Helicopters C

[retired1]

It might shock you the number of teams that show up for a competition that have not taken advantage of the bonuses when offered.

[ScottMaurer19]

It might shock you the number of teams that show up for a competition that have not taken advantage of the bonuses when offered.

Out of all the bonuses the only one that teams could undersandably miss is the chinook bonus. Every team should be able to take advantage of both the colored rotor and the preflight bonus with ease.

[Unome]

It might shock you the number of teams that show up for a competition that have not taken advantage of the bonuses when offered.

Out of all the bonuses the only one that teams could undersandably miss is the chinook bonus. Every team should be able to take advantage of both the colored rotor and the preflight bonus with ease.

As I'm sure you're aware, easy != most people doing it - Robo Cross 2015 illustrates this point quite well, with 180 points being a medal-worthy score at regional tournaments in Georgia.

[ScottMaurer19]

It might shock you the number of teams that show up for a competition that have not taken advantage of the bonuses when offered.

Out of all the bonuses the only one that teams could undersandably miss is the chinook bonus. Every team should be able to take advantage of both the colored rotor and the preflight bonus with ease.

As I'm sure you're aware, easy != most people doing it - Robo Cross 2015 illustrates this point quite well, with 180 points being a medal-worthy score at regional tournaments in Georgia.

As I said, two of the bonues are easy and SHOULD be utilized by every team. I do agree that many teams will not use them.

[Ten086]

Hey, so I've been looking through past years' forums and am just very confused in general. I did the event last year but was Not Great because I was just trying to get my helicopter to actually go up, so I'm trying to figure a few things out this year. I just want to say these are really dumb, basic questions because I don't know like anything about physics.

First of all, for the chinook design, a lot of people were talking about transmission systems for horizontal motors. Is using some kind of gear system very common? How do you even connect a rubber band to a gear like that..? And wouldn't that be quite heavy? Sorry, I feel really stupid because I've never really done anything with gears before and can't visualize how that would work. Does simply using thin tubes either curved or bent at a 90 degree angle also work?

Also, after struggling a lot last year with testing rubber bands, I figured I should probably actually like learn about torque...where can you get a torque meter and how do you use one with a rubber band? Again, sorry to anyone who's probably cringing at how dumb I am. I read posts, especially Jeff Anderson's, about how to use a torque meter to compare data and such but I don't even know how to use a torque meter period.....

For lubricating rubber bands, is armor-all considered the best lubricant? I remember something about using hand lotion, wouldn't that be bad for rubber bands?

Is the Freedom Flight kit really doing a chinook design this year? I'm kind of sad because our school's team just like didn't get funding this year because the money isn't for "classroom purposes" so we're frantically trying to raise money for builds, and I feel like it's not possible to be competitive in helicopters without the kit.

Sorry for such a long post.

[JasperKota]

...Also, after struggling a lot last year with testing rubber bands, I figured I should probably actually like learn about torque...where can you get a torque meter and how do you use one with a rubber band? Again, sorry to anyone who's probably cringing at how dumb I am. I read posts, especially Jeff Anderson's, about how to use a torque meter to compare data and such but I don't even know how to use a torque meter period.....

For lubricating rubber bands, is armor-all considered the best lubricant? I remember something about using hand lotion, wouldn't that be bad for rubber bands?

Is the Freedom Flight kit really doing a chinook design this year? I'm kind of sad because our school's team just like didn't get funding this year because the money isn't for "classroom purposes" so we're frantically trying to raise money for builds, and I feel like it's not possible to be competitive in helicopters without the kit.

Sorry for such a long post.

Armor-all is considered to be a standard lubricant that many people use. I found it to be good, and I've heard that silicon-based lubricants work very well (have never heard anything about hand lotion though). As for a torque meter, I know freedom flight models and laser cut planes sell one, but if budget is a problem you can also make your own from here: http://www.indoorspecialties.com/articl ... 0Meter.pdf Using a torque meter isn't that hard, but a bit difficult to explain in text - here's a video showing using one: https://www.youtube.com/watch?v=_MoozVXuuYY&t=32s As you wind the rubber clockwise, torque increases which is shown by the ticker turning clockwise.

Kits are a good starting point but don't let that discourage you. I'm pretty sure one of the national medalists last year didn't use a kit, and you can definitely be very successful with or without the kit or chinook bonus. Also, it seems like everyone on scioly.org knows what they're talking about, but there's plenty of people who don't (including myself) so don't be afraid to ask questions.

[coachchuckaahs]

Ten086:

While the kits are great starting points, you can quite easily build without a kit. It means you have to do some design work, and some more trial and error, but it is so much more rewarding.

Our team must develop contest birds without kits, because our Regionals are in January, and so the availability timing of the kits makes it hard to get a lot of flying. We started building and testing before the rules came out, using last year's rules as a starting point. Obviously we had to change, but that allowed us to get techniques started.

For simplicity, start with a simple x-style rotor with 0.020 carbon rods for LE and TE. Set up for 6-8" pitch for your first build. Make a foamboard or balsa fixture to set pitch and build the rotors. Play with chord, pitch. Weigh sheets of wood at local hobby shop, you will find tremendous variation in weight.

If you build two rotors (you have to), it is not much different to make a Chinook style. Use two vertical rubber motors. If mounted horizontal, then you have the transmission issue, and you still need two pieces of rubber for counter-rotating. Keep it as simple as possible. If you go Chinook, you will need some vanes for stability.

I would start simple with a traditional axial two-rotor system, and then adapt the same rotors to Chinook once proficient at flying the axial.

Like said by others, not all info on forums is good. Maybe mine is helpful, maybe it is rubbish. But don't be afraid to build without the kits.

Chuck
AAHS

[andrew lorino]

Hey, so I've been looking through past years' forums and am just very confused in general. I did the event last year but was Not Great because I was just trying to get my helicopter to actually go up, so I'm trying to figure a few things out this year. I just want to say these are really dumb, basic questions because I don't know like anything about physics.

First of all, for the chinook design, a lot of people were talking about transmission systems for horizontal motors. Is using some kind of gear system very common? How do you even connect a rubber band to a gear like that..? And wouldn't that be quite heavy? Sorry, I feel really stupid because I've never really done anything with gears before and can't visualize how that would work. Does simply using thin tubes either curved or bent at a 90 degree angle also work?

Also, after struggling a lot last year with testing rubber bands, I figured I should probably actually like learn about torque...where can you get a torque meter and how do you use one with a rubber band? Again, sorry to anyone who's probably cringing at how dumb I am. I read posts, especially Jeff Anderson's, about how to use a torque meter to compare data and such but I don't even know how to use a torque meter period.....

For lubricating rubber bands, is armor-all considered the best lubricant? I remember something about using hand lotion, wouldn't that be bad for rubber bands?

Is the Freedom Flight kit really doing a chinook design this year? I'm kind of sad because our school's team just like didn't get funding this year because the money isn't for "classroom purposes" so we're frantically trying to raise money for builds, and I feel like it's not possible to be competitive in helicopters without the kit.

Sorry for such a long post.

Don't worry, everyone is a novice at some point. Based on your level of experience, I would stick to a conventional helicopter for now. You'll learn more about what works and doesn't work that way, without the added variables of weight and torque balancing. Of course, this won't be competitive at anything but regionals, but you could build another helicopter when you get past that stage. Don't worry about gearing or any Chinook related problems until you have solved your normal helicopter problems. On torque, I would ignore it for now. It's really useful for finding the right thickness of rubber to use, to optimize performance, but it won't help you go from not flying to flying. If your helicopter has blades remotely similar to the FFM kit, use about .085 to .1 inch thick rubber, and get a good idea of how many winds it can take by testing. More winds is always better than less winds, all other factors constant. You also mentioned not having the funds for the FFM kit. I would strongly suggest trying to get enough money to buy it, if at all possible over building your own. The FFM instructions and materials are excellent, and personally made the difference for me. But if you can't afford the kit, here's a couple of things I learned in my first year of Helicopters:
Weight is everything. Use thin, light balsa if possible. Hot glue is a big no-no, use loctite gel superglue. Mylar is the best covering for blades, bar none. Make sure your blade covering is tight. Effective thrust bearings are extremely important. The nose button kits FFM sells are excellent for this. And good rubber is critical. FAI model supply is the best place to get it. Do not use office rubber bands.
Best of luck!

[jander14indoor]

Let me reinforce the others points.
If you aren't flying 1-2 minutes with a conventional design, don't even worry about the chinook bonus. Master basic construction techniques, winding and flying skills FIRST.
You MUST build to very near minimum weight and maximum size to get good flight times. A little off will fly, but the times drop FAST with excess weight or undersize rotors.
Minimum weight is CRITICAL.
Weight is important.
Yes, I'm repeating myself, it is that important.
Rubber, yep. FAI Tan Sport or Super Sport is the way to go.
Others have pointed to torque meters, once you've got one and tried to use it, you'll probably have more specific questions. Bring them back we're happy to answer. But is hard to be anything but generic with generic questions.

If you want a design that's proven and free, look for the River City Rocket, good design from a couple of years back and scale up or down as appropriate to this years rules. It'll fly well enough to win many regionals if you do your part.

Jeff Anderson
Livonia, MI

[DrDaveV]

Ten086:


For simplicity, start with a simple x-style rotor with 0.020 carbon rods for LE and TE. Set up for 6-8" pitch for your first build. Make a foamboard or balsa fixture to set pitch and build the rotors. Play with chord, pitch. Weigh sheets of wood at local hobby shop, you will find tremendous variation in weight.

If you build two rotors (you have to), it is not much different to make a Chinook style. Use two vertical rubber motors. If mounted horizontal, then you have the transmission issue, and you still need two pieces of rubber for counter-rotating. Keep it as simple as possible. If you go Chinook, you will need some vanes for stability.

I would start simple with a traditional axial two-rotor system, and then adapt the same rotors to Chinook once proficient at flying the axial.

Chuck
AAHS

I am a new coach with a lot of experience in other areas but little knoweledge of helicopters or planes.

I get a lot of the abrieviations like trailing edge and leading edge but really don't understand how all these things fit together.

6-8" pitch ??
Chord, I know what it is mathematically but what does that mean in terms of rotors?
What do people use for blade material?
Do you all use the same material rubber for the motors?

Where do you get your materials?

I know there is a lot of information here on Scioly and youtube but are ther any boks or websites with basic plans, designs, sketches, ...

Thanks in advance,
David