siddus74

Bought a lightly used gripen just needing a engine and sorting out .. had it painted for £60 ....

Am pleased ... turbines on a budget, beats the dull grey.

Scott.

rcjets_63

My Feedback: (4)

Hi Scott,

Welcome to Club Gripen (not Grippen). That's a pretty good looking paint scheme and the price for it was certainly right.

Incidentally, it looks like you may have a JetLegend Gripen since each wing has two aluminum spars. The Skymaster uses a single carbon spar that runs through the fuselage.

I've got 4 Gripens (or is it 5 now?) and love the plane. There is a thread that many Gripen owners/builders have been using over the past few years to amalgamate a lot of the info/ideas/suggestions into a single place rather than having a bunch of short threads. It's up to 17 pages now. Here is a link:

[link=http://www.rcuniverse.com/forum/m_7900053/mpage_1/key_/tm.htm]JAS-39 Gripen Owners/Build Thread[/link]

Please post some photos and let us all know how your Gripen is doing!!!

Regards,

Jim

ron Sweeney

Hi Scott, certainly loos like a JL one. Its exactly the same as mine, Ron.

siddus74

Thanks for heads up on the make boys .. does anybody have a JL Gripen manual to compare ...

Here is some pictures from the manual that was supplied with the airframe and some pictures of the model. The wing spares in the book seem to show 2 aluminum tubes but mine has plates? It does seem to have the correct canard controls?

Anybody?

Aero65

My Feedback: (2)

Hi Scott

Looks like you have one of the original Gripens from Skymaster, with the older aluminum blade spars.

Yes that the correct canard horn. Looks like the directions you have are for that version.
We flew one of the very early versions in Hawaii, and had several of the older one's and one of the Arf plus versions.

http://www.hawaiijets.com/aircraft/Gripen/Gripen.htm

siddus74

Areo thanks for comfiorming it, i was a little worried from the posts I hada amix and match ... Sp its an older one .... Any thing to be concerned about, problems etc? i have a p80 for mine what do you think?

Scott.

rcjets_63

My Feedback: (4)

There's lots of info on that and a bunch of other things in the [link=http://www.rcuniverse.com/forum/m_7900053/mpage_1/key_/tm.htm]JAS-39 Gripen Owners/Build Thread[/link]

The gear are in the scale location and you may have some difficulty rotating. The easy fix was to extend the nose gear leg. Later versions had the gear moved forward.

Jim

Eagle Driver

there is a special thrust tube from iq-hammer which let it rotate easily ...
i will search the pics for you ...

wojtek

My Feedback: (73)

id be curious about that myself .. I had a grippen and the takeoffs were always ugly .. on landing it did stick to the ground nicely however



~V~

ron Sweeney

I'm going to be a little controversial at this point. I bought a very early J.L. Grippen, second hand. I read all the comments, cautions and settings etc. I naturally experienced all the same issues as every body else. I fly from a 150 yard grass strip and use a wren supersport. I too experienced the take off 'leap' into the air and did use a lengthened nose leg. My biggest concern however was the planes propensity to tuck under in a dive and climb under full power. I really had to bully the model and this made it a little disconcerting. I had settled on average recomended throws and balance point but switched off the canards for landing. A recent and unexpected smooth take off and flight left me puzzled until I came to switch off the canards for landing and found that I had not enabled them during my pre-flight check.
I have also experienced flexing of the canards despite a good powerful servo and close tolerance linkage. This set me thinking so I bonded the canard to the fuselage to eliminate any flexing. I have had 5 flights with this change and the model has performed very well. No more tucking, no more zooming and surprisingly smooth rotation on take off. My model is finished in the factory sport paint scheme so since scale issues did not prevail I substituted the factory oleo for a trailing link strut which has also eliminated the continual bending of the swivel pin in the strut which is such a problem when flying from grass. Sorry if this commentary disrupts the flow of the thread but it was my default solution to flying this very enjoyable model Ron.

siddus74

Ron, thanks for your input. So your flying your gripen on an elevon only setup all the time now?

I wasnt aware that it was necessary to have the ailerons setup as elevons anyway, I had a Mick Reeves reaper with about 50 / 50 control with elevons and Canards and it flew nice .... the aileron control surfaces dont look big enough to be used for elevons only?

Scott

ron Sweeney

Scott, My aileron/elevator control is only one surface. They are not split, Ron

Aero65

My Feedback: (2)

Hi Scott

A P-80 should be fine we flew it with a PST J600R up to a Super Eagle from Jet Central, so it can take a wide range. The older heavier gripens of course were better suited for the bigger turbines.

As far as the nose wheel and mains, I agree with what everyone else said much easier to take off with around a 3 degree positve angle sitting on the runway.


I think Ron is right on with his post on the canards.

As far as the canards go, we flew with them fixed most of the flight and only turned them on for 3D type of aerobatics. It bleeds speed very bad in a turn with the canards on. We were thinking that due to the short cord of the canards that most of the canard acted similar to a flat plate airfoil and would cause more drag a even moderate angles of attack than lift. They really seem to work better as fixed canards.

The older Gripens had an aluminum shaft to control the canards which helped, although it did flex a bit, which may have caused some of Rons issues.

wojtek

My Feedback: (73)

I had the old Grippen with a P80 and it was good power ... it was fun yanking it around plowing it through the air (bleeding lots of speed ) .. i had at one point tried using reversed canards to the elevons, and surprisingly that made for very smooth tight turns .. it was a very slight amount however. Some interesting effects with reversed canards in high alpha flight with rearward CG as well. Its definitely a unique airframe to play around with different configurations ..

I kind of miss mine !

~V~

siddus74

Thanks for the info, 3 degrees when sat on the runway ... ma be easiert to shorten the rear main gear legs than to extend the front ... I dont want to spend any more than I have to on this one otherwise Ill be put off from really yanking it about ... I will consider only having very small canard control to start with.

Those of you using elevon only control, please can you post your throws?

Best regards,
Scott.