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Author Topic: T-Rex build  (Read 3557 times)

Offline Rod Claus

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T-Rex build
« on: June 19, 2019, 04:01:38 PM »
I'm in the process of building this ARF and not sure about the thrust line while putting on the engine mounts.
The directions aren't very specific. Any help would be appreciated.
Rod Claus
Kent,Wash.

Offline Kevin Muckleroy

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Re: T-Rex build
« Reply #1 on: June 19, 2019, 05:55:38 PM »
This will help. 5/8" CL motor to CL wing

Offline big ron

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Re: T-Rex build
« Reply #2 on: June 19, 2019, 08:33:32 PM »
This will help. 5/8" CL motor to CL wing
Is the full set of plans available for this Kevin?
John Blanchard
Brusly, Louisiana
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Offline Kevin Muckleroy

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Re: T-Rex build
« Reply #3 on: June 20, 2019, 12:32:16 AM »
I have no clue if they are. Need to call Brodak on that one.
 I am currently trying to resto-mod a used T-Rex ARF. Been Procrastinating on it for a few months. Need to call Brodak myself. would like to get a fuselage kit or just the bulkheads & formers. And of course a set of fullsize plans. I noticed none was listed on thier website but then again I have not been back to the Brodak site in several months due to a virus or mall ware or what not. My Norton AVS blocks it.

Offline Dave Hull

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Re: T-Rex build
« Reply #4 on: June 20, 2019, 12:43:44 AM »
The partial view of the plan shows 3/4" from the centerline of the engine to the centerline of the wing....

Offline Rod Claus

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Re: T-Rex build
« Reply #5 on: June 20, 2019, 04:09:31 AM »
Thanks for the info Kevin .Much appreciated.
Rod Claus
Kent,Wash.

Offline Rudy Taube

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Re: T-Rex build
« Reply #6 on: July 22, 2019, 12:42:19 AM »
To those who are building this excellent plane, please see the extensive build threads on this SH forum:

Go to the upper right corner of this page and you will see the word "search", in the empty box to the left of the word search type: T-REX BUILD then click on the word "search".

There are some important issues that may need to be considered when building this plane. You will see several build threads that will address any questions you may have. The electric build thread is comprehensive, the others may help too.

HISTORY PS: The designer of this excellent plane did an outstanding job. After incorporating some of the mods from the build threads mine flew very well.

The reason for the mods is NOT the designers fault. He was caught in the middle of a wood change caused by the new (and much improved) ARF Manufacturer now used by Brodak. For many years ARF manufactures in China used low-quality balsa and plywood, to compensate for this weaker wood they just made everything thicker and overbuilt the structure which resulted in a heavy plane. The designer of the T-Rex was very clever and called out thinner dimensions for all wood, he was depending on the use of the same overbuilding and too thick of wood by the Mfg.

His T-Rex was one of the 1st designs built during this transition to the new Mfg. They used light balsa and quality light ply. This meant that the designers compensating new dimensions were now thin all around. The plane comes out light, but it needs a few simple mods to ensure its structural integrity. Many have flown it in its stock condition with no problems, but I recommend reviewing the mod threads to help guide your decision.

This design makes a great stand-off scale P-47.  H^^

Regards,
Rudy Taube
Rudy
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Online Brett Buck

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Re: T-Rex build
« Reply #7 on: July 23, 2019, 12:07:19 AM »
Drop it. I wasted two years while trying to make it flyable. The wing airfoil is wrong - too thin - not enough of Cl for decent corners.

 Still on this, huh? Oy gevalt!

   There's nothing significant wrong with the T-Rex aerodynamic design and certainly not with the airfoil - straight off of Bob Hunt's "Saturn", which is also an excellent flier.

  There are some structural issues, with easy fixes, as Rudy notes.

     Brett

Offline Steve Berry

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Re: T-Rex build
« Reply #8 on: July 23, 2019, 11:37:42 AM »
Bob Hunt's flying record and trophy assortment speak otherwise. Before belittling the design, saying it can't fly properly, try trimming it out properly, use the work others have already done, and then decide.


Offline peabody

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Re: T-Rex build
« Reply #9 on: July 23, 2019, 02:56:23 PM »
I have seen several that flew extremely well....Joe Gilberts, for example....
Fix the glitches in the assembly (NOT design) and power it right and it's a winner.

Online Brett Buck

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Re: T-Rex build
« Reply #10 on: August 11, 2019, 03:15:59 PM »
A few people who observed my flights said they liked how it flew. But that didn't help me to fall in love with this model, although I put all my best efforts into it.
At the end it is not a bad flyer, but I have never enjoyed to fly it. Neither my wrist did.
So please do not ask me to stay quite, because I as a buyer and a long term user of the product have a right to share my opinion and experience.

   Absolutely, I think everyone else believes in the concept of free speech - but expect other people to do the same. Free speech is a two-way street.

   I think you are fooling yourself on the topic of airfoil simulation, since the airfoil you modeled is not the airfoil as implemented, and your simulation is completely naive, not modeling several other items that are clearly known to make a huge difference - the hinge line dynamics, and the finite span, to name just two whoppers. That alone makes blanket statements about some hypothetical properties of an actual airplane completely speculative.

    The fact that other people have flown the "same" airfoil with great success proves beyond a shadow of a doubt that you are just wrong. That's not a moral failing, but insisting on ignoring documented facts and real-life experience over your clearly hypothetical and obviously simplistic model does not speak to your "objectivity". 

   On the topic of your particular airplane, I wouldn't dispute your experiences, you didn't like it, fair enough. Of course there's a host of vastly more likely reasons for it not to fly well that you could look at before you start digging into airfoil polars. At this point you are so convinced it is hopeless, based on your simulation results, that every setback will be leapt upon as "proof" you were right all along.   

     That's a psychological problem called "confirmation bias", and would likely make the effort pointless for you and for the rest of us to try to help. A less clinical but more accurate description is "believing your own bullshit". Worse yet, you are trying to engage other people by helpfully descending on this thread to tell everyone they were wasting their time. You are perfectly within your rights to do that, just as the rest of us are within our rights to ignore you or dispute your premise.

   Other people, without the benefit of your "advanced knowledge", successfully got the airplane to work. It does have other problems, like durability, that are soluble, and a variant of "center of lateral area" theory that Brad and I got into a minor disagreement with on SSW when it first came out, but those are not fatal.

    If even one person got the airplane (or other airplanes) to work with this airfoil, then you are unequivocally, objectively, incorrect. Many other people have done exactly that, so...

   Anyway, that's *my* exercise of free speech for the day, and my objective (albeit speculative in some areas) evaluation of the situation here. 

     Brett

Offline James Holford

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Re: T-Rex build
« Reply #11 on: August 14, 2019, 02:19:55 PM »
Im beating a dead horse here but I know of a member here who flew one for a couple seasons with a Saito .56 and it made quite an impression on me to get a Saito .56!  Even moreso to get that powerplant and to get a T-Rex 1 day.

Sent from my SM-G965U using Tapatalk

Jamie Holford
Baton Rouge Bi-Liners
Lafayette, La
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Offline Joseph Patterson

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Re: T-Rex build
« Reply #12 on: August 20, 2019, 09:35:31 AM »
   I have to disagree too about the T-REX having aerodynamic deficiencies. I've seen at least 4 different T'S flown w/AVISTAR 61, SAITO 56, ST-60, and PA-75? (may have been a RO-JETT ). Three of the planes were flown by very capable EXPERT fliers, and the Saito 56 powered REX was flown by a very good ADVANCE flyer. They all flew very well - the fliers even stated they were satisfied with their performance. In fact, they sometimes won their events against other very good flyers flying R. SMITH, other Hunt designs, R Oliver dsgn, and Brickhaus dsgns. My favorite was the SAITO 56 REX. I'm not implying the T-R IS BETTER but it is a competitive design considering it is mass produced as an ARF/ARC. Most of the guys that flew the T-R have now gone on to building the SMITH, HUNT, BRICKHAUS, and other designs since then, but the T-R was a great lead-in design for ADV./EXPERT competition.
       Doug
         


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