HOW to make a Raptor 90 more agile

[iher]

I`m a proud owner of a Raptor 90 SE

I would like to gather experiences, trials, experiments and success modifications to make the raptor 90 a more agile machine.

The idea is to push the envelope and make the raptor 90 the most of what it can be 3D wise with real and smart modifications and no useless upgrades. ( eg: sometimes cheap plastic performs better than pricy metal or carbon fiber)

Are we going to let new helis sink the raptor dinasty? let`s find a way to make the rap evolve past factory settings!

Here are some ideas to star with:

- 10 pounds? lets lower it to 8, where can we reduce weight without risking structural failure
- which upgrades rrrrrealllly give it a boost

any ideas?

[rotorhead58d]

I`m a proud owner of a Raptor 90 SE

I would like to gather experiences, trials, experiments and success modifications to make the raptor 90 a more agile machine.

The idea is to push the envelope and make the raptor 90 the most of what it can be 3D wise

Are we going to let new helis sink the raptor dinasty? let`s find a way to make the rap evolve past factory settings!

Here are some ideas to star with:

- 10 pounds? lets lower it to 8, where can we reduce weight without risking structural failure
- which upgrades rrrrrealllly give it a boost

any ideas?

how about an E 90?

[iher]

Tempting!
But if you ask me, electrics are the ones making the 90 nitro look slugish.
We should be able to raise enough the power to weight ratio to make them sweat

This weight reduction was done with the 90 3D, but many own a 90 SE so I thought we could start from there.

The reality is that soon, electric tecnology will generate far more power than nitro.....I just want to level the field

[rotorhead58d]

Tempting!
But if you ask me, electrics are the ones making the 90 nitro look slugish.
We should be able to raise enough the power to weight ratio to make them sweat

This weight reduction was done with the 90 3D, but many own a 90 SE so I thought we could start from there.

i see where you are going with this. ya, go for it. i don't care how old the design is for these heli's. it works!

[iher]

Here is to get the juices flowing:

- Getting rid of the horizontal fin. and change the metal support for a lighter one ( the R 90 3D has this)
- Lighter canopy. It weighs a ton ( CF or fibre glass)
- I use a large li-ion bat , I will change to a smaller lighter one.
- lighter landing gear... my worry is how it will take hard bouncing
- Is the aluminum reinforcing plates really necessary? or can we do without? ( rap90 3D uses aluminum frames and eliminates the plates. is there a real weight benefit?)
- The plastic servo tray and fan housing are also heavy. Anyone up to making them in CF? I did it with a shuttle and the difference was noticeable.
- The main shaft bearing block are quite heavy. We could drill some holes to lighten them.

PS : funny avatar!

[vandelescrow]

In a different post I asked about potential and kinetic energy, spinning objects and objects at rest. This was in a thread about removing the Main Rotor Hub Pin to save weight in the head. I did not get any answers on this but since you are asking about shaving weight perhaps this is the right time to ask.

If you take say 1 gram of weight from a spinning object (I.E. main shaft) vs. 1 gram from a stationary object (I.E. main frame) which will give the greater benefit in weight savings or will it be the same?

BTW, about removing the Main Rotor Hub Pin, According to the book wrote by Ray (don't know the last name off hand but he is the one with the DVD series) all the weight of the heli rides on this pin. Probably a good idea to keep it on the heli, maybe it could be machined (hollowed out) to save weight.

Aftermarket parts to save weight: Carbon tail boom, carbon drive shaft, carbon boom supports, Quick UK makes a lighter motor mount, carbon collective control arm

Aftermarket parts to make it more agile: G-force Mixing arms

In addition to just shaving weight, if the weight can be repositioned so it is closer to the head, the heli will be more agile. Example, instead of the battery on the bottom of the stack on the servo frame, put it on top.

[iher]

Now THAT`S what I`m talking about! ... Intelligent conversations!

All right, regarding the weight in motion.
What we are looking for is to reduce mass. Every acceleration or change in motion requires energy. Lighter means less energy spent= faster response. Mass in the rotor means disturbing the balance created by a circular motion of the mass (kinetic energy)
For a spinning mass you need energy to keep it spinning and to change acceleration (in rotation or linear displacement).

more weight it`s like using heavier paddles. It takes more energy to change the rotor disk`s angle

So I think you are right, It`s double benefit: less spinning mass= less energy needed to change directions= faster response
on top of the general weight reduction of the whole heli.

-----------------
The main rotor hub pin in definitively needed. but I think there are alternatives to it. there is the pin in the bottom of the shaft and there is an aluminum ring at the top( under the top bearing block) these 2 ensure the shaft transfers the vertical force on to the frame ( up and down respectively).
This could be simplified probably by making a 2 diameter shaft so it can rest on the top bearing , thus eliminating the ring. Maybe at the bottom, replace the pin with a light E clip.

------------------

All of the upgrades you mentioned except the G-force Mixing arms and carbon main shaft are already included in the SE version. So it’s a good start

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Reditributing weight . Good point! the closer al the weight is to the center of gravity, the better.

[vandelescrow]

I did not mean just moving the weight closer to the main shaft, but closer to the head. Think of like a pendulum, If you have a weight at the end of a string, say 4 feet, and start to swing it, it will take longer to get the weight to start moving versus a string say 1 foot. Now aply that to your heli in a loop or roll. The closer the weight to the blades the quicker it will loop / roll.

RC heli magazine did a review of a new style heli a few months ago (sorry don't know the name) that is completly radical in its design. It is a 90 size heli. They made the entire heli shorter by moving stuff closer to the head, esentialy the limiting factor of this design is the length of the motor / clutch assembly.

Before I saw the review of the heli mentioned above, a few of us at our field were talking one day about how to make a heli where as much weight as possible was moved closer to the head. A few ideas were to turn the motor upside down from conventional mounting in a heli. Or mounting it horizontaly with the head facing up on the front side of a bevel gear (main gear) and the clutch assembly on the back side of the bevel gear, this clutch would provide power to both the bevel gear and tail. Of course we did not come up with a way to start the engine in these configurations. Also to move more weight closer to the head, a fuel tank shaped like a donut be moved to around the swash plate ( I don't know how that would work in diferent flight orientations).

I know this is not what you were asking for, just some thinking outside the box.

[vandelescrow]

I was thinking about what you said on the rings on the main shaft, replacing say both of them with E clips. The bottom of the start shaft is held in by the same type of clip. Actualy there is only one ring under the top bearing, what holds the other end is a bolt through the autorotation gear.

[iher]

yes I agree, moving the frame (battery/engine/tank/gears/ electronics)... center of gravity horizontally closer to the shaft will help in 2 things
1: pirouette faster ( but then again this weight has to compensate for the tail`s weight)
2. it will flip faster

Moving the center of gravity vertically closer to the blade disk center will make roll faster

So the idea would be:
1- to make the tail extra light to get the counterweight closer to the shaft.
2-move everything, (like you said, closer to the center of the disk) . Ideally this would mean the center of gravity of the main rotor disk should be the same as the frame`s center of gravity.....this would make a Reeaaallly fun machine. It would roll on its axis!
It would be like the ufo tipe of heli/saucer that the bad guys used in the movie "The Incredibles"

[Laurens]

Don't use the alu reinforcement plates, no base plate, no horizontal tail fin, plastic grips instead of alu. Also ditch the header tank.

[iher]

Great . I was wondering about the plates. does that mean that the CF frames break? or are just there to prevent flexing?

Without the H tank dont you run into bubbling problems?

[Divot]

Take a look at the tail trasmission box on this fellows heli.
This could be a real weight savings...not sure though.

http://www.runryder.com/rrpw.htm?d=/helicopter/gallery/62503/&i=3&a=0&s=-Welcome.txt

[vandelescrow]

Where can you get different colored landing gear for the R90, The photo in the last post showed green, I'm looking for orange, all I'm finding is the stock white.

[rotorhead58d]

Where can you get different colored landing gear for the R90, The photo in the last post showed green, I'm looking for orange, all I'm finding is the stock white.

some guys in another thread said they dyed theirs. rit dye? or something like that. pm buzzkill for the answer

[Badger50]

That's an elevated R/C tail case, http://www.heliproz.com/prodinfo.asp?number=254011 There is no appreciable weight differece, however, it does allow 2 things.
1) You can see what the dreaded pin is doing.
2) You get a little more slider traved for your tail rotor.
I really like mine a lot. http://www.helifreak.com/attachment.php?attachmentid=50592&stc=1&thumb=1&d=1212865182 (http://www.helifreak.com/attachment.php?attachmentid=50592&d=1212865182) See Ya.

[Divot]

That's an elevated R/C tail case, http://www.heliproz.com/prodinfo.asp?number=254011 There is no appreciable weight differece, however, it does allow 2 things.
1) You can see what the dreaded pin is doing.
2) You get a little more slider traved for your tail rotor.
I really like mine a lot. http://www.helifreak.com/attachment.php?attachmentid=50592&stc=1&thumb=1&d=1212865182 (http://www.helifreak.com/attachment.php?attachmentid=50592&d=1212865182) See Ya.

Badger,

If this is in response to my post.
I am referring to the front transmission not the tail case.

I have the same tail case. I also really like it.

[Divot]

Where can you get different colored landing gear for the R90, The photo in the last post showed green, I'm looking for orange, all I'm finding is the stock white.


Quick UK makes them. Ron has some of them in stock but not the orange ones.
I also have used rit-dye but after awhile it comes of and a re-dye is needed.

http://www.quickuk.eu/cat/general_parts/undercarriage.html

[iher]

OOOHHHHHHH!!!!!!!!! I burried my Rap into the ground for the first time this weekend!!!!!!!!! while doing fast caos a cloud moved and blinded me just enough to lose concentration and orientation I SLAMMED IT sideways into the dirt. I flatened my CY muscle pipe and damaged the engine port....THAT hurt!
Good oportunity to consider upgrades.

....besides that just boom, and blades. it seems the pipe absorbed all the energy. .....without the plates i`m sure the frames would have suffered.

Indeed, that boom clam should be extra light! where did you get it?

[Laurens]

I think thats the QuickUK Vmax tail mount.

[Kinger]

If you want a light tail boom support mount, look no further than the version that is included with the new 3D kits. It's made of plastic and it actually trips the boom supports between the plastic and a locking nut unlike the SE version that is just held on with a screw and loc-tite.

As for making the Raptor more agile, try using the Colin Bell mod to the mixing arms and adding a set of Radix Super Stubz paddles.

[ShinOBIWAN]

Also the Kasama Srimok increases the cyclic and pitch and is lighter than the stock 90SE part. The pitch can go right up to +15/-15 although you need to have well sorted collective skills so as not to bog the engine when using that much.

Combine with the 680 Radix blades and the Stubz on a shorter Stratus flybar and you'll have a whole new heli to re-experience.

Alternatively Kasama has the new flybarless head coming out later this year and this coupled with Stabi electronics should take the 90 even further.

[iher]

I have done the Colin Bell mod. It did make a diference.
I use 690 blades and stubs, but doesn`t a shorter flybar make the heli less stable and less responsive?

[vandelescrow]

Less stability = more responsive, less responsive = more stability. in either the flybar, mixing arms, blade selection.

Yes the QuickUK frame looks nice, lighter, eCCPM but with such a big modification to the heli, the way I look at it, it's no longer a Raptor

[ShinOBIWAN]

Less stability = more responsive, less responsive = more stability. in either the flybar, mixing arms, blade selection.

Yes the QuickUK frame looks nice, lighter, eCCPM but with such a big modification to the heli, the way I look at it, it's no longer a Raptor

Opinions seem to be mixed on the V-Max eCCPM kit, some claim it completely transforms the machine bringing it right in line with the latest kitsets and others say the trademark Raptor smoothness and stability is traded for a twitchier machine.

I almost bought one myself for my 90SE BUT I figured exactly the same as you just mentioned. It would no longer fly like a Raptor! I like my Raptor and if I want something that flies different I'll go buy a new 90 kit such as the Synergy, Vibe 90 or Aurora. Its very expensive and by the time you've put it on a 90 3D or even the 90SE its going to be quite a lot more outlay than other high end 90's like the ones I just mentioned.

I think if your after a similar flavour of performance offered by V-Max but still retain the faithful Raptor flight characteristics then look at servo selection. The Raptor 90 is extremely demanding of the servo quality and particularly on the collective. I recently moved over to a 7.4v setup with 2s Lipo and JR 8717 servo's. I thought I'd got good servo's on before this (Futaba S9451) but the difference was striking - more pop and response to the feel of the machine.

Like I said above, a good forumula for a solid Raptor 90 is:

Kasama Srimok Head
Stratus Flybar
Curtis Stubz
Radix 690 or 710SB blades
JR 8717 on 7.4v for cyclic and collective
Spartan DS760 gyro with Futaba BLS251 on tail
OS 91 C-Spec and Hatori SB17

That's the setup I use and its the same old 90SE feel but with some balls. Its also way more heli than my abilities can handle so I won't be swapping just for the sake of having the latest and greatest shiny thing. The only thing I'd consider changing is the engine which is getting on for 4 years old now. If something wears out I just replace it. I love the C-Spec, its served me so well and that's why I'm loathed to retire it.