Dave03B

The pilot at RIAT nearly had the same problem Don't think wind could be blamed

Glad to see you're having fun with this model. Shame it didn't fly at W&W on the Saturday. I'm sure I'll be seeing you at a meeting somewhen with it!

Cheers,
Dave

jeff sewell

My Feedback: (1)

Hey Paul,
I'm still doing stuff but tend not to travel much. I've got a Yellow F15 on the board, just bought a Skymaster Hawk and I have a couple of EDF's (great fun!). Not seen/heard much from Jim Fox - he's setting up a business in Thailand in case you didn't know; manufacturing kits again.
I am the last of the our bunch still doing jets[&o] although there is a slight revival. How do you like your Wren then? Do you think it would provide (more than) adequate power for either of the aforementioned models? I've got a Simjet 3000 but am looking for a second motor. the choice is really good these days compared to when we were having a go for the first time! Hope you get everything sorted - take it easy dude!!

Say hello to Adam and Joe (if you still see him)...

Laura H

Jeff,
How you doing - we miss your's and Jim's Northern wit!
Belgium: we only visited once when you 1st flew your gripen in primer and Jim flew his hawk not painted with a JPX t240. Many many years ago!
Talking about a Skymaster Hawk for the Mercury. Trouble is you can't get them here at the moment!
Had a go on a Boomerang at the weekend not the best looking model in the world, but I liked the way it flew!

Whats happened with big Steve?

Laura

GrayUK

Gents

Thanks to Dave and Jetbike.

Here is the link to the flight and crash video.


http://www.putfile.com/media.php?n=Grumania-Eurofighter

Strykaas

[&:]

GrayUK

Download link does not work for me?

Dave03B

The link you previously posted Paul, still works for me.

jeff sewell

My Feedback: (1)

Hey Laura,
How are you?
The reason why you don't see us any more is that Jim has buggered off to Thailand to start a factory making kits and to sample the ladies out there. I personally doubt you will see much of him ever again!
Steve went his separate way a long time ago after he and a few others started their own club.
You can't buy a Skymaster Hawk here? Well its a global market, go online and find somewhere else to buy it from! I have a YA F15 on the board at the moment and I am also interested in the Hawk. It looks like an excellent flyer.
Just come back from Woodvale Rally - it was ok - didn'y fly, just spectated. Say hello to anyone who remembers me - I may make the effort when I,ve completed something and go to a jet meet sometime.
Take care...

volkan

Hi Paul
Was this the one at Topgun?
If so i have more video here on tape that my dad took.
Still needs to be sent off, and edited....
Sorry about the crash.

GrayUK

Hi all.

As you know i crashed my Eurofighter last year at a Jet meet.[]
Video of this is mentioned else where.

Well it is almost re-built now.
The damage was limited to the air intake area of the FUS.

I re-constructed this from the bits adn it is now almost ready for painting.
I am going to do it in the English all blacks.

I received a set of the English decals from Grumania today, they are really good.
With the decals was a really good CD full of close up detailed pics and a 'where to put them' picture for more than one scheme.
Nice touch this, works for me

The also supply a sealer to paint on them.

The picture is the scheme i am doing.

Paul

GrayUK

Well
It is re-built now (see pics)
Finished apart from a new canopy which is on its way.

Flew it today, still as great as it was, goes like hell with a Wren 54 MK3 on board.

A really nice plane to land, comes in on throttle, use canards with elevons.

Very very happy with the re-build

bmichels

hello,

I will be interested to know the dry weight of your eurofighter.

thanks

bmichels

do you believe that a lightly built version will fly well with a WREN44 or that I should instead go for a PJPjets Eurofighter for my WREN44 ?

grumania

A lightened version definitely goes on the 44, we have even build electric ducted fan versions that have been clocked over 200 km/hour !
Its just a matter of the building technique. A lot of the rock steady internals can be lightened or left away. Also lighter retracts are available.
Although never designed around a 44, its not a question if it is possible - it is
Its rather a question if you want it. For those who want to give this a try , I will do my best to help. Lighter fuselages can be made.
Ilja

bmichels

here we are, after my Kolibri-Twinjet "pico-jet" ( [link=http://www.rcgroups.com/forums/showthread.php?t=537867]see complete built thread[/link]), I am for my 2nd Jet, and this time it will be "real size": A grumania Eurofighter.

But, as you know me, it has to be modified from the standard version: I will make a very light version in order to use only a WREN44 instead of the recommanded Wren54.

Dry weight is 4kg, which mean a very low wing loading. This should be 1500 grammes saved over the standard plane.

So, I went to Germany to pickup the kit and see Ilja.

The kit is very good quality, but boy... it is far from an RTF !! quite some work to be done !





Indeed, it is totaly empty ! ! All will need to be fixed by myself !



quite a nice size plane. The paint scheme will be yellow/black like the aeronaut EDF in front.

bmichels

But, already I have a question: The kit is made to use a Coke bottle as tank. I know this is quite usual, but i really feel that a coke bottle is VERY FRAGILE !

Is it really safe to use a coke or is there a similar size tank saffer and more robust ? ( I need between 1 and 1,5 Littre max)

Airforce7

My Feedback: (31)

bmichels,

I use a 3 liter soda bottle in mine and have never had a problem. I fitted the cap with two bulkhead barb fittings and Teflon tape around the threads. I use Tygon tubing inside for pickup and vent and Tygon tubing throughout the jet to the UAT and the pump.

I did a leak test over a couple of days and also accidentally dropped it off my work bench (32" high) full of Kero and it didn't crack or burst. Still using it today in my Rookie II.

Ken

GrayUK

Coke bottles are fine, i have used them since day, never had a problem.

Please keep us informed on the 44 version, lots of pics would be good.

Great stuff.

Paul Gray

bmichels

thanks for the coke experience. So I will use a bottle of "light coke" for ly "light eurofighter" project

bmichels

I weighted the complete Kit. Here are my results:



Fuselage (spécial lighter version) + Access door = 800 gr
2 wings uncovered = 840 gr
formers = 280 gr
canards = 50 gr
Accessories pack+wing spar+canopit= 430 gr

--------------------------------------------------------------�* Total kit = 2400 gr

Wren44 = 680 gr
Accessories + lipo = 300 gr
Airtrap tank + Coke bottle + tumbling = 100 gr

--------------------------------------------------------------�* Total propulsion = 1080 gr

3 retracts legs (trailing wheels type) = 108 gr
2 jet tronic valves = 64 gr
3 wheels = 130 gr
3 Jet A1 retracts mechanism (the light one normaly used in the SU-27) + brakes = 210 gr
Air bottle = 30 gr

--------------------------------------------------------------�* Total retract system = 530 gr

5 servos = 200 gr
2 rx = 60 gr
Rx Batterie + switches + accessories = 130 gr

------------------------------------------------------------�* Total RC system = 390 gr

Covering + painting = 150 gr
Glue + micelanous = 150 gr

------------------------------------------------------------�* Micelanous = 300 gr


TOTAL DRY SYSTEM = 4700 grammes


So, the Weight saving over the "standard grumania" version is 650 grammes (dry weight): “light” Fuselage: 100gr + Wren 44 instead of 54 : 400 gr + SU27 retract: 150 gr

Additional possible weight saving : lighter formers : -50 grammes ? xxxxxx ? Any other idea ?



So, Take off weight saving should therefore be around 1 kg since I don't need to carry as much kerozene as with a Wren54

I am quite disapointed, I was expecting a better weight ! ! Will this make a real difference ? ?

bmichels

What are the weights of your 1/9 eurofighters or 1/9 Rafale ?

are there place where you think I can save more weight or where my weight calculation is wrong ?

grumania

Bertrand,
if your calculations are correct then you have achieved an extreme weight saving compared to the standard kit. Regular ones are between 6000 gramms ( extremely light) and 7500 gramms ( heavy built).
It should be mentioned that most of your savings are due to the use of extreme light retracts ! these retracts could never be used with the MW 54 !!! So your calculations can not be mixed up with the regular equipped Eurofighter.
Also do not be concerned about coke bottles - these are well tested since the early days of turbine use. If you do not like them at all then just use the tank I gave you and your uncle - you asked me for the Dubro tank and I gave it to you.
In a mail to me you asked why I recommended to save every gramm at the tail because of tail heavyness that might arise using the MW 44 - you think that a lighter engine behind the CG is helping to avoid a tail heavy plane.
You forgot that the Eurofighter is normally flown with heavier battery packs ( 8cell NICAD`s) in the nose ! You use LIPOS !
Believe me : EVERY WEIGHT SAVING ON THE EUROFIGHTER STARTS WITH SAVINGS IN THE FIN !!! This is my strong advice
You told me that you are a beginner in jets - so please do not be disappointed now.Build the model and fly it - your calculations do not say a word about the fun you will have when flying the Eurofighter.I don`t give a lot on numbers and calculations.
I am shure you will be regarded in the end. Since the very first time I started selling this kit , I never heared a bad word in any aspect so it would be very surprisingly if you will not have a nice flying model in the end.
Ilja

bmichels

Ilja, I am sure I will be happy with the kit, and proud of my built once it is achieved. And as I said, it is very good qualitikit. Therefore I intend to quickly work on it, almost everyday, in order to get it airbone quite soon.

I know it is still a light plane at 4,7Kg dry. I am in fact disapointed when I compare this weight with the expected weight of 4500 gr WITH FUEL that you mentioned to me in an early mail, and then with the 5 Kg With fuel that wr discussed in your shop.

Regarding the coke bottle, I start indeed to consider that 1,5 little will be some sort of added security compared to the 1little dubro that you indeed provided to me. I am afraid that I will need quite few "test" approach before a good landing during the firts flights....

I still consider that a light turbine positionned behind the GC help to have LESS tail heavy problem. So, It is luky that I decided to go for the Wren44, this will help partialy to resolve the tail heavy concern of the plane.

grumania

Bertrand , the regular flying time is about 5 to 10 minutes - on most jet events it is even limited. So when you have a litre tank that gives you about 12 minutes flying time on the 44 GOLD, I do not understand why you need 1.5 litres - remembering that you are not even satisfied with the calculated weight with just one litre ? We should not forget that you are experimenting - never before the model was flown on a 44. So it should be accepted that this is project where compromises can not be avoided.Saving weight where ever possible is such a compromise, even if you can not fly half an hour.
Ilja

bmichels

GrayUK (and other Eurofighter and Rafale 1/9 owners), could you please tell me what is the Dry weight of your Eurofighter ? Also, I will be interested to know what servos you are using.

Indeed, I wonder is 5kg digital MG servos like the ds5491 (instead of the 8kg recomended) are strong enough for Tailrons and Canards ?

--> In other word, since I am building a "very light Wren44 based version", I wonder what are the LIGHTEST possible servos I cas resonnably use.