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#1 Herb Oct 17, 2009 02:21 PM

F-86 Sabre (90mm) Fast Foam
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Here's my latest project, a large FlyFly (or Fly Fly ) F-86 Sabre a la JePe Fast Foam,




The model's wingspan is around 55.9 inches, the length around 55.5 inches.

The original Sabre had a wingspan of around 37 feet, so that gives the model a 1:7.9 scale.

I entirely glassed the foam airframe using multiple layers of 3/4 oz glass cloth & laminating epoxy.
Now it flies on a 90mm fan on 9S lipos (4000mAh 40C's) at ca. 2900 W.
Weight rtf is around 8.3 lbs, so it's rather lightweight for its size - but nevertheless still reasonably fast and jet-like.

Here are the original instructions. An inspiration on the surface prep was the Dutch Master JePe Fast Foam site: http://jepe.org/

The main motivation for the project was to have a nice lightweight F-86 Sabre in the 90mm fan range, suitable for some
moderate aerobatics.

F-86 Video (Jan 2010):

F-86 Sabre EDF (JePe Fast Foam) FlyFly (2 min 50 sec)

Edit Sep 7: Added Guy H's pictures (Canon 7D) :) .


#2 Socomon Oct 17, 2009 10:53 PM


Any plans to clean up the ducting while you are at it. Have a look at Jjanti's ducting in the FlyFly f-86 thread. This plane will benefit quite a bit from a more scale nose and intake ducting that doesn't dramatically change diameter along its length.

it's a great airframe otherwise. I flew mine quite a bit until I sold it last month.

#3 HobbyCNC Oct 19, 2009 07:04 AM

Do you mind sharing with us the origin of the aircraft? Who's kit?


#4 Socomon Oct 19, 2009 07:06 AM


#5 Herb Oct 19, 2009 06:28 PM

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Originally Posted by Socomon
... Any plans to clean up the ducting while you are at it. ...


Originally Posted by Herb
... fully ducted intake & removable fan installation ....

I already made the intake ducts, I will post a picture at some point when I have a chance.

Dave, it's the FlyFly F-86 Sabre, http://www.flyflyhobby.com/eng/product.asp?pid=35









#6 Herb Oct 21, 2009 01:02 PM

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Here's a picture of the redesigned, more scale, intake (made out of yellow foam), and of the full intake ducting (reinforced rolled ply).

The original intake is 72dm^2 which is way too big for a 90mm fan, and still even too big for a 101mm fan (70dm^2 fsa).


#7 Herb Oct 21, 2009 01:09 PM

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I pressure tested the new retracts and they leaked. The air leak was traced back to a set screw that had been secured with some un-identifiable leak-prone substance.

Problem fixed with 5-min epoxy. Afterwards did the same on all other retract set screws.


#8 Herb Oct 22, 2009 07:11 PM

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EJF sent my a new intake as well as new cockpit set with pilot :)

Here's some more details on this cockpit kit:




#9 Reco Oct 23, 2009 10:56 AM

Is the RC Warbirds the same one as the FlyFly? And how well does the stock non glassed fly? I am think of getting one I have 2 brand new WemoTecs Midi's that I have been searching for home for, if its a great plane I might buy 2 and glass one like herb doing. By the way nice job looking good.

#10 Herb Oct 23, 2009 03:40 PM

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Originally Posted by Reco
... how well does the stock non glassed fly? I am thinking of getting one, I have 2 brand new WemoTecs Midi's that have been searching for a home, if it's a great plane I might buy 2 and glass one like Herb is doing. By the way nice job looking good.

Thanks, yes I think it's always the same large foam (flyfly) one.

If you do a search on youtube you will find quite a few videos of it.


Out of the box on 6S is seems to fly like a very large parkfyer :) .

This is one huge plane (wingspan 55.9 in)! It will take quite a bit more power to fly jet-like..

I've had the Kyosho F-86 (wingspan 39.5 in) for a few years, and it flies on 1300W. This new one is much bigger! It will take > 2600W to fly right.


Original Nick Ziroli review in MAN:



#11 Herb Oct 25, 2009 03:18 PM

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I did some work on the wing in preparation for the glassing.

The aileron servos and retract mounts were installed.

Then the bottom wing covers were reinforced on the inside with lighweight fiberglass tape and laminating epoxy to give some rigidity to the wing. I know it's not herex but a fg-foam-fg sandwich can be very rigid.

Then the covers were glued on using lighweight pu glue. Some more spackling and sanding was needed

This is a nicely engineerd kit. I like the wing design, it seems simple and yet functional.


#12 Herb Oct 25, 2009 03:27 PM

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The new cockpit is a bit nicer than the original one, although some work is needed to get the cockpit tub to fit into the fuse opening.

The vacuformed pilot looks credible too.




#13 Herb Oct 26, 2009 11:09 AM

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For fiberglassing foam, it's known that some products work and some don't :)

I use 3/4 oz glass cloth and some of the heavier cloth (like fg tape) to cover and reinforce.

On some surfaces the cloth is applied in two layers to add strength (ie wings).

The foam surface has to be prepared very well, otherwise later you end up inevitably sanding through the glass cloth, which is quite thin.

For laying up the glass cloth, quality laminating epoxy is the only sensible choice. It is light, structurally very strong (rigid), dries hard in 24hrs and sands very well.

The first coat or resin to get the fg cloth to adhere to the foam can be very light. It is just painted on top of the fg cloth once the latter has been spread out on the surface that needs to be glassed.

Water-based products such as polycrylic are unsuitable as they dry too slow, are structurally weak and completely gum up the sanding paper.

Non-water based polycrylic never dries hard enough to be useful. Polyurethane floor finishes are way too heavy. Epoxy resin is by far the best choice.

A second coat of epoxy can later be be added, possibly with more layers of fg, provided it is mixed with microballon filler to make it again light and sandable.

Finally a coat of lightweight automotive primer is added to fill in the weave. Most of it is wet sanded away later.

Blemishes and un-eveness in the surface can be filled with thicker primer or bondo-type filler.

h2o-type water based primers are way too heavy and don't sand well at all. Avoid like the plague for these kind of jobs.


#14 vq35721 Oct 26, 2009 04:58 PM

I'm assuming she'll be ready this weekend?

#15 Herb Oct 27, 2009 02:34 PM

Nah ... It will be a while :)

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