Removable Fin on Flyer?

BSquared18

Member
Hi, my wife and I like to carry some of our planes with us when we drive on long trips and stay at a destination for an extended period. Out minivan usually is pretty full. I'd like to be able to pack up the Flyer to bring along. One problem is the vertical fin. If there was a way to build the Flyer so that the fin could be removed, then the model could be packed in a much smaller space. (I'm at the stage right now where it's time to install the tail section on the Flyer I'm building.)

So, my question is, has anyone ever built a Flyer with a removable tail fin? If so, please point me to where the design is described or summarize it here. I did several searches and didn't come up with anything.

If no one has done it, I'll put my thinking cap on and see what I come up with. I'll be back to get feedback on any ideas I come up with.

Of course, any design would have to keep additional weight to a minimum. Also, of course, the rudder control rod will need to be easily detached from the rudder.

Bill
 

rockyboy

Skill Collector
Mentor
I don't have any tips on the removable rudder, but personally when I'm low on space I like to pack along a wing like the FT Arrow or Spear. I typically hang them from the ceiling of the car with bungee cords stretched between the handles above the doors or hooked into the sunroof molding.
 

mrjdstewart

Legendary member
arrow!

3D print the center pod and life is good. makes build a breeze. even without, it is one of the simpler FT builds, and funnest planes.

laters,

me :cool:
 

baronbernie

Member
There is realy no way to connect and remove the fin but if you want to try and design a way to use Velcro, go for it.
 

foamtest

Toothpick glider kid
Hmm... I need to rebuild my FT Flyer and I might try this as a challenge. Although I would recommend building a flying wing like the others have said here.
 

BSquared18

Member
There is really no way to connect and remove the fin

Well, here's the solution I came up with. Will find out if it works.

On each side of the fin is a strip of spongy foam made wide enough so that it puts pressure to hold the fin securely. Next, two sharpened zip tie strips with the fastener ends cut off are pushed through from one side to the other. The zip ties have been cut so that just a bit protrudes from the other side when the push is completed. The spongy foam holds the zip ties securely in place.

Once the zip-tie channels have been created, the zip ties slide easily in and out. Whether over time the channels will become larger, making the zip ties loose remains to be seen. If so, the zip ties can simply be pushed through at different spots.

Instead of the BBQ skewer that Flite Test recommends adding to the tail skid that protrudes from the bottom of the fuselage, I plan to use a section of sturdy zip tie cut to be narrow enough so it can pass in and out of the fin's slot. One advantage, I think, over the BBQ skewer is that the zip tie piece should have spring to it to absorb shocks.

If anyone sees a flaw with this design, sing out.

Bill


Removable-Fin-740.jpg
 
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foamtest

Toothpick glider kid
I like it the only thing I would change would to be to use BBQ skewers instead of the zip ties to hold the vertical stabilizer on. I am afraid that the zip ties might give to much causing the tail to come off during flight but it should work. I do really like the zip tie skid idea however, I might just use this from now on.
 

BSquared18

Member
Thanks for the feedback, Foamtest. The zip ties are quite sturdy, so I think they will work, given that the Flyer is slooooow. They are the reusable kind with a little trigger you can squeeze to release the fastener from the strip. Originally, I was planning to use the fasteners on the zip tie to hold everything more tightly, but I discovered that once a fastener is pushed up against the side wall, it's very difficult to release it. Then, I got to thinking that since I'll only be removing the fin/rudder for occasional travel, I could use fasteners and then just cut them off the next time I want to store the fin and use a new set of zip ties when ready to fly. Interesting how one idea leads to another. It's all still in flux as I work on a solution.

Bill
 

BSquared18

Member
I've made what I think are some improvements to the design. One problem with the original design is that it is very difficult trying to push the zip-tie strips through the spongy foam and have them come out the other side at the some location each time.

In the latest design, there are notches in each piece of spongy foam. The notches are located where the zip-tie strips pass through from one side wall to the other.

Another change is that now a zip-tie fastener is inserted on one end of a zip-tie strip (forward zip tie in the image) and the other end (rearward zip tie in the image) has been scored and reinforced with packing tape so the end can be bent down. The bendable end serves as a basic but effective stop to keep the zip tie from being pulled back through the side wall.

The steps are:

1. Pass the zip-tie strips in one side wall, through the fin, and out the other side wall.

2. Slide each zip-tie far enough so that the fastener can be added to the non-bendable end.

3. Insert the spongy foam cushions as shown in the image.

4. Slide a zip-tie fastener on each of the two zip ties.

5. Draw the zip tie back toward the side wall.

6. Bend down the zip-tie end that can be bent.

7. Push the fastener toward the side wall. When it is flush, push it a bit more until you hear a click. That means a bit more tension is being placed on the spongy foam and the fin.

8. To release a fastener, straighten the bend in the bendable end of the zip tie and push the zip tie far enough so that you can reach the fastener's trigger with thumb and finger to release the fastener and pull it off the zip tie. Or after straightening the bend in the zip tie, simply push the zip tie out from that side.

On a related issue, I glued a zip-tie piece to the tail skid. The zip tie had been cut along its length so that it would pass through the slot. However, I think I'm going to glue a second thickness to the first one because the single piece seems a bit weak. (UPDATE: I did that and it made a big difference; much stronger now.)

Bill

Removable Fin 02 740.jpg
 
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Bricks

Master member
What may also work is make the elevator and rudder as one piece and use plastic screws and glue the nuts inside the fuselage. Make a flat area for the elevator and rudder to bolt to as simple as I can explain it. Many ARF`s ( almost ready to fly ) are built this way.
 

BSquared18

Member
Interesting idea, Bricks. I think I see what you mean. Then the rudder/elevator combo would, I suppose, be packed in a separate box because, if I'm understanding the "elevator and rudder as one piece"concept correctly, there are still vertical and horizontal pieces connected together, which is what I'm trying to avoid for packing purposes.

Bill
 

Bricks

Master member
What you could try is glue a flat piece to the bottom of the rudder then thru bolt or what ever to hold the rudder maybe even use skewers and rubber bands like a wing.
 

BSquared18

Member
Bricks, I like the way you think outside the box. I've already finished installing my solution on the Flyer. I like the fact that it adds on 0.10 ounces to the weight and is very easy to install and uninstall. The proof will be in the flying. What's the procedure when one loses their fin and rudder? Reduce power to the motor, set up a glide path, and hope for the best, I suppose.

By the way, your feedback on my RCGroups build thread for this model would be much appreciated: "Building a Flite-Test Flyer Airplane from Speed-Build Kit and from Scratch."

Bill
 

Bricks

Master member
Another way to do this even thou I realize you are finished, when building the fuselage incorporate a slot for the rudder. then just use skewers thru the fuselage.
 

BSquared18

Member
when building the fuselage incorporate a slot for the rudder

If I understand, you're saying behind the wing add an upper foam deck to the fuselage and put a slot in it. So, the rudder would have two slots, one above and one below. Is that what you're suggesting? Sounds good. Seems like it would work.

Bill
 

Bricks

Master member
I was thinking more along the lines of the slot going thru the top and bottom of the fuselage right where the elevator sits for the entire length of the rudder. For the elevator to keep it level run a piece of triangle foam along the elevator either top or bottom or both depending on how the elevator sits. For elevator rigidity if needed run a piece of carbon or skewer in a slot cut in the elevator from tip to tip and glued in. Then slot the rudder to make room to slide the rudder down over the skewer. The rudder would actually sit flush with the bottom of the fuselage.
 

BSquared18

Member
Umm. I think I'll stick with my method. I want to keep it as simple as possible. I would need drawings to understand your design (I'm a visual guy).

But what I say earlier that I thought you meant would work too I think. Simply two slots that line up for the rudder to slide through.

Bill
 

VarietyPack

New member
If you lose the vertical and horizontal stabs, your plane will become a falling leaf lol.

I had an FT Mighty Mini Mustang build that did this. I pulled up out of a powered dive, trying to stress out the airframe, and the tail gave up. My plane pulled a dozen G's or more as it pitched up hard, going from about 60mph to a dead stop within maybe one foot. Then it flipped end-for-end as it tumbled like mad into the grass.

On later inspection, there was a deep crease in the right wing that I'm certain was from the violent pitch-up. I had forgotten to add more glue to the tail after recent repairs lol. :facepalm: It was only halfway glued, if even that much. Lesson learned!!

Happy flying with your Flyer!
 

BSquared18

Member
Happy flying with your Flyer!

I wonder if that comment is meant to be ironical... ;)

The two zip ties are very strong. And I've reinforced stress points. Also, it sounds like your plane has (had?) a lot more power than my Flyer will.

But time will tell. Wouldn't be the first time a design problem brought down an airplane. I'm reminded of the British de Havilland Comet, which was, if memory serves me, brought down by square windows. Unlike the Comet, I can say with some certainty that "no persons were harmed" if my plane crashes. A crash is more likely to be due to my flying flaws than to design flaws.

Bill
 

VarietyPack

New member
Haha definitely ironic.

Those zip ties sound good to me (not that I know anything), but I was saying that if your tail comes off there is no glide path, only a descent rate hahaha.