A CONVERSATION ABOUT TAKE APART STUNTERS

[Frank Imbriaco]

I have long wanted to do a take-apart. I fly a lot of R/C and many times wish that I had a ukie with me so that I could enjoy both on that day. I also want something that'll fit in our mid-sized SUV to take along for the beautiful winters in Florida.

Ideal for my purposes  would be something 40 sized maximum, electric.

Good windy weather flyer. (Florida can be quite windy during the winter months, especially along the east coast.)

 My opinion ? Outside of guys who need to travel  abroad for a World Team, very few among us are jacked on the idea. I've heard  criticisms/excuses about weight,  control system, mechanical failure  and other complexities.

Granted, they're legit.

But I think we have talented folks who can point the way, based on their successes.

There have been articles written in the past and Joe Daly recently included some nice pics in his column, but much more needs to be shared.

[John Paris]

Frank,
I think you will find some good info from Mike Alimov in the building section.  He is required to do take aparts so that his boys can compete.  Take a peek in the building section for his ideas.
John

[Frank Imbriaco]

Thanks, I'll check it out.

[ericrule]

Hi Frank;

I had exactly those thoughts a few years back. There are many ways to create "take apart" models. Some are very inventive (see Dave Fitzgeralds "Thunder Gazer" or Yuri's "Shark"). Both of these top line competition models are fully built-up which means their "take apart" systems have to be a bit involved.
 
My thoughts were based on a much simpler models (profile stunter) which would not require highly technical and difficult to build mechanical systems. The result of these thoughts were my creation of four profiles (Take-Apart Ringmaster, Magician, Tutor and Flite Streak). After designing the take apart sytem and building all four models we flew them to make certain that 1) the models would not come apart in the air, 2) The take apart system was easy to create and build and 3) the take apart system did not add too much weight. I think we accomplished those goals. Take a look at the RSM web site (www.rsmdistribution.com) to see the models. If I can assist you with any of the design details please drop me an e note at clflyer1943@gmail.com or call me at 951-409-1277 (Pacific Time Zone).
Regards
Eric Rule

[Brett Buck]

My opinion ? Outside of guys who need to travel  abroad for a World Team, very few among us are jacked on the idea. I've heard  criticisms/excuses about weight,  control system, mechanical failure  and other complexities.

Granted, they're legit.

But I think we have talented folks who can point the way, based on their successes.

    I think it is pretty well worked out, but I don't why you think that there are "excuses"  - it definitely requires different construction to avoid significant weight penalty, and that different construction has performance effects - weight is just one of them, there is also flexibility and mass properties differences. For instance, foam-core wings are very inefficient when you also have to add parts to hold them into a take-apart fixture. So, it makes sense to change to built-up construction - which makes of a *wildly different* set of engineering changes/compromises.

     A given aerodynamic design *will not fly the same* when you make a massive change in the construction. Of course you can make it work either way, but its not a trivial issue nor is is an "excuse".

    Brett

[Frank Imbriaco]

Hi Eric : I'm familiar with your profile models which appear quite nice. I'm thinking along the lines of a full fuse ship. Thanks !

Hi Brett :  I just thought that it would be good to share ideas about take-aparts, which I would guess make a up for a tiny fraction of all control line models. Personally, I don't look for excuses nor do I make them.

My only interest is seeing what others have done. Some detailed pictures and description.

Then, I'll take it from there.

[Brett Buck]

My only interest is seeing what others have done. Some detailed pictures and description.

   I think that most of them now use something similar to the Yatsenko system, which uses bolts in shear with what amounts to a clevis. I think Dallas Hanna makes most of the ones I have seen.

   Other common methods are the Tom Morris system which puts the bolts in tension and requires only simple machine work. The other common system is the RC-style where the entire wing remains in one piece and comes out of the fuselage (like Paul did for a while, and was used on the first Thundergazer), usually with screws front (through former F2) and rear (through the TE). I like that one the least, it makes the fuselage too weak and doesn't make the box much smaller.

   I haven't done any of these, but a lot of other people have, and the pros/cons are pretty well know.

     Ted had what I think is a great idea, to just have the ends of the wing come off, just outboard of the landing gear spar. That takes a lot of the load off the fittings. His idea was that you could use carbon tubes telescoped into fittings and just tape them on, but I think you need something to retain the tubes in tension. The fittings don't have to be overly strong since much more load is on the root than halfway out, but a simple bolts in tension should be more than enough, and you only have to beef it up slightly in the outer panels to take the point loads (since the landing gear spar already exists and can also hold the hardware). The downside is that the box ends up pretty big, although not as long as the one-piece wing version, it's a lot deeper. But the controls stay connected, there is no possibility of significant shifting of the alignment in the hardware (or having to require precision fits to prevent it, like tapered shoulder bolts).

    My version of this system is as close as I have gotten to actually building it myself, after I was the team alternate and was up to go. I also removed the fin/rudder to keep the box depth reasonable.


    Brett

[Dave_Trible]

I’ve had best luck doing it this way:  there are two pieces of hardwood motor mount stock glued into the fuselage plywood doublers to create hardpoints.  At the trailing edge plywood tabs go through the fuse and are screwed down from inside the pipe tunnel.  Two carbon tubes slip into plywood clips glued to ribs in the wing to absorb g-loads and landing shock so the wing joints don’t flex.

Dave

[Dave_Trible]

 ...

[Dave_Trible]

..

[Dave_Trible]

In order to get everything to be straight and attachment points to mate up the structure about has to be built as one unit in fixtures then separated.

[Dennis Toth]

Frank,
Look at Paul Walker's Impact take-a-part, It is pretty straight forward you basically build all the attaching formers and build the ship around them to get the alignment. I have done three ships this way, two Magnums and one Barnstormer and it is simple, light and repeatable. It is not the smallest package for take-a-part since the wing stays in one piece but allows a reasonable shipping box.

Best,    DennisT 

[Paul Walker]

Frank,
Look at Paul Walker's Impact take-a-part, It is pretty straight forward you basically build all the attaching formers and build the ship around them to get the alignment. I have done three ships this way, two Magnums and one Barnstormer and it is simple, light and repeatable. It is not the smallest package for take-a-part since the wing stays in one piece but allows a reasonable shipping box.

Best,    DennisT

Is that the one piece wing version or the two piece wing system?

[Gordon Van Tighem]

A simple, light change for my OTS Veco Mustang making it easy to transport to VSC. Now 4 years of active flying. Ready to fly at around 30 oz w/Enya 25.
G

[Dennis Toth]

Paul,
The version I have followed is the one piece wing approach. It's been strong, repeatable alignment, simple construction.

Best,   DennisT

[Paul Walker]

Paul,
The version I have followed is the one piece wing approach. It's been strong, repeatable alignment, simple construction.

Best,   DennisT

The one piece wing system works just fine. However, when travelling on the airlines, the one piece wing is too big now for them to accept. That is why I went to the two piece construction. It fits into their 62 inch box requirement.  It weighs an honest 2 ounces to install. That is for a 4 inch wide fuse. Lighter if the fuse is less "round".

[PerttiMe]

How is wear and tear on the take-apart systems?

Or looking at it another way...

Do people routinely take apart and assemble the model just for convenience of transportation and storage?

[Frank Imbriaco]

The one piece wing system works just fine. However, when travelling on the airlines, the one piece wing is too big now for them to accept. That is why I went to the two piece construction. It fits into their 62 inch box requirement.  It weighs an honest 2 ounces to install. That is for a 4 inch wide fuse. Lighter if the fuse is less "round".

Paul:
I would appreciate any pics or info about your two-piece system.
Frank

[FLOYD CARTER]

The main unit is more or less like Yatsenko's, but t.e. support is better adapted to a built-up wing.

[/quote]

Take apart is essential if you are going to a WC contest by airline.  Otherwise, it's a lot of extra work and weight if you are going to load your van to the local field.

I built a Fitzgerald "Thundegazer" from plans,  in one piece and saved a lot of extra work.  It fit in my van just fine.

[Kim Doherty]

Some more info on Take-Apart models.

https://stunthanger.com/smf/building-techniques/take-a-part-wings/


Kim.