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Old Aug 15, 2013, 10:02 PM
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Frankenheli FP Workshop

Frankenheli FP Workshop

This is a modding thread concerned with fixed pitch helicopters of all sizes as well as collective pitch heli's converted to fixed pitch. Fixed pitch helicopters are easier to fly and less maintenance than a collective pitch, but most fp helicopters are less than satisfactory when looking for performance and ability to fly in the wind.

BUT with a few mods a tame fixed pitch heli can be turned into high performance machine easily capable of handling 15+ mph winds and still have the ability to let go of the sticks to regain control if orientation is lost. We don't think we have found the limits of the fixed pitch helicopter just yet.

So this is a proving ground for collective minds who enjoy thinking outside of the box, where new ground can be broken with fixed pitch helicopters. But beware this may not be for the timid or those just looking for a quick fix, or for those looking for beginner guides for their new fp heli.

The pictures below are just some examples of what can be achieved, and consists of parts from multiple helicopters and also includes after market parts.


TIP: A lot of the regular posters will have their mods documented on their blogs. Click on their name to access.

Parts Mods for the V911 FP benchmark.

Ben Helios 100 Paddle Flybar for the v911
http://www.banggood.com/Wholesale-Be...5-p-49228.html

V911 swash plate ans CF shaft upgrade
http://www.banggood.com/Wholesale-V9...t-p-49035.html









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Old Aug 15, 2013, 10:31 PM
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United States, MI, Kingsley
Joined Jan 2013
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will be following

I've had a 9116 for about 7 months and love following all the up grades, have done a few minor ones. you guys are really pushing the envelope , looking forward to learning and modding more.

thanks for sharing all your research and tips, not counting the cash you have to put out to try this stuff.

thanks, happy flying,
Matt
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Old Aug 15, 2013, 10:34 PM
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Hi

I believe FP helis can loop and roll , they are quite agile and quite simple mechanically
I remember using a small FP glow heli that had only 1 link going to the flybar ,those were the good old days
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Old Aug 15, 2013, 10:40 PM
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Thanks for creating this thread. Subscribed!!!

-------------------------------------------------------------------------
I cut the upper frame side plates today to get the SG90 installed. One of my main goals was to get as much weight in front of the main shaft without adding balancing weight. This is because I want to provide the tail motor with greater "leverage" by lengthening my tail boom about 1.5". Doing this would move the center of gravity further to the rear, so counterweight is needed to keep things balanced.

It hovers nice and stable with a slight forward weight bias and the added weight does not have any noticeable affect due to the 380 motor. The heli (without canopy) currently weighs 259.1 grams. The canopy no longer fits due to the bell crank nut and I am still waiting for the new frame to arrive so I can get the the wires and battery mount cleaned up, and more firmly mount the front servo.

(left upper frame plate)






DH9116 with SG90 servos and 380 motor (0 min 25 sec)
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Old Aug 15, 2013, 10:50 PM
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Wow....that's what I call a Frankenheli fp.

Some ingenious thinking going on there, have you flown it yet?
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Old Aug 15, 2013, 10:54 PM
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Quote:
Originally Posted by Mattkingsley View Post
I've had a 9116 for about 7 months and love following all the up grades, have done a few minor ones. you guys are really pushing the envelope , looking forward to learning and modding more.

thanks for sharing all your research and tips, not counting the cash you have to put out to try this stuff.

thanks, happy flying,
Matt
A lot of the guys here came from the DH9116 and V912 forums. They are a good base helicopter for modding. But we encourage all forms fp heli modding where ever you come from......
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Old Aug 15, 2013, 11:01 PM
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Quote:
Originally Posted by Laidback_racer View Post
Wow....that's what I call a Frankenheli fp.

Some ingenious thinking going on there, have you flown it yet?
Thanks! No real flying yet, just hovering around the living room. You can see the front servo moving around on the double sided tape in the video and I would like to get it more securely mounted before I fly it around outside.
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Old Aug 15, 2013, 11:06 PM
Build the Weapon....
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Quote:
Originally Posted by aphex4000 View Post
Thanks! No real flying yet, just hovering around the living room. You can see the front servo moving around on the double sided tape in the video and I would like to get it more securely mounted before I fly it around outside.
Cool, keep us updated on your progress, your mods are always interesting. I like how you have mounted the rear servo inside the frame, the servo link is more upright giving better torque on the swash arm.
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Old Aug 16, 2013, 05:32 AM
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More work on Gygax's paddle mod today, my hardware is on the slowboat but I dummied up some old cut down 250 paddles and attached them with tape to my short flybar.

Its still blowing a gail here, but indoors the response and control is better with these tiny examples. It will be days before I can test outside most likely, but i think the paddles will give benefit.

Reporting back on the HXT-500 servo's with the V912 PCB and 9XR tx, I tested the same setup with the stock 9116 tx and the travel is around half of the 9XR.

I had the old Turnigy 1440A's with the 9XR installed previously and found I still needed the servo arm extension to gain full travel. I think it may be a combination of the HXT-500 servo and the 9XR, but perhaps the 9XR is giving the bigger benefit.
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Old Aug 16, 2013, 10:32 AM
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How well does the tape hold the angle? If the paddles pivot on the shaft,
I don't think they will work nearly as well.

But you won't have to worry about bending the balance bar.

My HK250GT paddles have very tiny set screws, and I got mine mounted
securely, but I'm not confident they will stay in place.

If Pa and Gygax are getting enough torque from the paddles to bend the shaft,
there are some serious forces at work.

When I tried the paddles, they were out way too far. If you look at the paddles on
the Helios and MSR flybars, they are very close to center, like you have done here.

Mine gave the "man standing in a rowboat" effect so badly it was not controllable,
and thanks to the collective experimentation, now I know where I went wrong.

Gygax and Pa Flyer.... Pictures Please. I wanna see these babies.

__________________________________________

Aphex, that is sooo sweeet !!!

Great work, the swash action is beautiful.
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Old Aug 16, 2013, 10:56 AM
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I have 3 layers of tape but I think you are right, but who knows a bit of flex at the right point could be another method of taming the paddle, but a better method would be required.

I was thinking of cutting a section from a 450 CP blade and drilling a hole down its length to slide my plastic flybar shaft through and then gluing. The plastic will not take a bend like steel perhaps...
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Old Aug 17, 2013, 11:52 AM
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Quote:
Originally Posted by Steve_ View Post
How well does the tape hold the angle? If the paddles pivot on the shaft,
I don't think they will work nearly as well.

But you won't have to worry about bending the balance bar.

My HK250GT paddles have very tiny set screws, and I got mine mounted
securely, but I'm not confident they will stay in place.

If Pa and Gygax are getting enough torque from the paddles to bend the shaft,
there are some serious forces at work.

When I tried the paddles, they were out way too far. If you look at the paddles on
the Helios and MSR flybars, they are very close to center, like you have done here.

Mine gave the "man standing in a rowboat" effect so badly it was not controllable,
and thanks to the collective experimentation, now I know where I went wrong.

Gygax and Pa Flyer.... Pictures Please. I wanna see these babies.

__________________________________________

Aphex, that is sooo sweeet !!!

Great work, the swash action is beautiful.

Steve I'll get some pictures posted for you this evening. I trimmed my paddles down to 31mm by 14 mm.

They are working perfectly now and I won't be trimming them any further. For my heli at least, this size is the sweet spot. They are not bending the balance bar any more either.

The cyclic response is now as good as my 250 conversion on roll and forward elevator and better on rear elevator. You can stand it on it's tail easily without even trying. The c.o.g. on my 250 isn't as high as it is on the 9116, which I'm sure has a big influence on it. And it's a bullet in fff.

I had the tail rotor tilted before as LBR suggested to increase left cyclic and also had weight on the left side of the frame. Neither is needed now. I flew it into the ground once trying out the left roll without enough altitude when it lost lift. Luckily no damage other then a slightly bent flybar.

Can you believe that I was looking at the 250 earlier to see if I can move some components around to raise it's c.o.g.to make it's performance match the 9116's? I never thought that it would have to play catch up to anything! Maybe with it's own set of paddles and a higher c.o.g. it'll be #1 again: then again, maybe it will just be a tie!
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Old Aug 17, 2013, 07:38 PM
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Here is my second attempt at paddles.

She is charging up now.




RESULTS:

Crazy cyclic.

And totally uncontrollable.

The weights and paddles need to be swapped around.

I lost all self centering ability.

Several times it was rolled 90 degrees to the ground, and I stood it on it's tail
on command.
___________________________________________

I have not been able to fly much lately, and I have a completely calm night,
so the paddle project can wait. I installed a stock balance bar until I can see
your design.

The belt on my 400 size CP takes priority, and I will work on that between V911,
9116, and F-45 flights.

I'm having a blast attacking my kid's V911's with the rotor wash from the F-45...
...when I can catch them.
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Old Aug 17, 2013, 07:39 PM
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Pictures

Steve , Here's a picture of the cut down paddles. Also a picture of my swash showing a spring underneath it and a small sleeve over it to take up any slack and fix it in position on the main shaft. Also notice the upper bearing block. The canopy struts are from a HK250 and I modded the block slightly so they would go in the front screw hole and move the canopy just a teeny bit more forward to give me more battery clearance.

Overall length of the flybar to the ends of the paddles is 206mm.

Your flybar looks much shorter than mine. It will be interesting to see if the full sized paddles work better with the shorter flybar or if you have a problem with stability.
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Old Aug 17, 2013, 08:56 PM
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Brilliant idea on the swash spring Pa, I was envisaging a smaller spring that tighly fitted the shaft. Your idea puts pressure on the swash to stay in place without any binding that would would reduce swash angle.

Great news on you trimmed paddles, how do you think stability will be in fast windy conditions?

I have been reading up on some 90 deg paddle designs for some older walkera models, the more high performance options had longer flybars. I wonder if the 90 deg paddle design stuff applies to us as well, from what I have read the further the paddle is away from the shaft the greater the speed which gives more stabilty AND cyclic.
Walkera 180Z-Pro Hybrid - Now Available at www.wowhobbies.com (2 min 7 sec)


http://www.wowhobbies.com/walkeracb1...ail-3-1-1.aspx
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