Details 4 Scale

My Feedback: (3)

Crazy,

What did you use for your undercoat on your Phenom?

Can't wait to see the finished paint job!

Dan

Crazy4Flight

My Feedback: (540)

Before letting the cat out of the bag...
I will get the paint done and see if it works.

bob

Details 4 Scale

My Feedback: (3)

YOU'RE NO FUN!!!

Crazy4Flight

My Feedback: (540)

if you bought the paint I am trying out, and your results were crapola before Mine got done who is to blame???

My test, my headache...OK?

I note I did not say...."if I tell you I'd have to kill you"

bob

vicman

My Feedback: (10)

Did Razor get his yet?

Crazy4Flight

My Feedback: (540)

A page back or so he (Razor) said he got his.
But does not have a Jett to supply the correct nose weight.

bob

vicman

My Feedback: (10)

Cool,
Stupid work gets in the way of really keeping in the loop of all that goes on

Razor-RCU

My Feedback: (50)

I got mine and I am going to start a "Ghetto Phenom" thread, wherein I use a simple OS-50SX engine and shaker paint cans for the finish. It has been freezing in my shed this weekend I plan to get her going a bit...

Cheers

crasharama

Hi Crazy,

That stuff works well, I used it this time last year on my pylon model. You guys don't have to worry about this at the moment, but don't use it when the humidity & temp is high, as the undercoat gets grit in it, as it was drying before it went on to the surface. I had to sand it back off again,top & base coat, as I didn't know that it was wrong & have another go, but when it is right it looks great.

Tony.

bob27s

My Feedback: (19)

From what I understand, they designed the plane basically for the .48 size fan engines... so that RE configuration seems to fit well.

Id probably make it a good home for the SS-40 engine.... just need the standard backplate for the installation.

Details 4 Scale

My Feedback: (3)

Bob,

After talking to Russ,

He said the Phenom was designed so that it could accept the O.S. .46 VXDF rear intake style motors. He said, you'll find that the .46 VXDF is a "perfect fit" into the airframe as are the JETT FIRE .50RE and .60RE. All make great choices for the Phenom. If you want to really go 200+mph, this airframe will get you there!

Dan

I-Love-Jets

Obviously the 200 mph “myth” of very fast prop deltas does work well in terms of marketing. Diamond Dust and Whiplash are examples worth mentioning, and now the Phenom. [sm=wink_smile.gif]

So reffering to the speed freaks’ substantial experience over here, you definitely will not be able to reach real 200 mph (average speed to exclude the wind factor) with the OS .46 VX-DF or JETT 60 LX. Sorry to say, but we need more power (at least about 4 HP) to achieve that on a design like the Phenom. [sm=disappointed.gif]

Though deltas mostly look super fast, this kind of design always needs an extra portion of OOMPH to keep up with conventional speed airframes…

Details 4 Scale

My Feedback: (3)

True, Most airframes cannot attain the 200+ MPH without help... dive, wind, etc. Even in the days of DF speed jets, the 200mph club was not easy to attain even out of a dive. The "Vortex Supreme" DF Jet that I designed over a decade ago managed to hit speeds in excess of 240+ out of a dive, measured by a "Speedmaster" speed trap. Like I said, "out of a dive". This is what defined the 200 mph club back then.
Deltas have long been a very good choice for speed airframes. They have very little frontal area along with very low drag coeficients, due to their relatively low wing loading and high power to weight ratios. Obviously in order to keep that drag low, the airframes need a very low "induced" drag. Make them too heavy and they simply waste too much energy just trying to stay in the air. Every speed design will have trade offs. I guess what makes the deltas so popular is that they look cool, go very fast and are within the piloting skills of most pilots. Their shear simplicity has to make them popular as well. I guess the whole 200+ mph thing is simply up to one's interpretation as too what one chooses to define going 200 mph...Just my .02cents [8D]

Dan

bob27s

My Feedback: (19)

Yes, level flight 200 mph is not going to happen,

but we have a number documented 200mph passes on several Whiplash aircraft (and derivative designs) coming out of an extended dive. Those were all with high timed SJ-50 FIRE engines - LX configuration. Some took some creative prop selection, and a carefully set needle.

Is all of the data I refer to 100% accurate. Probably not, and hard to know for sure. But more than one example has been demonstrated.


I do not believe I have data on a DD getting to 200 though ...... highest one I see in my notes is 186.

We shall see - the Phenom has some potential aero advantages over the Whip..... looks like Bob (Crazy4Flight) will be the first test case with the 60LX.

A little work with the doppler stuff and a radar will get a general idea.

cmopar

Anyone run the k&b 45 df ? Are they strong runners ? I havent run the one i have and might try it first .

Corey

Crazy4Flight

My Feedback: (540)

The Phenom is in the paint department now.
Winter is in the snow+cold program...Spring is not to far off tho.

Two years ago I had a Yellow whip with a sport Jett 50 that moved out. Its picture is on the Jett Engineering web page.

I never got a radar gun on it or any real accurate timing. Just a stopwatch, one operator at mid field, watching plane and shadow crossing start and end of a 385' paved runway. Times were about 1.40 to 1.45 seconds. somewhere about 180-190 mph.

Details 4 Scale

My Feedback: (3)

Corey,

I had a K&B 7.5 DF motor with front intake (old style) I mounted an OS 8M carb from a an old OS .61FSR on it. It turned an APC 10X10 prop at around 17K on the ground on 12.5% nitro. It also sucked fuel something aweful. I had it on a Q-500 that I designed many years ago. Well over 200 out of a dive. About 170 in level flight. I don't have any idea what it unloaded to in the air, but the unloading was significant. Haven't used it in many years. Needs new bearings (I wonder why...lol). Just haven't bothered to put them in. The K&B 7.5DF sounds like a good choice for the Phenom. You'd obviously have to remove the impeller extension and change out the prop screw, but that wouldn't be too difficult. If my old tired 7.5 is any indication of the power available from the old K&B DF motors, it should do well in a Phenom.

Dan

Mike Connor

My Feedback: (5)

A 10x10 is a lot of prop. Will you varify the size?

Details 4 Scale

My Feedback: (3)

Mike,

I think I still have the prop. and I think it's still on the motor. I'll check to be sure. It was over 10 years ago, but I'm pretty sure that was the prop. The plane was always really slow getting on step, but once it got there and the prop unloaded, it was a lot of fun. I'll see if I can dig up a picture of it. I put over 300 fights on that Quickee and I never changed the prop. I know I got my money out of that one! I sold it to a friend and he put it in the following week. ARGH!!! [&:]

Dan

Details 4 Scale

My Feedback: (3)

Ok, so I am getting old...

It was an 8x10 prop. Well, I got it half right anyway.

I-Love-Jets

Oh yes – that would be a very helpful test case, if Bob’s team will document the entire flight (down + headwind passes) using simultaneously:

a) a speed trap with stop watches

b) a microphone within the speed trap




Explanations:

To a)
To compare your flight speeds objectively with the “German speeds“, you need at least 4 stop watches within a 150 or 200 m meters speed trap. The Germans did use two independent stop watch teams (4 guys) per flight during the last 30 years to ensure objectivity while comparing speeds. Objectivity means if the time-lag per log between each team and pass was over 0.05 sec, then this particular time measurement was invalid. That postulates very high accuracy requirements on both stop watch teams.


To b)
A good mic placed within the center of the 150 m trap will make sure for smallest deviations from actual speed. Within the speed trap the Phenom has to fly at horizontal altitude, because a hyperbolic flight pattern will distort speeds derived by Doppler shift calculations.




Of course following the very rigid FAI rules (like in Germany) is the best way to resolve all doubts. But in this case I believe it would be sufficient to give a) and b) combined a try. If these two different measuremets simultaneously deliver almost identical results, then even the Europeans will finally believe in fast prop deltas. [sm=wink_smile.gif]


Good luck with your Jett 60 LX powered Phenom!


P.S. Since last fall (Speedcup 2006) a new speed measurement tool has been introduced.

http://www.rcuniverse.com/forum/fb.asp?m=5273689

This photoelectric barrier system has replaced the stop watches and works extremely accurate. No human error or cosine error (audio + radar) possible.
[b]

Mike Connor

My Feedback: (5)

I understand the getting old part.
Thanks, That makes more sense to me.

Crazy4Flight

My Feedback: (540)

I dont need the FAI rules in German or any other language. [sm=tongue_smile.gif]
You see I like to go fast and and spend money. [8D]
( spending money is a requirement to go fast )

I fly for fun, not records, prizes, or trophys.
I really don't care if the Phenom does 201.652 MPH or it goes only 199.734.
I doubt if I would notice the difference. [sm=bananahead.gif]

THE pipe came the other day for the 60LX and it is the quiet pip not the rat pipe. Yes I will loose out on a few hundred RPM but my club has neighbors and we dont want to loose the field.

I am sure one day I will get with Bob27 and make a few speed passes....

bob

BTW any bonus point for inverted runs????

I-Love-Jets

Bob, I think there’s a misunderstanding. I don’t want anybody to use FAI regulations, but it is absolutely necessary to use an objective measurement tool (speed trap) to believe speeds posted here.

Again the mysterious 200 mph mark was mentioned in connection with a prop delta, which is exaggerated with the current setup. Again, it will be impossible to reach real (averaged) 200 mph with the JETT 60 LX and a very good custom made prop. I am confident you are in the 185 mph to 190 mph range.

So we need to spend even more money for at least 4 HP output to get us there with the Phenom.

You know what I mean? These 200 mph advertisings and forum talks of prop driven deltas will always remain insubstantial for the speed freaks as long as it has not been objectively veryfied.

This verification would cost you only a few beers at most, to “pay” the 4 stop watch buddies (each operating a stop watch) for doing a great job.

So the nitro fuel spent for the speed runs should finally be more expensive than those beers. Btw, such a speed measurement afternoon does make fun too.


[b]

Razor-RCU

My Feedback: (50)

I am with Crazy, I do not care how fast I am going as long as I am going... Getting all technical takes the fun away for me at least.

I have to compete every day as a salesman, playing cards and almost everything else I do, I don't wanna worry about it with my RC stuff

If you told me my fastest airplane ACTUALLY went 93mph, my reaction would be... "still looked like 200 to me"

Also It is worth mentioning that for me I actually like Delta's, and I really do not like Q-500's. Soo even if the Scat-Cat turns faster and loses less speed, and it has little wheels on it, I still prefer the hand launch, hair raising, almost invisible, belly landing deltas like my Whip and my soon to be Phenom!

Good times man, good times---