RunRyder - Graupner NH90 Kit

rrTV-PHOTO

New HD TV

HOME rrTV-PHOTO GALLERIES MY GALLERY HELP-FAQ

myHOME PM pmRR MEMBERS 343 ONLINE 25 EVENTS SEARCH REGISTER START HERE

2 pages [ << < ( 1 ) 2 NEXT >> ]

2521 views

POST REPLY

Advantage Hobby	.	Revolution Models	.	CarbonXtreme
	.		.

Got Jet Fuel? Turbine Helicopters > Graupner NH90 Kit

cloudmax
Senior Heliman
Location: Bay Ridge Brooklyn,NY

About 3 weeks or so into the build and it's getting there.
Though I haven't taken some of the "Creative Liberty" that Wiwanczyk has taken with his my boring ol' NH90 should turn out pretty good.
The kit is a pleasure to work with.

I'm thinking of going with this paint scheme. It makes it look a little "meaner".

12-28-2003 Over year old.

Sandy S.
Heliman
Location: FLORIDA USA

Nice work! thats a good scheme considering we have the four blade head in alu, a fully dampend four blade tail rotor, billet alu tail rotor gear box and complete scale set including scoops, steps, flir and working drop off fuel tanks just like in the pic coming this jan.

Youll want to insulate that drive shaft tube for about 12 inched back from the bulkhead (retract)

12-28-2003 Over year old.

cloudmax
Senior Heliman
Location: Bay Ridge Brooklyn,NY

>>Youll want to insulate that drive shaft tube for about 12 inched back from the bulkhead (retract)<<

You mean it gets hot back there?

Yeah,just waiting on the insulation. And a couple of switches..hint,hint.

I will soooo be calling you about the 4 blade rotors and other goodies.

12-28-2003 Over year old.

Sandy S.
Heliman
Location: FLORIDA USA

yup, its a good idea to cover it..although the pipe runs cool in that arrangment, the alu picks heat pretty easily.

I should be in tommorow...give me a shout.
(closed til jan 5th).

12-28-2003 Over year old.

optikaman
Veteran
Location: EnglishTown N.J.

Cloudmax that would look sweet in military colors.

Can't wait to see it finished.....

Alan...

12-29-2003 Over year old.

heliVoY
Veteran
Location: NJ

Cloudmax,

if you hang some balls on that heli (like the tanks, and the guns in the window) I think it will look cool ... the 4 bladed head is somehting i have through of also, however for now im sticking to the 2 bladed flybar head on my SB-90 because it should be a bit more manouverable and stable that way . Eventually it has been my intention to go 4 blade though ,,,, , i guess frst I'll see how the 4 blade head on my EC-135 performs ..

Hey Sandy,
what kind of blades is the 4 bladed head made for ? is it a single bolt through blade, ot a 2 bolt per blade design ? and is the hub 10 or 12 mm ? $$ ?? ...

Wojtek

12-29-2003 Over year old.

Sandy S.
Heliman
Location: FLORIDA USA

no pricing yet sorry. due late jan.

youll see pics on our site next week with all the details... in short, you dont need gyros to fly this head, or special blades.. same blades. same as for tail. (which is a work of art itself, fully articualted tail hub).
No plastic molded hubs! I flew it and it flies awesome and very agile. hub is 10 mm as per jetcat standard equip. tornado and split s moves were accomplished with ease..
Full video will be up soon as well, its amazing and the sound is totally scale now! This is the first multi I have ever enjoyed flying. well worth the wait.

(there is a tiny pic of it in flight on our main page with SAR package installed)

12-29-2003 Over year old.

heliVoY
Veteran
Location: NJ

If a split S is doable with ease, now that is cool !! Is there going to be a heb available for a 12 mm shaft ? ... Its funny, but my NH-90 seems to be coming out a lot lighter than my 230 is .. so far it looks like it will be quite a manouverable bird .... im very curious as to the flight characteristics with the 18deg of pitch ... i still cant6 believe that !

I had a 4 blade head long time ago on the small Vario EC-135, and it fle ok for me then, (thn again i only knew basic hover and FF back then) .. I have seen Optikaman fly his 5 bladed Vario head on the 500, and now with the ccpm gyro and fine tunning, it flies very nicely .. however, i would not think of doing anything inverted like a split S with it ... It will be interesting to see an alternative to the Vario head and how it performs .... also sounds that with this new head Sandy is talking about, that blade suply wont be an issue either ...

Wojtek

12-29-2003 Over year old.

Sandy S.
Heliman
Location: FLORIDA USA

you will love the video.....

there might be enuff beef in the hub to go 12 mm, not sure yet. you will run a few degrees less pitch at hover due to increased lift.

12-29-2003 Over year old.

edg
Senior Heliman
Location: San Francisco, CA

Hey Cloudmax,

My thinking is along the same line as yours. Basically a 3 color camo scheme. I think that makes the NH-90 look best. I really wasn't in love with the look of the NH-90 at first. However, I think it's just not very photogenic

In person, it looks a lot better and my first test flight yesterday was sweet! A camo scheme will really bring it home...

01-16-2004 Over year old.

HOMEPAGE

heliVoY
Veteran
Location: NJ

Any of you guys going to the WRAM show ? Im bringing my SB-90 there (if i finish it in time, but i think i have plenty of time with 5 weeks) ...... Building this thing has been more of a pain in the ass than i though it would be ... The EC-135 that im doing after this should be a relaxing breze ...

hey Cloudmax, would you happen by any chance to have pics of your tail drive set up ? I still have not finsihed my tail, and am leaving it for the last thing i do, just before final paint ... Im still bothered using that wire drive ... I know its been used over and over again, but it just seems so delicate ... I wish someone made a boom mountable 40 deg gear box ... id just run a carbon boom through the tail, and up to the top, with a ballraced torque shaft .... but im going to give the wire drive a chance anyway ...

Wojtek

01-16-2004 Over year old.

edg
Senior Heliman
Location: San Francisco, CA

Woj,

Well the wire drive seems to work just fine. I know the torque tube would seem beefier, but I think you could set something up like: use a very short 2mm shaft to exit the gearbox and put a dogbone coupler on it (from Vario). Then, you could use another coupler to mate it to a torque tube. IMO, Seems a bit too complicated and you'd still have a somewhat of a weak link at the 2mm part, but that part would be very short.

My Jetcopter's output has a dogbone, so I deviated from the instructions. I use a dogbone to connect to the main shaft and I also use a dogbone on the T/R gearbox.

The dogbone works well. I couldn't detect any vibrations in the tail when i test flew it. Also, I've had a very bad experience with the "Shepard's Crook" coupling in a Kobold. I had massive RF interference that I finally tracked down to that coupling. I guess the crook wiggled a bit in the slot. I'll never use one of those again.

01-16-2004 Over year old.

HOMEPAGE

heliVoY
Veteran
Location: NJ

which one is the Shepard's Crook coupling ? that not the one with the rubber dampner is it ? i could see that being problematic outside of a boom set up ... i use the one with the rubber dampner between 2 fork couplers on my bell 230 and it work fine .. (the shaft is in a ballraced boom however ... )

Wojtek

01-16-2004 Over year old.

cloudmax
Senior Heliman
Location: Bay Ridge Brooklyn,NY

I'm in Colorado for a couple of weeks so I can't post any pics.
I agree with you on the tail thing though. I've only heard good things but I can't get the thought of how flimsy it looks out of my head!
I just have a few electronics left to deal with and I'll be ready for a test flight. (As soon as the weather returns to something humans can go outside in!)
I'll let you know. (Fingers definitely crossed.)

01-16-2004 Over year old.

heliVoY
Veteran
Location: NJ

Sounds ike I'll be letting you know how the tail works first

... I have under 5 weeks to go from primer (which i am in now) to the finished heli , and this includes setting up the tail, as well as installing all my servos and electronics ... i also still have to set up the pneumatic system for the gear doors and the sequencer .... i can wait to finish it ...

Wojtek

01-16-2004 Over year old.

edg
Senior Heliman
Location: San Francisco, CA

The Shepards crook is the bent end of the 2mm drive wire which goes into a slot in the output shaft coming out of the mechs. Then that whole thing has a plastic bell that slips over it and is secured with a collar and setscrew.

The dogbone's are the ones with the rubber piece that mates the 2 metal pieces (Which both have a kind of double wedge cut out on the mating face).

Dogbone's work great. The NH-90 kit calls for using the crook. I assume if you get the Jetcat mechs from Graupner, you get the crook. I got mine from Vario, so I had the dogbone.

While some seem to have no problem with the crooks, I know that many many people who bought Kobolds -- which have the same type of crook coupling -- had really bad RF lockouts all traced to the coupling. Myself included. I'll never use a coupling like that again. Especially not on something that's got about $8000 invested in it

...

I emailed Sandy about that and he said he's had no probs with the crooks and that the dogbones don't run "hubcentric". Not quite sure what that means, but I had no vibe in my tail when tested.

01-17-2004 Over year old.

HOMEPAGE

Phil Cole
Veteran
Location: Redwood City CA

I have one Graupner "shepherd's crook" and there have been no problems at all. I was pleasantly surprised at how well the Graupner wire drive works. This is in a .60, not a turbine, but the interference issue should be the same, provided the fit of the wire into the drive coupling is the same. Only one more data point, but it may help.

Jetcats ECUs are not all that fast in their response to collective inputs, so the tail doesn't really have to respond to rapid main rotor torque changes. I suspect that this means that wire drive has an easier time than it would with a piston engine, which can change torque in the time it takes for the throttle servo to respond to input from the receiver.

The limited flying I've done with Jakos leads me to believe their ECUs are no more responsive that Jetcat's.

I do know someone that converted his Graupner wire drive to tube drive, using Vario parts, I think. It didn't work any better than my wire drive. Again, this is all 0.60s.

Does the NH90 use the plastic 40° box? If so, drill out the holes for the bolts that join the halves and use through-bolts with nuts. Even in the 0.60, the self-tapping into plastic doesn't work.

01-17-2004 Over year old.

edg
Senior Heliman
Location: San Francisco, CA

Hey Phil,

Yeah the 90 uses a plastic gear case. But, as I recall it didn't have self-tapping screws. I'm not sure though. I do remember that at least 2 of them are 2mm screws w/bolts.

One bitten, twice shy. I won't use crooks again. I think if the fit is just a bit loose you'll get some metal-on-metal twitching in there. To be clear: I'm still using a 2mm wire. I just cut off the crook part and attached a coupler to the (now) straight end.

BTW, you have any more belts break on your JetCopter?

01-17-2004 Over year old.

HOMEPAGE

heliVoY
Veteran
Location: NJ

Quote
BTW, you have any more belts break on your JetCopter?

im not sure if that was addressed to me or not, if it was .. well no, i have not had any more belt problems ... When my belt did fail on one of the early PH3T units i had in a jetcopter, JetcatUSA 100% honored their waranty, and not a $ was lost out of my pocket ... I have been flying the crap out of one of my HP5s (which is now in my bell230) ... the only problem i had was that the FOD screen got sucked in once, and i had to sent the turbine in for service ... JetcatUSA covered it under their waranty ... The only other problem i have had (well, you could say i was the problem here

) was when i had my head spining at 1400rpm on my 30lbs+ bell230, and from the ground, i punched in 12deg of colective .... looked impresive, but i overheated the turbine to almost 1000c ... The ECU responded by fropping to 80% power allowing me to land safely .. Turbine is fine, and all i probably did was shorten my bearing life by a few hours

... (wont be doing that again, but it was fun to try ! )

I am VERY impressed wih how the ECU hanndled this ... sure beats having been shut down
Wojtek

01-17-2004 Over year old.

Dave Hollins
Senior Heliman
Location: UK

1000c

Why did the turbine continue to run at 1000c??? Surely the ECU should stop the turbine way before this temp

They must have changed the firmware. I think I would prefer the turbine to shutdown at about 750c. My 3 HP5s have never got near to 750c

01-17-2004 Over year old.

2 pages [ << < ( 1 ) 2 NEXT >> ]

2521 views

POST REPLY

Midland Helicopters	.	HeliProz	.	ZoomsHobbies
	.		.

Got Jet Fuel? Turbine Helicopters > Graupner NH90 Kit

PRINT TOPIC

Advertisers

Subscribe to This Topic