Re: Baby Flite Streak build thread

[RknRusty]

I'm still working on the wing. Going slow because my son and his entourage came to visit for a couple of days. The lead edge problem is all fixed and test fits into the fuse perfectly. I used Titebond in a Monoject priming syringe to strengthen the joints inside of it.

I almost had a catastrophe, y'all would have laughed your asses off at me if I hadn't reacted quickly enough. I was shrinking some heat shrink tubing around the leadout connection at the bellcrank. I was using a tiny torch, and I nicked a rib with the flame and it started flaming up like flash paper!
I blew out the flame but the smoldering kept consuming balsa like flesh eating strep. I finally spit on my fingers and pinched it out. Good save. I can imagine me posting to my build log that the whole thing was just a wing skeleton shaped pile of ashes. I cut a new rib-tip and replaced it and it looks like it never happened.

I'll do a little work on it tomorrow and put it on hold. I have hand surgery Thursday and so will probably be out of action for a couple of weeks.

[Cribbs74]

Keystone model building!

Good one Rusty, glad it's all sorted. What's the hand surgery for? I assume it's not because you burned your fingers pinching out flames.

[Ivanhoe]

Open flame + balsa + glues = Aaaaaaaahhhhhhhhh!!!!!

Never, EVER, get a flame near a model! shrink tubing etc. with a heatgun or a soldering iron

[RknRusty]

Open flame + balsa + glues = Aaaaaaaahhhhhhhhh!!!!!
Never, EVER, get a flame near a model! shrink tubing etc. with a heatgun or a soldering iron

Yyyyyyep, I'm thinking that too.

I meant to mention above that I added an extra brace to the bellcrank mount so I don't crack it pulling it out of the stooge like what happened to the Jumpin' Bean.

Keystone model building!

Good one Rusty, glad it's all sorted. What's the hand surgery for? I assume it's not because you burned your fingers pinching out flames.

The surgery is for what I hope is carpal tunnel syndrome. For the last 8-10 weeks, I've had no sense of touch and hard tingling. Luckily I have a patch of feeling on the side of my right thumb, so can feel if something is hot, cold, smooth, rough, etc. Sometimes find my hand is empty when I thought I was holding something. It's pretty common in dialysis patients, and if that's really what it is, it should greatly improve. If it works, I'll have the other hand fixed later.

[RknRusty]

Here she is. I'll post a writeup tomorrow.

[RknRusty]

I started a thread over at RCG asking about the rudder placement. Yes... I... I... cheated on CEF. They have a lot of Flitestreak builders, but I never did get a satisfactory answer. It's not critical, but if you want to take a look, and have anything to add. We can post about it here.

http://www.rcgroups.com/forums/showthread.php?t=1648469

Here are the pictures of the plans and instructions:

[SuperDave]

Rusty:

Does the BFS call for offsetting the engine just a twitch?

My Baby Ringmaster doesn't allow very much rudder offset so I'm thinking of offsetting the engine too. I can always adjust the engine offset if the BR pulls too hard in flight.

The BFS has a much larger wingspan than the BR (26+" vs 18")

[Ken Cook]

Hello Rusty, looking at the the picture of your rudder, I see a problem with the way that grain is running in R1. That grain should be only running vertical or slightly angled to follow the leading edge of that part. Seeing in the picture that it is running parallel to the fuse it is going to break on landing if it flips over and more than likely warp in the finishing stages.You can see the vertical grain in step 34 on the build sheet. I certainly would cut another piece. I strongly suggest not placing a washer under the engine as shown on the plans. Brodak sells offset wedges with set degrees of 1 deg, 2deg, and 3 deg. These allow for a larger footprint so to speak and prevents that pinpoint washer from crushing into the wood. This helps in turn keeping the engine tight. When we introduce rudder offset, it probably has more negative effects than positive as well. This yaws the rear of the plane outward which in turns slows the plane down as it's causing drag. Holding your plane by the leadouts, let it hang like a plumb bob. Take note to how the nose is pointing. Sweeping the leadouts forward where they exit at the tip will inherently point the nose into the flying circle, while sweeping them back is going to point the nose out of the circle. If your looking for more positive line tension sweep the leadouts to the rear of the wingtip. I fly 1/2A combat in which these planes have no rudder or engine offset. Were flying on 42' .012's. Intial line tension is created by using approx 2 pennies for wingtip weight. Too much weight will cause the wingtips to drop in the maneuvers so it's important to not overdo the weight. Line tension is then created by speed. During the build stage prior to cementing the lead out guides to the wingtip, I tape them into position or tack them with ca and then check by the method I suggested above. The majority of modern stunters have 0 deg incidence on rudder and engine offset so this doesn't slow the plane down. We also have a .15 size racing event known as clown racing. These models have high powered .15's that actually have engine inset. This gets a little hairy on takeoff especially when were flying 3-4 in the same circle. But again, no rudder offset and engine inset which still keeps plenty of line tension when up to speed. This is something I don't recommend for the beginner but it certainly allows for quicker speeds. For initial flights, having engine offset may give you a better piece of mind so I would use it. It's not permanent like gluing the rudder and can be adjusted to suit. The Baby Flitestreak is a real nice flying plane. Ken

[RknRusty]

Rusty:

Does the BFS call for offsetting the engine just a twitch?

My Baby Ringmaster doesn't allow very much rudder offset so I'm thinking of offsetting the engine too. I can always adjust the engine offset if the BR pulls too hard in flight.

The BFS has a much larger wingspan than the BR (26+" vs 18")

Yes it does call for a little engine offset. I'm probably going to mount the rudder straight and if I decide I need some outboard rudder I'll add an adjustable trim tab.
Shawn, I know about the rudder's grain, I have already cut a new one. I don't know what Brodak was thinking with that. And the wood is not going to be the surface supporting the screws. I will look into the wedges too.

I'm trying to reconcile what the booklet says with what I see in the plans. If there was an overhead view, I could see how the rudder is supposed to be positioned.

[Ken Cook]

Rusty, this is what happens in commercial products. Many times kits were changed as well to get the kit into the box. Since balsa would come in 36" length's they did whatever it took to minimize the waste. At least it was easy enough to cut another. Rudder offset was just something that was traditional. Many designers used it through the decades. I found that models that I would take the rudder off flying low inverted would inherently fly better without it. For the little offset that you would be able to provide on the Streak your more than likely not even going to notice it's performance qualities. Your going from one side of 1/4" fuse to the other for the entire length of that rudder. It would be more of personal preference. If I may add another suggestion. The plans show the centerline of the gear axle even with the front of the leading edge. The causes the plane to trip on it's gear on landing. I personally don't like to bend the gear if I don't have to. It would be better to swing the gear forward about a 1/4" forward of what the plans show. Seeing your picture up above , I see you already drilled for the copper thread to tie the gear to the fuse. Ken

[RknRusty]

Okay, for the next topic: Finishing, and I'm going to need advice with this. I should be there next week. I am well practiced with Ultracote for the base layer. But I want the traditional color scheme on this plane. Here is what it should look like:


I hope I can find red paint for the fuselage that matches the red on the wing. What I have never done is a multi colored scheme like the wings. I'm thinking I should use white to cover the entire wing. Then use trim strips for the other colors. I think Ultracote makes trim strips, I know Monokote does. Does anyone have experience laying down the dark blue and red strips? Laying the dark blue down on that wing tip looks tough. Any tips and tricks for not botching the job?
As usual, Thanks,
Rusty

[ZACATTACK]

Why not ultrakote the fuselage Rusty?? You can apply this covering anywhere on the plane I believe!!??

[RknRusty]

Paint is easier, mask and blast. With a good clear coat it keeps its glassy shine better too.

[dinsdale]

Titebond + Monoject

Bingo! I hadn't thought of that. I've never built with wood glue, but it should be more flexible, strong and hopefully lighter than epoxy. I see a trip to Lowes in my near future. I have one of those curved tip Monoject priming syringes. Thanks, Ahrma.

When I was a student manual arts teacher we, as a class, had to make a whole heap of "joints" out of 3 common types of timber used in cabinet making. eg 4 cross halving joints in pinus radiata, 4 cross halving joints in nyatoh and 4 cross halving joints in jarrah. We had to do the same thing for 3 other common joints - 48 in all. The joints had to be prepared meticulously. We then glued them and clamped them in accordance with the directions on the containers of slow epoxy (Araldite), Selleys Resorcinol, yellow aliphatic resin and good ol' white PVA (Selleys Aquadhere).

We then "opened a book" on which glues would turn out to be the strongest. I put all my money on the epoxy for every joint and every type of wood. So stop reading now and decide amongst yourselves which is the strongest glue.












A week later we began testing all the joints to destruction. To my complete surprise and dismay (I lost a lot of money), the glue seam failed on only 1 of the 48 samples, and that was Resorcinol on Jarrah in a cross joint (1 piece of wood at rt angles across another - very simple) In ALL other cases the wood itself gave way whilst the glue seam remained intact.

So, if the joint is going to remain dry (either not in water or else well sealed) then it's just a case of pick one and go. Given that more often than not it's balsa your gluing you'd almost get away with flour and water . PVA will soon fall apart when it gets wet and unless there's a positive locater nitche of some sore it can "creep" over time. It does remain pliable though. Yellow aliphatics are sort of water resistant(ish), are less pliable than PVA but won't "creep". Epoxy is waterproof, remains pliable and won't "creep". Resorcinol is waterproof, dries hard and brittle, but won't "creep".

ps Any terms you don't understand - Google is your friend!

[Ken Cook]

Rusty, I'm a fan of dope of silkspan and use it extensively. The problem though is that when using it on 1/2A size planes it will get damaged. There's just no avoiding it and it can be a pain in the rear. More than likely it's the lightest covering out there assuming you don't go too heavy on the dope. One way to achieve a light colored finish is to apply the silkspan and continue to build clear coats on it. I now use a product made by Dave Brown known as Flex-All http://www.dbproducts.com/store/flex.htm which gives the silkspan flexibility almost to the point of iron on film coverings. Leaving the silkspan clear, you can trim colored Jap tissue and apply the tissue to the doped framework. I apply the tissue by just brushing thinner over it after the clear coats are on the main frame. More of a old school way of finishing but extremely light. Follow the tissue with additional clear coats. Domestic tissue like the type used in wrapping gifts can be used as well except that Jap tissue already has one side shinier than the other which allows for less filling and dope. Finishes like this will fade overtime when exposed to the sun for long periods though. Ken

[SuperDave]

Shawn:

I strongly suggest not placing a washer under the engine as shown on the plans. Ken

Shawn:

Curious, why not?

For mounting my TD .049-.051 engines I use #2X56 cap screws secured by #2 Nylok nuts with #2 washers. If I wish more offset I can always add more washers under the engine's forward mounting lugs. With Nylok nuts in place I don't tighten the cap screw enough to crush the underlying wooden mounts.

Offsetting wedges may be available but are not as convenienent or or inexpensive as #2 washers.

Comment please?

[Ken Cook]

Hello Dave, having that tiny little washer under the lug is just going to crush the washer in due time. Maybe not immediately but it will eventually. When the engine does find its way loose more than likely your going to see grayish oil all over the nose of the model. Aluminum when exposed to oil and grit quickly make a lapping compound that can really even oval out the holes in the case. In general especially in larger models using cast cases, it's just not a good practice as it can put a lot of stress on the case. Yes it's cheap and yes it works (temporarily). My Brodak Baby Flite Streak has so many flights on it the nose is getting a bit soft due to oil soaking. I've had to put 3/32 aluminum pads under the engine lugs for the same reason. I use it as a temporary fix then use alternative methods. I was just making a suggestion. Ken

[SuperDave]

Thank you for the explanation Ken. (Shaun?)

I'll initially go with washers until I determine the amount of offset needed and then switch to something that you have suggested. Any CL plane needs a degree of "pull" to keep on the outside of the flying circle; too much offset causes the plane to fly "crab-like" which detracts from plane performance in my experience.

[Ken Cook]

Just for record Dave, my name is Ken. I apologize for the confusion. My son Shawn actually signed onto the forum and it was just easy for me to log on. I will create my own account so no one is confused. I'll even figure out how to post pics someday. He does that for me. I guess I'm just old. I do however agree to your statement that too much offset causes the plane to really act funny. I in fact have foregone all rudder offset and engine offset on all new models. I do have older models that still use it. It's just to difficult to go back and straighten rudders for instance. I had a Jumping Bean that had almost 5/16"-3/8" offset and flew terribly. I stated in my one post above that on one particular day flying low inverted that the rudder hit the ground and broke off. The model instantly flew better. That rudder was cut and glued back on straight. I also tend to look at a model that should last forever. My methods may seem unorthodox, I'm just always trying to constantly improve on building and methods to increase the longevity of the model.Ken

[RknRusty]

Titebond + Monoject

Bingo! I hadn't thought of that. I've never built with wood glue, but it should be more flexible, strong and hopefully lighter than epoxy...

...So, if the joint is going to remain dry (either not in water or else well sealed) then it's just a case of pick one and go. Given that more often than not it's balsa your gluing you'd almost get away with flour and water . PVA will soon fall apart when it gets wet and unless there's a positive locater nitche of some sore it can "creep" over time. It does remain pliable though. Yellow aliphatics are sort of water resistant(ish), are less pliable than PVA but won't "creep". Epoxy is waterproof, remains pliable and won't "creep". Resorcinol is waterproof, dries hard and brittle, but won't "creep".

ps Any terms you don't understand - Google is your friend!

Hmmm, I suppose I kind of knew that, academically anyway. But I get lost in over thinking frequently. But you're right, glue should be like a weld, stronger than the surrounding material. The only argument I can think of for more flexible glue, is that a springier compound might resist transmitting shock throughout the impact area thereby reducing cumulative stress fractures.

Ken, sorry but I'm not going old school, I'm using the product I'm good with for covering, Ultracote. But I've never done multi-colors before, so I need to have a plan before I go to the hobby shop. I'll probably get Ultra-trim and stick it over a white base which is the center color. I never have used Monokote, but I read that their trim is heavy and Ultra is not. I hope that's true. It must be, I read it on a forum. Now what I'm hoping, is that some of you who are skilled Ultracoters, can help me get this stuff laid on so it doesn't look like a kindergarten art project when I finish. I'm open for advice with this.

Back to the rudder for a moment; I didn't have any 3/32" balsa so I cut a new one out of 1/8", to be mounted straight on the centerline. I sanded a pretty airfoil shape on the inboard side. I don't know if that little bit will give it any angular pull, but after reading here and at RCG, of the planes that flew better with no rudder, that's okay too. But it looks cool, and that extra 32nd" isn't much weight difference. I sanded a lot of it off anyway.

[Ken Cook]

Rusty, I had a lot of people tell me that Monokote is no good due to weight. I truly don't believe that to be entirely true. I certainly think Ultra and also Monokote make a fairly light finish and really durable. The other plus is that you can twist and tweak the wing with a little ironing a lot easier than you can do with dope and silkspan. I got a pic of my Flitestreak. All up weight is 7.48 oz's. I think that may a be a bit porky. That's 3 brushed coats to seal wood, one brushed attachment coat for silkspan, 2 brushed coats to fill silkspan. The entire plane was sprayed white mainly a blocker coat. The other trim colors were masked and sprayed followed by two spray coats of clear. Colors were Brodak and final clear coats were Sig Lite Coat. A lot of work actually. I'm quite sure I could've knocked 3/4 oz's from this plane doing a bit more sanding. Ken

[ZACATTACK]

What would be a weight comparison with Monokote vs your job Ken?? Nice plane!!

[RknRusty]

Yeah, that's a pretty one. You have what I plan to do, an aluminum plate between the engine and the wood. I want to do that on both sides. Have you ever had a hard nose-in crash?

[Ken Cook]

Rusty, I did have a bad crash, The Flitestreak has a decent airfoil. It can get a little floaty so don't get caught into the wind at the end of the flight without power. I guess I wasn't paying enough attention to the fuel economy and I was overhead as well. The plane sailed across the circle and I did the no no of running for line tension. When the plane jerked it broke one of the leadouts off of the bellcrank. No structural damage but I do the beefing up internally as well. It certainly took a hard nose shot. The tail though broke directly behind the wing. With all the weight from the stab and rudder it just whipped over and broke. I was pretty upset by that. I was able to get inside and put a new leadout in by crimping it. This kind of reminds me of your experience with the fire. I clipped the tail of the leadout with cable cutters. There was a little fray of cable that kept catching on a rib. I took the Dremel with a stone to deburr it. It grabbed the leadout ripping it through the wing and breaking all kinds of stuff. I'd like to do that plate as one solid plate on the engine side. Ken

[John Goddard]

There's a school of thought over here Rusty that wood glue/aliphatics
Are best due to being flexible and indeed among other benefits lead to
A quieter model. Something to do with resonances.
I say "pass me that kicker".

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