jetdryvr

Congrats again guys. Looks great. Nice deadstick too! Oh yea, that reminds me... Is 2 1/2 minutes the normal fly time for this beauty or was there a problem of sorts? Just curious.

Great Job,
Erik

C_Roundy

Erik, I probably used about 1/3 of my PERFECTLY available fuel when the pipe system suddenly blew its self again at new and fascinating spots.

C_Roundy

For Mike Conner
[/quote]
I like Jett engines but I wonder if a 90 vrdf would work better on this plane.
[/quote]

Here is the simple truth, I bought a brand new OS VRDF .91 just for the purpose of comparing the same props at the same pipe length as my engine of choice (the JETT)

The rest of my reasons why I stayed with Dub Jett, you will have to find out in your own way in your own time.

Julian537

My Feedback: (9)

C. Roundy

why is it such a mystery about the difference between the OS VRDF and the Jett?
I thought this forum was all about sharing? Isn't that why you posted this thread, so you could share your great airplane with all of us?

rmenke

My Feedback: (13)

CR:

Yes, the throwing arm has atrophied along with some unmentionable things since college ball, never NFL, darn. Due to the scars on the top of my head, hand launch is not even considered. Real airplanes have landing gear, so should ours, IMHO. Was impressed with the launch and vidio, 196 huh. Thats daunting, but not discourageing. Think I may have something for you there, but not buy a bunch for sure. Will have to make a pilgrimage when things warm up a little, just for grins. After all, the Yellow Jacket is partially your design by proxy and does have a rpm advantage with the Jett 60LX. Does run down a standard quickee/nelson with ease, so maby? Maby you will get a pic here, maby not. No vids, no camera in our old stone age group. ENJOY

bob27s

My Feedback: (19)

They are just two different engines with a different purpose. One is designed to run at 22,000 rpm with a 5" fan on it, the other is designed to run at 16,000 rpm with an 11" prop on it.

Some have had good success using the ducted fan engine for prop driven applications. Big carb, rear rotor, lots of flowpath. It can make good power when propped and piped correctly. Rear intake makes for a nice cowled-in installation too. However many have struggled trying to find that perfect setup.

Some choose not to struggle at all.

I don't want to speek for Chuck here, but if I were designing an aircraft or investing in a mold to perhaps produce an airframe for sale some time down the road, I would definately want to baseline a reliable powerplant that is available and usable without experimenting.

I tell ya what though... the OS .91 RE Heli engine would probably make a better conversion for this application than the fan engine.

C_Roundy

No Big mysteries, in my experience the metalurgy of Dubb's A.A.C. engines is drasticly tougher than anything the other manufacturers have ever offered. I am experimenting with high pitched carbon props running at high rpm, on very short tuned pipe lengths, with very limited amounts of airflow through the cowling in this airplane; And I can guarantee you that the O.S. VRDF .91 would already have blown a hole in its piston and disintegrated from some of the things I have subjected the JETT F.I.R.E 90 to

C_Roundy

OK Julian, I have more time to answer you properly now so here I go...
I mentioned in my earlier first response to you that Dub's metalurgy is flat out, the best. I will use "RMenke" as my personal opinion best example of a proponent for JETT users, the way he talks about his Jett .35 coming on stronger, and stronger across the years that he has owned it. Make no mistake about it, Ronald did'nt just fall off the turnip truck.

Bob27 is a PRICELESS resource to anyone who wants to learn two stroke breathing, regardless of whether they care about supporting American made products.

The O.S. VRDF .91 represents the absolute best of an old school MASS producer. I recently deduced that the VRDF is the only engine left in the O.S. lineup that still employs an actual CHROMIUM alloy liner plating (somebody correct me if I am wrong). Funny is'nt it, they talk about their "A.B.L." "Advanced Bi-metalic Liner" as being the superior plating system now, but when it comes to manufacturing an extreme high output engine the truth is that they rely on good old chromium alloy.
As opposed to greater Asia (China) continent where they are less concerned with polluting ground water tables with chrome proccess by-products than increasing their market share "RIGHT NOW", thats how you gain leverage in an open market, and thats what the chinese do. They are not dumb.

Now back to my favorite, MR. Dub Jett and Jett Engineering Inc. I can promise you that his processes are 100 % containment because thats what it takes to do business HOMEBREW.
If you step up to the plate and buy a Jett, you are are buying into something very special.

I personally have bought and owned about 15 or 20 Jett engines depending on the way you count; And maybe 15 or 20 more for CUSTOMERS directly, I count myself EXTREMELY lucky to be included in the very small set of Dub's authorized dealers (I seem to remember that Dub admitted to me a couple of years ago that one by one, he let almost all his "dealers" go because it became an inescapedly lost cause) The truth is that when I hand a Jett to someone I prefer to own and run it first, that is how I usually make SURE that Dub's interests are represented to the best of my ability.

Of all those engines that I've owned and run, and with all the cumulative experience of running these piped dragons have taught me, I will NOT abandon the JETT 90, what I WILL do is invite discussion of the differences between, say for instance the Henry Nelson / BVM .96 and my BELOVED JETT 90. That will depend on whether or not somebody steps up to the plate and talks about their experiences with that world class engine (with or without burning a hole clean throught the piston)

Oh, by the way, I turn a 9 by 12 NARROW Chord carbon prop at 19200 rpm running well and truly rich.

Our first video that I have had posted to this forum , was a (and I kid you not) was a perfect break in run setting (disgusstingly rich) on a wide bladed 9.5 x 9.5...

bob27s

My Feedback: (19)

Amazing what ya can do with the right prop

I finally was able to watch the video last night. Sweet.....

I kept thinking though.... is it possible to embed a pair of racing wheels into the ventral fins. The hard surface landing made me cringe [&:]

rmenke

My Feedback: (13)

Bob:


Bob:

My reaction, big time. Think you are on the right track for these thingeys. A racing wheel with the axle inside the airframe with less than half out, two or three locations. Yes, still gotta get it off the ground, and unless you have a arm like Chuck, you better create a launch ramp. The two or three wheel landing wheels, may also offer a solution to keeping the thing streight at launch, a couple of pvc guides should do the trick. There are a couple of "Mach Racers" laying around the shop waiting for some inspiration to tinker, think you just provided it. No real speed there, but easy design concepts are. A true go faster must be built from the ground up. Perhaps there may be some use for those two OS 90 VRDF nib in the engine cabinet. Yea, a streemlined quickee concept powered by one of those beasts may just be fun. Must admit I have been in a black hole for a while as a result of eyesight problems. Being able to sneak up on and fly with the fast guys has been great fun for a lot of years. You can make up a little with experience and treachery, but you still have to see the darned things well. If any of you come across a good launch ramp design, would appreciate a pictue.

ENJOY Bro 119

C_Roundy

Bob Look closer, the Jett racing wheels are there! layed up in five layers of carbon cloth woven between steel strips for strut forks.[sm=49_49.gif]

bob27s

My Feedback: (19)

ah... yeah... something like that <G>

rmenke

My Feedback: (13)

CR:

Ah-ha. Looks like built in guides for the launch ramp to me. Guess I had better keep the Jett 90L adttached to a just too slow Allley Cat gonna peddle soon? Am thinking you guys are intending to produce and market this swettie? How good could it get. Add 11 X 8 and fly sport and 3D, change prop to 9 X 12 and scoot around for a while. Afraid our gang may change my description from "Crazy old man" to "Insane old man". But what the heck, truth is truth. ENJOY Bro 119

Julian537

My Feedback: (9)

what ever happen to this project?

C_Roundy

The truth is, we have been going through some pretty serious engineering trips to come up with the optimum prop to mold.
Stay tuned for some serious action brother.

Strykaas

[8D]

Julian537

My Feedback: (9)

CR.

What has become of this great project?

freakingfast

My Feedback: (3)

He flew it two weeks ago, it radared at 219mph level flight with the wind but the engine sounded sick. It turned out that the header had broken so the engine was not getting on the pipe fully.
Nearly melted the top, it smelled like cooked fiberglass. No real harm done.

jetdryvr

Video Anyone?....Anyone?
Hope it wasn't hurt too much.

mk1spitfire

I love this Delta. Its so cool it was my screensaver for a while. Real work of art.

Hoping you can provide us again with some quality video footage.

When are the kits going to be out.!!!!!

freakingfast

My Feedback: (3)

I saw someone there with a video camera, maybe the quality was no good. He took it so dang far out on the turns as to not have gained speed from a dive that it would have been easy to loose it in the view finder.

He's got a ton of work in that thing, I never herd him talk about kiting it. It would be cool thou.
This time it was launched with the aid of a steer-able dolly.

mk1spitfire

Bet you would like a go on it freaking fast!

soarrich

My Feedback: (98)

I get the embedded wheels, but what is at the nose? I don't see any skid or scratches.

evan-RCU

In the picture it is upside down. If you look closely there is a wire nose skid going up behind the opening.

soarrich

My Feedback: (98)

OH. OK I see it now. Round is a bad shape for speed, a little airfoiling of that might be in order.