 degree difference between the wing and stab is significant but maybe not unusual for a plane with such a small stab. Also, your trim changes with speed and it could be that this particular model is more sensitive to it than others helping mask the effect of the engine down thrust. I would say that some down thrust and a little right thrust would be a good thing to have.
Teo
Teo
05-16-2013, 06:29 PM
#216
RE: EIII Restoration
I dont think it's time for the hangar either. My plane was the worst airplane I have ever flown. I had a club mate take 1/4 of a wing off a sport pattern plane and it was 100 times better flying. I know it goes against the grain, but if it gets to the point that it stays a handful, build a 50% bigger stab. Ok After you stop throwing things, the plane is an experiment, you have experimented in this configuration. Might be a time for a change. Turning it into a reliable rc plane seems to be the objective, and it might mean turning to the dark side.
05-16-2013, 08:02 PM
#217
Thread Starter
RE: EIII Restoration
ORIGINAL: TFF
...build a 50% bigger stab. Ok After you stop throwing things, the plane is an experiment, you have experimented in this configuration. Might be a time for a change. Turning it into a reliable rc plane seems to be the objective, and it might mean turning to the dark side.
...build a 50% bigger stab. Ok After you stop throwing things, the plane is an experiment, you have experimented in this configuration. Might be a time for a change. Turning it into a reliable rc plane seems to be the objective, and it might mean turning to the dark side.
Again, thanks everyone. I really need to put the thinking cap on and process all of these different suggestions. I agree that the CG needs to be moved back up to 25-28% MAC. That's where I always thought it should be anyway. However, LarryC's large 1/3 EIII (which it's stab/elevaor configuration) did balance out at 30%. I had already decided after the last flight that I was going to put some of the weight back in. I'll start by going back to the heavier APC prop.
Regarding wing/elevator decalage, I've always heard that what's wanted is for the "stab" (which a scale EIII doesn't have) to be POSITIVE relative to the main wing, for example, say, +1 on the wing and +2 or +3 on the "stab." That is, the stab is "canted up" relative to the angle of attack of the wing. With a full-flying elevator with no stab, it's a little less clear how this should be. At the moment, however, what I have is the elevator sitting at MINUS 3 degrees relative to the wing. Another problem with my elevator is that 10 years ago when I built it, I was ignorant of the correct cross-section and so I build something that is flat on the bottom but with a but of a curve on the top, so in effect a flat-bottomed airfoil. I'm sure that's causing problems, but I had hoped I could "fly through them."
On the topic of engine down thrust, it already has -2 degrees relative to the centerline and -3 relative to the main wing.
05-16-2013, 09:16 PM
#218
Thread Starter
RE: EIII Restoration
Time for a reset:
1. Elevator at ZERO (i.e. on the centerline).
2. Wing at PLUS 1 to the centerline (measured LE to TE, not on the flat airfoil bottom, which is at zero).
3. The engine, well, for now, I think I'll just leave that with MINUS 2 relative to the centerline.
4. CG at 28%.
The throws on the ailerons are fine. The rudder throw could be reduced slightly. It's very effective even though it's the scale size. I'm hesitant to reduce the amount of available elevator throw since the damage on the first landing seemed to come from not being able to flair on landing since I had run out of elevator.
If it survives another flight like this, at least I'll have some more (and hopefully more reliable) flight data.
1. Elevator at ZERO (i.e. on the centerline).
2. Wing at PLUS 1 to the centerline (measured LE to TE, not on the flat airfoil bottom, which is at zero).
3. The engine, well, for now, I think I'll just leave that with MINUS 2 relative to the centerline.
4. CG at 28%.
The throws on the ailerons are fine. The rudder throw could be reduced slightly. It's very effective even though it's the scale size. I'm hesitant to reduce the amount of available elevator throw since the damage on the first landing seemed to come from not being able to flair on landing since I had run out of elevator.
If it survives another flight like this, at least I'll have some more (and hopefully more reliable) flight data.
05-16-2013, 09:52 PM
#219
RE: EIII Restoration
FLat bottom and under cambered airfoils can have high pitching moments. More than going faster and it wanting to climb because of more lift, going faster can make the plane pitch up like adding elevator. Trim will be varied more than normal. Adding nose weight can soften the reaction.
I figure another stab would do one important thing, give you a relationship for a go/no go if you end up wanting to build something similar at the same size. Most things are possible at 1/4, but smaller gets harry. I would never hold you to leaving it that way. Proof of concept and then return to original.
I figure another stab would do one important thing, give you a relationship for a go/no go if you end up wanting to build something similar at the same size. Most things are possible at 1/4, but smaller gets harry. I would never hold you to leaving it that way. Proof of concept and then return to original.
05-17-2013, 05:50 AM
#220
Thread Starter
RE: EIII Restoration
Looks like I need to undo everything I've done since the first "re-maiden." To get the CG forward (again) to 28% I'll need to put the lead weights back in the dummy and use the APC prop. So the total weight will go back up to about 6.6 pounds. This is about one pound heavier than a stock BUSA eindecker of the same span and airfoil would be.
As I mentioned above, the bottom of the flat-bottomed wing is level with the centerline but the line from LE to TE (as measured on the meter) is +1 degree. The engine has 2 degrees of down thrust relative to the centerline (so -3 degrees relative to the wing). Is that too much?
The real question is how to set the elevator. I reset it back to +1 (same as the wing) although I feel it's supposed to be more like +2 (i.e. more than the main wing). But maybe that's only for a fixed stab and all bets are off on a full-flying elevator. I'm not sure there's anything else I can do other than just try again like this...and have my spotter standing by to help me dial in elevator trim if I'm in a pickle.
As I mentioned above, the bottom of the flat-bottomed wing is level with the centerline but the line from LE to TE (as measured on the meter) is +1 degree. The engine has 2 degrees of down thrust relative to the centerline (so -3 degrees relative to the wing). Is that too much?
The real question is how to set the elevator. I reset it back to +1 (same as the wing) although I feel it's supposed to be more like +2 (i.e. more than the main wing). But maybe that's only for a fixed stab and all bets are off on a full-flying elevator. I'm not sure there's anything else I can do other than just try again like this...and have my spotter standing by to help me dial in elevator trim if I'm in a pickle.
05-17-2013, 06:44 AM
#221
Thread Starter
RE: EIII Restoration
I need to delve deeper into the past. Back 10 years when this model flew for the first few times. Here are the first couple of flight reports and some photos for those flights.
ORIGINAL: abufletcher
Trev, first things first. SHE FLEW!!! So strange to see the model up in the air as opposed to on my workbench! I had the club president who also happens to be our resident ace fly it. He has competed in several national scale championships often being recruited to be the pilot for someone else's plane. After checking it out and everything checked out perfectly he took it up for two 10 minutes flights. The throws were fine and the CG was perfect without any additional weight in the nose. CG was about 3'' back from the leading edge. This was without the dummy engine so with the dummy it'll be just a bit further forward. I quickly shot off 3 rolls of 36 print film but focus was a problem and I'll be lucky if I get 2 or 3 sharp pix. If any turn out I'll post them. If not well there's always next week.
Now on to the flight report. Carl says the plane is a challenge to handle. At 8 lbs it seems to be underpowered with the 52FS turning a 13/5 prop. Maybe I can squeeze a bit more power out of it. But I might also eventually consider whether I could be using a Magnum 70FS. Carl says you have to be willing to allow it to climb out very slowly and to use the rudder A LOT! He just tried lazy patterns around the fileld and nothing fancy. With all the drag you also have to keep the throttle up and fly it onto the runway. When he cut power it came down fast. He said he doubted that it would fly with a scale airfoil. All in all, he recommended that I get a bit more flying experience before I try to fly it myself and that's perfectly OK since in two weeks I'm off to Japan and the EIII isn't coming with me. It'll give me something to shoot for.
All in all building the EIII has been an immensily enjoyable and educational experience. I feel that I've finally after years and years of looking at scale planes finally got my feet wet just a bit.
One your question about styrene, according to one English-German dictionary site ''styrene'' is ''das Styrol'' though it's probably used in one of those incredibly long German compounds like ''Heerengruentischkugelstossspielanlage'' (which apparently was once used as a substitute for ''billiard'' during a period of German nationalism when they sought to replace French terms with ''native'' German ones (others ''sauce'' - ''ueberguss'', ''trottroire'' (sp.?) with ''buegersteig''). Anyway, you ought to be able to buy styrene sheets in any well-stocked plastic model shop or maybe online.
Oh, and here are a couple of non-flying shots at the field Southern Cal is pretty dry this time of year (and all year long if we weren't constantly sucking the *** of the Colorado River. No grass field take-offs here. Maybe I should have done the EIII up in Turkish colors and imagined it was flying in Ottoman Palestine!
Trev, first things first. SHE FLEW!!! So strange to see the model up in the air as opposed to on my workbench!
I had the club president who also happens to be our resident ace fly it. He has competed in several national scale championships often being recruited to be the pilot for someone else's plane. After checking it out and everything checked out perfectly he took it up for two 10 minutes flights. The throws were fine and the CG was perfect without any additional weight in the nose. CG was about 3'' back from the leading edge. This was without the dummy engine so with the dummy it'll be just a bit further forward. I quickly shot off 3 rolls of 36 print film but focus was a problem and I'll be lucky if I get 2 or 3 sharp pix. If any turn out I'll post them. If not well there's always next week.Now on to the flight report. Carl says the plane is a challenge to handle. At 8 lbs it seems to be underpowered with the 52FS turning a 13/5 prop. Maybe I can squeeze a bit more power out of it. But I might also eventually consider whether I could be using a Magnum 70FS. Carl says you have to be willing to allow it to climb out very slowly and to use the rudder A LOT! He just tried lazy patterns around the fileld and nothing fancy. With all the drag you also have to keep the throttle up and fly it onto the runway. When he cut power it came down fast. He said he doubted that it would fly with a scale airfoil. All in all, he recommended that I get a bit more flying experience before I try to fly it myself and that's perfectly OK since in two weeks I'm off to Japan and the EIII isn't coming with me. It'll give me something to shoot for.
All in all building the EIII has been an immensily enjoyable and educational experience. I feel that I've finally after years and years of looking at scale planes finally got my feet wet just a bit.
One your question about styrene, according to one English-German dictionary site ''styrene'' is ''das Styrol'' though it's probably used in one of those incredibly long German compounds like ''Heerengruentischkugelstossspielanlage'' (which apparently was once used as a substitute for ''billiard'' during a period of German nationalism when they sought to replace French terms with ''native'' German ones (others ''sauce'' - ''ueberguss'', ''trottroire'' (sp.?) with ''buegersteig''). Anyway, you ought to be able to buy styrene sheets in any well-stocked plastic model shop or maybe online.
Oh, and here are a couple of non-flying shots at the field Southern Cal is pretty dry this time of year (and all year long if we weren't constantly sucking the *** of the Colorado River. No grass field take-offs here. Maybe I should have done the EIII up in Turkish colors and imagined it was flying in Ottoman Palestine!
ORIGINAL: abufletcher
Here's an update on its second day of flying. Sorry no new pix yet. Once again I had the local ace Carl Lindou do the flying while I shot pictures. Later, however, we did hook up a buddy box and I got to experience the feel of sitting in the pilot's seat of my EIII. I just wanted to report on how it flew this time out.
First of all, Carl reports that it seemed to have a little more power this time even though I hadn't changed anything. It's a new engine with relatively little break-in time on a stand so maybe just running it helped out. Also we (Carl) tweeked the throttle a bit. It's still a bit of a handful but Carl was able to put it through a more extensive set of paces today including a loop (starting with a bit of a dive as you suggested, John) and a simple roll. Landings have been picture perfect each and every time. The take-offs today seemed particularly scale long and slow.
As it turns out having the tank above the servos and therefore way above the carb turned out to be no problem at all. I don't even need the clamp I was using. No fuel runs out. And it starts as easily as my trainer. In fact the biggest pain in the a** is that damn green bare prop plug that you stuff into the electric starter. It comes out just about every time we start no matter how hard we push it in. Seems really dangerous!
Now on to my experience flying it. Carl took it up high (which takes awhile no ''going vertical'' with this plane) and we spend a few minutes getting the trims on the buddy box right. This turned out to be a little difficult. We never quite got the throttles sync'd. Anyway, I was able to wallow around the sky in lazy circles. It definitely needs rudder on the turns and is a little sensitive. But I'd still say it's pretty stable. Being small it is also quite susceptible to turbulance and occasionally bobbles around. It wasn't squirrly though and I think if I had a few more days with it, I'd be ready to solo (again).
All in all, it flies like the original. It sure isn't fast but then that's just right. It can do a loop and a roll and probably an (real) Immelmann though we didn't give that a shot today. It takes off and lands with the grace of all scale taildraggers particularly in the hands of an expert.
Here's an update on its second day of flying. Sorry no new pix yet. Once again I had the local ace Carl Lindou do the flying while I shot pictures. Later, however, we did hook up a buddy box and I got to experience the feel of sitting in the pilot's seat of my EIII. I just wanted to report on how it flew this time out.
First of all, Carl reports that it seemed to have a little more power this time even though I hadn't changed anything. It's a new engine with relatively little break-in time on a stand so maybe just running it helped out. Also we (Carl) tweeked the throttle a bit. It's still a bit of a handful but Carl was able to put it through a more extensive set of paces today including a loop (starting with a bit of a dive as you suggested, John) and a simple roll. Landings have been picture perfect each and every time. The take-offs today seemed particularly scale long and slow.
As it turns out having the tank above the servos and therefore way above the carb turned out to be no problem at all. I don't even need the clamp I was using. No fuel runs out. And it starts as easily as my trainer. In fact the biggest pain in the a** is that damn green bare prop plug that you stuff into the electric starter. It comes out just about every time we start no matter how hard we push it in. Seems really dangerous!
Now on to my experience flying it. Carl took it up high (which takes awhile no ''going vertical'' with this plane) and we spend a few minutes getting the trims on the buddy box right. This turned out to be a little difficult. We never quite got the throttles sync'd. Anyway, I was able to wallow around the sky in lazy circles. It definitely needs rudder on the turns and is a little sensitive. But I'd still say it's pretty stable. Being small it is also quite susceptible to turbulance and occasionally bobbles around. It wasn't squirrly though and I think if I had a few more days with it, I'd be ready to solo (again).
All in all, it flies like the original. It sure isn't fast but then that's just right. It can do a loop and a roll and probably an (real) Immelmann though we didn't give that a shot today. It takes off and lands with the grace of all scale taildraggers particularly in the hands of an expert.
05-17-2013, 06:47 AM
#222
Thread Starter
RE: EIII Restoration
When it flew for these first times, it flew without the dummy, with a wooden propeller, and with the Rx battery behind the CG in the dummy pilot. I see that CG is given as being 3" behind the LE (i.e. 27%). That makes no sense at all. It's at about 30% now WITH the dummy engine (with weights) and the Rx battery moved up through the firewall. And I don't see how it could possibly have been 8lbs without the dummy. Something isn't right.
I just realized, since my Puppeteer bit the dust, I have a Saito 62a just sitting around! And it would fit exactly where the Saito 56 fits! Now that I've re-read that first flight report, that sounds like a good change to make.
I just realized, since my Puppeteer bit the dust, I have a Saito 62a just sitting around! And it would fit exactly where the Saito 56 fits! Now that I've re-read that first flight report, that sounds like a good change to make.
05-17-2013, 07:47 AM
#223
RE: EIII Restoration
I found with the Bellanca that the CG spread calculations were only 2-3% form going nose to tail heavy. It was really hard to pinpoint it. Setting the incidence on a flying stab is impossible. When you trim the plane, you are changing the incidence. Trim is where it flies. Where the down thrust and CG come into play is trying to keep the trim angle as clse as possible. What you need to do is take the plane up and throttle it back into a glide. If you can trim a good glide, but adding power makes it ballon, start adding down thrust until the trim is close to the glide trim.
05-17-2013, 07:50 AM
#224
RE: EIII Restoration
If it does not glide, work on the CG until it glides then go to down thrust. The plane has to be made flyable in some area to have something to work with.
05-17-2013, 05:39 PM
#225
RE: EIII Restoration
Add to all that, the closer you get your model to the real thing...you begin to realise just what the early aviators had to put up with, and they had to fight in the thing too...big drag changes with speed changes, big pitch changes with speed changes...limited power and no throttle, in the accepted sense. had to be brave just to fly the things...
Evan, WB #12.
Evan, WB #12.