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Old Jun 06, 2012, 11:45 PM
Wonderfully Wicked
The Don's Avatar
Willoughby, Ohio
Joined Jan 2002
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In stock here, it is LX version not Max Jet

http://www.bphobbies.com/view.asp?id...8&pid=D0626114

Don
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Old Jun 07, 2012, 12:36 AM
Shameful Warbirdaholic.
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Maple Valley, WA
Joined Apr 2006
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Thanks Don! Stacker had sent me that link...Appreciate the help from everyone!
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Old Jun 16, 2012, 08:16 PM
Build'm,Fly'm,Crash'm
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Sacramento CA
Joined Oct 2009
629 Posts
Interesting mod, stack...not sure how that eliminates the need for an elevator. Maybe you could elaborate. The drooping LE will calm things down, but will keep the model from achieving top speed, due to drag. This may not be important to some, but being an SR, kinda goes against the grain.

Do you have an AUW you could share as this seems to be the killer for this model. I've seen models on this thread 50+ ounces with not so good flight reports or lifespan...at less than two square feet of wing area, that would calc out to over 25 ounces psf. Not a friendly neighborhood for this draggy airframe.

The LG that comes with the model is fine, as long as you don't fly heavy...and the stock gear weighs almost nothing. We fly just a bit heavy and have been using the stock LG for around fifty landings with zero problems. Actually, the foam around the LG was getting a bit soft, so some CF was installed, but the gear itself has never failed of even hinted at failure. Not sure why this item gets bagged, other than the heavies...If heavy, then it will give you problems, especially if you gomer the landing, but then no LG will help in that situation anyway. It should be changed out if you're really heavy, but then you're on a slippery slope...now it weighs even more, which means stouter stuff, which weighs even more....etc....

A model with the extra elevator and rudders will fly way better than the same model without...common sense dictats that...and less drag than with a model with drooping leading edges...and under 45 ounces to keep the thing together while landing.

Example...just the mount for the exterior camera shots we posted awhile back reduced the speed almost 15 mph, and that was 12 grams of streamlined aluminum tubes. Worse when the camera was on it...the throttle was pretty much firewalled for the entire flight.

And the LX is by far superior to the MJ...

Joe
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Old Jun 16, 2012, 09:55 PM
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Maple Valley, WA
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Good post redlite. Very good points.

However, I am curious why the LX is considered "far superior" to the Maxjet? I've had both and I couldn't tell any obvious difference. Is there some flight dynamic difference or in the scale fidelity area?

I ordered a kit that should arrive on Tuesday. Once I get all the guts put back in I will weigh her to get the AUW.
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Old Jun 16, 2012, 09:58 PM
Wonderfully Wicked
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Willoughby, Ohio
Joined Jan 2002
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I think watt for watt the LX was faster. My guess as to why is the molded panel lines on the Max Jet version. I don't recall the LX having them so deep but it has been a long time since I had the kit though.Maybe it is just in my head????
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Old Jun 16, 2012, 11:14 PM
Build'm,Fly'm,Crash'm
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Sacramento CA
Joined Oct 2009
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The MJ is a stolen design from LX. To do it, they had to change some things so it wouldn't be a complete slap in the face to LX. What they changed was some of the things you guys have pointed out, i.e., deep panel lines and other deviations from scale finish. The foam is shiny on the MJ and lots of the scale surface details on LX are missing or misplaced on the MJ...on purpose, to make it 'their' model, as if we couldn't figure it out..

Think about it, they couldn't make it better, but they could take shortcuts that LX didn't and save some $ and then pass some of those $ onto us as a incentive to buy them, instead of the guys that did the engineering, LX, on the original model.

I have both and as far as I can tell, the planes are the same as far as outlines are concerned, so they should fly the same. That's one thing MJ couldn't change anyway...it has to fly and fly well, so airfoil, etc., has to be near identical if not exactly.

My take on the two models is...if you are experimenting, then the MJ is less painful to lose...for demonstration flying, i.e., in front of a crowd, then the LX is a better choice.

And if you are over 50 ounces, take the blame for the fiery crash, it was enevitable...but don't feel bad, only the best can tame the wing loading repeatedly, without incident.

Joe
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Old Jun 17, 2012, 11:11 AM
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Salt Lake City Utah
Joined Mar 2004
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Quote:
Originally Posted by redlite View Post
Interesting mod, stack...not sure how that eliminates the need for an elevator. Maybe you could elaborate. The drooping LE will calm things down, but will keep the model from achieving top speed, due to drag. This may not be important to some, but being an SR, kinda goes against the grain.

Do you have an AUW you could share as this seems to be the killer for this model. I've seen models on this thread 50+ ounces with not so good flight reports or lifespan...at less than two square feet of wing area, that would calc out to over 25 ounces psf. Not a friendly neighborhood for this draggy airframe.

The LG that comes with the model is fine, as long as you don't fly heavy...and the stock gear weighs almost nothing. We fly just a bit heavy and have been using the stock LG for around fifty landings with zero problems. Actually, the foam around the LG was getting a bit soft, so some CF was installed, but the gear itself has never failed of even hinted at failure. Not sure why this item gets bagged, other than the heavies...If heavy, then it will give you problems, especially if you gomer the landing, but then no LG will help in that situation anyway. It should be changed out if you're really heavy, but then you're on a slippery slope...now it weighs even more, which means stouter stuff, which weighs even more....etc....

A model with the extra elevator and rudders will fly way better than the same model without...common sense dictats that...and less drag than with a model with drooping leading edges...and under 45 ounces to keep the thing together while landing.

Example...just the mount for the exterior camera shots we posted awhile back reduced the speed almost 15 mph, and that was 12 grams of streamlined aluminum tubes. Worse when the camera was on it...the throttle was pretty much firewalled for the entire flight.

And the LX is by far superior to the MJ...

Joe
If you are happy that is good and pay no attention to my mods.

I believe my all up weight was below 44 ounces but will verify. I found no need for whale tail but I'm sure it makes for a more effective control surface. Rudders would be nice but I left them off also. Leading edge droop will effect airspeed but I believe flying plane nose heavy with a large amount of up trim will also effect speed as many are doing. With my older eyes I'm not going for max. speed as I'd have to paint the plane day glow pink to see. Fun plane to experiment with and sad to see so many go in.

I may have to buy a LX version to compare to the Max as right now I don't see the Max version available.

Cheers -- Stacker
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Old Jun 19, 2012, 03:12 PM
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Number 8. I should make a custom "Magic 8 Ball" logo for her.

And the addiction continues...
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Old Jun 19, 2012, 08:33 PM
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Having really paid attention to the quality, I agree the LX is much better than the Maxjet.
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Old Jun 19, 2012, 09:24 PM
Wonderfully Wicked
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Willoughby, Ohio
Joined Jan 2002
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Go #8 !!!!
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Old Jun 20, 2012, 12:14 PM
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Maple Valley, WA
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Thanks again Don for the link! When I get some more money I'm going to order a few!
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Old Jun 20, 2012, 12:15 PM
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United States, FL, Sebring
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Time for me to finish up my SR-71 as well. Too many pressing issues lately and my builds had been forced to the back burner.
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Old Jun 20, 2012, 01:48 PM
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Maple Valley, WA
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I opted to go for stacker's washout mod. In theory, it should reduce some stall tendencies...It will be interesting to see if I notice any difference from previous versions (aka crash test air frames, lol).

I'm going to go sans decals for this one, at least until I have a good dozen flights or so and it's not a waste of time.
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Old Jun 20, 2012, 02:11 PM
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Salt Lake City Utah
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Looks good Aros,

LX version does look nicer then the Max version. Wonder if the CG differs at all between the two? Are you going to try the stock landing gear?

Take care -- Stacker
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Old Jun 20, 2012, 02:51 PM
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Maple Valley, WA
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I thought about it but decided not to. As much as I think it's more stable with gear for takeoffs, I just don't have the opportunity to fly EDFs with small retracts at the local school. Usually there's sports going on and I feel the least confident flying this particular plane more than any other I have ever owned so I don't want to risk flying it around a crowd of kids and parents.

So back to the hand toss paradigm. However, I've learned a lot over the past year which should help. One, I will try to only have others I trust toss her for me. I need both hands on the controls from the start. I think the lack of success and subsequent crashes on 90 percent of my hand tosses could be contributed to poor toss technique and dumb thumbs trying to quickly gain control. Since the SR-71 does not have a good base to grip from for the toss, I think my fingers get a little stuck in the holes I make for it which creates all kinds of bad AOA.

Two of my buddies I know have both done excellent jobs hand tossing her. I think I will wait to fly until one of them are available to toss her for me. I really do feel that will greatly increase her long-term survive-ability. That and keeping the weight down and using a good, trusty battery.

Speaking of batteries...What are some really good ones people here have had success with in this bird? I think my 45C 4000's are too heavy and I don't notice any increase in air time than with the 2200's I used to run moons ago. Looking for some good quality, good priced drop-in batteries for her. Thanks!
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Last edited by Aros; Jun 20, 2012 at 03:00 PM. Reason: Battery question
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