I'm nearing completion of the wing for my Brodak Flite Streak and I need to confirm a few things. It's been quite a while since I've flown C/L. Flew a Li'l Wizard with my younger Cousin back in the 80's and before that it was back in the early 70's.

!.) Tip weight. Instructions call for 1 ounce. Sufficient?

2.) Leadout guide placement and spacing. My Flying Around book says the they should be behind the C.G. for a beginner. I really don't have the option at this point to install adjustable guides and I'm not sure they would even be necessary in my case. On the plan they are behind the C.G. which brings me to my next question.

3.) C.G. The plans show a very far forward C.G., at least compared to any RC airplane I've ever flown. The C.G. is maybe an inch behind the L.E., no where near the spar where I'm used to seeing it. Is this typical on a C/L model? I have heard that on the Flite StreaK ARF they call out a much too far aft C.G. that makes for a very tricky flight.

Power will be a Fox .35 Stunt I recently acquired. I know, the Fox isn't the best engine compared to what's available but my interest in C/L after decades of RC flying is driven more by nostalgia than anything else. This same motivating force caused me to start gathering all the Cox engines I could get my hands on. I'm even thinking of building a C/L model to use one of the Cox .15 engines I have.




Mike

The CG on the Brodak plan is correct. I have seen several copies of George's Flite Streak plans, and that is the right CG. I also have George's proof copies of plans for the Brodak Jr. Flite Streak and the large Streak. On my Jr. Flite Streak, I put the CG @ 3/8 inch in front of the plan CG, and was quite happy with how it flew. I'd start out with the CG where shown on the plan, and move it back if the airplane is not maneuverable enough for you. My large Streak has the CG maybe 1/2 in farther back and flies fine.

1) An ounce is probably a little excessive, but for what you need it is a good place to start.

2) Leadout point (midpoint between the two leadout guides) should ALWAYS be behind the CG - but anywhere from "a little" (like 1 inch) to "some" (~ 2") is going to be fine. Mainly, you want to be sure that line drag doesn't pull the nose of the plane into the circle. Likewise a small amount of out-thrust on the engine - a washer under the front mounting lug holes - won't hurt anything, and might be beneficial in some situations.

3) CG on a Flite Streak can also be quite broad-ranged, depending on pilot experience and what the actual job you want done is. For re-acquainting yourself with control-line, 1" is probably a good start. With the very short nose of a Flite-Streak, it doesn't take much tailweight to move it rearward and all the way back to the spar would likely be way too far. And your observation is correct - Control line models are generally flown rather nose-heavy compared to RC models - about .17- .20 MGC for C/L, vs .25-.28 MGC for sport RC.

Nothing wrong with a Fox .35 Stunt, either. They are generally easy to handle and run well. DO USE CASTOR BASED FUEL, in them, though. The 16-18% Synthetics that pass for fuel these days will make your Fox very hard to live with. If the engine is well broken in, 20% oil with at least 1/2 of that Castor is OK, but 25% is better - Sig sells 25% all castor and 20% all castor fuels in 5-15% Nitro. So Powermaster, I think.

Thanks guys for the replies.

When I first read this I thought it said "Do not use" and I thought , whoa, what's this![X(] Maybe it is time for some new glasses.

I have already done a lot of reading up on fuel for Fox as well as Cox engines. When I was a kid I just went to the hobby shop and picked up 1/2A fuel. I now know that Cox engines need a lot of castor in the fuel as do the Fox .35 Stunt. One guy who responded to my question on Fox fuel said use at least 25% oil, preferably 29% with at least 50% of it castor.

I'm assuming that 10% nitro is sufficient? I'll probably run 25% 50/50, 29% seems a little much.


Mike

29% is not a bit much for the engine, but it makes a huge mess! 25% castor will be fine. 10% nitro is really good, and 15% nitro really makes them a nice needling engine with plenty of power, which you will NOT need on the Flite Streak...
One of the reasons for the forward cg is that the wing has a straight leading edge. Swept leading edge c/l Stunters often fly with 25 to 30% MAC cg locations for competition. On control line models, the control movements are quite a bit more than on R/C models, 35 to 45 degrees on a C/L elevator compared to 6 to 8 on an R/C model, so there are some trade offs for stability.
Have fun, sounds like a great model to start back with!
Chris...

Mike,

Fox Superfuel, which has 29% all-castor lube was offered by Fox back when engines had mostly iron/steel piston/cylinders. As an iron/steel (well, mehanite/steel) engine like the Fox .35 wears out, it will gain compression by building a castor varnish on the piston. More than a few percent of synthetic will clean off the varnish seal.

Bottom line... if your Fox is fairly new, a synthetic/castor blend of ~25% will keep it clean and well lubed. If it is a very high mileage, that same mix can remove the varnish seal and you may lose compression. Switching to all-castor will restore compression as the varnish seal forms.

The amount of lube in some RC fuels is brewed for large ABC, ABN BB engines. That amount is usually insufficient for smaller, bushed engines.

Your choice.

George

I have never built a flight streak, though I've seen plenty of them and Ihave a couple of Fox .35's so a FS would be a good project for the summer. It'll be an eyeball version though since I'm poor and I'll have to make it a "stand-off-scale" and guestimate the general outlines and airfoils. (hint)
As to that .35, I still love that knuckle buster and the castor oil anti-coagulant it uses for fuel. For my first run on a Flight Streak I'll probably hang my Fox .29 on it, though, and, who knows later I might get my hands on a square venturi .36X and set it up for slow combat.
(Too bad there don't seem to be any C/L'rs here in North Central MA.)
Let me see some of those Flight streak pictures so Ican put them in my Blog, OK?

I had adjustable weight box and adjustable leadouts on both my Flite Streaks. 20-25 degrees up and down is all you need on the elevator.

25% it is then! I can just imagine what a mess 29% would make. The most I've ever run in my non Cox engines is 20% (all synthetic) and that was in my heli engines. My fixed wing got no more than 18%.

I just got it today. It seems to be in really good shape, very good compression with no excessive play in the bushings. Hopefully I'll get a chance to fire it up soon, it's pretty cold right now here in Wisconsin. What size prop would be good for it? And tank. When I bought the kit I picked up a Brodak 3 ounce tank which is what they recommended.

I'm planning to do the classic color scheme on it but I haven't decided if I'm going to use Ultracoat or Koverall. I really don't like the idea of having to dope it but it would have more of the classic look. I'll be sure to post some pictures of it.



Mike

One more question comes to mind. I had originally thought of installing a standard 2 wheel gear since I want to be able to use a stooge. Then I thought maybe a 2 gear setup wouldn't be necessary. Sure, one wing will be on the ground and if I'm launching off of a hard surface I might need some form of scuff guard but would it launch alright? It will certainly be less work to use the stock 1 wheel gear and it will be more correct but can a person get by with a single wheel unassisted?



Mike

The short answer is yes, one wheel will be just fine. I used the same setup with a stooge on a scratch build a few years back. Possibly use the tip weight as the scuff guard.?
Regarding the covering, might Isuggest you use one of the contemporary coverings so you can get it into the air and get used to flying it. Iprefer dope and silk/silkspan myself, but i've been doing old school since before the iron ons were invented. After it has survived a few circuits, maybe a full flying season, you can either build another (keeping this one as primary) or strip the covering during the down time and recover with traditional stuff.
Have a great time and keep us posted!

I think I am going to use the single wheel, mainly just because that's what it's supposed to have. As far as covering I've been going back and forth on it but the bottom line is I remember what a pain it was doping my 1/3 scale Spacewalker and I swore I'd never do it again. Any future projects requiring a paint look will be water based but the problem with them is they're expensive. I was laid off 3 weeks ago but I have some Ultracoat laying around that was bought for a now defunct project. It's red and yellow so the classic look is out. Not sure how easy it would be to do with plastic anyway.



Mike

I did both my recent Streaks with red and yellow; silk and silkspan. I've been flying my Fox stunt 35's with 11 x 5 props. The APC 10.5 x 4.5 is highly recommended for Fox 35's. Any 10 x 5 will work OK. Best, once you get flying, to try all the different props you can afford. Once you figure it out, a Fox stunt 35 is a reliable one or two flip engine. However, at the VSC last year, for my early in the cool morning flight, to compensate for the cold, I over primed. My Fox 35 started backwards three times before I got it unflooded.

Really? That's what I'm using right now! Ultracoat though.

It's good to hear the Fox is a good runner. It's been a while since I ran one, back in the late sixties when I was about 12! My older brother had one too, on a Ringmaster.



Mike

You can use the single wheel gear with a stooge just fine. Put a skid on the outboard wingtip, and toss a rag on the back of the outboard wing to keep it tilted to the right while you walk out. I do this all the time.

Well here's what I ended up with. Just gotta get some .018" flying lines and wait for a nice day. Took the engine out the other day on a test stand and it fired right up.

Really nice job! Makes me want to build one even more.

Thanks! Can't wait to get out and fly it. It's been a while since I flew C/L.




Mike

Let's see...a nice yellow spinner and an AMA number and you'll be just about set!

Mike,

I just returned to C/L after 40 years of R/C. Take it from me, the "dizzy factor" is very real for the first few flights! I only filled the tank 1/4 full giving me about ten laps of pure dizziness for about ten flights. After that, I was pretty comfortable. Until...I tried a wing over and lost the horizon. Fell to my knees like the town drunk! I was just getting comfortable when the rain/mud settled in for the past two months. I'll have to start all over again, if I ever get the rain to go away. Have fun!

Paul

I'm anticipating a little dizziness. I'm 52 and haven't flown C/L for quite a while. But who knows. I'll start with one of my 1/2A models just in case. And I plan to heed the advice I found in the Flying Around book of not fixating on the model and allowing the background to blur. Also short flights at first. I guess I'll find out.



Mike

Mike
If you want to make sure the dizzies don't get you stand in the middle of the room and hold your hand/arm out level in front of you and then spin is circles while focused on hand until you fall down. Get up after the room stops spinning and do it again and again until you don't get dizzy.
Then for fun do it with the cat in your hands! If you can out last the cat you can out last the airplane...probably.

What to tell the wife and kids your up to-that's your problem!!!!!!!!!

Mine already know that I am teaching the cat to fly.

Finally got around to flying my FS today! Went pretty well, didn't even get too dizzy. Well, at least not to the point of falling down! Put on 3 flights this morning using a stooge which worked out well. I was worried about dragging the outboard tip on the runway but it leveled out right away. I didn't do anything but straight and level since I had the elevator throws set up pretty mild but it sure did bring back memories! Can't wait to go again.



Mike

Way to go Mike

ALL RIGHT MIKE!