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#1 erich Feb 14, 2008 11:43 PM

6 Attachment(s)

Have had Ron Williams book ("Building and flying Indoor Models"), sitting on my shelf for too many years. So....have finally decided to open it up and build one of his planes, an EZB.

Have build many lightweight (GL, Mirage, etc.) RC gliders, but never anything as small and light as one of these indoor planes. Got a feeling I'm going to discover a whole new way of building.

Am starting with the wing. The book suggests using 1/16 x 1/16 or 1/16 x 1/32 sized balsa for ribs LE and TE. Decided to go with the bigger sized stuff. Light balsa for ribs and a little stiffer stuff for the LE and TE. Made a small curved 1/8" thick ply jig to cut the curved ribs on. Ribs ended up a little bit bigger than the 1/16 by 1/16 called for, so sanded em down a little. Found it pretty difficult to make perfectly square ribs and spars. Ended up with a kind of rhombus shape. Taped supports for LE and TE in place making sure the mating edges were quite straight. Am doing double gluing using Elmers. Also framed up stab and rudder, using what I feel is light wt. balsa. Cut out the prop blanks using very light 1/16" stuff.

Hopefully more to come.


#2 BMatthews Feb 15, 2008 02:13 AM

Great fun isn't it. Do yourself a favour though. Re-do the prop with 1/32. It's pleanty strong enough.

Most of the fear in making stuff too light is more in your head. Soon enough you'll find that if it can support it's own weight then it is strong enough to fly. My last EZB that I built more than 3 decades ago is still flyable. The wing spars are 1/32 x 1/16, ribs are from 1/32 sanded down to 1/64 then ribs sliced from that. Prop blades are 1/64 with a hard balsa 1/16 spar. Tail surfaces are made from the same stuff.

The next issue will be finding a supply of suitable rubber strip for this. You'll be wanting some .060 to .075 wide rubber. Do you have a supplier lined up for this?

#3 erich Feb 15, 2008 09:07 AM

6 Attachment(s)

You got that head thing right. Couldn't believe one could make a rib using 1/32 stuff let along a prop blade. So I did try using 1/32 balsa for the blade and 1/16 sq. for the shaft. This new prop I made, actually came out better then my first one, which uses 1/16 for the blade and 1/8 for the shaft. Am going to use the heavier prop however and save the lighter one for Ron Williams ezb #3 which I hope to make next. Shouldn't take me too long to destroy this first one. Bought some 3/16 sig rubber from a local hobby shop. I know someone with a stripper, who'll help me slice it down to 1/16 or so. Thanks for the help.

Enough of this fun stuff....on with the building:

Had an old FF model kit (purchased in 1985), which had some paper tissue with it. It may be Japanese tissue (not sure). Anywho, am using it to cover this plane. Mixed elmers with water and brushed on to LE an TE edges. Moistened opposite side of spars to keep wood from warping, due to using the elmers and water. Covered v. stab first, cause it seemed the easiest to do (no bends or curves). Next the h. stab. Did LE first, let dry, then TE. Didn't put any glue on ribs. Was easier then anticipated. After everything dried, cut surplus tissue with new razor. With the stabs under my belt, had enough courage to go for the wing. Did the center section first. Then glued (elmers) in one tip with proper polyhedral (3"). After that dried, attached paper to last center section rib, when dry lightly stretched paper to end rib, applying glue to LE, TE, and end rib. Had to be careful here to keep from destroying tip section. With success on one tip had enough confidence to do the other one. After trimming excess paper, wing and tail surfaces look pretty good, but are most likely way too heavy.

I did wet the tissue down before applying so it wouldn't shrink later. Not sure if it is necessary with this stuff. But decided not to chance it.


#4 Trisquire Feb 15, 2008 09:52 AM

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Reminds me of the yellow, tissue covered one which I built first. The rear one, with condenser paper, came later.


#5 BMatthews Feb 15, 2008 01:15 PM

Remember that sandpaper is your friend. Back when I was doing my indoor models I had a supply of 1/32 contest wood but no indoor stock. I sanded down the 1/32 to whatever sizes I needed. That included .010 to .012 for rolled fuselage booms and a tapered blank of .010 to .006 for a tapered rolled boom for the couple of microfilm models I made.

That last example wasn't intended to intimidate but rather to encourage you to experiment with seeing just how little you can use.

#6 erich Feb 15, 2008 02:53 PM


So what I'm using looks like tissue? Condenser paper is lighter? That yeller one looks mighty familiar. BMatthews, you succeeded on both accounts. Wait till you see my third prop.


#7 Trisquire Feb 15, 2008 05:07 PM


Originally Posted by erich

So what I'm using looks like tissue? Condenser paper is lighter? That yeller one looks mighty familiar. BMatthews, you succeeded on both accounts. Wait till you see my third prop.



Yes, condenser paper is lighter. I'm not sure what EZBs are covered with these days. It might be some kind of film. Your plane is well constructed. You'll get some nice flights out of it.


#8 TheNightowl Feb 15, 2008 09:52 PM

Tim Goldstein, at A2Z, bought out Peck's when Sandy Peck retired, and also apparently picked up most of what Lew Gitlow was carrying from Indoor Model Supply. Their website is here: http://www.peck-polymers.com/store/
(Scroll down the right side of the page a ways to find their free-flight supplies.)
They carry the .09-.05 micron (yes, micron; under "covering") thick film that is used to cover indoor models nowadays. MUCH easier and more consistent than the old water-poured microfilm.

A good introduction to indoor models would be any of the Science Olympiad kits.

F.A.I. Model supply has some stuff, and of course is the home of Tan rubber (Super Sport, now). But to get smaller than 1/16th anymore, I think you'll have to have a stripper.

#9 erich Feb 15, 2008 10:02 PM


Hope your right about the plane, will find out soon. There's a fun fly at a local gym coming up, hope to have this plane flying there.


Will use some of the new films soon, just want to do a plane or two using the old tissue, wet down, dry and iron, method. Don't know why I am going this way, but
it is the way am going to build a few of Ron's EZB's. Maybe just to appreciate the new and possibly better ways of applying covering. Have ordered a few of A2Z's kits. For now am going to work my way through a few scratch built ezb's. Thanks for the help.


#10 BMatthews Feb 15, 2008 10:23 PM

The new films may be easier since you just roll them off and use them but I still have very fond memories of the magic moment that I pulled my first sheet of microfilm off the home made pond of water that I set up on my mom's dining room table while she was out for the day..... I was even more agiggle when the recomended water mixed with spit worked as a covering "glue".

Rolls of film...... PAH!


Erich, one thing about playing with indoor. You'll never be able to look at the "overbuilt" outdoor models the same ever again. Every aeromodeller should have a chance at a couple of seasons at least with indoor. It really teaches you just how little you can get away with using and still produce a flying machine.

And it's damned good fun to boot.

#11 TLyttle Feb 15, 2008 11:46 PM

Amen to that!!

#12 erich Feb 16, 2008 02:43 AM

You guys are making me extremely anxious to fly this thing. Well maybe next day or so, have almost got it done. Wasn't sure whether I'd care for this kinda of micro building. To my amazment, have discovered I DO LIKE IT. A lot different from putting together a 14' span, Cross Country Ship (glider). One real great thing is, a whole plane can be built in a few days, or maybe even a day if I get good at it. Am used to taking up to 1/2 a year to put together a ship. Great to see something take shape in a much shorter time span. Also makes it possible to make more mistakes, and fix em up.

Well back to the bench.


#13 erich Feb 16, 2008 02:58 AM

5 Attachment(s)
Time to put together a propeller. The book (Ron Williams') called for a bottle 4"-5" in dia. Didn't have any left over from my drinking days so...made a balsa propeller block. Using small block plane roughed out block then finished with some sanding and 2 coats of epoxy resin. The thing should last forever. Cut out some blade blanks from light 1/16" balsa, then did a lot of presandiing, to taper blade from center line out and from base to tip. After soaking blade in hot water and ammonia for 5 min. lined up blade onto block and wrapped with 1" wide linen strips. Cooked at 250 deg. for 15 minutes and served it up. The blade came out with some real cool looking curves to it. Did the second blade then glued them to 1/8" sq. hard balsa spar. Had made the prop alignment jig, called for in book. But ended up aligning blades and spar using eyesight and a small steal ruler. The jig just kinda confused me. Anywho the prop looks good from my house.

Bent up some .015 size wire used to make the prop shaft. Had to make up two. On the first one, forgot to insert shaft through prop BEFORE making last bend. Duh!!

Made up 2 little aluminum washer out of some thin scrap, I had, and a teflon one, for shaft bearings. Hardest part was making them round, used a nail file to round off edges. Also made up a small mount for front of motor stick, glued it on with a little 5 min epoxy and super glued a small strip of kevlar tow around that and also the rear, rubber hook, which I bent out of the same .015 wire. So all the parts are pretty much done.


#14 Trisquire Feb 16, 2008 08:34 AM


Originally Posted by BMatthews
.........Erich, one thing about playing with indoor. You'll never be able to look at the "overbuilt" outdoor models the same ever again. Every aeromodeller should have a chance at a couple of seasons at least with indoor. It really teaches you just how little you can get away with using and still produce a flying machine.

And it's damned good fun to boot.

........and your future RC sailplanes will be lighter.


#15 BMatthews Feb 16, 2008 11:07 AM

She looks great Erich. The prop came out looking nice. You're obviously starting to get your mind wrapped around this whole indoor thing and realize that custom wood sizes are only a few strokes of the sanding block away. For that prop I sure hope you meant 0.9 grams and not 9. Or was that 9 grams for the whole model?

And I see a knot in that motor. I sure hope you're not planning on using that for any flying. It's WAY too big.

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