Tempest FAI Headsetup

[heliman123]

I flew a Tempest FAI last year and have converted over to the stratus frameset.

My question is about the head setup.

On my tempest I used the setup on the MA site and the only item I experimented with was the delta. I think right now I more than the -5.3 degrees as I using the spacer and a 0109 ball.

So now the head is on the stratus which is lighter and they changed the FAI manuevers so I need a stiffer setup I think.

I only know what I have learned about the FAI (clueless) as it is my first MA heli.

What would be a good starting place on the headsetup to get me close with the status?

[DavidH]

Swapping the head from Tempest to Stratus, really don't think you would have to change the setup.

Yes the F3C maneuevers have changed for 2006. From my experience just a little more negative pitch is needed and the cyclic speed can be increased some.
For increasing speed on the cyclics, maybe just lighten the paddles some more. You might also run four 60 durometer dampeners in the head.

My Tempest FAI rotor head set up
60 durometer dampeners (1) .25mm shim on each side.
Flybar paddles Pro III weighing 45 grams flybar arm in middle hole.
Bell/Hiller ratio 1 to .90
-3.3 mm delta offset
700 mm TG blades 195 grams.
David

[heliman123]

Thanks David

I'll get a set of the 60 durometer dampeners and take my flybar weights off to get started.

I got the heli converted to a Stratus just haven't had a chance to fly the heli.

I am using the Funtec FAI paddles, flybar weights, four 50 durometer dampeners, 0.90 BH ratio, Rotortech 720mm blades and more delta offset than your using.

[DavidH]

I have used the Carbon Tech 720mm. They are same as Rotor Tech, Century just puts the Rotor Tech name on them. FunKey name is Carbon Tech.
They work really well also.

The FunTech paddles are also very nice. I am probably going to run a set of the 30 gram Fun Tech's this year. Just got to get with OMI and get some of them from James.

David

[heliman123]

Well I have the 45g paddles right now and the heli was very stable.

I'll have to give James a call also and get a set of the 30g paddles to try :D

[GM1]

I am running the .9:1 flybar ratio, Funtech 45gr paddles on the long MA flybar, RotorTech 720s at 200 grams on a stratus with YS 91 with 7.91 gear ratio. I have a set of Radix 710s at 185gr for testing but have not flown them yet.
Gordie

[heliman123]

Something I've always wondered about is how you all are getting blades that weigh a certain amount.

When I order blades they don't give me a chance to pick the weight :?: .

From what I remember my Rotortech 720 weigh 195g....


Thanks

[DavidH]

You can get blade weight as desired in two ways.

1st- You can add weight to the blade by slotting the blade and adding as much weight as wanted. Where you want it or need it. There is several F3C pilots that do this to some blades. They will add as much as 30 grams to some blades. It can be done safely. I have drilled holes and added as much as 10 grams to blades without problems.

2nd- You can request the weight of the blades when you purchase them. Most blade manufactuers mark the weight of the blades on the package. So it is not difficult for a dealer to look at a package and see what the blades weigh. Just request a specific weight range, like 190-200 grams for example. I have also done that without a problem.

David

[Dr.Ben]

RE getting the blade weight you want, one thing you can do is pick a smaller dealer that will talk to you on the phone, like Ron Lund. If you ask nicely, you can generally get them to weigh out at least a few sets of blades and pick the set(s) that weight the closest to your desired weight. The other neat way to do it is to order several sets with a friend, then group the sets into subsets that weigh the closest to each other for your two models. I've never had a issue with a set of blades that weight 2-5 grams less than another set WRT how the model flies, but it does make a difference when one model has 190 g blades and the other has 195's. It's tough to make those models fly exactly the same.

Ben Minor

[Dr.Ben]

My head set up is a bit different. I've taken a set of Tempest 3D arms and have them on the head. I then take a second set of those arms and PRECISION drill the tip so I can screw a 10.5 mm ball into it. After the drilling, the tip of the arm is cut off just outboard of the holes where the bell mixers mount in the stock 3D head. That little piece is then screwed to the outside of the existing 3D arm mounted on the head. Doing this mod moves the ball a bit closer to the centerline of the head. This increases the feedback/flybar ratio to at or just over 1:1 when the balls in the bell mixers are at the 90% position. The increased flybar ratio makes the model hover better in the wind. The other benefit of the mod is that I now get several extra degrees of collective range and at least one full extra degree of cyclic. When you add the 10.5mm ball to the tip of the arm, the overall delta approaches 14mm. This makes the model hover EXTREMELY well in the wind. I use 60/50 D orings (inboard/outboard) and the 0.25mm shim. Hover rpm is 1490 rpm. There are no issues with mast bumping unless the head slows down to about 1000 rpm at the tail end of an auto. It's not bad at all, and well worth performance gain. Blades are 720mm RT's at 195g. I flew this mod all last season. It's SAFE, rigid, and will blow your mind how well the model works in the wind. The geometries of the ball links are all good at extremes of travel, too. My thanks to Wayne Mann for teaching me how all of the delta and feedback ratio stuff works.

If I were using the stock pitch arms, I would probably use the .85 mix ratio and my same 40 g paddles. Schedule A and B isn't horribly demanding of roll rate, especially since they bagged that nasty full roll after the inverted piro (easy for a 3D model but not for a model that will sit still in the wind) but Schedule C with its full roll on the inside/outside eight takes plenty of it. I've flown Cliff Hiatt's model set up with this mix ratio, and it still sat well in the wind. The cool thing also is that if I drop back the the .85 holes on my head with the modified pitch arms, I'll still have more like .90 PLUS the added roll rate. Kinda having your cake and eating it too.

Ben Minor

[Zilly]

My head set up is a bit different. I've taken a set of Tempest 3D arms and have them on the head. I then take a second set of those arms and PRECISION drill the tip so I can screw a 10.5 mm ball into it. After the drilling, the tip of the arm is cut off just outboard of the holes where the bell mixers mount in the stock 3D head. That little piece is then screwed to the outside of the existing 3D arm mounted on the head. Doing this mod moves the ball a bit closer to the centerline of the head.

Ben,

Any chance you can post some pics of this set up?

z

[Dr.Ben]

We need to take up a "Buy Ben a digital camera" fund :D .

I'll get a friend of mine to shoot a few pics this week.

Ben

[heliman123]

yes Dr Ben we need to get you a digital camera, I would like to see your setup also.

Between Dr Ben, GM1 and DavidH you all have allot of experience with the FAI head and I would like to know as much as I can learn.

The delta of the head has me baffled. I think I read somewhere about positive delta for FFF and negative delta for hovering.
So on the FAI head I started with -3.3 degrees of delta and ended up using more negative delta to make the link geometry straight and never tried any of the positive delta setting. I could tell the more negative delta I used the better the heli would hover in the wind but I really picked the ball length to make the link geometry straight :oops:

Also when they say the head has -3.3 degrees of delta, which reference line are they using for the delta measurement?

[DavidH]

Also when they say the head has -3.3 degrees of delta, which reference line are they using for the delta measurement?


Using the center of the head block as the reference to measure the amount of delta. You see the screw that holds the head block to the yoke? That is if you have the two piece head block and yoke.

Using the center of that allen bolt. The delta mount is determined by how far the center of the ball on the pitch arm is one way or the the other from the center of the head( allen bolt).

For example if the center of the pivot ball on the pitch arm is offset from the center of the head towards the opposite grip. Then that is negative delta on a leading edge pitch arm arrangement. On a leading edge pitch arm, and the center of the ball is offset towards to the grip the arm is mounted then that is positive delta.

On the FAI head, pitch arm leading on grip. No spacer on arm and short ball, that is 0 deg of delta if I remember correctly. Ball on pitch arm will be centered with center line of head.
Pitch arm with spacer, and 107 ball I believe which is 4.5 mm length I believe. That gives 3.3 mm of negative delta.

I hope I have explained it where it is understandable. Maybe Ben or Gordie can explain it better.

David

[Gary O]

It sounds like each pilot is going to have to experiment to find what settings are going to work best for their flying style and if they are looking for more stability in hovering for windy conditions, or a more aggressive set up for the aeros. I'm not schooled on FAI yet and that's what I'm really working on right now so understanding all the stuff on Delta settings is good to know. I guess it could also be one of those things you could use come contest day depending on what type of flying conditions you will be flying in.

[DavidH]

I guess it could also be one of those things you could use come contest day depending on what type of flying conditions you will be flying in.

Not really. From my experience, once a contest pilot has found a delta setting that works . The pilot will most likely not make any delta changes once they get to the contest. The reason would be they have already been practicing with a setup and they are in tune with its reactions. So a delta change would throw the timing of the pilots reactions off some.
At contest, it can be dead calm one minute and the wind blowing 10-15 mph or more from any direction the next. That is pretty much normal at every contest I have been too. There is usually very little time it is dead calm, unless it is in the early morning or late evening.

David

[Dr.Ben]

David is right. We'd never alter the delta at or near contest. It can be pretty critical getting the set up just right to avoid any mast bumping when the delta is run as high as possible. Backing off a little wouldn't hurt, but adding more could be a serious no-no. About the most we'd fiddle around with at an event are the damper shims, MAYBE the damper durometer if the weather really changed, flybar weight position, and possibly the tape covering holes in a horizontal stab as needed for FFF trim.

Ben Minor

[Alfred]

David

Good to see somebody else having discovered the value of the Fun Tech blades.
We have been using them here in OZ for a while now.
There value for money compared to the more established blade is excellent.
Yep, I have seen quite a few guys pull of their top of the line blades and use the Fun Tech for FAI.
I use TG's,V2's and Carbon Techs

[DavidH]

Alfred,
The blades a lot of the contest pilots use here in the States are not Fun Tech.
The blades we use are made by Fun Key. They go under the name Rotor Tech's from Century. Fun Key markets them with the name Carbon Tech.
FunKey and Fun Tech are too different companies. Fun Tech is in Japan and owned by the Sensui's. Fun Tech also markets blades, but I have not used any of them.

FunKey is in Hong Kong
FunTech is in Japan

David

[Alfred]

Sorry David
You know...it's late at night..brain half switched off ....:arggg:
I meant Fun Key, as in the blades name going under CArbon Tech.
I use both, the Black normal CF blades and the 3D ones which have yellow blue etc stripes.