Profile w/Rear Exh. piped engine-Any Ideas?

[Ward Van Duzer]

Hi, Thinking of building a modified Profile fuse for a Pathfinder Arf that I could use my OS 46 VF piped engine on. Has anyone built a profile for a rear exhaust engine? How do you handle the plumbing? Any Pictures?

I thought I saw one or two around here!


W.

[Bootlegger]

 Ward, If you set it up with an R/C mount simular to Ted Fancher's Imitation, then it shouldn't be a problem with the pipe.
  I have a rear exhaust muffler that I want to set up this way also.
  Keep me informed of your progress...Gil
  email address gil6964atcoxdotnet

[Richard Grogan]

Ward,
Randy Powell designed his new Ringmaster Deluxe around that motor, or the 40VF.He designed the engine mount canted 45 degrees. Maybe he will chime in here with some pictures of that full-tilt-boogie beast!

If you are a member of the Brotherhood of the Ring, you can check it out at:

http://www.brotherhoodofthering.info/flightline/forums/thread-view.asp?tid=2828&start=31

Best of luck with this!

[Steve Helmick]

FWIW, Randy's model had a wood nose, while Mike Haverly's uses a plastic R/C mount. Both are canted, both piped, but Randy's uses the .40VF, while Mike's uses a Magnum .36 with a PA side/rear manifold like PTG used in the Diva. So, it looks like either plot will work, but the clocking is no doubt easier with the plastic mount. Mike's plane has the mount covered up with a shell, so you really have to look closely to see the ugly part. Probably lighter than the wood nose...but Randy's plane was noseheavy, and Mike's was tailheavy. FWIW.   Steve

[Randy Powell]

Well, the new one isn't nose heavy. The 40VF is a boat anchor. The Magnum is a feather. Makes a difference. The wood now I did is actually pretty light, but the nose moment was too long. So I shortened the new one up an inch and the thing balances pretty well now.

I just set up a set of bulkheads with the mount canted so that the pipe tucks under the wing. They are fixed to a center section that is wrapped around with a carved balsa shell. The new one looks better than the old one at this stage. It's about 10 ounces lighter, too.

[Howard Rush]

The old one was pretty cool.

[Randy Powell]

Yea, well, the new one will be cooler-er. Maybe.

[Mark Scarborough]

Randy, lighter IS cooler right?
now see what you started, all the "cheater " profiles are coming out of the woodwork,, yours, Mike H's,, sheesh, piped profiles,, whats next some high zoot electric profile or something,, 

Oh wait,, thats what I am building,,

Actually, I think pipes on a profile makes a lot of sense for guys who want to get experience with a pip,, everything is right out there in the open to fiddle with,,

I really like both Your RMD and Mikes plane, cool stuff

[Andrew Borgogna]

Something else that should be noted, a muffled tune pipe is a very quite setup.  Having recently being chased off a place I have been flying on for years made me think about how quite with muffled tune pipes are.  One thing that really struck me was how long the setup was on the pictured plane.  I am guessing that's a result of setting the pipe up for stunt and not max power.  Does anybody know what the  timing on the exhaust port is?   Are these R/C engines that are timed for pipes?  Just curious.
Andy

[Bill Gruby]

Yea, well, the new one will be cooler-er. Maybe.

 COOLER is where you put your brewski. COOLER-ER is where you put the brewski for your friends.   

 Seriously, I have seen pictures of the new one, it's gonna be a killer.

  "G-Man"   

[Randy Powell]

Bill,

We can hope. It's about 10 ounces lighter than the original was at this stage. Should be putting the fillets on tonight or tomorrow then just need to cover and paint the fuse. That is if I can quite distracting myself with car issues and drawing the new PA plane. 

 

[Tim Wescott]

How about a custom tank?

[Allan Perret]

Bill,

We can hope. It's about 10 ounces lighter than the original was at this stage. Should be putting the fillets on tonight or tomorrow then just need to cover and paint the fuse. That is if I can quite distracting myself with car issues and drawing the new PA plane.  

 

How did you save 10 oz   ?

I did a search and found the thread from your first Ring Delux.  In there you said it weighted 49oz.  So now your thinking #2 will come in under 40 ??

[Randy Powell]

Allen,

The first Ringmaster was about 49oz, ready to fly but prior to finish. By the time I finished it AND had to add more than 3 oz. to the tail to get it to balance, it was about 57oz (that's on about 600 square inches). Heavy, but not horrible. The new one is about 39oz, ready to fly prior to finish. With the nose shortened an inch, it balances right now at about 3/4" an inch ahead of the final balance point. Figure the finish should take it back to to proposed balance point. So no 3oz of tail weight this time. If I can keep the finish under 10 oz (I'm doping and painting the fuse and iron on on the flying surfaces) that shouldn't be a big problem. So the final, all up weight will be somewhere around 50oz. Perhaps a bit less, depending on balance issues like tip weight and such.

The first plane was built out of the scrap box and I didn't pay much attention to wood weight. The whole point was to finish it without purchasing new materials or using any more wood from the stash than absolutely necessary (which is why the wings and tail area actually different colors). When I did use new wood, I tended to take stuff that I probably wouldn't use in a competition ship. I did end up having to buy some more iron on as I didn't have quite enough. But the rest was out of the scrap box. With this one, I spent some time selecting wood and came up with a few tricks to lighten it up, particularly the nose and wing structure. Amazing the difference when you use 4lb wood as apposed to 9lb wood.

We'll see what we get in the end. The gear is a bit heavier than I had planned so I may lose some weight with another molding. And I am going pretty easy on the paint.

[Allan Perret]

What about the plan I got from Pat Johnston,  does it show the 1" shoter nose or your original longer nose.  
Somewhere in another thread you mentioned that there were some other differences on Pat's plan vs your design.
Can you elaborate on those ?

What motor you putting in the new one ?

[Ward Van Duzer]

Steve,

FWIW, Randy's model had an wood nose, while Mike Haverly's uses a plastic R/C mount. Both are canted, both piped, but Randy's uses the .40VF, while Mike's uses a Magnum .36 with a PA side/rear manifold like PTG used in the Diva. So, it looks like either plot will work, but the clocking is no doubt easier with the plastic mount. Mike's plane has the mount covered up with a shell, so you really have to look closely to see the ugly part. Probably lighter than the wood nose...but Randy's plane was noseheavy, and Mike's was tailheavy. FWIW.   Steve

Any pics of Haverly's shell over the Motor mount? Looked around but couldn't find one...

W.

[Mike Haverly]

     The RC mount is attached to a plywood mount on the front of the fuselage.  I had the model ready to paint and couldn't get past the naked look of the front end so I just moulded a 1/16 shell around the whole thing with a standard nose ring front.  It is a little tricky to make it so the engine is easily removed.  A larger spinner would help, this one is 1 3/4.  Northwest "Profile" rules require the motor mount to be uncovered, so I had to keep that in mind also.
    Hope this helped a little.

Mike

[Randy Powell]

Allen,

If you build the plan from Pat, it will fly fine. Especially if you use the standard side mount he shows. I was (and plan to use in the new plane) an OS 40VF. As you know, this thing is a boat anchor so on the new plane, I shortened the nose an inch to accommodate it. If you were to use a Magnum 36, PA 40UL or a new Enya 32 rear exhaust, you could leave the nose as it is shown on the plan since they are much lighter engines.

The other differences are that Pat made the overall wing chord about a half inch wider over the length of the wing than the original plan. This had to do with interpreting my scribbles, not any change Pat made on his own. Wacking a 1/2" off the trailing edge brings it back to the original plan form (though it would made for a thick trailing edge).

The other difference is that Pat used the original Ringmaster tail plane shape and just blew it up to the span of mine. This made for a 20% bigger stab than I used (the shape of mine is somewhat different, but is the generally elliptical layout that the original Ring had). Not a big deal, but I liked my better, so I stuck with that.

I also used a much more complex gear setup, but the one Pat shows would work just fine. I wanted to mold up a carbon gear and it turned out to be more complicated than most guys would want to bother with.

That's about it. It's a nice flying plane if kept under 58 or so ounces overall.