I know the video isn't great. The square 8's had the outside part kinda cut off, but you're not missing much.
Thanks guys.
Brett, what you're saying is the biggest reason I wanted to get up to the stunt clinic. Get someone to fly my plane. See where it's at, and what it needs trim-wise.
But, on the topic of sizes - compare this video to yours:
http://www.youtube.com/watch?v=F9u-vpeEyJE&feature=youtu.be
Brett
The engine run seems pretty ragged, for some reason, especially late in the flight. What's that all about? H^^ Steve
Oh my!
Yes! OMG is appropriate. I'd very much like to see Igor fly in person. I'd be happy to run score sheets, which is THE best job you can get at any stunt contest. Be there & ready to watch the whole flight. Don't say a word, don't utter a sound. Observe the pilot carefully, as he gets ready to start the engine, signaling, walking to the handle, right through to the end of the landing roll. 8) Steve
Oh my!
You also have a prototypical example of what is shown here:
https://stunthanger.com/smf/open-forum/incessant-problems-1-hourglass-2nd-corner/msg494948/#msg494948
Your hourglass looks just like the first drawing, to the extent we can see it.
I think as you try to shrink it down, you will run into other problems, particularly with engine setup and trim. The engine sounds like it is coming on very hard at times, which is OK if you make the maneuver large enough to recover from it, but will be a problem if it is still changing when the next corner comes up. That's why flying large is so tempting, everything smooths itself out before you have to do the next element.
Brett
Ok, I've been thinking about this particular part of this thread. Let's start with the fact that the hour glass needs to go as high as the wing over. Reading the rule book, I understand that, but I don't know how "capable" my plane is of that at this point. Hearing what you're saying and reading through the other thread, what happens to me, when flying this plane is that I feel like I would loose tension up there because of the quick turns. I'll try to get over there after work and just practice hourglass after hourglass and see if I can get it to climb all the way up and still make turn 2.
Thanks a bunch!
"Capable" - in quotes because I really don't know if it is or not.
Ok, I've been thinking about this particular part of this thread. Let's start with the fact that the hour glass needs to go as high as the wing over. Reading the rule book, I understand that, but I don't know how "capable" my plane is of that at this point. Hearing what you're saying and reading through the other thread, what happens to me, when flying this plane is that I feel like I would loose tension up there because of the quick turns. I'll try to get over there after work and just practice hourglass after hourglass and see if I can get it to climb all the way up and still make turn 2.
Thanks a bunch!
"Capable" - in quotes because I really don't know if it is or not.
(P.S. I've no idea why all the "strikethroughs" showed up in the preamble to this document. The document download appears to be as originally formatted)
While having some trouble today, I realized it felt like I have more up than down. So, I am fixing my rudder and removing the offset, and pulled the LO's. Here's all the up and all the down. I really shot myself in the foot on the controls I guess.I am curious how you noticed you had more up than down. Was it while flying or simply visual? You should not be using full control to make any corners. This is a subject that is far from settled but I like a bit more control movement than it takes to hit the pressure wall. For me this usually comes out to a bit under 45 degrees on the elevator and around 30 on the flaps. If you take Ted's advice you will never come even close to even being tempted to use it but it will be there in an emergency. One other side note. The only way to truly know if your plane turns the same inside and out is to let someone experienced in flying other peoples planes fly it. It is really hard to tell the difference between the plane turning and your turning it.
I think there's enough adjustability in the push rods to correct this.
I am curious how you noticed you had more up than down. Was it while flying or simply visual? You should not be using full control to make any corners. This is a subject that is far from settled but I like a bit more control movement as it takes to hit the pressure wall. For me this usually comes out to a bit under 45 degrees on the elevator and around 30 on the flaps. If you take Ted's advice you will never come even close to even being tempted to use it but it will be there in an emergency. One other side note. The only way to truly know if your plane turns the same inside and out is to let someone experienced in flying other peoples planes fly it. It is really hard to tell the difference between the plane turning and your turning it.
Good luck!
Ken
While flying, it took more handle movement to do outsides than insides. Especially noticeable in the figure 8. It's always felt like that so I ignored it.If you have eliminated handle bias then that definitely is one way to tell. If your flaps and elevator both hit -0- at the same time the cause is is probably the design, the bellcrank, or the handle. The handle can be the cause or the cure but if you are going to take Ted's advice it would be better if it was neither. It appears from your pictures that you have more than enough control movement to do a decent corner if you are not too nose heavy. The amount of total up vs down is only an issue if you are pegging the controls or have a flexing pushrod but it is a symptom of a misaligned bellcrank. Since the weak pushrod has the opposite symptom we can rule that out. Two things happen when the bellcrank is not aligned properly. First the amount of up vs down is different and second which is worse, the rate that the surfaces move for a given input is different. Before I did anything else to the plane I would get this right. Fortunately you have a profile so it is really easy fix. I sincerely hope you have adjustable connections. Since you can't see the bellcrank you have to keep adjusting the flap linkage till equal movement of the leadouts produces equal flap movement. That should pull the bellcrank into alignment. This may be your whole problem so I would fly it again. The next step is to lock the flaps at zero and adjust the elevator up a little bit at a time till it turns the same. You may need to tweak your handle a bit when you are done since your natural level setting will change.
There's far less down than up, so the entire modulation of the elevator feels softer, not just at the extremes. If I'm explaining that right.
snip
These "HTML tags" are essentially a language for formatting web pages, and it's the fundamental way your computer knows how to make things look the way they do. Actually, real HTML tags use triangular brackets (like "less than symbol s greater than symbol") Sparky's board uses square brackets but mostly the same tags, and most HTML tags will work here (like "leftbracket quote rightbracket" that you use all the time).
Brett
The elevator and flaps are 0-0 together when the lead out's are held together (zeroed on the bench).
Thanks Brett...not that I fully understand it!
Brett,
You wrote: "This is not the greatest flight I ever flew, but it was using a nearly 30-year-old primary stunt trainer and a $47 engine:
https://www.youtube.com/watch?time_continue=276&v=VS6v8y7F4QA (starting at about 4:20). "
What was the $47.00 engine?
Ken,
There's no handle bias, it's a hard point handle.
The elevator and flaps are 0-0 together when the lead out's are held together (zeroed on the bench).
Everything that connects to the flaps and elevator are adjustable.
I'm thinking I get how to fix it, but then my lead out's won't be centered? Like measure up and down in degrees, split the difference and then re-neutralize. Then I'd have to cut and redo one lead out. Does that sounds reasonable?
Ken,I didn't see Brett's post before I posted this so some of it will be redundant...sorry.
There's no handle bias, it's a hard point handle.
The elevator and flaps are 0-0 together when the lead out's are held together (zeroed on the bench).
Everything that connects to the flaps and elevator are adjustable.
I'm thinking I get how to fix it, but then my lead out's won't be centered? Like measure up and down in degrees, split the difference and then re-neutralize. Then I'd have to cut and redo one lead out. Does that sounds reasonable?
When you say Hard Point does that mean that you cannot adjust even the bias? If that is the case you may want to hold off till you can get a set of variable length line connectors or a new handle. You can't cut and wrap just one leadout if you can't adjust the handle, and if you can adjust the handle you don't need to cut the leadout. Catch 22
OS 20FP, purchased new in about 1993 from PECS Hobbies in Mountain View California, and run extensively since then (including a few minutes on a mixture of gasoline, Wesson Oil, and a bit of Ys2020 just to make it fire). It is superior in run quality to all vintage engines, and most current engines, aside from piped full-stunt systems like the 40VF, PA, Ro-Jett and more effective as a stunt power plant to all vintage engines 35 and below. The last version of the 25LA is even better.
Here is the list of the modifications required to make it run so well:
I assume there was supposed to be a website link at the end of the last sentence. Could you try sending that website link again? Thanks.
Brett,
I assume there was supposed to be a website link at the end of the last sentence. Could you try sending that website link again? Thanks.
Joe Ed
Zero handle bias. Vertical. It may take some mental recalibration to become accustomed to a truly vertical handle. Make the mental recalibrations.
Hard point handles have no cables to adjust neutral. Lines are directly connected to the handle via clips. Adjust neutral with different length line clips.
If you have staggered length leadouts, you make one line correspondingly shorter and fine tune neutral with different length line clips.
With the Derek Moran line clip bender available from Jim Lee, you make clips with 1/16 length increments. (1/32" increments if you ask for it)
There are several good options for this type of handle on the market. Paul Walker has developed a very light carbon handle. Kaz Minato offers a nice aluminum handle. Tom Morris and Brodak offer hard point handles. The Fancher Handle is probably the most well known and widely used variety of the breed.
I don't want to get too off subject but what is the advantage of the hard point vs the fully adjustable handle?
Ken
Brett,
I assume there was supposed to be a website link at the end of the last sentence. Could you try sending that website link again? Thanks.
Joe Ed
Thanks Brett.
In addition I remembered after I posted (Senior moment) that I had printed an article you wrote on the OS FP .20 and OS .25 in the Nov/Dec 2014 Stunt News that described just what you learned about these two engines.
Joe Ed
It is a frustrating situation because almost *no one* actually believes me. They try a 20FP or similar, come to me saying it doesn't work...
Crisis averted. Sorry guys. I can't believe I've never noticed this.
I don't want to get too off subject but what is the advantage of the hard point vs the fully adjustable handle?
There's a "leftbracket S rightbracket" at the end of the word "helps". Edit the post and remove that, strikethrough will go away. The problem is that things inside brackets are interpreted as "tags", which are intended to create the formatting you see. "bracket s closebracket" is the tag to start a section of strikethrough text formatting ("leftbracket /s rightbracket" would end it, ending the section). I can't type it directly, becauseit will do the same thing to me.
These "HTML tags" are essentially a language for formatting web pages, and it's the fundamental way your computer knows how to make things look the way they do. Actually, real HTML tags use triangular brackets (like "less than symbol s greater than symbol") Sparky's board uses square brackets but mostly the same tags, and most HTML tags will work here (like "leftbracket quote rightbracket" that you use all the time).
Brett
Those two are not mutually exclusive, but hard point handles have much less compliance than cable-based handles, particularly the Baron-style cable handles. Meaning the response is much more immediate, you move your hand, the controls move right then, not after the compliance has been taken up.I am going to have to try one. I used to fly using the large red EZ-Just. Everybody told me I needed one of those fancy new fully adjustable ones. Not sure I don't like the EZ-Just better. Fancher's handle seems to have enough adjustment to allow for minor line length differences and I assume somebody makes the different size clips. I think I will give that a try before I get too used to the wire ones.
Brett
\ Rokit Science is magic! y1 y1
D'OH!
Brett
p.s. If you move the pushrod to the other side of the horn, you might miss the inner edge completely, no more cut-outs.
I am going to have to try one. I used to fly using the large red EZ-Just. Everybody told me I needed one of those fancy new fully adjustable ones. Not sure I don't like the EZ-Just better. Fancher's handle seems to have enough adjustment to allow for minor line length differences and I assume somebody makes the different size clips. I think I will give that a try before I get too used to the wire ones.
Thanks - Ken
This is about as far from science as it gets - it's computer science, which is a science in the same sense that a refrigerator is a species of dinosaur.
Below is a snip of the code it takes to generate your post, everything you see in between the <> brackets is a "tag". They are instructions to the computer to make the things appear. There seems to be a lot of it, but the entire thing (thousands of lines) is very compact in internet terms, so easy to download. Your web browser knows how to read the instructions, and does most of the work of making it show as it does. This approach minimizes the amount of data that has to be transmitted. The language itself is called HyperText Markup Language, or HTML.
Essentially, you are downloading not a "web page" as you see it, but a relatively compact computer script/program that your browser knows how to execute that generates the web page locally on your machine.
Sparky's software knows how to generate new source code based on your inputs (note that only a tiny fraction of it is things you type), and creates links and updates the page source. When you click a link, the page source text file is downloaded, your browser "renders" it as you see using your processing power.
The problem was that when you posted your response, you inadvertently used one of the tags (the strikethrough tag) as part of your text. Being a computer, it was stupid and just did what you (accidentally) told it to do.
Brett
Like most pilots, I don't read Sanskrit, only look at the pictures....
dg
Uh. OK. Thanks ??? :-\ :o ;D
p.s. You do understand, my friend, that me reading the attachment to your message was like trying to digest the Kama Sutra written in Sanskrit, don't you?
Immediate response.Ok - your shameless marketing and convincing logic has beat me into submission and I have ordered a one of your "Hard Point" handles. You should have a PM by now. Does the certificate guarantying a 100 point increase in scores come with the handle or will that be by Email?
No dullness of feeling.
No induced spring action from the cable.
No cable to fail.
Less overhang for less effort. (generally)
Ok - your shameless marketing and convincing logic has beat me into submission and I have ordered a one of your "Hard Point" handles. You should have a PM by now. Does the certificate guarantying a 100 point increase in scores come with the handle or will that be by Email?
Ken
Immediate response.PayPal for the clips is on the way. Enjoyed talking with you today. The "I" flew on a Fox35. I am 17 in that pix. "II" and "III" were a bit smaller and went through several McCoy 35's. The profile in the Pix is what I am flying now. It is a slightly smaller profile of the "IV" which will host the OS46FX and be my PA machine ( If it survives the new handle!)
No dullness of feeling.
No induced spring action from the cable.
No cable to fail.
Less overhang for less effort. (generally)
Ok, as Ken suggested, this has kinda turned into an online clinic for my plane and getting it to fly through the pattern a little better for me. So here's the tweaks so far....Sorry I hijacked your thread over my handle issues. Can't wait to see what it flies like now. Having a ship capable is step #1. On the tank issue - you hit the cause on the head but, there are two acceptable solutions and one will probably work better than the other. Plan "A" is uniflow. Probably best if you can make it work. Personally I have never had much success with Uniflow on a clunk. Probably me. If they just made a uniflow pickup fitting! You can add muffler pressure to unifow if propwash doesn't give you the desired fix. Plan "B" is simple muffler pressure with the pickup in the upper forward inside corner of a tank that is at least 1oz larger than the amount of fuel you plan to use. Try this only if the Uniflow doesn't work out. Either way you might consider adding a vent tube to the inside front corner that you cap off after filling to keep your engine from filling up with fuel.
1) Pitch control correction. Minor building error. Up and down are equal now, flap to elevator rates seem equal also.
2) Engine run inconsistencies - tank issue. Attached pic of how it was. Vent was at the top of the tank. Inverted flight meant the vent was immersed, upright flight the vent was open to atmosphere. That can't be good. Plumbed tank for uniflow.
3) Bringing Paul Walkers trim article to the field with me. Hopefully a test flight tomorrow.
4) Go-pro and tripod ready for next test flight.
2) Engine run inconsistencies - tank issue. Attached pic of how it was. Vent was at the top of the tank. Inverted flight meant the vent was immersed, upright flight the vent was open to atmosphere. That can't be good. Plumbed tank for uniflow.
I run non-uniflow clunks with muffler pressure on most of my profiles. If the uniflow tank doesn't give satisfaction, try muffler pressure. For that matter, take some fuel tube with you, and try muffler pressure to the uniflow. Note that it will change your needle setting, dramatically.
Is the tank height adjustable in a consistent and repeatable manner? If it's located in the up/down direction by the tank hooks, consider opening up the distance by at least 1/8" and then holding the tank in place with balsa shims. I've gone to carrying my tanks on a tray (plywood or thin aluminum with lots of holes) with slotted screw-holes.
Second, well maybe more important.... the engine is border line not enough. I hate to admit that because I love small engines. But that might be the case. Let's see if I get the run better how true that is.
I've gone to carrying my tanks on a tray (plywood or thin aluminum with lots of holes) with slotted screw-holes.Every time I think I have come up with a new Idea I find out that somebody did it first! I use balsa wedges to get the height on my tray then I MonoKote them in. Your way is probably better. Forgive the finish, this plane is 100% MonoKote.
Well you see the thing is this. I built this before I ever considered giving stunt a real shake. So there's some things that are half @$$-ed at best. Not the build quality, but for example, the tank. Not adjustable at all. So! I made the vent line in the middle have the ability to adjust up and down.
Second, well maybe more important.... the engine is border line not enough. I hate to admit that because I love small engines. But that might be the case. Let's see if I get the run better how true that is.
Ken, hijack away. These things wander all over the place. It's all been great discussion and a lot of fun anyway. Where are you in Texas? I got family I see regularly out there often. Dallas area and Houston area.
What engine is that, an iron-liner 25SF (with what appear to be a huge venturi)? Based on the video, you aren't coming close to running out of power, the engine is 4-stroking for most of the flight. You can get much better performance by reducing the pitch and running the engine faster and in a 2-stroke. That will also smooth it out. You might have to adjust the venturi size (smaller) to keep it from going "over the top".
Brett
That is a pic before VSC. Jim Lee and Chris McMillan got my venturi "right-er". I've always felt the tank was an issue. So, that was a wishlist item. The control and the tank is the only change right now. I will not alter the way I fly (I'll keep them big) so I can see what's the difference.
Thanks!
Oh sorry, I missed the engine part, it's a magnum 28 pro. The ball bearing engine. Running a 9x4 on 20% excaliber fuel.
Oh sorry, I missed the engine part, it's a magnum 28 pro. The ball bearing engine. Running a 9x4 on 20% excaliber fuel.
In the effort to follow your advice of not doing too many things at once, I'm going to leave that alone and see what changes the improved controls yields. I think we can comfortably say it can get through the pattern with this much power. Does that sound like a reasonable approach?
That should be a reasonable engine. I'm not sure if Brett was hearing too fast or too slow (I should watch the video with sound on...).I just listened to it for the 1st time with the volume up enough. Sounds just like a bearing engine running a bit rich and it is making noises that it doesn't like the prop you gave it. The only time I heard it break into it's power envelope was at the end of the tank. I also think that some of what we hear on the video is Doppler. Lower pitch prop and let it run faster. BB's want to run fast.
Do you have a tach? What RPM are you launching at?
Just enough to get it off the ground, not enough to make it run hot. ;D
I only run APC 9x4, and that's not the venturi I run. That's an old pic just to show how the tank was.
Here's from right now, at the completely empty airfield.
I came out to test / practice and can not. Maybe next time.
I erased that other pic. It didn't serve the purpose I intended.
You may want to reconsider the 9x4 even if it's normally all you run.
Even if it's a sprinkler type, that venturi looks like it's way too small (so on the good side, you have the problem bracketed!)
If APC made it, I'd say try a 10x3.5. But they don't. They make a 9.something x 3.75 that may be worthwhile to try, though.
Why no practice -- no stooge?
Correct sir. Nothing to help launch today. Usually I have my wife, or kids, or just lucky enough for someone to be at the airfield. I guess the 115 degree weather scared everyone off. Lol.
I'm not saying my prop selection is correct or any of that stuff. Just giving the most current information about my set up. I figure if I'm asking for help, I better help with full disclosure!
Get the stooge from Brodak MFG. Expensive but worth every penny when flying tike gear multi engine planes. I still have my stooge Bobby Hunt sold at one time. H^^
Every time I think I have come up with a new Idea I find out that somebody did it first! I use balsa wedges to get the height on my tray then I MonoKote them in. Your way is probably better. Forgive the finish, this plane is 100% MonoKote.
The last pix is for Dane. This is what I was talking about in my last post looks like. Simple muffler pressure. 6oz tank and a pattern run is 3.5 to 3.75oz depending on the weather.
The more I look at your set up on that tank, the more I want to take my tank off and build a little slider table like Tim mentioned. That's really neat! If my current tank works out, I'll leave it. But there's always options.Dane:
What engine is that pictured that you say you run about 3.75 oz fuel for the pattern?
I'm not sure that I would recommend this to anyone. I'm posting a pic because Tim is a cool dude and asked me to do so. *Disclaimer *I don't advocate emulating my set ups, unless you're using the definition as to surpass my set up.
The more I look at your set up on that tank, the more I want to take my tank off and build a little slider table like Tim mentioned. That's really neat! If my current tank works out, I'll leave it. But there's always options.
Dane:Oh my. That's great fuel economy. I'm running 3.75 oz fuel through my little 28 for the pattern.
That one is an OS46LA. They are famous for their miserly fuel consumption. There are probably a lot of people who have dropped them into old 35 size ships simply because they didn't have to put in a bigger tank! They are up there with the OS35s and Fox 35 as one of the best non-piped stunt engines ever made. I actually had an overrun at a contest recently with only 3.25 on board -weather & a bit lean. FYI, I use the big OS Muffler for nose weight.
Glad you are getting better engine runs and the plane is flying better!
Ken
Oh my. That's great fuel economy. I'm running 3.75 oz fuel through my little 28 for the pattern.
This has been a great thread for me. I feel like I'm nailing down some important things on this plane. I want to use this to learn trimming stuff for when I build my Stuka.
I have a hand me down Still's Stuka. Yet to be flown. I gotta stick an engine in it. But I was going to measure the tank with a syringe. That'll tell me me if there's enough fuel to fly the pattern with my engine choice.Beautiful ship but I still love the Still Stuka. When you drop in an engine let me know what it is. I don't have anything under a .35 right now and the modern engines around .25 are way too powerful for that tinny plane. I saw Still flying one in 1964 with a Fox 25. Serious corners.
The Stuka I'm building is the Hi Johnson Stuka. 59" gull wing and all. It'll be electric powered and classic legal. Hopefully done for next VSC.
I have a hand me down Still's Stuka. Yet to be flown. I gotta stick an engine in it. But I was going to measure the tank with a syringe. That'll tell me me if there's enough fuel to fly the pattern with my engine choice.
That one is an OS46LA. They are famous for their miserly fuel consumption. There are probably a lot of people who have dropped them into old 35 size ships simply because they didn't have to put in a bigger tank! They are up there with the OS35s and Fox 35 as one of the best non-piped stunt engines ever made. I actually had an overrun at a contest recently with only 3.25 on board -weather & a bit lean. FYI, I use the big OS Muffler for nose weight.
Well team, today marks the end of my trusty twister. I'd like to pretend I'm not the kind of guy that crashes often (combat is a different story) but it happened. I've felt this plane can't make outside turns very well. At the end of this flight, I was doing figure 8's and stuff to run the tank out. I looped 'er round, and applied the down. But the down, she did not do. And a pile of balsa was all that remained.Something broke loose. You can see it start the outside turn then turn inside and...plop. You didn't kill it, it committed suicide!
Yeah the engines cool. That grass is surprisingly soft. We've all hit the ground out there, changed a prop and got right back in the air. This didn't even bend the needle! But it nosed in straight. Really did a number on the wing.
It sounds like something was getting ready to go, and it went in the middle of an outside loop.
I don't think anything let go, or at least until it hit the ground.
Yeah the engines cool. That grass is surprisingly soft. We've all hit the ground out there, changed a prop and got right back in the air. This didn't even bend the needle! But it nosed in straight. Really did a number on the wing.Really does look like a "Phoenix" short kit. MonoKote will hide just about anything and clear Gorilla packaging tape is fuelproof and really strong. Apologize to your engine and get back in the air.
PS - Just out of curiosity, was your elevator pushrod still connected to the flaps when the crash truck arrived? It has been a very long time ago but I have had 2 clevises strip on the elevator horns and both planes did exactly what yours did. The exception was that I was high enough on the 2nd one to control the crash with just flaps. I know they are popular and super easy to adjust but I get super nervous now with any control connection that can come undone in flight. We all underestimate the forces we put on those pushrods.
Outsides didn't look that bad to me other than the fact you start a little low and hammer it pretty hard. You fly at altitude, it needs a chance to fly! FWIW entrance to clover needs to be higher also.
Rebuild and carry on. All of the pieces are there and good size at that. Beauty isn't important at this stage.
The elevator push rod was disconnected at the flap horn, and the pushrod was straight like it hadn't been hit. The little retaining device for the ez-just was missing.Game, Set and Match.
Game, Set and Match.
Ken
Yes and before you say it, I'm a ding-a-ling for trusting those little plastic push on retainers. Haha! !
Dane, see my second post. Not too low, just a little too violent!
Dane brother...slip that sucker in the trash and finish the one built for me and practice practice practice....seriously