Viper trim report (pics added)

[RC Storick]

Today was suppose to be wash out but we did get 10 flights in, in the morning. I have been working to get this plane up to NATS trim. It was hunting a little, I adjusted some down elevator into it. The hunt went away totally. I had been working on lap speed I finally settled in at a 5.5 the only problem was that it being so hot and humid today I kept screwing the needle in. So my solution was a bigger venturi. I have a 8 oz tank and was only using 5.75 for a pattern. I really don't need more power but it was getting hard to start. The larger venturi allowed the needle to be screwed out some for better fuel draw while starting.

The next trick was over control. Even tho this planes CG is foreword its very responsive because of its weight. So I opted for a KAZ handle. I had started out at the same line spacing as my wood HOT ROCK I have used for years (it was like loosing a old pair of shoes) After talking to Randy he had said it would be to my advantage to use it. So after some doctoring on the wood to make it fit my hand better I said I would try. After the initial flights with the wide spacing I started to come down in size. The turn couldn't be better. Crisp,flat and in control.

So all in all it was a very productive day. I am cleaning my shop now and I will start fixing all the Hangar rash  to get ready for the show. The next 30 days will be hrs of practice (weather permitting) to see if I can make the cut.

I will post a few pics tomorrow.

[Brett Buck]

Today was suppose to be wash out but we did get 10 flights in, in the morning. I have been working to get this plane up to NATS trim. It was hunting a little, I adjusted some down elevator into it. The hunt went away totally. I had been working on lap speed I finally settled in at a 5.5 the only problem was that it being so hot and humid today I kept screwing the needle in. So my solution was a bigger venturi. I have a 8 oz tank and was only using 5.75 for a pattern. I really don't need more power but it was getting hard to start. The larger venturi allowed the needle to be screwed out some for better fuel draw while starting.

    5.5 oz? That's not very much fuel. What nitro are you running?  In those conditions I wouldn't even spend any time with 10%, just go straight to 15 and be prepared to go up from there.  You can keep the venturi size down and still get the power.

     Brett

[RC Storick]

Brett I met a old next door neighbor of yours today. Pierson, can't remember his first name.

[Brett Buck]

Brett I met a old next door neighbor of yours today. Pierson, can't remember his first name.

  Jason!  You'll like him, and he was a complete natural as a flier. Flew some incredibly horrific airplanes to quite respectable results. His dad was famous in WAM for years - he built the quadra-powered Banshee, as I recall.

     Jason really matured since he left the bad influences he had on him here. Next-door neighbor is no joke, his former home is within 100 yards of my house and I can see it out the front window. Now he's a big deal in the air show (full-scale) world now.

     Brett

[Crist Rigotti]

Sounds good Sparky.  See you in 4 weeks.

[Bradley Walker]

What motor is this?

[RC Storick]

PA.65

[Bradley Walker]

    5.5 oz? That's not very much fuel. What nitro are you running?  In those conditions I wouldn't even spend any time with 10%, just go straight to 15 and be prepared to go up from there.  You can keep the venturi size down and still get the power.

     Brett

That is what we found too.  Especially if you want to run in the very deep 4 cycle.

[Doug Moon]

Got any pics? 

Weight?

Nice when they are close off the board huh?  Makes it alot more fun.

[Randy Powell]

Odd, I use about 6.6oz for my RO_Jett .65

[RC Storick]

OK here's another approach. While talking to Randy he suggested I pitch up the prop 2 /10 and turn the needle out. What a concept.. LOL

  I guess I had a Blond moment  

[Dan McEntee]

  Jason!  You'll like him, and he was a complete natural as a flier. Flew some incredibly horrific airplanes to quite respectable results. His dad was famous in WAM for years - he built the quadra-powered Banshee, as I recall.

     Jason really matured since he left the bad influences he had on him here. Next-door neighbor is no joke, his former home is within 100 yards of my house and I can see it out the front window. Now he's a big deal in the air show (full-scale) world now.

     Brett

I first met Jason in Oshkosh while working the C/L circles at KidVenture. He was working with Jimmy Franklin at the time and the Masters of Disaster until disaster did strike. Then he worked for Jim LeRoy until he had his accident. Now he is working on building a new "Shock Wave" jet powered truck with Ken Shockly, I believe. Jason lives in down state Illinois now, and makes the trip to the st. Louis area for model airshows and our contests occasionally. He flies combat, stunt and has a large array of R/C models that he flies in demonstrations. You would love to see him fly his all pine (yes, ALL PINE) Twister. I think it weighs about 70 ounces or maybe more but he can fly a pretty respectable pattern with it. I think he even trophied with it at one of our contests a few years back. I think he said his dad cut the wood for the Twister and they built them because they wanted tough airplanes or something like that! Jason is a talented flier and all around nice guy! He's even into dirt bikes when he's not busy doing all the other stuff!
    Type at you later,
   Dan McEntee

[Brett Buck]

You would love to see him fly his all pine (yes, ALL PINE) Twister. I think it weighs about 70 ounces or maybe more but he can fly a pretty respectable pattern with it. I think he even trophied with it at one of our contests a few years back. I think he said his dad cut the wood for the Twister and they built them because they wanted tough airplanes or something like that!

   Oh, I saw that very close up. I saw its first flight, I think.

    Brett

[Brett Buck]

OK here's another approach. While talking to Randy he suggested I pitch up the prop 2 /10 and turn the needle out. What a concept..

   With all due respect to everyone involved, I like my way better - and here is why. With the more pitch, you end up launching a little slower, and that puts you deeper in a 4 or further away from the break, which is what you want. But, you are just accepting the lost "power" due to the air density and making up for it by running slightly higher prop efficiency.

  If you add nitro, instead of losing the "power" and compensating for it, you retain the "power" you had in the cool, so there is nothing much to compensate for.

 I actually prefer the venturi change to the prop change in principle, but it has the obvious flaw of having to change the venturi (and maybe get over the top on the venturi size). At least the venturi change is intended to maintain the power level.

 
     The goal in either case is to try to maintain the engine "operating point" where you are used to it, and keep the power boost or 4-2 breaks where they were in the thick air.

   This is the trick we have been using for years to both maintain power and handle radical (far more radical than you are talking about) atmospheric changes. I literally *never* change anything, from 45 degrees and raining, to 105 degrees and dead dry, to 1000 feet, 90 degrees, and oppressively humid, other than the nitro. I have gone down all these roads any number of times, and to me it's hands-down better to change the nitro.

  The fact that you are running 5.5 oz of fuel instead of a more usual 7+ certainly suggesting running it leaner or with less power overall, or a combination of both.


     In any case, it's easy enough to try it both ways and see.

      Brett

[Harleyman]

Any photos?         

[RandySmith]

 "With all due respect to everyone involved, I like my way better - and here is why. With the more pitch, you end up launching a little slower, and that puts you deeper in a 4 or further away from the break, which is what you want. But, you are just accepting the lost "power" due to the air density and making up for it by running slightly higher prop efficiency. "


Hi Brett

My way doesn't put you into a deeper 4 cycle, it puts you exactly back to the same 4 cycle you were using before the loss of prop efficiency. Also Sparky didn't mention this but I also  use higher nitro in hotter weather. I have taught many many people to do this.
I have 3 base nitros setups I use, 5  , 7.5  , and 10.   If for some reason I need to go to 12 or 15 I can do that.
 I have not had to except for Lubbock.
So we are not doing things too much differant. You could easily setup to use 5 , 10 , 15 if you wanted too.
I don't have less power, I have the same power using my setup. and the same all year around, You can also take out or add a shim, this is much easier to do than switch venturies and I almost never have to do that.
I use 6 ounces on my 51 , 6 ounces on my 61, and about 6.5 to 7 on my 65 with this setup.
There are more than 1 way to setup motors, As long as it works well, that is all that matters

Randy

[Doug Moon]

  ******
   This is the trick we have been using for years to both maintain power and handle radical (far more radical than you are talking about) atmospheric changes. I literally *never* change anything, from 45 degrees and raining, to 105 degrees and dead dry, to 1000 feet, 90 degrees, and oppressively humid, other than the nitro. I have gone down all these roads any number of times, and to me it's hands-down better to change the nitro.

  The fact that you are running 5.5 oz of fuel instead of a more usual 7+ certainly suggesting running it leaner or with less power overall, or a combination of both.


     In any case, it's easy enough to try it both ways and see.

      Brett

I agree.  I do the exact same thing.  Rarely do I run less than 15 and now I am running 20.  I think I use 7.5 oz.

It is pretty much a no brainer for me and the type of plane I like to fly.

I think on the viper, light weight low drag it should work flawlessly.

I also noticed when I started using this type of setup my flying improved dramatically.  Coincidence?  Maybe so but I tend to think the set it a forget it way of running this thing let me concentrate on flying and not motor runs since it was the same every time.  

[RC Storick]

Well I guess I have made a drastic error. Last year I had bought some Sig syn fuel. I had mixed it with 5% making it 7.5%. I added more 5% left over from another jug. So basically its down to 5%. This was my problem. After buying more 10% fuel and thinking what had happened I realized what had happened.

So fresh fuel and all is well, No change..

[Brett Buck]

My way doesn't put you into a deeper 4 cycle, it puts you exactly back to the same 4 cycle you were using before the loss of prop efficiency. Also Sparky didn't mention this but I also  use higher nitro in hotter weather.

    Right - I meant deeper than it was in the hot air, back the way it was in the cool. At least at the same point relative to the 4-2 point.

There are more than 1 way to setup motors, As long as it works well, that is all that matters

   Of course, and really only one way to find out what works in a particular case - try it and see.

    Brett

[Brett Buck]

Well I guess I have made a drastic error. Last year I had bought some Sig syn fuel. I had mixed it with 5% making it 7.5%. I added more 5% left over from another jug. So basically its down to 5%. This was my problem. After buying more 10% fuel and thinking what had happened I realized what had happened.

So fresh fuel and all is well, No change..

   That will do it!  I got a jug of SIG "10%" at the 99 NATs. It was incredibly gutless, had to be in a dead 2 on the ground, and was breaking and charging all over the place in the air. All sorts of problems.  I set it down next to David's "identical" fuel and noticed that it was a much lighter color, and curiously, $2.00 a jug less. Just exactly what they were charging for 5%, in fact. I tried a tank of David's "identical" fuel and found that, hey, not too bad. That was the year Ted and I ended up on 15%, but it was clear that the original fuel was really 5%, not 10 as marked.

    It was an interesting experiment - Normal fuel at sea level was about 7.4 oz of SIG 10%. On 5%, at Muncie, I was down to about 6.0 oz., and had to run in nearly a 2-stroke in level flight. The needle was in about a turn and a quarter (usual adjustment range about 1/8 turn from morning to mid-afternoon), and it was completely gutless.  Oh, and it melted the front end of the pipe in one flight. On 10% I was back to about 6.8 oz, and was about 1/2 a turn in from home, and felt pretty respectable although it would still break into a 2 in the squares.  On 15%, the needle went to exactly the same as 10% at sea level, the fuel consumption was back up to 7.4 ounces, and it thundered around in a 4-stroke while dislocating my shoulder, just like home. That's the same engine I used in 2001, and had someone compliment me on how well I got my 4-stroke running!

  BTW, of course I am like every other stunt flier, therefore, if a little is good, a lot is better. I got a quart of 25%, and kept going from 17.5%, to 20%, and to 25% (just mixing in the syringe). 17.5 was still better than 15, but was very close on duration with a 7.6 oz tank. 20% flew better still, but wouldn't make it, and 25% was hardly any further improvement. And it sounded like an R-2800.  I am sure I could have gotten more out of 25 if was willing to change the setup, but it ran *just fine* with absolutely no other changes.


      Brett

[RC Storick]

Got any pics?  

Weight?

Nice when they are close off the board huh?  Makes it alot more fun.

Continental on the wall is PA.75 powered 62 inch span and 72 oz.(lumber wagon) and the new Viper is PA .65 powered 59 inch span and 52 oz. The Continental got me close last year the Viper takes 50% less work to fly and fly's twice as good. How many dirties will I have to add to make it fly like last years plane?   20?

[Matt Colan]

Continental on the wall is PA.75 powered 62 inch span and 72 oz.(lumber wagon) and the new Viper is PA .65 powered 59 inch span and 52 oz. The Continental got me close last year the Viper takes 50% less work to fly and fly's twice as good. How many dirties will I have to add to make it fly like last years plane?   20?

it's almost like comparing a thoroughbred to an ox.  The thoroughbred being the viper of course    How was this plane built.  I remember reading something about it before the crash but can't remember.  Was it a molded fuselage?

[Crist Rigotti]

<snip>
How many dirties will I have to add to make it fly like last years plane?   20?

That's a good one Sparky!  

[RC Storick]

it's almost like comparing a thoroughbred to an ox.  The thoroughbred being the viper of course    How was this plane built.  I remember reading something about it before the crash but can't remember.  Was it a molded fuselage?

Matt most everything I do now is molded to save weight and to Crist If I throw enough dirties against the wall some are bound to stick

[Dennis Adamisin]

Continental on the wall is PA.75 powered 62 inch span and 72 oz.(lumber wagon) and the new Viper is PA .65 powered 59 inch span and 52 oz.

I'll bet your arms are back to nearly the same length too!  Your shoulder thanks you, your back thanks you, but I'll bet the competition will hold its thank yous!!!  

[Bradley Walker]

Robert that is a stunning new plane.  I bet it *does* fly really well.  It just looks right.

Heck you might go even a little smaller on the next one!!!

[john e. holliday]

Sparky I think you have outdone yourself on this one.  I love the different color treatments you have done to it.  If it flies as well as it looks, you should be a shoo in.  Just don't let the competition get to you.  Have fun,  DOC Holliday

[RC Storick]

Thanks guys. I would have rather painted it white but gray was chosen because of its covering quality's. It flew a tighter patted with the PA.40 in it at 47.5 oz. however I decided to opt out for the PA.65 for the sheer power. It corners like a combat ship under control, nice and flat. I have been playing with trim adjustments. I have the LO almost as far foreword as they can go and I think its close. The next one will have a slightly shorter nose and I will take more care in sanding to try and achieve a lighter airframe. I would like this plane set up in the mid 40tys.
 
It has great directional stability and good groove. The trailing edge is swept foreword 1 inch, in turn moves the plotted CG foreword. It has relatively fast controls and I had to reduce the line spacing to make it less sensitive. Not quite sure on which way I will go on the next one as far as controls.

[Matt Colan]

What paint did you use to paint the plane?

[RC Storick]

What paint did you use to paint the plane?

Its all from Wicks aircraft, its Randolph

[Doug Moon]

Robert,

That is a really nice plane!  I like the scallops.

Question: is that a carved wood canopy, or a plastic one?

[RC Storick]

Its wood.

[Doug Moon]

Its wood.

You have molded top and bottom, then carve a wood one to fit or do you mold that as well?

I ask because i use plastic and I think wood wood would be easier to finish as there is no fillet to contend with at the end.

What I am really asking is how do you do it?

Thanks in advance.

[Ted Fancher]

Beautiful, Sparky!

 

Ted Fancher

[RC Storick]

Beautiful, Sparky!

 

Ted Fancher

Thanks Ted but reserve judgement till you see it up close. There is no paint on it. Just enought to cover and I am flying it so it has some rash but it does fly good.

[Ted Fancher]

Sparky,

As you well know, there is a "LOT" more to an attractive airplane than paint.  That's an attractive airplane!

Ted

[Matt Colan]

Sparky,

As you well know, there is a "LOT" more to an attractive airplane than paint.  That's an attractive airplane!

Ted

Like asthetics, I love the asthetics on that plane.  As long as it flies good, right? Thats all that matters.

[RC Storick]

Like asthetics, I love the asthetics on that plane.  As long as it flies good, right? Thats all that matters.

Well trim is coming along good. Today after flying I weighed the plane again. Gary Hajek suggested I add some nose wight (cringe) So I added a steel prop nut. That seemed to help. I also moved the elevators down some more. Along with the new fuel and trim changes it all worked out great. I did have one pucker factor today, missed the wind in the hourglass and the last turn pull out was six inches (if that) above the deck.

Last night I had added more clear on the bottom wings and with the trim changes its up to a whopping 53 oz. Its almost back breaking (along with heart breaking) to hoist the thing...    .015 lines and have to pull 33 LBS is my speed. The fuel change made .65 hum along just as it did before.