combatpigg

My Feedback: (3)

Stiff stringers / spars are a good thing, but sometimes resist normal efforts to lay in like they are supposed to....but here is how to do it. Take one of those plastic tubes that you see at the K&S display rack and fill it with pure ammonia. Stuff those stubborn stringers in there for a few minutes and they will soften right up. You can CA glue them while wet, or just form them over the formers and wait for them to dry enough to glue them later. Most of the original strength will return after they dry.

planebuilder66

My Feedback: (8)

Easy on the mexican jokes, my GF is part mexican, ......Maybe that's why she's taking soo long to get her masters! Damn, and I thought she just wanted the easy life and live off of me. But anyway, pick up the pieces and start running again, it's best if you jump in head first, otherwise you'l just sit there staring at it thinking of what to do.
Good luck.

combatpigg

My Feedback: (3)

PB66, talk to anyone who was around when they were trying to build a highway that bypassed Tijuana in the 1970s. Tijuana stood to lose so much business because of this bypass that the new road suffered from constant sabotage. I think it finally took about 10 years to lay in 20 miles, no joke.

slim_pkns

Hey now... I may be slow but I'm consistently slow.

Thanks a lot for the help though! I appreciate all the tips and 'encouragement'.

I made decent progress yesterday. I should have all the remaining stringers in today and be able to move on to the next step. Based on build light's comments, the stringers should form the shape of the fuselage after covering. Some of my stringers are set in too deep while others are too far out compared to the depth of the side keel pieces. Maybe some sanding and a little shaving of the formers will clean it up later.

Great learning experience!

combatpigg

My Feedback: (3)

Nice work SP! This looks like it will be a nice flyer.

tangerine-jack

Here is a link that will do wonders for you.
http://www.ffscale.co.uk/page4e.htm


I started out in FF back in the 70's and it's still where my heart is, this web page has all the tricks and tips for a great finish for your project. Guillows kits are rotten for flying rubber band, too heavy in designs and poor wood quality. Comet kits have better wood, lighter design and fly as you would hope. Guillows DO make halfway decent RC flyers after some reinforcing.

Good luck, I'm looking forward to seeing how this project turns out. Perhaps in the future I can convince you that .049 free flight is a better way to spend your hobby dollars...

slim_pkns

Thanks for the link tangerine-jack! I'll spend some time sorting through that. I hear what you're saying about spending and I'd love to get into the right "zone" for free flight as well as small scale electric RC. I'd like to use glow but after looking around, I don't see .020 or .049 much anymore. I don't think I can buy either at my local hobby shops.

I'm still interested in getting this one in the air using electric power but I'm focused on just getting it completed now. I also started a thread for a vintage VK Cherokee Babe kit that fell in my lap and I'm anxious to get started on it. This Guillow's build may end up being for static display and experience. If you were going to do the unthinkable and make this Guillow's Super Cub a glow FF, what would you suggest?

As for continuing my build. I have almost all the stringers in place that can be added without waiting on other parts like the tail and landing gear struts. I'll post a picture later this afternoon.

slim_pkns

Finally!!! After a breakup with a girlfriend, a move to a new house, and a few months of time... I've got the stringers glued on and I'm on to the next step! WOOHOO!

Lessons learned:

I need to focus on where the stringers sit compared to the rest before gluing them in. I want them to be the furthest point out on the sides of the fuselage so that it will make a nice clean look when covered. So I also learned that is the reason you don't want your fuselage former notches to be too deep. You will have a tendency to push the stringer to the bottom of the notch to get the glue all around. Next time, any deep notches I make will be shimmed with balsa scrap so the stringer sits on top.

Next step in the limited instructions is to work on the cabin and then the landing gear struts. You can see my first of two cabin sides in the picture...

planebuilder66

My Feedback: (8)

CP, I was kidding, I remember seeing a documentary on that years ago on history channel.

slim_pkns

Good progress this weekend. I've almost completed the fuselage. Just a couple of pieces to support the landing gear struts and the last couple of stringers to glue in and I can start the wings.

TheAdge

Hey slim, great build! Looks like she's coming along beautifully. I've got a similar project going, and I thought I'd share. I don't know if you still intend to make your bird R/C, but I have some info you may find useful. My build is actually a 20" Super Cub 95. It's a very simple model, but I think it will work well for what I have in mind. And for 10 bucks, can't go wrong!

Anyway, when I'm trying to figure out if or how well a potential RC model will fly, I use two factors. Wing loading (oz/ft2) and Power Ratio (watts/lb). The power ratio is what has helped me demystify electrics a bit. Actually knowing how much thrust a motor/prop will generate is nice. I find the testing to find these figures a bit boring, and probably more appropriate with nitro models. Wattage is a measure of how much power an electric powerplant is ACTUALLY making. Most manufacturers will list maximum wattage figures for their motors, as actual wattage can vary greatly. Use a higher voltage battery, the wattage goes up. Use a larger/steeper prop, the wattage goes up. Many motors will have an optimum "stock" setup listed in their instructions. What we're interested in is the max wattage of the motor, so we can find the watts/lb ratio, which will give us a good idea of how the plane will perform power-wise. 50 watts/lb is generally the minimum for trainer-like flying and power. At 100-120 watts/lb, the plane will be able to hang on its prop. Many all-out 3D electrics will have unlimited performance at 200 watts/lb. I usually shoot for around 80 watts/lb for all-around great flying.

Wing loading is a bit more obvious, and it gives a rough idea of how fast or slow a plane will fly.

So I applied all this to my little plane, using some measured and some estimated figures. My way of asking mathematically, "is this project feasible?" For this one, I knew I'd have to change a thing or two about the design of the plane. I knew the wing would need to be a bit larger, to handle the extra weight of the electronics and keep wing loading low. In order to test different sizes if I want to, I made the wing out of 5mm depron, which will be lightened with cutout holes, and sanded to shape. I plan to cover this plane with industrial saran-wrap. Before anyone says anything on the saran-wrap, yes, I know it's weird. This is a test plane. Anyway, the wing will be secured to the top of the fuse with 4 small screws. I made the wing mount on the fuse flat, and added a couple of lite-ply crossbeams to secure the wing to. I decided that for this model, I will go with elevator and aileron control, with the rudder locked. The depron wing makes installing ailerons much easier. So without further delay, here are the specs. Keep in mind that some figures are measured, and others are estimated. If I'm way off I'm sure someone will correct me =)

****Stock****

Estimated all-up flying weight: 40g (1.4oz)
Wing area (3"x8.5" per wing) : 51sq.in (.354sq.ft)
Wing loading: ~4 oz/sq.ft

This kind of wing loading is what I'm used to with light slow-flier models. My goal was to get as close as I could to this.

****RC Converted****
(Resized wing: 4"x11" per wing. 88sq.in (.61 sq.ft)

Airframe w/ wing: ~30g
ESC: Castle Creations Tbird 9, 8g
Servos: GWS Pico: 5.5g, x2 = 11g
RX: Spektrum AR6000: 7g (big for this bird, I know.)
Motor: E-flite Park 180 outrunner, 30watts Max: 8.5g
Battery: 1-cell 270mAH lipo: 6g (more on this in a moment)
-
Grand total: ~70g (2.5 oz)
Wing loading: ~4.1 oz/sq.in
Power ratio: 96W/lb

The E-flite motor is designed to produce 30w of power on 2-3 lipo cells. On 1-cell, I figure I'll be at around 15w, which is worth the weight savings. And as you can see, the power ratio is already quite high. This will be just fine for testing (extra power is a plus for testing )

Anyhow, I hope this provides a bit of insight for your power system concerns. And my apologies for the long post

slim_pkns

THANKS!!! No apology necessary. I really appreciate the info. I'm still toying with the idea of making this a 3-channel R/C model. I'm going to put some more thought into it before I start the tail section. I'll study your info further and get feedback from others if there is any. I was actually thinking a smaller motor would be better. I really would like a scale flight characteristics. I haven't found a good gym to fly in but thought I would fly this baby indoors if at all.

Any other comments? More pictures coming tomorrow. I have a three day weekend ahead so should make some more good progress.

TheAdge

Actually, the reason I'm building this plane is because I had my first indoor gym flight the other day. My brother and I each got a Parkzone Vapor, and we've been flying them in the evening, when there is little wind. But when the wind came up, we decided to try going to the local high school, originally to use the racketball court as a windbreak, which did more bad than good. So we went over to the gym, as a bunch of the kids were leaving from basketball practice. The gym was open and empty, save for some maintenance guys who didn't seem to notice we were even there. 2 hours later, they killed the lights. But what a night! I had never imagined that smaller planes could fly so well. Anyhow, I'd say just go to the nearest school gym in the early evening, when practice is running down, and just walk on in. The worst they can possibly do is say you can't fly there.

If it's stable, scale performance is what you're after, I have another option altogether you may want to consider. A parkzone vapor costs ~$130 for the "everything you need to fly it" package. It's not really the plane you're after, but the electronics package it carries, which is beyond lightweight. Ready to fly, the thing weighs 14g! It has more than enough thrust for its size, I'd say at least 16g, as it can climb vertically. Although it's running a tiny 70mAH battery, flight times tend to be at least 15 minutes, with a 20-minute charge on the included portable charger. But here's the kicker: the ENTIRE electrical package on this plane weighs only 8g! That's motor, battery, and the real gem here: the "brick".

http://www.parkzone.com/Products/Def...ProdID=PKZ3351

This "brick" is a 2.4ghz reciever, ESC, and 2 fully proportional (i.e., not full on or full off) servos built into one unit, weighing only 3.3g! I most certainly intend to use this system on even smaller aircraft, and I may even try it on the Super Cub I'm working on now. The brick is sold separately for around $50, and can be "bound" to many 2.4ghz radios. No RX crystals! With 16g of thrust, I'd imagine it would pull a 30-40g plane in a very scale-like way. Worst comes to worst, you could always just fly the Vapor Definitely one of the most amazing planes I've ever flown, and I've flown more than my share.

Have you weighed any of your Cub parts yet?

{edit} forgot a word

slim_pkns

No, I haven't weighed any parts yet. To be more honest than before... I'm actually in Houston even though my profile doesn't acknowledge it. Ike really hit us hard and I'm trying to get back to some type of normalcy. I've been out of power since Friday at around 5:30pm... before the storm hit actually but, whatever. I was gluing a part of the wing spar in when it all started. No new pics to post since that occurred. I hope to get back at it soon!

Say a prayer for us all down here if you're spiritual!

More soon...

slim_pkns AKA Mick

planebuilder66

My Feedback: (8)

You should get a generator and mount it on a 12' pole, to keep the flood water from getting to it, that way we will never have to deal with interputions in your build thread! Well, good luck and keep trudging through it, it'll be a good flier when your done, just don't forget to add the -incidence to the motor and the right thrust, otherwise it will climb like a bear and torque to the left like crazy.

slim_pkns

Good idea planebuilder66! Fortunately, no flood water. Just no electricity. Thank God there was a cold front that moved through. It's pretty nice right now so we're really lucky! I'm on day four without power but hopefully it will be up tonight!

On the bright side... I'm alive, no planes were damaged, and I'm getting payed even though I'm not working! YEEEEHAAAA!

I did start the wing before the storm hit so I'm anxious to get back at it this week.

More soon...

slim_pkns

slim_pkns

Well, it's rough for a lot of us in the area but I've been blessed. I have power, water, and gas. There were over two million people without power early in the week and some won't get it back until mid October.

Anyway... I'M BACK TO MY BUILD! Thank God!

Working on the left wing today. Hope to have it completed and on to the right before the end of the day. Here's a current shot. Leading edge was being glued in when the power went out before Ike hit. I was lucky that I got it in correctly. Once again... feeling blessed!

slim_pkns

Didn't get the wings completed but made pretty good progress today. I don't know if it was mentioned in this thread or not but I got a good tip from someone regarding getting these die-cut parts out.

If you sand the back of the parts sheet before trying to get the pieces out, it helps immensely! I was able to get all the ribs out without any problems. There tabs for the stringers are just as bad as the fuselage former tabs were but it was A LOT easier over all. Once again, I used an angle to make sure the ribs were 90 degrees off the building board while the leading and trailing edge were pinned down.

Hopefully I can finish up the wings over the next few evenings and move on to the tail.

slim_pkns

I almost can't believe it myself but I finished up the wings this evening. After sanding, I think they look great! I used a razor blade to trim up the leading edge where it should blend into the wing tip. I doesn't look half bad for 'winging it'... (pun intended)

I used a sanding block rather than just a sheet of fine grit paper to sand everything down. I really can't believe how well the separate curved pieces blended after sanding. The pictures don't show enough detail of the curves and leading edge so I'll try posting a few more after I charge my digital cameras battery.

Now, on to the tail. If this is going to be 3-channel RC, I need to be careful about getting the rudder and elevator right. Not sure of the weight at this point. We'll see. I still need to get a good digital scale.

slim_pkns

I'm playing hooky from work today. Wanted to get on with the tail section. I've already started the vertical stab and rudder but then I started thinking...

If I want this to be a 3-channel RC model, I need to get the control surfaces right for this type of flight. Should I build the vertical and horizontal stab first and then cut the rudder and elevator out? The plans already include dashed lines where they should be separated but while I have the vertical stab pinned to it, I can't see where to make the cuts.

Another lesson to learn... Pics of current progress in a few.

slim_pkns

OK... here's a couple of pictures of the vertical stabilizer and beginnings of the horizontal stabilizer. Still can't believe how much it helps to sand the back of the parts sheet real good before cutting the pieces out. That was probably the best tip I've received for Guillow's die-cut kits.

Thankfully, I have pictures already posted of the plans with a good view of the rudder and fin separation dashed lines. I'm going to get the last stringer glued in and just cut it while pinned down. I glued the stringers in sideways so it would be easier for me to cut them in half where the rudder should separate. Hope it turns out alright.

Mr Cox

Rather than cutting those thin stringers into two, you could simply build it using double stringers at the places of the cross-hatch line. All you have to do then is to cut in the balsa parts making the outline.

The hinge can be made from the covering film if you will be using something like the solite covering, otherwise you should think of a hinge method too.

hkbii

Howdie gents. mr.cox beat me to it. I would use two stringers . Cut the angle on the leading eage of the rudder and elve, I do'nt think the stringer would be strong enough if cut in half. hkbii.

build light

Exactly right gentlemen. Those lines lines were drawn on the plane to indicate where the scale seperation of the flying surfaces are on the real thing. Purpose? So that you can draw or pen the lines onto the finished model for greater detail and a more realistic look and also to show others like yourself where they hinge if it were scale. Never was the intention of Guillow to have you split the tiny stringer material. Even better than using the double stringers would be to use 1/8" wide strips each side or a single 1/4" wide instead which you can easily gut in two and have no worries.
Even you recognised that they were too small when you elected to lay the stringers flat to give you more material left on each half once cut.

Many modelers enlarge the flying surfaces for better flying performance so long as the model is not to be judged in a scale contest. Also for simplicity many modelers make a simple straight across seperation (or up and down) for instance both the rudder and ele on the cub have "L" shapes on the seperation lines. Just depends if you want more simple or more scale.

Robert

slim_pkns

For the vertical stab, there wasn't much I could do since I had already started before the post. Thanks for the help though. I've held off on adding stringers to the horizontal stab to study the results and reevaluate.

I think the rudder and vertical stab separated pretty well. It's about the size the plans call for 3/32" wide but I know what you're saying about the strength required to hold the rudder and hinges. I guess I could glue another strip along the same stringers that form the area for the hinges or I could just brace the hinge area to try to save weight.

I'll be looking over and thinking about the elevator for a bit. I'm hoping the pics below give you an idea of what I'm up against. Hopefully I can get some more input before moving on.