Mini A Heli modification: no burn string

[BABAR]

My modded Mini A Heli flew twice yesterday, and deployed perfectly without blowing apart. Success!

The first flight was on a 1/2A3-2T, which is not a recommended motor but I couldn't think of any reason it wouldn't work. Indeed, it wasn't very high but a perfectly satisfactory flight, with nominal deployment and a good helicopter descent. On the second flight I tried an A10-3, which was fine except it recovered upside-down, which works but doesn't spin as fast. I don't know if the motor choice played a role in the descent orientation; I'll keep an eye on that in the future.

The only slight cautionary note is that the slide mechanism feels a little rougher than before. I'll have to keep an eye on that as well. The current model is not build to allow disassembly or any cleaning or maintenance of the slide. I've thought about that a bit but haven't come up with any ideas I really like yet.

Overall I'm very happy with this mod. It works, and made flight prep a 5-second affair: fold the rotors, slide into place, load motor and go.

Here's a lousy video of the second flight. Tracking with a smartphone is pretty difficult and I'm very much out of practice; somehow, amazingly, I kept the rocket in frame the whole time, although I had no idea at the time.
View attachment 479777

Stuck the landing! Not easy to do with a helicopter.

i have had a number of invented descents, physics don’t make sense to me, but it happens.

congrats on your flights!

I am working on a Go-With-The-Flow chopper with no burn string or bands, no pull bands, and internal string rotor stops, but won’t start build until I get to Vancouver in a couple of weeks.

 

[Aeronerd]

My modded Mini A Heli flew twice yesterday, and deployed perfectly without blowing apart. Success!

The first flight was on a 1/2A3-2T, which is not a recommended motor but I couldn't think of any reason it wouldn't work. Indeed, it wasn't very high but a perfectly satisfactory flight, with nominal deployment and a good helicopter descent. On the second flight I tried an A10-3, which was fine except it recovered upside-down, which works but doesn't spin as fast. I don't know if the motor choice played a role in the descent orientation; I'll keep an eye on that in the future.

The only slight cautionary note is that the slide mechanism feels a little rougher than before. I'll have to keep an eye on that as well. The current model is not build to allow disassembly or any cleaning or maintenance of the slide. I've thought about that a bit but haven't come up with any ideas I really like yet.

Overall I'm very happy with this mod. It works, and made flight prep a 5-second affair: fold the rotors, slide into place, load motor and go.

Here's a lousy video of the second flight. Tracking with a smartphone is pretty difficult and I'm very much out of practice; somehow, amazingly, I kept the rocket in frame the whole time, although I had no idea at the time.
View attachment 479777

Success! Such a great feeling when a concept works. Congrats!

 

[Aeronerd]

My modded Mini A Heli flew twice yesterday, and deployed perfectly without blowing apart. Success!

The first flight was on a 1/2A3-2T, which is not a recommended motor but I couldn't think of any reason it wouldn't work. Indeed, it wasn't very high but a perfectly satisfactory flight, with nominal deployment and a good helicopter descent. On the second flight I tried an A10-3, which was fine except it recovered upside-down, which works but doesn't spin as fast. I don't know if the motor choice played a role in the descent orientation; I'll keep an eye on that in the future.

The only slight cautionary note is that the slide mechanism feels a little rougher than before. I'll have to keep an eye on that as well. The current model is not build to allow disassembly or any cleaning or maintenance of the slide. I've thought about that a bit but haven't come up with any ideas I really like yet.

Overall I'm very happy with this mod. It works, and made flight prep a 5-second affair: fold the rotors, slide into place, load motor and go.

Success! Such a great feeling when a concept works. Congrats!

 

[Aeronerd]

My modded Mini A Heli flew twice yesterday, and deployed perfectly without blowing apart. Success!

The first flight was on a 1/2A3-2T, which is not a recommended motor but I couldn't think of any reason it wouldn't work. Indeed, it wasn't very high but a perfectly satisfactory flight, with nominal deployment and a good helicopter descent. On the second flight I tried an A10-3, which was fine except it recovered upside-down, which works but doesn't spin as fast. I don't know if the motor choice played a role in the descent orientation; I'll keep an eye on that in the future.

The only slight cautionary note is that the slide mechanism feels a little rougher than before. I'll have to keep an eye on that as well. The current model is not build to allow disassembly or any cleaning or maintenance of the slide. I've thought about that a bit but haven't come up with any ideas I really like yet.

Overall I'm very happy with this mod. It works, and made flight prep a 5-second affair: fold the rotors, slide into place, load motor and go.

Success! Such a great feeling when a concept works. Congrats!

 

[neil_w]

Success! Such a great feeling when a concept works. Congrats!

Indeed. Also I've never flown a helicopter model before and I have to say watching the rotors unfold is pretty darn cool. I can see why @BABAR loves his heli and drag recovery models. Easy prep, fun to fly.

 

[neil_w]

Three more successful flights for this rocket today. First on a 1/2A3-2 (nominal), then an A3-4 (nominal, caught this one before it landed), then another A3-4 (came down upside down, but otherwise still good). The deployment mechanism worked perfectly each time. I did notice that the blades are a bit slow to unfold, although this has nothing to do with my mods, just the nature of the rubber band mechanism.

All in all a super fun rocket to fly, and a real crowd pleaser. When it comes down right-side-up, it really helicopters nicely. Highly recommended.

 

[Amsterdam]

All in all a super fun rocket to fly, and a real crowd pleaser. When it comes down right-side-up, it really helicopters nicely. Highly recommended.

Agreed!! Modified or stock this is one of my top five favorite estes kits.

 

[Alan R]

This is how I ended up modding mine. A little printed clip on the end, short kevlar attachment to main body. the piece of motor sticking out from main is just a coupler.

 

[neil_w]

This is how I ended up modding mine. A little printed clip on the end, short kevlar attachment to main body. the piece of motor sticking out from main is just a coupler.

That is a good and simple setup. It does seem to dirty up the blades at the separation point where the ejection charge first exits.

Have you had any flights descend upside down? Curious what happens to the fin unit flopping around in that case. Thus far I've had 2 out of 5 flights upside down.

 

[Alan R]

Have you had any flights descend upside down? Curious what happens to the fin unit flopping around in that case. Thus far I've had 2 out of 5 flights upside down.

no upside down flights. The first iteration of this, the attachment thread was about a foot long. Second flight it flopped over a wing and did a red baron, so I shortened it considerably. It's worked great every time I've flown it since - maybe 4-5x now.

 

[neil_w]

Interesting, I wonder if the flopping fin unit helps keep it right-side-up somehow?

Please keep us updated as you accumulate more flights.

 

[Alan R]

Interesting, I wonder if the flopping fin unit helps keep it right-side-up somehow?

Please keep us updated as you accumulate more flights.

Well... it makes CG way below the copter.

 

[Amsterdam]

no upside down flights. The first iteration of this, the attachment thread was about a foot long. Second flight it flopped over a wing and did a red baron, so I shortened it considerably. It's worked great every time I've flown it since - maybe 4-5x now.

Have you a “one piece” heli to compare decents?
my tethered models consistently drifted further on decent. i.e a lateral decline downwind
VS
The more straight down flight of solid models.

the models varied in size design and AOA of blades so it might all be moot

EDIT:
Based on what i saw i attributed the drifting to the turbulence from the swinging motor changing the AOA of the blades resulting in a more erratic decent

 

[Alan R]

my tethered models consistently drifted further on decent. i.e a lateral decline downwind
VS
The more straight down flight of solid models.

Don't know, don't remember the first flights which were one piece. But even lateral movement is pretty minimal

 

[Alan R]

Was working well. Then that third flight yesterday ...:

 

[neil_w]

Ouch. Was that an A10T?

I’ve been using the A3-4T, works well. I’m reluctant to fly the A10Ts I have in my stash.

 

[Alan R]

A3, but here's a nice pic someone took from a previous flight..

 

[Alan R]

I'm repairing after the cato and made me think maybe someone wants to play with this. I added the fins to the clip this time because fin gluing is annoying.
Here are the stl files in case anyone else wants to print. The 2 files are the clip with and sans fins. I'll cross-post to the 3d repository.