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Oct 17, 2014, 10:06 PM
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ray foley's Avatar
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The "Either-Or" a club scratch build project


hi there from Toledo

I am a member of the Toledo Flying Tigers R/C Club and those of us of the retired persuasion have a "Monday morning Coffee and lie about airplanes" get together every week. During one such get together the topic turned to damaged airplanes and that some if not many of the fellows were ill at ease with what I would consider minor repairs to wings and fuselages. It seems that most of them are "ARFers" and do not have the basic building skills that are learned in kit construction or scratch building. I don't suffer from that particular affliction, being a dyed in the wool scratch builder and occasional kit builder as well as a ARF repairer for some of the guys.

So, the direction of the discussion changed when I suggested a scratch build project of an idea I was pondering. The "Either-Or" is a sport plane similar to a quicky500 on steroids except the wing can mount "Either" on top "Or" on the bottom of the fuselage. Imagine a Q500 and/or an ugly stick ( Actually an Ugly Stick and a Kwik FlyIII). These aircraft are golden oldies which were designed by the late Phil Kraft, may he rest in peace. The KF3 was a low wing pattern plane of the late sixties, 60 glow fuel, fully symmetrical airfoil, quite groovy, and PK's weapon of choice in the pattern competitions of the day. PK was the proprietor of the late lamented Kraft Systems, inc. and as such he designed the US as a test bed airplane for flying repaired equipment before shipment to the customer. The US used the same airfoil as the KF3 but with an open frame construction versus the fully sheeted KF3 wing. The fuselage lengths and moments were identical but the wing tips and tail groups were quite different due to the WW1 motif of the US and the precision pattern requirements of the KF3, but I digress.

So the KF3 and the US are half-brothers of the same father. Sadly the KF3 has virtually faded into R/C history/obscurity (well, maybe not so much, there was a recent ARF of the KF if memory serves). The US however has been in production by numerous manufacturers ever since eg: quick stick, big stick, ultra stick, etc. the list goes on and on. I am sure PK is amused or miffed or both by all this interest in his test bed knock off of the KF3. Go Figure. I guess I was not finished digressing.

Oh well, back to the "Either-Or". So what we decided was to design and build a bunch of prototypes which have about a 5' wing with 12" chord symmetrical airfoil similar to the KF3/US airfoil and a fuselage which can mount the wing as a shoulder wing or as a low wing or both, tail dragger with a simple box fuselage, built up wing and empennage, and suitable for a 46 size electric motor or glow engine. The fuselage will have a filler panel which can be installed on top or bottom depending on the wing location preference for the "both" version.

Simple, no? Yeah well maybe or...

At present we have met twice at a LHS meeting room to make parts for the "Either-Or" and thus far PK has not launched lightening bolts at us from the afterlife so he must approve of our efforts. Thanks Phil.

We have been busy making formers, tail feathers, fire walls, LG mounts, wing sheeting and have just sent a largish order to Balsa USA for the remaining building materials and are waiting impatiently for the delivery person.

So what's your pleasure today, high or low, "Either-Or" or both?

ciao -rjf
Last edited by ray foley; Dec 18, 2014 at 12:02 PM.
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Oct 19, 2014, 08:01 AM
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Stephen M's Avatar
Ray

Any pics of the QF3? I tried a Google image search and came up with Kraft dinner!

Stephen
Oct 19, 2014, 08:23 AM
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Paul's Avatar
Here you go...
Oct 19, 2014, 10:44 AM
David
dmarusa's Avatar
Sounds like a fun project. There are a few ARFs out there with changable wings. I think one is by Flyzone and called the Switch. It I remember correctly, it is for transitioning from trainer to low wing.
Oct 19, 2014, 10:54 AM
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ray foley's Avatar
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hi there from Toledo

What a great photo of the KF3!! See, Phil, some of us still remember, thanks.

I found some low res jpegs of the "Either-Or". I thought it might add to the conversation. So the EO can be built as a high wing, a low wing, or both. So far those interested will build 1 high wing version, 1 low wing version, and 2 both versions.

That there are other designs with a relocatable wing is interesting, however, this is intended as RC101, a course in scratch building of an original intermediate sport plane aimed at guys who want to build up their skill set. As such I have a lot of other jpegs of the parts and pieces which I will post along the way, let's start with the airfoil. As mentioned above the finished wing chord is 12". The sheeting reduced wing rib blank is 9 1//8" long.

Oh yeah, the EO airfoil is a little different from the KF3 and the US, so don't beat me up on that issue, sorry, Phil. I admit to being influenced by the Kaos and Ucando3D and 50 years of too many airplanes to keep them all straight anymore, so it goes.

ciao -rjf
Last edited by ray foley; Dec 18, 2014 at 12:04 PM.
Oct 19, 2014, 11:55 AM
Bellanca Kruesair
epoxyearl's Avatar
I wish more people would commit to team building...We had so much fun building together..Don, his son Eddy, Butch and my self all had favorite parts to build or cover, and we advanced with the same airplanes.......Falcon 56, Senior Falcon, 1/4 scale Cubs, then went our separate ways.

Those were a few good years, and we will always remember being part of something larger.

Good luck- great choice..
Best Regards, Earl
Latest blog entry: Ban Birds.
Oct 19, 2014, 04:23 PM
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ray foley's Avatar
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Hi there from Toledo

Last Monday we had enough pieces/parts prepared so construction could tentatively begin. I sent the guys home with parts for the Hstab, Vstab and a promise for the rudders and elevators at the next meeting, tomorrow morning. We plan to make former F3 and F4. We will also add triangle stock to all formers and the firewall. We may also sub assemble the Vstab and Hstab with 3/8" triangle stock. OOH, progress.

ciao -rjf

ps: Some views of things to come. -r
Last edited by ray foley; Oct 19, 2014 at 04:30 PM.
Oct 20, 2014, 04:10 PM
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hi there from Toledo

The balsa butchers met again this morning and continued making parts and assemblies. One of the guys assembled two Hstabs, another fellow assembled two rudders, a third guy built two Vstabs, a fourth guy made fuselage formers F5 and was kibitzing and helping, sort of, while I kept people supplied with materials, hints, ideas and tool selection for the tasks at hand. Each of the parts was a built up assembly.

The V stab is a balsa sandwich with 1/16" balsa skins, 1/4" by 1/2" rudder post and LE , and 1/4" square stick ribs. The rudder post and LE are glued to one skin and then the ribs are fitted and glued to that skin. The second skin was then laminated to complete the Vstab.

The Hstab is also a balsa sandwich with 1/16" balsa skins, 1/8" by 3/4" TE, 1/8" by 1/2" LE and ribs, with a 1/8" by 2" center rib. The LE and TE pieces were glued to one of the skins. The center rib was fitted and glued next. Then the ribs were fitted and glued. Finally the second skin was laminated to the rest to complete the Hstab.

The rudder is a tapered balsa sandwich with 1/16" balsa skins, 1/4" by !/2" balsa LE and a 1/4" by 1/2" filler to support the control horn, and 1/4" square stick ribs. The ribs and skins are planed and sanded to a "point" at the TE about 1/32" thick. Then the skins are laminated to the rudder post and ribs, etc. A 1/8" bass wood stick was then added to the bottom of the rudder and sanded to fit. Then a 1/4" triangle stick was glued to the LE of the rudder and sanded to fit.

Along the way, the balsa butchers were introduced to the Master Air Screw razor plane and balsa stripper. I am sure they will be looking for their own real soon. They were also introduced to my collection of PermaGrit sanding tools for general sanding and shaping and removing CA from their fingers. One guy was so into his gluing and fitting that he glued himself to a stab skin -- Doh! no, not me.

So now we have enough Hstabs, Vstabs, and Rudders for the initial build. Next week we will build elevators and tie bars. The balsa order should arrive by then so we can also start cutting fuselage sides. The dorsal fins will be fabricated later on after the Stabs are fitted to the fuselage.

The idea of cutting the ribs ourselves, 16 root ribs and 72 other ribs, went over like a lead balloon and the consensus was "How about laser cut ribs?" So we will look into that option.

There is a fair amount of work in a prototype build but spreading the work amongst 5 people makes it really is easy. However for most of the balsa butchers this is a first time event and the original idea still applies-- learn about building r/c airplanes and, oh yeah, actually build some airplanes while we are at it. Cool!

ciao -rjf

ps: the formers F3 and F4 will have to wait for now, I left the home -- DOH! -r
Last edited by ray foley; Nov 04, 2014 at 02:26 PM.
Oct 23, 2014, 09:28 AM
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Hi there from Toledo

One of the balsa butchers found a local sign company that could laser cut balsa and lite ply. So I prepared a test file and took some balsa and ply wood to them to evaluate their capabilities and so forth. After a few hours samples were cut for evaluation. The quality was good for the balsa and ply wood, however the price quoted was prohibitive. Time for plans B, C, etc.

ciao -rjf
Last edited by ray foley; Nov 04, 2014 at 02:27 PM.
Oct 23, 2014, 10:26 PM
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hi there from Toledo

I attended the Weak Signals meeting tonight and asked if anyone knew of a good laser cutter.

One fellow said he had a laser cutter but no computer nor software to run it ...Hmmm.

Another fellow said he has a CNC 3 axis milling machine and he has made lots of ribs and all he needs is a dwg or dxf file ... double Hmmm. I would also have to supply the balsa stock ... okay.

Well at least we have some options to explore ... Cool.

ciao -rjf
Oct 25, 2014, 10:09 PM
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Hi there from Toledo

Well, the UPS truck brought a box from Balsa USA. All the wood was of good quality and arrived undamaged, hooray!

Part of the original plan was to cut our own ribs but the balsa butchers opted for laser or machined ribs...Hmmm. But, before the change of direction, I had ordered the 3/32" sheet for the ribs, quite a stack and paid for too. This definitely tips the rib manufacturing toward the machined ribs.

Laser cutting is the current high tech method but the burned edged discolor white ultracoat if you don't sand off the char, extra work. Machining may need sanding touch up too. Six of one, 0110 of the other. Oh well, so it goes.

ciao -rjf
Oct 27, 2014, 01:29 PM
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ray foley's Avatar
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Hi there from Toledo

So we, the balsa butchers, went to the HTUSA meeting room after coffee this morning only to find the parking lot filled with resurfacing equipment and surly looking crew members. The HTUSA was closed for the day ... Hmmm, how rude.

We will try again next week, I was able to help a newbie with questions regarding a plastic canopy versus his balsa replacement, and TE construction techniques. So the day was not a complete wash out.

I will meet with our local supplier of machined ribs this week and see how it goes.

ciao -rjf
Oct 30, 2014, 02:02 PM
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hi there from Toledo

I met with Kevin of Matney models last night and we machined ribs for the Either-Or wing. Kevin used his 3 axis milling machine, totally cool, and showed me the ins and outs of cutting ribs with his machine. I had made a dxf file of the rib design which he imported to his software package. We then laid out the ribs and balsa sheet size for best fit and maximum part yield, an interesting process which can be automatic or manual. We tried both but manual gave the highest yield. A couple hours later there were enough ribs for four airplanes, subarctically cool ( my highest praise, if you were wondering.)

The ribs need a little sanding before construction, no issue there. So now I am preparing Kit packages of all the previously made parts and subassemblies. I am also checking the plans for any last minute stuff we may have neglected. ( Like: formers F3 and F4, the battery mount floor, servo rails and supports, oops!).

Well this is supposed to be a winter build project so no hurry, no worries.

ciao -rjf
Oct 31, 2014, 05:21 PM
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Hi there from Toledo

The ribs have a 1/2" hole just behind the spar as shown in post # 5. These holes will play two roles, firstly, as an alignment tool for sanding the balsa fuzz off the ribs and, secondly, as a channel for the aileron servo wires.

So I stacked the ribs for one wing on a 1/2" aluminum tube that I got at HD. I had to chamfer the end of the tube for easier fit of the ribs, then everything went well. The stacked ribs were then aligned at the TE. I then took a scrap of 1/4" square hard balsa stick and installed it in the LE notch, a nice snug fit. Then I T-pinned the stack at the LE and TE, so the ribs wouldn't wander around while sanding off the fuzz.

I like Perma-Grit tools so I used a fine PG tool to sand away the balsa fuzz from the machined edges, easy and quick. I was also able to inspect the stack of ribs and found one that had slipped during machining. That rib was removed and replaced by a spare.

The spar slots also needed a touch up, so I made a custom sanding tool from bass wood and 150 grit sand paper which fits the main and gluing spars perfectly. a couple of passes and done. I spent less time removing fuzz from the machined ribs than it would have taken to remove char from laser cut ribs. I really like the machined ribs I got from Matney Models.

I left the remaining stacks of ribs for the balsa butchers on monday so they could learn about balsa fuzz and how easy it is to deal with.

More Progress!!

ciao -rjf
Last edited by ray foley; Oct 31, 2014 at 07:48 PM.
Nov 03, 2014, 09:20 PM
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ray foley's Avatar
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Hi there from Toledo

After coffee this morning the balsa butchers convened at HTUSA's meeting room for more butchering of balsa wood, bass wood, and ply wood. The fuselage sides were laid out and cut from the 4" wide, 48" long, 1/8" thick balsa sheets enough for four Either-Or fuselages. We also cut the plywood doublers for the fuselage, trimmed the spars, the TE pieces, the gluing spars, the aileron stock, and the LE stock. The balsa strippers were busy too making the gluing spars. The Xacto knives, scroll saw, and zona saws got plenty of use today. The rib sets were defuzzed and readied for assembly. Before we knew it, it was 1 pm and we broke for lunch and will reconvene next week.

So the balsa butchers have finally decided that the fuselage option with the high and low wing cutouts is what will be built, maximum flexibility, cool.

I am going to build two wings, the standard 54" wing, and a stretched wing 66" version, "I like big wings and I can not lie...". I like floaty airplanes, so it goes. The stretch was easy, I merely cut the spar wood to 36", and increased the rib spacing to 4.5" in the outer wing bays, no changes to the sheeted root ribs. . Of course, the shear webs were also increased in the outer wing bays.

I started a dry assembly of the stretched wing today after lunch. The longer wing panel framed up easily, I like building planes, Can you tell?

Ciao -rjf
Last edited by ray foley; Nov 10, 2014 at 08:03 PM.


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