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View Full Version : Estes- New A Helicopter Model just Announced


JumpJet
01-04-2018, 10:41 AM
This was a fun model to design.


https://www.estesrockets.com/coming-soon/007272-mini-a-helitm




John Boren

BEC
01-04-2018, 01:00 PM
John, that is cool! Give Apogee some competition there. When will these be available?

astronwolf
01-04-2018, 01:03 PM
John, that is cool! Give Apogee some competition there. When will these be available?
March.

A Fish Named Wallyum
01-04-2018, 03:18 PM
This was a fun model to design.


https://www.estesrockets.com/coming-soon/007272-mini-a-helitm




John Boren
:eek: :cool: Definitely on my list. The dark art of helicopter recovery has always been shrouded in mystery for me. Then again, so has the dark art of hitting the bowl, yet I persist.

Gus
01-04-2018, 06:07 PM
John,

Very cool!

If you're allowed, could you post some pictures of the hub. Are the blades set at a fixed angle?

Also, why was this fun to design?

Steve

Scott_650
01-04-2018, 10:57 PM
It looks like the hinge/hub is made from laser cut fiberboard - you can the parts in the photo on Estes website. Along with what appears to be a jig for setting the blade angles and...a tube cutting guide? The yellow gizmo in the center of the parts collection photo looks like one...

JumpJet
01-05-2018, 12:12 AM
The blades are glued to the fiber hinge at a 90 degree angle. You set the blade pitch or what ever you wish to call it with a set of three jigs.


Attached is an image of the blade jigs in use and a close up of the hub.


Also, why was this fun to design?

Helicopter and Glide recovery models are my two favorite types of models.


John Boren

blackshire
01-05-2018, 12:33 AM
Thank you for coming out with this FAI-type heli-roc kit, John! This configuration is also popular in Europe (and in FAI-CIAM spacemodeling competition countries elsewhere in the world), and it might even become the "Renger Sky Slash of the heli-roc field," in its total impulse category.

Scott_650
01-05-2018, 07:06 AM
Does this use a burn string to retain the blades for launch? The diagram Mr. Boren posted appears to show some kind of sleeve that I assume would slide upwards when the recovery charge goes off which implies a catch of some kind to hold the rotors down. Either way I’m intrigued - should be a fun build and a fun flyer.

blackshire
01-05-2018, 07:33 AM
Does this use a burn string to retain the blades for launch? The diagram Mr. Boren posted appears to show some kind of sleeve that I assume would slide upwards when the recovery charge goes off which implies a catch of some kind to hold the rotors down. Either way I’m intrigued - should be a fun build and a fun flyer.That's a good question (that I hadn't thought of, and to which I don't have an anaswer), but... If the kit does utilize a burn string, maybe we can look forward to future Estes boost-glider (B/G) kits (similar to the original-design Renger Sky Slash, which had pop-up elevators) and/or rocket glider (RG) kits that use burn string-retained sliding wings or motor pods, and:

With today's laser-cut sheet balsa (and laser-cut basswood, fiber [beveridge board], and even thin modeling plywood sheet parts), and molded plastic "fulcrum" or interface parts such as rotor hubs, hinges, and motor pod lug/hooks, it is now possible to produce helicopter, B/G, and RG kits that are relatively easy to build and reliable to operate, compared with such kits of a generation ago. Back then, many of these parts had to be cut, shaped, and size-matched by the builder, which made the models tricky to build and more likely to fail in flight. One early (1973) step in the direction of today's kits was Centuri's Hummingbird boost-glider (see: http://www.ninfinger.org/rockets/nostalgia/73cen70e.html ), which had all-die-cut fiber wings and tail surfaces.

astronwolf
01-05-2018, 07:36 AM
Attached is an image of the blade jigs in use and a close up of the hub.


Do you really prep for flight by routing the rubber bands inside the hinge? That's a pinch point. I'd keep the bands out of the hinge mechanism. Putting the bands inside the hinge "ears" could lead to a no-deploy. I'd route the bands around the outside of the hinge "ears," not like what is shown in the diagram.

tbzep
01-05-2018, 07:57 AM
Do you really prep for flight by routing the rubber bands inside the hinge? That's a pinch point. I'd keep the bands out of the hinge mechanism. Putting the bands inside the hinge "ears" could lead to a no-deploy. I'd route the bands around the outside of the hinge "ears," not like what is shown in the diagram.
Looks like the bands go across a solid piece that holds the rotors at the correct deployment angle. If that's the case, they shouldn't get pinched.

I just went back and looked at the parts layout. I don't see anything like that, so I see your point.

JumpJet
01-05-2018, 11:04 AM
If you follow the directions and put the rubber bands where they are supposed to go you won't have a problem since there is nothing to pinch the rubber bands.



John Boren

mwtoelle
01-05-2018, 03:21 PM
Thank you for coming out with this FAI-type heli-roc kit, John! This configuration is also popular in Europe (and in FAI-CIAM spacemodeling competition countries elsewhere in the world), and it might even become the "Renger Sky Slash of the heli-roc field," in its total impulse category.
Definitely not a FAI compatible kit, for S9A the outer diameter of the rocket must be at least 40mm in diameter and 500mm long. Most FAI heli-rocs that I have seen are internal rotor designs with a sharp boattail on the tail end. As the Estes website says, it is legal for NAR competition.

chrism
01-05-2018, 04:37 PM
This will be a neat rocket. I really like giving the "mini-Brutes" some love!!!

neil_w
01-05-2018, 07:58 PM
This is absolutely on my "must buy" list. I am finding that I really appreciate rockets that don't need wadding or chute packing. Shove in an engine and launch!

That hub design looks extremely clean, I look forward to fiddling with it.

georgegassaway
01-05-2018, 10:06 PM
Thank you for coming out with this FAI-type heli-roc kit, John! This configuration is also popular in Europe
(and in FAI-CIAM spacemodeling competition countries elsewhere in the world), and it might even become the
"Renger Sky Slash of the heli-roc field," in its total impulse category.
FAI requires the duration model body tube to be at least 40mm OD, which is why nearly all FAI S9 Copters use internal blades.

The most popular and pretty much definitive classic deployable external rotor copter is the Rotaroc series dating back to August 1975.

http://www.psc473.org/naram51/contest/Pics2/rotaroc.gif

The basic design has been copied and cloned by many.

http://georgesrockets.com/GRP/CONTEST/Plans-C/Copter/CopterPlan/IMG_5366.JPG

PDF file of plans: http://georgesrockets.com/GRP/CONTEST/Plans-C/Copter/CopterPlan/Rotaroc_A.pdf

Web page instructions on how to build a limited “kit” I made up for club members one year:

http://georgesrockets.com/GRP/CONTEST/Plans-C/Copter/CopterPlan/Rotaroc-A.html

https://i.imgur.com/nIuR2YU.jpg

https://i.imgur.com/zjVw9sB.jpg

https://i.imgur.com/s0IC9iV.jpg


That said, I’m really glad to see this kit, and will get a couple to check out.

Here’s a video of some model testing last June. Second flight is a D Rotaroc rigged not to rotate much so as not to risk losing it
(was a boost structural test and deployment test flight).
Third flight was an E9 powered test of a G Rotaroc (3 x 36” blades, BT-55), which was flown at NARAM on G12 power (and won Team Div).

https://youtu.be/Bf3yjJKRBb8

Gus
01-06-2018, 12:54 AM
John, George,

Am I correct in thinking that this is the first balsa-blade helicopter that Estes has ever offered?

There was the plastic bladed SkyWinder and the numerous helicopter nose-cone kits, but I don't recall any balsa blade designs. Gyroc had balsa wings but was a pseudo-helicopter.


Steve

Jerry Irvine
01-06-2018, 07:06 AM
Helicopter and Glide recovery models are my two favorite types of models.
We had to use outsized fins to make ours fly right back in the day.

http://v-serv.com/usr/kits/helioroc.htm

I like gliders too, but ones not power limited. :D

http://v-serv.com/usr/kits/fdart.htm

Just Jerry

Looking forward to buying dozens of Patriots.

JumpJet
01-06-2018, 10:37 AM
I believe this is the first Estes kit with Balsa blades but I'm not positive.



John Boren

Jerry Irvine
01-06-2018, 10:51 AM
I believe this is the first Estes kit with Balsa blades but I'm not positive.
John BorenAgreed but laser cutting has made a bunch of stuff possible for the E business model only plastic could do in the past. Time for a balsa glider for 29mm motors!

JumpJet
01-07-2018, 03:03 PM
I found a couple of images of the real model that might help in seeing what the hinge portion looks like.


John Boren

astronwolf
01-07-2018, 05:27 PM
I found a couple of images of the real model that might help in seeing what the hinge portion looks like.
See that elastic in the second pic all skwunched up inside the ears of the hinge? That's a potential cause of a no-deploy.

jetlag
01-07-2018, 05:50 PM
See that elastic in the second pic all skwunched up inside the ears of the hinge? That's a potential cause of a no-deploy.

It looks like it will work fine to me....

JumpJet
01-07-2018, 06:04 PM
You mean those rubber bands resting peacefully in the groove waiting for the thread to burn through so they can EASILY deploy the blades. Yes, I see that.

Anyone who decides to purchase and build on of these please simply follow the directions. I've never NOT had a blade deploy. The design gives the rubber bands a ton of leverage to deploy the blades. I used this same hinge mechanism on the F Helicopter model I flew at NSL last year.



John Boren

Jerry Irvine
01-07-2018, 06:42 PM
I agree with John. Oh, no!

neil_w
01-07-2018, 06:52 PM
You mean those rubber bands resting peacefully in the groove waiting for the thread to burn through so they can EASILY deploy the blades. Yes, I see that.


Ah, thread burn-through. Well that answers another question. I'm curious to see where and how the thread is tied in. Just above the motor mount?

JumpJet
01-07-2018, 08:35 PM
No the thread is much higher up to keep the blades from bowing out. I've also found that the thread burns through much more reliably when higher up. I don't know why it works better but it does for me.


John Boren

ghrocketman
01-08-2018, 12:37 AM
John-
Thanks for actually finding the "optimal" burn string position by actual experimentation/field-testing instead of relying on THEORY (just assuming) placing it lower "has" to be better.
I'm an engineer, and those in my field often get caught up with determining "why" something works rather than insuring/testing it DOES WORK.

BEC
01-08-2018, 01:16 AM
Indeed. I've heard it said that "one good test is worth a thousand expert opinions". I got that one from Tom Hunt - a test engineer at Grumman who was very active in the world of RC airplanes, electric power in particular, for many years.

blackshire
01-08-2018, 01:27 AM
Definitely not a FAI compatible kit, for S9A the outer diameter of the rocket must be at least 40mm in diameter and 500mm long. Most FAI heli-rocs that I have seen are internal rotor designs with a sharp boattail on the tail end. As the Estes website says, it is legal for NAR competition.I said it was an FAI-type kit, not an FAI rules-compatible kit--"FAI-style" would have been a clearer descriptor.

JumpJet
01-08-2018, 09:33 AM
"optimal" burn string position"


I'm not sure it's optimal but I used to put the string maybe a half inch in front of the motor like I've seen everyone else do. I've Crashed SO MANY HD models because of the string not burning through that I started to move it further up which has the added benefit of holding the blade in, since the rubber bands always bowed them out. I don't believe I've ever had a string not burn through since moving it up. I'm sure one day it's going to not burn through my percentage of success is still going to be much higher then it ever was before.



John Boren

Jerry Irvine
01-08-2018, 10:53 AM
It looks like you found a way to increase A10-3T sales. :D

I'm not sure it's optimal butIf it works reliably it is optimal.

astronwolf
01-08-2018, 11:03 AM
I said it was an FAI-type kit, not an FAI rules-compatible kit--"FAI-style" would have been a clearer descriptor.
We still love you Blackshire.... but, eh, this kit is not even close to FAI-style either.

Jerry Irvine
01-08-2018, 05:56 PM
On the other hand nobody has posted an FAI style version.

blackshire
01-10-2018, 03:53 AM
We still love you Blackshire.... but, eh, this kit is not even close to FAI-style either.The term "Formula One race car" brings quite different images to mind (see the historical lineup picture here: http://en.wikipedia.org/wiki/History_of_Formula_One ) depending on one's age, especially if one doesn't follow the sport closely, but they're all Formula One race cars. The same is true of FAI heli-roc models (and other non-scale types of FAI space models [such as streamer duration rockets], whose typical appearances have changed over the years). I don't follow FAI heli-roc competition closely, and the pictures I've seen of such models (which date back to the 1990s, in Stuart Lodge's books) showed models that looked like the new Estes kit.

mwtoelle
01-10-2018, 06:36 PM
Apogee has a FAI legal HD (S9A) model. You can find it here: https://www.apogeerockets.com/Rocket-Kits/Skill-Level-4-Model-Rocket-Kits/Rotary-Revolution?cPath=1_307&zenid=lcp9s9uh43dr2el4a0al1pgl77

georgegassaway
01-10-2018, 10:48 PM
The term "Formula One race car" brings quite different images to mind (see the historical lineup picture here: http://en.wikipedia.org/wiki/History_of_Formula_One ) depending on one's age, especially if one doesn't follow the sport closely, but they're all Formula One race cars. The same is true of FAI heli-roc models (and other non-scale types of FAI space models [such as streamer duration rockets], whose typical appearances have changed over the years). I don't follow FAI heli-roc competition closely, and the pictures I've seen of such models (which date back to the 1990s, in Stuart Lodge's books) showed models that looked like the new Estes kit.

You must be thinking of something else. The FAI S9A event originally required a minimum diameter body of 30mm, which later became 40mm. The only competitive design approach when forced to use a 30mm or larger tube, is to go with internal rotor blades.

Now, I do recall some article by Stu Lodge, about copters, which included an external bladed model, but it was forced to use a 30mm (or 40mm) main body, so it was huge, draggy, heavy,and not competitive for FAI. Now, he may also have shown some non-FAI copters, which naturally would indeed look like Rotaroc designs - with skinny body tubes (main tube diameter = engine mount diameter).

Now, there my have been one "FAI" external blade design he had a photo of years back, where the blade airfoils were something like 120 degree arcs, and when folded, it created a 40mm diameter tube, sort of. However, that design would have been easily protested as the FAI body is supposed to be continuous, no air gaps. If I am recalling it correctly, then most likely nobody else protested it since it didn't perform well enough to be a contender (strategically allow a competitor to keep using a dead-end design rather than protest it and force them to design something better that might win). I sure never saw one like that actually entered in a WSMC, most likely it was flown at the British version of "NARAM”, or local contest.

You've gotten the impression either from the image of a poor design that did not perform very well, or images of non-FAI Copters (NAR contest type copters) and think that's what the standard FAI copters have been like.

I already posted pictures and plans of what Rotarocs (dating back to 1975) look like, which is the basic design of what this new kit looks like.

As for FAI Copters (S9A Gyrocopter), they look more like this (at launch):

https://i.imgur.com/6n61Tce.jpg

Note that the main 40mm body of this particular one is Kapton, a brown-orangish transparent tube, so the folded balsa blades are seen inside. Below that is a fiberglass tailcone/engine mount assembly. Usually the bodies are all-fiberglass, built very lightly.

And they look like this after deployment (model on the right.....)

https://i.imgur.com/twkWj7r.jpg

blackshire
01-12-2018, 02:50 AM
Thank you, Mike and George. No one, I suppose, is attracted by all facets of any hobby (the great variety of aeromodels, from indoor microfilm "slow flyers" to turbojet-powered scale models, and everything in between, demonstrates that), and while heli-rocs aren't my thing, I can appreciate the difficulties and design trade-offs that are involved in getting them to operate reliably and at the highest possible levels of performance.

Gus
01-15-2018, 12:28 PM
FAI requires the duration model body tube to be at least 40mm OD, which is why nearly all FAI S9 Copters use internal blades.

The most popular and pretty much definitive classic deployable external rotor copter is the Rotaroc series dating back to August 1975.

http://www.psc473.org/naram51/contest/Pics2/rotaroc.gif

The basic design has been copied and cloned by many.

https://youtu.be/Bf3yjJKRBb8

George,

If I am not mistaken the original Rotaroc design came from you, is that correct? I think NCR did a version of it years ago and Fliskits currently has a version. Would you mind giving us a bit of history of how it came to be, modifications, etc. I'm also not sure where Art Rose's version came in.

What I do remember is that the first competition helicopters Emma and I ever built (terribly) were your designs and we flew them (terribly) at our first team tryouts 10 years ago. Our flights were so bad that you came over, unasked, and helped us tweak them to at least get qualified flights. We have never forgotten that kindness. :)

Steve

astronwolf
01-15-2018, 01:18 PM
There's a lot of Helicopter stuff that George and Trip put on the NAR website. It's a "best of" what digital resources are available. I hope George takes the time to add more in this thread.
https://www.nar.org/contest-flying/competition-guide/duration-events/helicopter-duration/

The story of Art Rose and the Rose-a-Roc is also there in Craig Beyer's article:
https://www.nar.org/wp-content/uploads/2014/05/Rose-a-Roc-B-C-HD-Rose.pdf

BEC
03-24-2018, 02:14 PM
This new helicopter model is now showing up in stock at Estes.....

astronwolf
03-24-2018, 06:06 PM
This new helicopter model is now showing up in stock at Estes.....
...and at AC Supply.

chrism
03-24-2018, 06:23 PM
Let us know if anyone sees them at Hobby Lobby.

Scott_650
03-24-2018, 06:59 PM
Still not in stock at AC Supply - status is “Due End Mar”.

BEC
03-24-2018, 10:31 PM
Yup - not yet at AC Supply or Hobbylinc. I have an email notification set up for Hobbylinc.

Kartman
04-17-2018, 04:38 PM
Yup - not yet at AC Supply or Hobbylinc. I have an email notification set up for Hobbylinc.

I received mine yesterday from Hobbylinc. I think I will start building it after I send this out ;)

Tom

BEC
04-17-2018, 05:50 PM
I have three of them (along with some other stuff) in transit from AC Supply. So - soon.

Kartman
04-23-2018, 01:02 PM
I completed my Mini A Heli two days ago. The kit is all of Level 3 IMHO. Trying to not cut all the way through the rotors is a challenge. I was successful on two of the rotor blades :)
You can only do so much with a multi-language pictorial instructions. You will need to study them carefully. Kinda reminds me of the Quinstar ;)
I attached two additional photos showing some issues with the rotor laser cut balsa sheet. The photo near the hub shows an extra "bump out" that needs to be removed. More serious is the photo of the rotor tips showing two of the laser etched marking lines are wrong. Copy the rotor marking line on the rightmost rotor.
I'm flying this May 5 weather permitting. Hopefully all the snow will be gone by then :rolleyes:
I'll let you know how it flies.

Tom

JumpJet
04-23-2018, 02:46 PM
As we discussed you laser cut balsa sheet was cut incorrectly. It appears the sheet of wood moved during the cutting process. I'm happy to see you were able to work around this issue.


John Boren

BEC
04-23-2018, 04:38 PM
My AC Supply order came Saturday and I am well along in building one of these. My rotor blade sheet doesn't have that issue. It is warped in a way that would give the blades some dihedral but the shaping process should straighten them right out.

I'm looking forward to flying this. It seems the key to getting a score in a helicopter recovery event is getting a reliable blade deployment. This design looks like that is one of the main objectives, so I'm looking forward to getting some good practice with this model.

hcmbanjo
04-23-2018, 07:01 PM
I completed my Mini A Heli two days ago. The kit is all of Level 3 IMHO. Trying to not cut all the way through the rotors is a challenge. I was successful on two of the rotor blades :)
You can only do so much with a multi-language pictorial instructions. You will need to study them carefully. Kinda reminds me of the Quinstar ;)
I attached two additional photos showing some issues with the rotor laser cut balsa sheet. The photo near the hub shows an extra "bump out" that needs to be removed. More serious is the photo of the rotor tips showing two of the laser etched marking lines are wrong. Copy the rotor marking line on the rightmost rotor.

Tom

I just finished a build of the Mini Heli A. Mine didn't have and rotor blade laser cut issues. No "bump out", my laser etched lines were correct.

A very interesting build, it'll be featured on my blog after the Mini Little Joe II is finished.

tlainhart
05-04-2018, 03:35 PM
I loved building this kit - the instructions were great.

Look forward to flying it.

BEC
05-23-2018, 12:55 PM
This past weekend I put five flights on my Mini A Heli - which were my very first-ever helicopter recovery flights (not counting the Gyroc). It works just wonderfully!

The first flight (on the recommended A10-3T) boosted with only a little roll, deployed the blades at the top and proceeded to spin up, coming down very slowly so that it wound up almost at the edge of the field some 600 feet from the launch point. Several long-time rocketeers remarked on how well it worked and are now contemplating getting this kit for themselves.

The next day, after the Cub Scouts were all gone, I put up four more flights, two on A10s and two on A3-4Ts and this time I timed them as well. I got over a minute in dead air on two of the flights (one on each motor type), one 20-odd second flight which recovered safely even though I forgot to attach the rubber bands to the blades before launching it :eek and one in the mid 30s where it turned nose down as it deployed and came down that way.

My model was built entirely stock - no modifications or tweaks at all - and per directions. There are a couple of tweaks I want to try for models for NARAM but one thing I will not change is the mechanical arrangement, which works every time as designed. My competition philosophy has always been "getting a good score every flight is better than getting a great score once in awhile" and this model is right in line with that.

Thanks to JumpJet for a great design and to Estes for a good execution of the design and for making it available at a nice price.