Originally posted by janmb
View Post
Announcement
Collapse
No announcement yet.
Official Freewing JAS 39 Gripen 80mm EDF Jet
Collapse
X
-
Originally posted by janmb View Post
Damn, so what you are saying is that the Gripen is more hungry than the EF? That is certainly not what I would expect.
Or, more precisely, the 80mm 8S Jetfan setup (9 blades) with 1865kv motor (installed in the Gripen) is more power-hungry than a 90mm 8S 5-6 blades EDF (either Wemo or RCLander) with a 1600kv HET motor installed in the Euro.
Certainly the JAS ducting is much less 'efficient' (very thin ducts) than that of the Euro, and 90mm EDFs in general work better than smaller diameters in my experience.
Of course, regardless of the ducts, we are comparing 1865kv on 9 blades vs 1600kv on 5-6 blades, so there's probably the big difference.
Still one would hope that a smaller-diameter EDF should compensate for lack of cross section with higher rpms and more or less maintain power but nope.
90mm works best, what can I say?
It'd be interesting to test a 6 blade rotor on the 1865kv motor, but not feeling like doing that ATM.
Originally posted by kallend View PostThe EF has a very light wing loading, which means it can cruise around happily at low throttle settings (at least, mine can). Not so with my Gripen.
And the jet still takes a lot of time to accelerate compared to others, which again, I'd atribute to the ducting and to the fan being 80mm.
Comment
-
Last edited by Mtpisgah99; Jan 31, 2021, 04:31 AM. Reason: https://www.youtube.com/watch?v=zsSB42_56NY
Comment
-
Originally posted by kallend View Post
The EF has a very light wing loading, which means it can cruise around happily at low throttle settings (at least, mine can). Not so with my Gripen.Freewing A-10 turbine conversion: http://fb.me/FreewingA10TurbineConversion
Comment
-
Originally posted by Airguardian View PostAnd the jet still takes a lot of time to accelerate compared to others, which again, I'd atribute to the ducting and to the fan being 80mm.
Freewing A-10 turbine conversion: http://fb.me/FreewingA10TurbineConversion
Comment
-
Originally posted by Mtpisgah99 View Post
Comment
-
It's amazing how long a cockpit can take with all the fiddly details- lots of compromises with scale too but here it is. It was hard to find good photos of the rear deck equipment so it's very much an approximation but I guess the main aim is to maker it believable.
The pilot is a JHH 1/10 figure (not sure if they're still in business) and the canopy frame was made with "lightweight foam clay" from Michaels. Weight gain over stock is 35 grams- not so bad but of course this jet doesn't need more weight in the nose.
Just a couple of rear view mirrors to add and I'll call it done and glue the canopy back on.
Tom
- Likes 3
Comment
-
Originally posted by Airguardian View Post
You should be much better served with a kero engine in there :)Freewing A-10 turbine conversion: http://fb.me/FreewingA10TurbineConversion
Comment
-
One for " EVAN D " or anyone else that can advise me on these settings .Just want to make sure I have set up my Gripen right before I fly it .I have decided to use the canards only on pitch not on roll ,I have the elevator set at 17mm ,21mm,and 25 mm .To get the canards right at for pitch 20 mm low 25 mm mid and 30 mm high .that makes the canards on pitch 74% on the mix .Is that right or should I have the canards at 100% on the mix like Motion RC recommend Bit confusing ?????
Comment
-
Originally posted by Captain Moron View PostDid anyone have to put lead in the tail of the Gripin to get the right c of g or is it just me. I am using the Admiral Pro 6s 4000 battery?
Comment
-
Originally posted by Captain Moron View PostDid anyone have to put lead in the tail of the Gripin to get the right c of g or is it just me. I am using the Admiral Pro 6s 4000 battery?
The Gripen needs weight in the tail to achieve an acceptable CG position. This nozzle has accommodation for up to 60g of small lead weights, in addition to weighing over 60 grams itself. Print wide-side down, with supports. You will need to peel off the plastic outer of the stock nozzle, and trim back the foam to leave a stub 13mm long to which you glue the new nozzle. I suggest taping the join on the inside to ensure smooth airflow,
(This has been discussed extensively in this thread - see https://www.hobbysquawk.com/forum/rc...348#post285348 ).
Comment
Comment