Green Air F-15 build

[gouda]

Here we go. I received a Green Air designs F-15 a few weeks ago and finally got started on the build. Check out their web site for info on this and other kits they make.

http://www.rcelectricflight.com


Some details:

Basically all CNC cut Depron, with some wood parts in the taileron and motor mounting area.

I have never built a depron model before so there was a bit of a learning curve. See details with the photos for more information.

I tried to use Zap foam safe CA. Didn't work. It started to eat away the foam. I switched to 15 minute epoxy and used it in a different manner than would be expected to keep the weight down. Works very well. there is another thread that gives some information on my method and what some others are using for this material.
http://www.rcgroups.com/forums/showthread.php?s=&threadid=205901&perpage=15&pagenumber=2

First impressions: This is a nice kit. The parts are cleanly cut, fit reasonable well and it goes together quickly. It comes out light IMHO. You'll see some weights given with the photos.

The airframe does require quite a bit of sanding to get the wing airfoil section and the fuse away from it's as assembled square shape. But it sands very easy and doesn't flake or tear during the shaping. Just a bit of elbow grease and you're there. You do have to be sure that you're putting things together properly. I missed a couple of things in the instructions because I didn't read carefully enough. I'd recommend dry fitting everything before starting in with the glue. It will give you a better idea of the fit of the parts and if you have to make any adjustments to parts in the process.

I wouldn't say this is a beginners plane. the instructions are clear, but it takes some knowledge of basic building techniques to get everything together as needed. Also, I don't think it's performance would be appropriate for a beginner. Way to fast! there are videos on the web site if you care to have a look.

You need a radio with mixing. It is a taileron controlled plane. It requires two servos. I'm using HiTec 55's.

I'm still decieding on what power system to use. It will not be brushless however.

Some places, like assembling the nose section to the central duct tub need some carefull measuring before the glue is applied. Some thing's like centering the wing on the fuse also need to be done carefully. Here is where some experience comes in handy. Things that should be obvious, may not be to a inexperienced builder. There is no going back once glued.
Using a slower curing adhesive may be helpful, but frankly my building time is to precious and infrequent to be waiting for some adhesives.

I'll be posting photos and more info later in the day for your viewing. Check back

Again, check their web site and/or mine http://home.centurytel.net/reair for more info.

The photo below is basically a finished plane waiting for it's finishing and detailing. (Green Air photo).

[mjblack]

Lookign forward to seeing the build.

Mike.

[gouda]

this is the lower nose section of the F-15. The threads you see are CF tows that are laminated between the 3 parts shown to add strength. I'd use epoxy for this part of the build no matter what I used for the rest.

[gouda]

This is te center duct assembly. It's also where I found that the CA was not foam safe. But I saved the parts. This is one of the assemblies where you must preform the sides to meet shape of the duct floor. I used a very slight amount of heat. This made it much easier to hold in place while the glue cures. FYI, you can't pin Depron very well.

[gouda]

Here is the nose section with some more parts added. This was easy. Note the slots for some of wing related pieces.

[gouda]

Here is a pic of the nose section complete, less the actual nose cone. I figured that would get damaged from banging around on the workbench, so it can wait until I get the sanding block out. I did lightly sand the edges of the various parts to ensure a good bond and eliminate any gaps. Didn't take much.

[gouda]

This is the assembly in which the nose and duct are joined. This needs to be done with care. There is a lot of alignment between those parts, the wing and wing front cover. take your time and remeasure as many times as you need to ensure everything is right. Use a Sharpie to make marks once you're happy with everything. Otherwise how will you get it back together with glus. I wouldn't use a fast curing adhesive either.
Can you see the lines of the F-15 coming together??

More to follow...

[Kempf]

I wondered how these planes were built, looks like a laminate layer by layer right? I'm wondering what the best adhesive is that's available in the USA? Liquid Nails or Elmer's glue?

[mjblack]

Hi all, Nice plane, anyone know where i can get one?

being serious, very nicely done! keep up the good work ross,

NEW!! also this guy is about to start being our USA Destributor, lowering th costs of the kits in the US, ald he is a top gentleman and helpfull to the last,

please kep checking back!

Best regards,

Mike.

www.greenairdesigns.com

[nickr100]

hi all

just signing in to follow the thread :)

cheers

nick

[mjblack]

Also ross, i have been inundated with questions about PU glue, so we are going to stock it!, and sell as an accompanyment to our planes, easy to use, light, and quick setting!
so will be in touch about this!

mike.

www.greenairdesigns.com

[gouda]

Kempf, I think one of the better ones here would be Elmers probond. If you read the begining or thread, you'll see I had issues with foam safe CA. I wouldn't even bother. I'm building the entire plane, with the exception of the wood assemblies using 15 minute epoxy. I believe I can use it carefully enough that I can add less weight with epoxy than any thing else. There is another thread referenced in the 1st post with more info. Drying time was one thing I didn't like about probond.

[jfassino]

Can you report on the cost of this kit ? I tried to find the price on their site but no international price was available even though it looks like they have a price link.

Thanks

Jim

[gouda]

Just convert their price in pounds to USD. The shipping wasn't all that much. I think 7 or 8 pounds considering it's international. Here is a link to a currency converter: http://www.xe.com/ucc/

I got the plane in about 5 days. Good service.

[gouda]

It amounts to about 90 USD + international shipping difference. The total amount is given when you go to checkout on their site.

[mjblack]

Hi head cheese!, uk CNC Monkey here, got some of the glue i mentioned today so will send it with your order.

Hope your well,

Mike.

[Kempf]

Is this F-15 available in a ducted fan version?

How do you finish these depron builds, paint and etc?

[Ed Waldrep]

Kempf there is a balsa F-15 edf for MF480 available here:
http://gcmdesigns.co.uk/page3.html

There's a thread on it here on the Ezone I believe, you could search for F-15 or Jones Boy who designs them.

The Green Air design in this thread is smaller at 30 inches long vs 40 for the GCM F-15, and of course it's a pusher prop as well. It'd be easier to hand launch the pusher prop bird vs the edf which may need a bungee, but then the edf has the 'fan coolness factor'. Two different designs in different categories but the more to chose from the better!

You maybe could add fans to this Greenair design but I don't know how tall the fuselage is. You'd have to add ducting as well, and might need two fans.

[Kempf]

Ed:

Thanks for the info, looks like a nice plane.

[gouda]

Kempf;
I have a set of EDF-55 & EDF-50 fans. I see how they fit in the F-15 and post a photo. I know there is plently of width, but not sure about the height of the duct.

[Steve Wrona]

Is there a benefit in building a plane like this in foam rather than balsa that I just havent realised yet?

GEE whiz, thats an interesting F-15 youv'e got there!

Steve

[nickr100]

the benifit is depron is a lot easier to work with. its stronger than EPS and easier to shape than balsa. for a given solid mass. i ve built one of these '15's and it goes together very quickly, quicker than a balsa equivelent and is much lighter too :)

cheers

nick

[mjblack]

Hi ross and nick, how ya doing, well put about the build, easy, quick from box to feild, with carbon tubes and spars stronger than most aicraft of their size.....and with the right finishing.durable....now thats the upside that poor old steve hasnt seen yet....steve i have been trying to look at your site due to i blelieve you have interestin stuf and i wondered if there could be some mutual benefit for us to trade equipment/etc...maybe you would be interested?..........but GEE wiz i dont know?.....give me a knok and we should have a chat about it........

michealjblack@hotmail.com

wwwgreenairdesigns.com

best regards.


Mike.

[Kempf]

So what is the best way to finish these after building is complete? Just paint with a foam safe primer and that's it? No glassing required?

[mjblack]

Hi kempf how we finish ours, is to give a final sand......slop on some liftweight filler mixed with water so it looks like, sloppy icing....and slop all over...i know i keep i#using the word slop, but i mean it....slop it on..leave it for half hour, slop a load more on....and leave over night....next day, rub down with 18-240 grit adn paint on PVA thinned 50% with water let dry, do again and quick rub with 240-400 grit......and paint with acrylics or enamels!!! be very carefull which enaml you use and NO CELLULOSE!

it usualy adds 1oz to the weight of my planes which is nothing to worry about, but i belive gouda has another way of doing it...so its not difficult....another of my customers has glassed his....so the chioces are endless i just dont like glass very much....so mines filled an painted!.

hope this helps.

Mike.

www.greenairdesigns.com

[mjblack]

Just a pic of a painted in sea grey...lol

Mike.

[gouda]

A bit more progress to show. The basic fuse was complete, the wing built (2 parts!, the wing and a CF rod) and sanded. The Depron is easy to work with, sands easy and takes a shape nicely. AS you'll see below.

Here is a pic of the wing attachment. About 4 glue joints, a bit of measuring and some weight to hold things in place (the brown bottle is full of sand) Yeah, sure..Anywat shaping the wing as shown in the instructions is easy, just use a fine grade of sandpaper to keep from gouging the foam.

[gouda]

Next was assembling the wood parts that ends up being the motor mount, taileron mounting and servo mount. I'd suggest doing a dry assembly to understand how the parts fit and to make sure everything fits properly. I needed to do some triming for my servos and slightly adjust the overall width. The pic is the dry fit. Not very difficult.

[gouda]

Now the boring part in my opinion: sanding and shaping. Never been one of my favorite things on balsa planes, but I found this much easier, but a bit messy. The foam sands well and is easy to shape. You can do a lot of trimming with a shape blade before starting the sanding. The photo shows the roughed out shape, it's not quite done, but I wore out my arm. I'll work my way down in grit size and I expect it to turn out great. There are a number of other assemblies that are easiest to assemble and shape before mounting to the airframe. I'm not sure what the material used for the nose is, but it's not normal blue foam. It has more density and almost seems a bit rubbery. Should take a few rough landings.

[gouda]

This shot shows the other foam sanded assemblies that are attached to the airframe. I'll final attach them after they are finished.
Weight so far is 122 grams. That includes the airframe and wood assemblies.

The good: very easy material to work with.
Light
Quick to sand and shape.
Builds fast.
Looks great.

The bad: Sanding.
more sanding.
Have to be careful of hanger rash.

[gouda]

dfty

[gouda]

Kempf;

Here is a shot with a couple of GWS EDF-55's sitting in rear of the airframe. I think this could work. You'd just have to design some mounting parts and make the top rear of the plane slightly different. I think if you were to hollow out the parts that look like the tops of the turbines, it would work. Don't know if there is enough power there, but that could be figured out.

[gouda]

The two fans weigh 140 grams. I think the total weight of the plane, fans, servos & receiver would come out about 240 grams or about 10 oz. Not sure what batteries would be best, but likely lipos.

According to GWS these fans have 5.5 oz's of thrust at 9.6 v. Sounds like it might just work if you could keep the total weight down to about 15 oz or less.

Oh, it's a bit deciving in the photo above, they onlly stick about 3/8's" above the top of the fuse rear.

Mike, any thoughts?

[mjblack]

Hi Ross,

Loverly build pics..cool, bet serously recommend you dont put those fans in it...with 140w of edfs and motors the plane was no where near fast enough....so stick with the pusher on this one nd i will send you another kit for testind with if thats ok?

iv been down this road, and the planes not quite big enough for it, but we have scaled the F-15 up to take th minifan...so perhaps at some point we wil release that.

you will be the first to know when we do you know that BOSS!!

now replying to your email, hopeyour well

and talk soon.

Mike.

[mjblack]

Hi ross, hows it going?

got your email, and looking forward to reply on taileron mounts.

also made some progress with the F-104 what ya think, ...soaring magestic bird or frigthning, balistic missile?....lol....know which i think it will be....lol.....some one forgot to give it wings.

hope you well,

Mike.
green air designs.

[gouda]

ohhh, I like that F-104. I've read about other 104 models and it seems like people think they fly as well as a jet with less wing area. At least with turbines. So I think likely it will be successful. Maybe a bit fast for the underskilled, but jets are generally that way anyway. Is is a pusher of DF power system? Looks like a DF.

[mjblack]

glad you like it!....cos your flying it..i aint!!! .lol.......thanks friend......just had to play with something else for a while

gonna test it this W/E waether accordingly...

its pusher for this one but here is enough areas inside for minifan but im gonna test this on brushless first....lol....make sure it flies first....

thanks

mike.

go visit me forum....lol....

[gouda]

Here is where I am at as of today. The airframe is finished, shaped, sanded and ready for finishing. The control and power module is complete with servos installed and linkages connected. However, I wm not going to install that until I have the finishing done. I'll also install the 480 motor, ESC etc, at that time.
I have added 2 mm CF rods to the LE of the wing and made a 1 mm balsa base for the canopy/hatch access to the radio compartment. It needed a bit of stiffening and this seemed like a easy and light way to do that.

Now if the ground would un-freeze in the next few weeks or so (way to hard for the not unexpected hard landing that usually happens when I fly) we'll be ready to go shortly.

[gouda]

Oh, all the other bits needed to complete the plane are ready for finishing (vertical stabs, module cover, engine tunnels etc.) and will be installed after finishing. Weight including everything but the motor and batteries is 5.5.oz. We'll see what the finishing (low temp film) adds.

[mixer911]

Gouda, could you post some close ups of the front and rear angles. Also the wood areas. I am in the process of getting one from mike and would like to get an idea in my head for planning. Gonna get all the electronic situated before so I can have it ready to install.

[mjblack]

Hi ross! loooookin` gooooood!!!!

hi mixer how ya doing.....if you want any pics you only have to ask between "Head Cheese" and I we have every angle you can possibly think of!!

what ya need?

best regards,

Mike.

[mixer911]

Thanks Mike! Either one would be ok. Mike, how do you think a razor 400 would work? Also thinking about maybe glassin it.

[mjblack]

Heard real good things about the razor 400, if you mean the Razor RZ400...then its very comperable to the mega etc.....nad yeah will work a dream!!!!!

8 cells 6x4 prop, should be and animal!!!!! cool

and i have included a couple of pics in closeup...sorta to help.

Mike.

[mjblack]

and another

[mjblack]

and finaly.

thanks all, and please visitors pop to our site and register with us for info please takes 2 secs

greenairdesigns

Mike.

[mjblack]

sorry, forgot the pic.....lol


Mike.

[gouda]

T anyone who has been following this thread, sorry for no updatse lately. Other stuff going on. And PC problems. that's now solved.

So, here is my Green Air F-15 with the contol/power module in place and covered with Econokote. The Econokote worked great on the depron. Iron was set to about 240 degrees F. Only areas that were difficult were the compound curves. Solved that by using smaller pieces of the covering.
I know it's not a scale finish, but by the time I'm completely done I think it will look great. Just have to put the rear cover in place and the rest of the radio gear.

[gouda]

The color is actually quite a bit darker than it looks in the photo. It's like the Blue Angels blue.

[mjblack]

That looks very nice!.....justr need some batts, blue sky and some yellow tips!.......

keep up the good work chap!

excellent
regards

Mike.

[RCParkflyer]

Great Job on the F-15 Guys !!

[RCParkflyer]

This is a nice High Vis Paint Scheme used by the Test Pilot School at Edwards AFB.

(Hey How'd that F-22 Get in there :) )

[mjblack]

Sorry all, no improvements recently!...been moving to larger premisis, place now painted, 2 benches built, and 3rd nealr there!

so loking to get back online next week, when machinery is all moved!

mike

[mjblack]

Hi all, just posting one of the new F/A-18 Hornet Vids, see what you all think?

please visit our site for the other Vids.

http://www.rcelectricflight.com/f-18fast.wmv

Best regards

Mike.

greenairdesigns

[Franz2002_01]

Hi, I am in the process of finishing my Greenair F-15.

As I am trying to decide on the battery hatch position I am wondering where the CG (center of gravity) should be. I looked on Greenair's website and in the docu but could not find it.

Also does someone have some closeup picture of the elevon linkage system?

Regards

Franz

[ctoms]

I am nearly finished with my F-15 and was wondering if I would be able to add landing gear and do a rolling takeoff and landing. I may even add a servo and make the nose steerable. I am not looking for max speed with this plane but it still needs to fly and I have never used a launch ramp before and the idea sort of intimidates me.

I do not know where I would mount them but I have a pretty good idea.

Thanks
Charlie

[jefferyj]

GWS carries the micro retracts you could use them on the F-15. I think that mike used them on his mig..I don't see a problem taking off from the ground you just need clearance for the prop in the back and speed..

Thanks,
Jeff

[jefferyj]

Heres a link to the retracts
http://www.balsapr.com/catalog/wheels/UltraSmallRetractsView.asp?ProductId=T713518

Thanks,
Jeff

[bmaaa]

One question about the wing : does it use a "real" airfoil, or is it just a "flat" depron sheet ?

can you post a picture of the profile of the wing please ?

many thanks

[termite]

All of the GAD kits have a profiled wing NOT flat plate!!!!

Randy
www.dynamoelectrics.com

[roccobro]

Looking good Gouda!

Was ready to maiden my GAD F5a tomorrow when I found the NIB Cirrus 6.5 servos were shot. :angry:

Randy, thanks for the support and I love the Little Screamer motor!! 7x3.5 @ 13,300 RPM, 7.8A from a 3s iRate 830 pack. Guessing around 16+ oz's thrust from thrusthp program (1.27#'s :confused: )

Justin

[Alex B]

First of all I would like to say hello as I'm new here and on to flying jets...will see if I can fly it safely :eek: once it's finished !!!

I don't want to highjack the thread but I'm almost done except for the filling before painting my GAD F15 and I'm not too sure of what sort of filler to use as in Spain is not easy to find such speciallised things...so if somebody could help would appreciate the most.

One last question about landing gears....is it really possible to fit one on this aircraft ?...will it affect handling ?

Thanks and best regards...a really helpfull forum indeed ;)

Alex :D

[RCParkflyer]

Hi Alex B,

Welcome to the RC Groups E-Zone!!

The type of "Filler" you want can be something as simple as "Paper Mache" Paste (flour and water, mixed very thin, like heavy cream) that you paint on your foam plane, and sand smooth after it drys. In the States we use thinned out Vinyl Wall Spackling (Used to fill holes and cracks in plaster walls)

Once your plane is smooth, you can paint and decal it. After everything is finished some people like to use a "Finish sealer" usually some type of water based Polyurethane sealant, like what you would brush onto wooden furniture, or outdoor sundecks, to seal them.

I hope that helps

As far as landing gear goes, You would be better off avoiding using them, as they add a lot of weight to your plane.
Any landing gear that you make has to be longer than your prop diameter, so you could land without striking the prop.
You are better off not using them, if you want to protect the bottom of your plane, just use some clear packaging tape, the same stuff you use to seal boxes for mailing or shipping.

Just cut off your motor when landing to avoid damaging your props.

ANYTHING you add to your plane affects the handling, the lighter you can keep it, the better and faster it will fly.

Best of luck, and post some pictures of your F-15 :)

Tom - Milwaukee

[roccobro]

Yes, keep it light. I just ironed on some film to my GAD F-5 to make the top and bottom distinguishable. Added a bit of strength and almost zero weight. Makes repairs alot easier than on a painted plane too. :o Plane still weighs 7.7 oz's after ALOT of repairs.

Justin

[Alex B]

Thanks a lot I will post pics once done...and before first flight just in case :p

Alex

[Alex B]

Sorry but I have a question for the experts...I've purchased a Typhoon 15/10 brushless motor along with a 20 amp controller and 1500 3 piece lipo pack...will this be ok for this aircraft ?..and which prop should I use ?...

Thanks again,

Alex ;)

[RCParkflyer]

http://www.e-flight.co.uk/shopexd.asp?id=273

These guys have your motor listed and it looks like your on the right track as far as your set-up. they have a listing of all the specifications you need including prop 9 X 6

Recomonded watts is 200 so your looking at about 18 amps @ 10C so you could go to a slightly larger 3S Pack if you want too, like a 1800mAh. Since companys are notorious for there conservative ratings you could probably push the amps even higher with a 3S 2100mAh pack (as long as you keep the motor cool).

Hope that helps
Tom - Milwaukee
www.parkjets.com

[Alex B]

Tom thanks very much again...now I can't wait to finish the plane and test it !!!


Alex :D

[jfassino]

Just got my F-15 and was looking for advice. Has anyone tried conventional elevators with conventional ailerons rather than elevons?

My first look at the kit leads me to think the plane could be setup this way with just two servos or three at most. Any thoughts would be welcome.

Got mine from Randy at www.dynamoelectrics.com
Good fast service. Thanks Randy.

Jim

[Alex B]

What do you think of this motor ? (http://www.justgofly.com/tech_450DH.htm) although it was designed for a heli seems to be a beast :D

I would like to try it on a 2 pack 1500 3S lipo set and 9x6 APC prop and 35 speed controller...

Alex ;)

[KenP]

Oh for anyone building this plane can someone try this idea. I used to have one of these planes but I sold it because of the need to bungee launch when flying by yourself. Can someone buy a bomb drop from hobby-lobby and make a bomb that looks like a F-15 drop tank. Then you have a nice handle for a hand launch then once in the air you do a fly by and drop the belly tank so you have a nice clean bottom for the belly landing.

[Alex B]

So nobody can help me out on this one ?...I'm really confused...pleaseeeee

Alex ;)

[Alex B]

Thanks to Vinnie at justgofly.com (http://justgofly.com/) my quest on a good motor for my toys has come to and end and I'll be enjoying my GAD F15 like a kid on new socks ;)

I'll report on my maiden flight and how things have developed...my first Jet and brushless set...so danger seems to be ahead or should say above your heads...lol....!!!

Cheers,

Alex

[Alex B]

Today motor from justgofly arrived and I'll be finishing the jet hopefully this week so if everything goes smooth next weekend should fly its first flight...wish me luck as I've never done it before :eek: and I'm really scared to crash it on its first take off !!!

Alex

[roccobro]

Don't be afraid of crashing. I was all jitters on my first (of three) maiden of my GAD. The repairs are quick, and can be done unnoticable if you take an extra few minutes. Be sure to collect all the small foam bitsif it doesn't stay airborn the first time. This depron is great stuff to repair. All else fail, you can graft on a new nose with the spare piece he sends with the kits.

YOU CAN DO IT! :D

Justin

[RCParkflyer]

Fly it like you stole it!! :D

[Alex B]

Motor installation and control adjustments should be done very soon....then I'm thinking on glassing the F15 to make it last a bit longer :rolleyes:

Will report how things come up at the end....thanks for the encoragement !!! ;)

Alex