slim_pkns

Howdy all! I'm not a very experienced model builder and the last one I built was more than twenty years ago. I wanted to get some help with a Guillow's Piper Super Cub I picked up at my local hobby shop. I've searched the internet for other builds of this model and there just aren't many to go by. If anyone can help or wants to comment, please join in.

Some thoughts:

This is advertised as a flying model and I would like to build it as one. I haven't settled on free flight or RC yet but I'm leaning towards free flight if I can find an .020 engine. It's die-cut and after attempting to get the fuselage formers out, I found it to be a real pain. I've damaged several and I may need to make some new one. I purchased an extra sheet of 1/16" balsa just in case. An old-timer I talked to out at the airfield told me about a trick he used to use that may help. He suggested I get some fine sandpaper and lightly sand the back of the parts sheet to get the parts closer to falling out. I purchased a bottle of Titebond White Glue. I've never used white glue for modeling but a lot of forum threads mention using it instead of CA since it will dry clear and sands easily. I decided this was the model to try it on. Also, I noticed the parts sheets were kind of warped when I took them out of the box. Individual parts don't look too bad but I was wondering what others thought about this if I want to build this to fly.

Any comments, thoughts, suggestions, encouragement, etc. is welcomed and appreciated!

slim_pkns

It's hard to make out but if you look at the picture of the parts sheet from my last post, you can see the warping I mentioned. Several of the sheets have a bow in them.

Here are a couple of shots of the plan:

Hueydriver

Probably the best on-line resource for rubber models is: smallflyingarts.com It's all about smaller free flight aircraft in scale/sport/glider venues. You will find loads of info on how to lighten a Guillows kit into something that will fly well. The big thing is the balsa....waaayyy too heavy out of the kit. You can use it as templates for re-cutting fuse formers but it is generally too heavy. Same with the strip stock for spars etc. You may want to reduce the number of ribs in the wing panels, lighten the formers and verticle/horizontal stab outlines, but even if you do build stock from the plans (using lighter, or sanded balsa as you mentioned), you should get this machine to give you some fun flying. The Super Cub is one of Guillows better kits from that series of light civil aircraft. Herr makes a larger Super Cub on floats for rubber power as well.

Go to the website I mentioned above and you will quickly spend an entire afternoon soaking up good gen. Also try Mikes Scale Model Pages: http://www.ffscale.co.uk/ (awesome site!!!!!) Hope this helps.

BMatthews

I built one of those years ago and used an 049 for control line flying. An 020 for free flight would be grossly overpowered unless you mount the prop on backwards. Even then there would be enough power that it would be tricky to trim.

As built from the kit the model is actually too heavy to fly decently as a rubber powered model.

An 020 with light RC gear would work as well as the smaller 13 grm brushless motors.

Tee Bee

I've built a handful of Guillow's planes and ,like others, have found most of them most suitable as static display models instead of flyers. Some of them make great control line planes but the wood is usually pretty heavy for free-flight rubber power unless you make new parts from lighter wood and strategically leave pieces out of the airframe. I do enjoy building them and having them around on display and I intend to build more in the future. I built the Super Cub you've got but I was a teenager at the time and that was about 20 or so years ago. Earlier this year, I built the Guillow's Triplane and found these forums very helpful. http://balsamodels.com/phpBB/viewforum.php?f=2 I enjoy a good, old tissue covered model once in a while but have no experience converting them to RC. Good luck.

slim_pkns

The box and plans both show .020 glow engines as options for free flight. I could see where an .049 might be over powered but .020?

BMatthews

For free flight it would be a handful. One wrong bit of trim and it would be "sticks in a bag" time. For RC an 020 would be fine since you can compensate for any bad trim.

slim_pkns

As I mentioned above, I had a hard time getting the fuselage formers out without damage. I looked over them one more time before deciding to go ahead and use all but one. I used two of the formers with broken tips and glued them back on with a drop of CA each. One piece was so badly damaged that I had no choice but to cut out a new one. I found a great tip in another thread that really helped me out. I bought a Scotch/3M Restickable Glue Stick and made a copy of the section of the plan with the former I needed. I was able to cut out the piece I needed from the plan, glue it to the balsa sheet, and make a perfect copy with a nice new sharp razor blade. Worked great!

lildiesel

You'd be surprised at how much power a Pee Wee .02 has. Sometimes I would make a simple exhaust restrictor to tame them for single channel flight. I wouldn't risk puting a Pee Wee in anything that might fly away these days: we're not going to get any more. You might consider hunting up a Babe Bee or a Sure Start and restricting that for two channel flight, but they would probably end up too large and heavy for a 24" wingspan plane.

slim_pkns

Yeeeeehaawwwww!!! Hope everyone had a great New Year's Eve. Now I'm starting the new year out right by spending my day off building!

I started gluing on the first half of the fuselage formers today. I'm not used to using this white glue but it feels pretty tacky after just a minute or so. I used an angle to try to keep them as close to 90 degrees off the top and bottom keel as possible. I think a couple of thick balsa blocks to keep the angle upright would be best but I didn't have any on hand and I'm pretty sure the hobby shop is closed on New Year's Day. Seems to be working out OK though. We'll find out for sure when I try to fit the side keel. I read somewhere that if I have to force the side keel to fit in the slots, its warped pretty badly.

digital_trucker

One thing you might want to try is using a toothpick to apply your glue. Trying to apply it straight out of the nozzle often puts it on too heavy...you want a little to squeeze out of the joint, but not much (just enough to ensure full coverage of the joint).

BMatthews

A suggestion since you're making this for RC. Before you go further run out and buy a stock of 1/16 sq basswood from one of the hobby shops that caters to serious model train folks and use that for your fuselage stringers. The added weight will be minimal but you'll add a lot of strength to help resist the vibration from the 020 or some of the harder landings that don't actually qualify as a crash. And use bass wood for the wing spars for the same reason. The kit doesn't have truly proper wing spars, just a bunch of 1/16 sq strips as I recall. Or use a stack of glued together hacksaw blades to cut in a new spar slot at the high point of the airfoil that is 1/4 deep by 1/8 wide for a hard balsa spar.

slim_pkns

digital_tucker: thanks for the tip. I'm scared of using too little glue. I'm really not used to using white glue but I understand your point. I've been trying to use a tip from another thread that suggested created a more tacky bond earlier by adding glue to the parts, sticking them together, and then pulling them apart and adding a tiny bit more glue. Wait for the second application of glue to dry for sixty seconds or so and then put the parts back together. It seems to work pretty well so far. I don't have to hold the parts together very long. When I use CA, I always try to add as little as possible. I know this is best practice.

BMathews: I'm sure you're right but I was hoping to build this one without any modifications. I'm not sure I can since I want it to fly and it has no hinged surfaces but I'm trying. I have NO experience with free flight other than rubber powered and even that was just a simple model that had an adjustable wing that moved forward and back.

How do free flight models adjust trim? What are some techniques?



I sure appreciate the help!

BMatthews

On regular free flight models the wing and often the tail is removable for transport. From there it's simple to add shims to adjust the incidence angles. The balance point is another key item that we alter to adjust the flying.

To some extent you can steam the surfaces to add warps for washin or washout to the wing and to curl in some down or up trim in the stabilizer or turn in the fin but it's best to allow for some mods that let you shim such things in rather than relying on the flexibility of the structure and covering. This need is just one more reason that Guillows kits are more geared to display than flying. They make no allowances for this sort of trimming of the surfaces.

Also this really isn't the best free flight "trainer". As I mentioned before it will be overpowered with a PeeWee. A larger model would be far easier to trim and would provide you with a lower power to weight ratio which would be more likely to survive the adrenaline filled risky first flights.

For some nice options check out the Kieth Laumer thread. Any of those designs in their original size would fly very nicely with a PeeWee.

The other option for your SuperCub would be to use a small brushed electric motor like the very cheap but capable Johnson 250 and 4 or 5 cells combined with a motor timing circuit. If you decide to go that way I've got a circuit here that I've built a couple of that works great and gives from a 5 to 50 second motor run time that is variable.

BuzzBomber

My Feedback: (4)

I have one of those super cub 95s hanging in my spare bedroom. I built it to reinforce my stick building skills some years ago. I doped it clear and added panel lines with a felt pen, never did get around to adding decals and/or trying to fly it...

frednjess

Good luck on the kit build. They're lots of fun. I have to disagree on using a Johnson 250 motor for this plane and instead would agree with the earlier comment on using a small brushless motor. Small two cell lithium batteries are very inexpensive as are the motors and speed controls. I'd also use light servos, 5 gram or less. Check www.hobbycity.com for very inexpensive parts that work very well.

I've talked with some of the older builders who have more experience with the Guillows kits and they all agree that extending the wing chord slightly will result in a more flyable plane. The increased wing area makes the plane more stable and allows for a greater range of weight tolerances.

build light

Quote by slim_pkns:
"digital_tucker: thanks for the tip. I'm scared of using too little glue."

Don't be. You will be suprised at how strong the bond is on the parts of a model this size.

The method I have learned to use and recommend is to use the toothpick method that digital_trucker mentioned but after applying the glue to bothe surfaces let them dry completely before using just a tiny bit more to join them.
You could also thin the glue slightly and still be good on a model this size. Not too thin, maybe one drop of water to three or four drops of glue. This will save even more weight and lessen the likelyhood of having large blobs of glue in places where you do not need them.

There are lots of little trick to learn when building small to save weight.

Good luck on this project!

Robert

buzzard bait

I'm with the guys who say the .020 is too much, no matter what the plans say. Back when free flight was more common, a typical wing span for a model like that, powered by an 020, would have been 3 feet. And that would be with an oversized prop and/or backwards prop.

And yes, the construction is too heavy. I once built the Cessna 170 in the same series and couldn't get it to fly on rubber even with a much larger prop than stock and a lot more rubber. I never got a Guillow model to fly well using the stock construction, and it wasn't from a lack of trying. Looking back, I'm amazed I kept at it after all the Guillow kits I built that wouldn't fly.

I later built a Sig Monocoupe of the same size -- 24 inch wingspan, high wing cabin -- very similar but much lighter construction. I powered mine with a little CO2 motor that couldn't have had a fifth the power of an .020. Total weight was 2 oz and it flew beautifully. The Guillow model will be heavier than that without lightening it.

Weight will require higher flying speeds, make it harder to trim, and increase crash damage.

With a little weight reduction it could be a nice plane. The Guillow kits do look nice when they're finished. CO2 motors are relatively rare now, but I think they are still available. They are ideal -- just the right power, and they make a delightful sound.

And of course, electric will work well too, and can be very light.

Good luck, and show us some more pics as you progress. Jim

Big Al-RCU

Slim, another way is to qpply a generous amount of glue, (enough so that it squeezes out both sides of the joint) and then wipe off the excess with a damp cotton swab (Q-Tip). It's not only fast, light and strong, but results in a nice clean appearance. Lots of guys use this method when covering with one of the semi-transparent coverings where the structure will show.
al

slim_pkns

Lots of great info!!! Thanks everyone. I'm trying out the toothpick application method but my girlfriend has no toothpicks in the house so I used a match stick and shaved it down to a point. I seems to work well for now but I can still apply too much at times as it globs down at the point. Learn something new every day I say. Thanks again!

I added the first side keel today and it didn't fit as nicely as I had hoped but I don't think it's too big a deal. I didn't really have to force it but it looks like there is a slight misalignment in the fuselage former halves. I hope it doesn't cause a twist when I add the stringers. Pics below kind of show what I mean. I don't like that some of the former halves don't touch the plan at the points that will meet the other former halves. There are parts of the side keel that stick too far out of the former notches here an there that I guess I should sand down smooth. One former doesn't sit high enough up to make a smooth transition from section to section. I'm hoping it doesn't effect my covering too much. I've never covered with tissue and dope, The models I build with my dad used that method but he always did it. Usually after I was already in bed. Thinking about it brings back fond memories though.

Anyway, I have a few more days off and the girlfriend is being extra nice right now so more to come!!!

slim_pkns

OH, almost forget to mention that I LOVE working with the white glue. I'm using Titebond All Purpose White Glue. It was cheap for 8 oz. ($1.98 at Home Depot?). It's pretty tacky after a 30 seconds or so and it really does dry clear. No more fingers stuck to stuff and having time to adjust things is really necessary for this model. Especially getting those formers 90 deg. off the keel. I have a vintage VK Cherokee Babe I'm hoping to start soon and I'm going to use white glue for most of it as well.

BMatthews

As mentioned do NOT worry about double glueing on this size of model. Single glue and just enough to wet the joint is all you will need. The real enemy is parts that are a sloppy fit in the notch. It's important that they fit well. But often you can cheat a little. If the notch is sloppy keep some small tapered slivers of balsa handy and "wedge" the gap full with the wood and then snap off the excess.

Frednjess, while I agree with you as to the brushless it is just not practical if he wants to make it for free flight. The brushless motors require the right ESC and that means radio to run it. With a brushed motor he can use a simple motor timer.

slim_pkns

I've been contemplating making it RC but I'm just not sure I can build it up to be worth the time, money, and effort. I'll have to make a decision pretty soon though. Right now I'm still leaning towards free flight. I've never tried it and the field I fly at has a dedicated free flight area that never gets used. There is a large group that meets every Tuesday and Thursday that call themselves the "Oldtimers". Some of them are SAM members/enthusiasts and I know I could get some to help me if I asked. As I get a bit farther into this model, I plan to take it out there and let them chew my ear for a while about it.

Half-A-Hec

Go ahead and make it RC! Personally, I enjoy trying to convert a free flight model to RC. I think your cub may be a good canidate as a tow vehicle for my Glider!

Hec

frednjess

I guess I missed out on the part about keeping it free flight. I just figured that it was going the RC route. With all of the latest advancements in battery and motor technology, and super low prices (thank you Communist China!)[sm=lol.gif], it is finally practical to make the old Guillows kits controllable. I think you could get all of the parts for this model for under $75, minus transmitter. I'm keen on this idea since I'm working on the 24" Cessna 170 for RC.