Ok, I understand that but doesnt that make the servo install permanent after the fin is glued inplace? Maybe I am mistaken that the fin is not permanently fixed.

Cody

The fin is not glued. It is held in place by a bolt from inside the fuse. If you need access to the servo you'd have to unbolt and remove the fin.

Joe

Cool, Thanks Joe

Cody

This was discussed earlier in the thread, maybe 10 pages back or so. I went through the same debate. I weighed my Wren SS and all of the components, then measured their locations from the CG in both cases. According to my calculations the plane would come out slightly heavier if I put the engine in the tail. The plane needs a lot of nose weight to balance it. I put it in the conventional location, shifted as far forward as I could and still need 24 oz. of batteries in the nose.

From their website a Wren SS is only 30 gm. or one oz. lighter than a 54, so there isn't much difference. My take is that I wouldn't mount any engine heavier than a P-60 or Super Bee (850 gm.) in the tail. Mine came out 20 lbs. A lighter tailpipe, like Keith used, would help.

In your case it boils down to personal preference. The SS could be mounted in either location. I chose to go conventionally because that is what I'm familiar with and saw no reason to tail mount it if it wouldn't save any weight. I prefer to have the airflow through the fuse to be directed by ductwork and a tailpipe, rather than worry about pressurizing the fuse or wires and hoses flopping around in the breeze.

Joe

Be VERY CAUTIOUS if using the control surface linkages provided with the kit. My F-15 Elevator and Rudder kwik links were NO GOOD AT ALL and stripped easily when I tested them prior to final assembly. They looked fine but when I pulled on them with my bare hands they are no good at all. Since it is all metric I thru it all in the garbage and am making all new from sullivan / dubro parts.

Mike,
the bottom of my verticle does look like that. Can't fit much of a servo in there as the width of the opening is only 14mm, and not much room to widen it. I have some time to think about it. I may use yor sketch and mount it where others have. FEJ told me the reason for the change was simply cosmetic.

Joe,
According to a turbine perfomance chart it looks like the SS is only 2g heavier than the Superbee (engine) weight, and 100g heavier than the p60. Yet the install weight of the SS is appox 1/2lb lighter than either of the other 2. I wonder, with careful placement of equipment, if balance might be achieved with the SS in the tail , without adding weight? Someone here has a tail mounted p-60 and a cg at 160 with a full UAT. My info states a cg of 130-140. If 160 is more accurate, it might be a consideration for me to try a SS in the tail. I wish it would thaw there so you could fly yours.

Cody

Cody,

I was going by the engine only weights shown on the Wren, Jet Central, and Jetcat websites. I assume that you are looking at the chart that is published in RCJI. I'm sure that there are some inconsistancies from manufacturer to manufacturer and perhaps on Tom Wilkinson's chart that make direct comparisons difficult. I can tell you that my Wren SS with mount, TC, and wiring harness weighs 2lbs. 4 oz. My comparably equipped Artes Bee on the same scale weighs 2 lbs. 0 oz.

I'd be carefull about comparing installed weights because Wilkinson's chart includes the weight of 5 minutes worth of fuel in that number. The SS installed weight looks quite favorable because it comes with miniature valves and a lipo battery, which means you'll need more nose weight. Some of the engines he reviewed two years ago have updated their equipment in the meantime.

The engine is mounted behind the CG and all of the other turbine equipment is in front of the CG with either mounting scheme. There aren't a lot of options on where to mount some of the equipment in the F-16. So it's primarily the engine weight that matters when you're trying to decide where to mount a particular engine. If you remove the 13 oz. tailpipe and move a 2 lbs.+ engine from 4 inches behind the CG to 2 feet further rearward you'll need a lot more nose weight. I allowed for the weight of the plywood mounts and even tailpipe insulation and in the case of my Wren SS the plane would come out slightly heavier if the engine were mounted in the tailcone. My guess is that if the engine were 4 oz. lighter (like a P-60 or Bee) then the plane would be slightly lighter.

Once you get your plane and all your equipment it's not hard for you to weigh everything, figure out placement of all the components for each mounting scheme, measure distances from the recommended CG, calculate the bending moments, and determine the extra nose weight required for balance. Based on my analysis it doesn't appear that there is a significant weight advantage, so where you mount the engine comes down to personal preference. If we were talking about larger heavier engines then they obviously should be conventionally mounted.

Joe

I sent an email to the factory about the thrust angle and here is the reply.........

Hi Sir:

You should march the black line. Thank you for drawing the picture for me. In fact my English isn’t good enough to describe it. Thank you again.



Note: If you need a new frame for you to install your turbine in rear position, please let me know that, I will send a new one for you.

Best regards,

FLY EAGLE JET MODEL FACTORY

E-mail: [email protected] (office China)

TEL: (86)0756-7766768

FAX: (86)0756-7766286

E-mail: [email protected] (office USA)

FAX: (1)301-933-4013

http://flyeaglejet.com

Hi Cody
Well that clears that up....we were right and a 0 thrust line is the answer. I've been away for a few days so haven't managed to post some pics.....Are you going to modify the U former to get it level?...thats what i should have done...weather here in the UK is awful so haven't been able to get out flying again but we have a two day jet event coming up so fingers crossed.
Keep us informed on your progress
Regards
Mark

Joe,
I'm wondering if a Wren Gold 44 with the Wren Augmenter (11 lbs of thrust) would fly this model.
I would only need to carry 40 oz of fuel plus a UAT.
What would you calculate the empty weight to be? The 44 is 1.87 lbs plus the pipe.
Bob

Hi Bob,

Mine came out a little over 20 lbs. with a Wren SS. With your Wren Gold 44 and a lighter pipe you're still looking at about 18 lbs. dry. I think it was Mark who mounted a Wren 54 in the tail, even with no ailerons his came out 19 lbs. dry.

I think their F-16 is a bit too big and heavy for 11# of thrust. Your take off weight would be about 20 lbs. I'm sure it would fly but not very well. 14# is the minimum I'd put in one of these. Their Rafale might be a better candidate for a Wren 44. Unfortunately it has a bifricated pipe which would loose some thrust.

Joe

Joe/Bob

My final weight for the Rafale is 15.8lbs dry. That is with a P60. You would save over a pound with the '44. Yes it would probably fly with a 44, but so far nobody has flown the Rafale except the factory and I am not sure what effect the bifurcated pipe will have.

John

Still waiting on my Rafale was surposed to be dispatched on the 25th of March but still havn't herd anything.... Is my birthday tomorrow so some good news would be nice.... Also waiting on the JR DSX9 2.4 gig to land but that keeps being put further back............... Hate waiting but then we aint gonna fly nothing in this weather

Hi John,
That's encouraging for weight Mine so far is weighing in at 13.6lbs without the vertical fin on (waiting for my servo) and without the missle rails but with everything else. Power is a PST600R.
Don't want to sound like a wimp, but hurry up and fly yours so you can give me a flight report LOL!!!
Jeremy

Hey guys,

any video posted of the F16 yet?

Ziv

Hello,
mine is now finish for maidenflight.
Total weight 8,5kg (18,7lb) dry, the turbine (FunSonic FS 70) is mounted in the rear.
Can anyone who has flown already the F 16 give me the movements of the aileron and elevator?
Is anyone fly the Falcon only with the tailerons or useing additionly the ailerons at the wing?
CG is 140mm, correct?


Thanks

Christian

mike
Thanks for the tanks and the missiles they look great. Not got my f16 yet [&o] but is there a way of temporarily fixing the missiles to the rails just in case they get scraped so i can get the spares on. are there any pics of an install to do this ?

Hi Rob,

Thanks, I just installed a pair of them on my JL F-16 and make them removable. I drilled 2 holes on the missiles and the rail for 2 4-40 screws. added some wood parts in between the rails and the missiles for the blind nuts. I will post more picture later.

Mike

Cheers mike
Have you got a set of the new landing gear on that or am i seeing things does the new gear fit the old kits. As i said have not even got mine from the uk rep yet comes mid april i think which gear will be on it ??

Hi,
I think, you get the normal LG, because the new one is more expensive.

@Mike,
your JL F 16 looks great, I try to fix the missiles (after I got them) with two little strong magnets.

Christian

Hi Christian,

You know I am a bargain hunter. These JL L/G are the improved versions and got them at the same price, but I only got one pair so far. My other F-16s are still leg-less.

Great idea with the magnets. What can I say about German Engineering. Now I know how to fix real rockets on the missiles rails. I will experiment with it and see if I can shoot them off.

Mike

hi mikedenilin,

thanks for the missiles and fuel tanks, superb,i have just finished painting the first pair....the other i think i will leave them white...see my pictures...do you like the painting colours??

Hey Lookilook,
How are the missiles attached to the wing?

Ziv

hi ziv,

they are currently attached to the rail with a very strong double tape that i use on real aircraft ,cause is not ready for flight yet i cannot say for sure that is a good idea,tomorrow i will make an effort to copy a system that i saw in a model show f16 where you make 2 L shape "teeth" on the side of the missile and 2 slots on the rail and these 2 teeth are slotted inside in the direction that the wind will be pushing them against the slots so as to not drop or move.....may be not so clear but when i finish it i will post some pictures
to see...

regards NICOS

Use 4 mm gold connectors that you use on ESC's have the male on the misile and the female in the end of the wing.... They are very tight and wont come off in flight

Dennis