Official Freewing JAS 39 Gripen 80mm EDF Jet

[Evan D]

That is very surprising. I would have never guessed you'd need that. Maybe when John makes a 3D printed exhaust it'll let you remove the lead.

Not liking the foam nozzle I put the plastic from my old one on the TV nozzle today...


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[xviper]

I never weighed it and now their stuck onto the plane. I used thin lead sheets that we used to use for radioisotope shielding when I worked in medical research. The sheets are about 2mm thick and I cut out what I estimate to be a strip about 3/4" wide and 12" long, cut into 3 pieces, 2 of which was doubled over. Weighing a similar strip of lead, it was 65g.
You can see the 2 double thickness strips on the bottom. There is one more single layer strip on top.

[Evan D]

How much weight did you add?

[xviper]

My Gens are 45C, 725g, 45mm X 45mm X 155mm. It's shoved right back to where the foam angles inward. I didn't weigh the weight, just kept adding till it balanced at the marks. It already looked like a lot so I didn't add any more to get the balance aft of the marks. Will fly it first (carefully) and see if I like it that way. It just seems like a terrible thing to have to add so much weight.
I may change my mind about the Assan. I have other planes that are quite darty on the ground that can use one. (I did buy the 5 pack.)
Thanks.

[Evan D]

The picture was taken before the TVs. I would say it's average weight. The JF is about the same as the stock fan and shroud. The HET may be a little more than the stock inrunner but not much. I have a Turnigy 120HV ESC about the same weight as the stock 100A HW. My batteries and series adapter are 880g. Paint added a little, maybe more paint aft of the balance point??? I think I added 75-80g of lead in the stock rear fuselage to balance it at 15-18mm behind the mark. The TV rear part is 13g heavier than the old rear with lead. My batteries are 48mm wide so maybe I am able to push them back a bit more?

My receiver is aft under the battery tray. I shortened any extensions I could. My satellite us under the vertical fin. I do have a steering gyro up front and if I was building it again I wouldn't use it since the Gripen's forward gear position isn't as tippy as I thought it would be.. What is the weight and dimensions of your battery? I assume you have it laying in a way that's the most narrow.

Edit... if you are using the 45C battery yours is narrower and should go back further but are 20mm longer than mine so extend further forward... But they are only 716g? But they have others with other C ratings...

[xviper]

There is a balance mark molded in the foam under the wing that I use as a reference. I am 15-18mm behind the mark.

Is your EDF a lot heavier than the 6s one? I can't get my battery as far back as yours without cutting into the foam that separates the internal compartment from the air intake plenum. I'm using the Gens Ace 5000. I don't want to cut into the foam to get the battery further back so I've added some tail weight and that only achieves balance at the marks (and that's with the VT nozzle installed). I see you've got the Assan steering gyro. How does that work for you? I also have one on mine but some say it's not required. I can't maiden till spring.

[Evan D]

I am using a 6S plus a 2S. They are one atop the other. I'll find a picture. I post more in RCG than here and have more information and pictures there.

There is a balance mark molded in the foam under the wing that I use as a reference. I am 15-18mm behind the mark.

Are you using 6s not 4s x 2 batteries? Do you have both batteries in front?
15-18mm behind CG recomandation?

[rms]

Hard questions... I don't have the answers to the total weight. I am balanced 15-18mm behind the marks under the wings.5200 6+2 @ 880g. 12S can work. I have 3500 6S 60C packs that fit. They are 890g for two.
Are you using 6s not 4s x 2 batteries? Do you have both batteries in front?
15-18mm behind CG recomandation?

[Evan D]

Hard questions... I don't have the answers to the total weight. I am balanced 15-18mm behind the marks under the wings.5200 6+2 @ 880g. 12S can work. I have 3500 6S 60C packs that fit. They are 890g for two.

Very nice. where du you have the batteries og what is the CG? Is it flying good?
What is the total weight of your Gripen? Weight, size of the batteries?
I`m considder to go 8s or even 12s if I find a good solution for the CG...

[janmb]

Here is the revised version. Same Thingiverse location.

Looks great :D

[rms]

Between being a delta, canards, thrust vectoring and 8s power I’m not bored.

Very nice. where du you have the batteries og what is the CG? Is it flying good?
What is the total weight of your Gripen? Weight, size of the batteries?
I`m considder to go 8s or even 12s if I find a good solution for the CG...

[Nigel]

Hi hope the thrust vectoring unit turn up before spring because I have told every one in my club who would listen about this and I am starting to have people ask me through you are going to fit this kit you keep banging on about ? Foot note don’t jump to early

[Evan D]

On the plane in the picture above. Flew a bunch of flights with it and like it. I put more info about my set up and numbers on RCG.

[SanExup]

Between being a delta, canards, thrust vectoring and 8s power I’m not bored.

Did you receive the TV unit!?

[kallend]

Thanks. I finally got a good dimension for the long lateral fins. The narrow chord ones at the tail are still a bit of a guess. Updated the Thingi files.

Here is the revised version. Same Thingiverse location.

[janmb]

If you get bored with the Gripen ;-)
Did som flying with a FW Mirage i bought used from JanMB here now.

Nice scenery light :-) https://www.youtube.com/watch?v=kjmVR29xxKM
Low, hige alpha training, but bad light with overcast..https://www.youtube.com/watch?v=L3HO8pWhFE0&t=208s

Nice flying - glad to see you are enjoying her :D

[janmb]

Quite likely - I couldn't find a 3-view or definitive dimensions for the vanes so I guesstimated.

Try now! (Pretty easy to clip them off with an STL editor if you still think they're too long.)

Thanks.

[Evan D]

Between being a delta, canards, thrust vectoring and 8s power I’m not bored.

[rms]

If you get bored with the Gripen ;-)
Did som flying with a FW Mirage i bought used from JanMB here now.

Nice scenery light :-) https://www.youtube.com/watch?v=kjmVR29xxKM
Low, hige alpha training, but bad light with overcast..https://www.youtube.com/watch?v=L3HO8pWhFE0&t=208s

[Evan D]

Cool!