stunthanger.com
News:
CLICK HERE---->    <----CLICK HERE
 
 
*
Welcome, Guest. Please login or register. October 25, 2014, 12:17:41 AM


Login with username, password and session length



Pages: 1 ... 5 6 [7] 8 9 10
 61 
 on: Yesterday at 01:59:37 PM 
Started by Bootlegger - Last post by RandySmith
 I can see where Dave gets his spelling hints...

   All I can say is that this IS NOT consistent with my experience, and when we started running spigot venturis the grotesque inside/outside speed differences we had with the PA40 and 61 went away almost completely. And don't forget that we ran it stock, first, for a long time. We clued in after Billy managed to tame that with, hey, how about that, a spigot venturi, first discovered by us when David found out about it at the WC in Germany.

    The "dribble hole" does indeed "dribble" and fail to atomize sometimes, Dave and I have both seen it happen on stock, out-of-the-box, "trueest of the true" Randy-blessed venturis, on the test stand. A drip forms, builds, then drops off, engine goes "blurp" for a moment. If it makes you feel any better, the original Jett venturi with the .100 diameter dribble hole did it far worse. That's why I asked for a smaller hole, which helped it considerably. The problem was cured forever with a spigot venturi, which curiously happened to fit perfectly in the hole size I requested.

    I think the effect is moderated enough in the midwest and southeast (which definitely does seem to be different) that you have convinced yourself there is no issue. Although I heard several of your buddies with very similar issues, and they also had the tell-tale surging on the ground of the unsealed and leaking  case/spraybar interface. All denied that it happened afterwards, of course.


    Brett

HI Brett ,I don't doubt you have seen this, that is why I did so many test on my bench, and asked MANY people from all over the US and the World to check if they have it, The last person that checked this for me was Bruce Perry when he was breaking in his latest PAs, He saw nothing at any time except a white high velocity spray going toward the center of the venturie. There was never a surge or a dribble, It is very hard to even see the hole when looking at a running engine, . If you see the hole in the side, and see a dribble build below the hole, then you have a venturie that has been drilled out and has a straight section in the middle, or you have one that was made wrong, or a mistake. No less than 2 dozen people have helped me in researching this.
 I do not take anything that you or David say lightly, or blow it off. Which is why I took that seriously and did so much checking/testing.

As far as the side seal, this is a problem with ANY engine, and most every time I see or hear this is when the spraybar has been removed, put back in with debris between the flat hex of the bar, and the side of the case,This happens when they compress the venturie, force the bar thru, nick off some al. or delrin debris with the threads, and install the nut with the debris still in the thread, it then goes toward the case and ends up being trapped between the nut and the case. I have seen this many dozens of times with many engines, STs, OS, TTs, Aero Tigers, PAs and others.

 I never claimed that does not exist, it does, and makes for inconsistent runs. However I, personally have had ZERO problems with this . I am not sure who you are saying denies that exist, it does, and I have covered that above.

 I have NEVER sealed a bar with any PA engines. others... not so much.  I don't think it is just "my buddies" that have had this happen, It happens to many people, and I have also seen big problems caused by the sloppy application of sealant on many types of engines, especially PA , ST and Thunder Tigers.
by the way Billy won a WC with a non spigot true venturie, I was there and looked, so has other people, plus NATs, so obviously they both work. And there have been many top 5 flyers use and test both, that are using true venturies now. This is really not an issue to fight over, use what you like, its all fine by me, I have no problems with that at all.
You should send one of the dribble holes venturies to me for testing, so I can see what went wrong.
and by the way, problems with fuel post are in play too, like not being able to tell the size, never being able to make the excat same ones, having the brass post come out and go thru the motor (is have seen that happen over a dozen times) and having to send them back to me for a new PS crank or sometimes case. There are other but you  get my point.

I will give one caution here on dribble venturies I have seen, they had the fuel feedhole drilled out much larger to use a fuel post (piece of brass tube, or eyelet) then when it was removed they tried to use it as is, the larger hole (way too big) would NOT  feed correctly and  did  dribble into the engine.

regards
Randy

 62 
 on: Yesterday at 01:29:51 PM 
Started by Andrew Tinsley - Last post by Ara Dedekian


       As the old saying states," know who your sources are!"
       
       So I'm issuing the disclaimer that I'll probably go to my grave never having successfully learned or flown the Pattern.

       For what it's worth then, I have an Enya 45 RC - 6002 that I converted to control line and mounted on an ARF Tudor. I made the venturi with a .250" ID opening at the narrow portion ( That Looks About Right!). Can't remember if the spay bar/needle is OS or Enya. Zinger 11/5 prop, Enya muffler, 10/27 fuel, and .015" x 65' lines. The runs are rock steady (no 4-2-4) and good line tension in all the maneuvers that I can do. The plane/engine combo gives tremendous confidence in trying maneuvers that scare me to death; verticle eights, hourglass and cloverleaf.

       The -6002 is a single ring, baffle, ball bearing engine. Have no info on the internal differences between the -6001 and -6002. The Tudor is set up with carbon fiber/titanium push rods, line slider and taped hinges. A great trainer.


        Ara

 63 
 on: Yesterday at 01:28:30 PM 
Started by roger gebhart - Last post by John Park
Folks:
I've always preferred the look of the exposed-cylinder Mk. 1 T'bird (which I've always called the 'pointy-nose' version).  Was there a specific kit or plan for that version, or did people simply build it that way because they didn't like cowls?  By the way, I know Juhani Kari used Palmer differential flaps on his 'Nakke' design - I have the plan, love the design, and like the idea of building one, so the question is: with or without differential flaps?  Any recommendations?

 64 
 on: Yesterday at 01:22:37 PM 
Started by Garf - Last post by Garf
My normal flying partner has problems that keep him from flying, so I need a backup flying partner for Sunday AM in the area of Ft.Lauderdale/Sunrise Florida about 30 miles north of Miami.

 65 
 on: Yesterday at 01:16:26 PM 
Started by proparc - Last post by Balsa Butcher
If history runs true - it is the real deal but may be awhile in coming. Once here, get 'em if you want 'em because they will sell out quick and won't be back for awhile...if ever.  Cool

 66 
 on: Yesterday at 12:48:42 PM 
Started by Mike Griffin - Last post by Mike Griffin
I know Perry but I forgot to get them from him..  I picked up the phone today and got some from him....was really good to see you in BR.....

Mike

 67 
 on: Yesterday at 12:47:33 PM 
Started by roger gebhart - Last post by EddyR
I have tried to post this picture three times and the web page hangs up.
This is my speed cowl version as most were built this way from the kits around 1960. This model was built in 1986

 68 
 on: Yesterday at 12:46:58 PM 
Started by Bootlegger - Last post by Brett Buck
A true venturie, made correctly , NOT drilled out and destroyed, is the best way to get a really good run, and they do not dribble when used properly with the correct angles, they may dribble when they have been drilled straight thru, and ruined.. When used and made right there is a white spray coming out of the venturie going across the middle.

  I can see where Dave gets his spelling hints...

   All I can say is that this IS NOT consistent with my experience, and when we started running spigot venturis the grotesque inside/outside speed differences we had with the PA40 and 61 went away almost completely. And don't forget that we ran it stock, first, for a long time. We clued in after Billy managed to tame that with, hey, how about that, a spigot venturi, first discovered by us when David found out about it at the WC in Germany.

    The "dribble hole" does indeed "dribble" and fail to atomize sometimes, Dave and I have both seen it happen on stock, out-of-the-box, "trueest of the true" Randy-blessed venturis, on the test stand. A drip forms, builds, then drops off, engine goes "blurp" for a moment. If it makes you feel any better, the original Jett venturi with the .100 diameter dribble hole did it far worse. That's why I asked for a smaller hole, which helped it considerably. The problem was cured forever with a spigot venturi, which curiously happened to fit perfectly in the hole size I requested.

    I think the effect is moderated enough in the midwest and southeast (which definitely does seem to be different) that you have convinced yourself there is no issue. Although I heard several of your buddies with very similar issues, and they also had the tell-tale surging on the ground of the unsealed and leaking  case/spraybar interface. All denied that it happened afterwards, of course.


    Brett

 69 
 on: Yesterday at 12:20:56 PM 
Started by proparc - Last post by Steve Fitton
Is that new engine real or vaporware?  It looks interesting...

 70 
 on: Yesterday at 12:17:56 PM 
Started by Bootlegger - Last post by RandySmith
Hi Randy,
Maybe you would like to define the various fuel atomisation systems that you talked off. Many people don't know a spigot venturi from Adam. Nor a true venturi come to that. Just helps to clarify the discussion.

Thanks,

Andrew.

Hi Andrew

I will post a couple off the site Chris listed then try soon to take pictures of ones I make here, The venturie is posted above, plus anyone who has seen the more than  10,000 I have made know what they look like
Below is Restrictor, like you find in OS and  some ST  FOX engines.  then a  Fuel post venturie, I made these many years ago for OS OPS and some other engines that were hard To make true venturies for. Lauri has also posted some of the ones he makes in the engine forum.
I have also made many sets of venturies that have aluminum bodies and delrin inserts that you can just pull in and out to change size in about 10 seconds, these are also ajustable up and down, so it makes tank ajustments very easy, if your within about an 8th of an inch, they have 2 small o-rings just above and below the feedhole, and seal against the aluminum wall of the base. I modeled these from ones that Scott Bair made so he could adjust the fuel flow in his Stuntfires, which had the tanks permanyly glued in. Then made the different size sets from there, KAZ Minato used to run ones I made for him years ago, and now has a shop in Japan making similar ones for PAs.

Pages: 1 ... 5 6 [7] 8 9 10

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines

Valid XHTML 1.0! Valid CSS! Dilber MC Theme by HarzeM