OK powered Dakota

The Dakota is a perfect plane for small areas. It turns tight turns to the left and glides out in circles to the right when the power cuts. Having the eye dropper fuel tank one can easily monitor the fuel level and use it as a guide to allow for short or longer duration. You also want a very anemic engine.

That is a very nice looking plane.I would like too try free flight some day. I built a Viking free flight plane 30 years ago but I never found a suitible area where I could fly it and retrive it.

Sounds like the Dakota would be the ideal FF gasser because of the way it flies, probably less susceptible to thermaling. Ken, sounds like you had a blast, and perhaps one of these days when I live in a place where we don't have as much wind and calmer days would be the kind of ticket for a relaxing early evening.

Some time back I bought plans of Joe Wagner's Osprey, which is a scaled up version of the Dakota but for RC. At 30" span, a .049 reedie or appropriately sized electric would make it an ideal sport plane for boring holes in the sky in a relaxing way. Plus, similar to the Dakota it is all sheet construction, which would build quickly. Outerzone now has a plan for it:

https://outerzone.co.uk/plan_details.asp?ID=7191

Beautiful plane !! Sounds like you had alot of fun regardless of the cold .

It looks like the Cub has an Austin Craft NV. Is it stock otherwise?

The needle valve is a old Perfect needle. The engine is completely stock otherwise. I had purchased a Atwood Wasp for it and changed my mind to use a Anderson .045. The case had some broken ears on the .045 so I decided to use the OK. I have several OK engines. I never used any of them, I just would run them on the bench for fun. I really enjoy doing that with them. Many told me this would be too much but I will say I ran it rich and enjoyed the heck out of watching it. I do have a few videos, I just need to figure out how to get them onto here.

Free flight IS lots of fun! I have a few FF planes which are great fun, and easy to build. A Baby Biwinger, an Ebeneezer, an XB-70 Valkyrie, a Flying Saucer- just to name a few.
Free flight is an entirely different experience: to let an airplane go into the sky, with no control, other than your ability to build, and test-glide the plane over tall grass, then to give it power, and let it go! Great fun!

Have you examined the internals on the Cub? (i.e. removed cylinder to see if it is a single or two port crankcase, cast aluminum or machined steel con rod)

Victor, you just took me to school on these engines. I never realized those differences prior to your post. I own 3 .049's and many others in larger displacement. I took the 3 .o49's last weekend and ran them. The two that were running strong received a Sharpie smiley face in the backplate area. I took the anemic one and put it on the Dakota. Looking at it now I can clearly see my two have dual porting whereas the engine on the Dakota is a single. The dual ported versions have aluminum rods and I don't know what's in the single ported version. On another subject, I ran the .19's I have and they're the loudest .19 size engines I have ever heard.

The Cub .049 is a fundamentally sound design (largely based on Ray Arden's .099 and .19. But the QC and haphazard parts mixing means you need luck or several engines to put together a really good one. There is literature on how to put one together with proper parts selection and doing clean up machine shop work that yield 18K specimins

I am a big Cub Fan, I have about a Dozen different ones. I am putting together a Skyray as a test bed for them now. I laugh at what people are asking on Ebay for them There was an .049A on ebay for $65.00, They are still $20.00 new from OK Engine ! I sent them 2 with crash damage from my younger days but that had a lot of sentimental value to me and he rebuilt them to new specs for $20.00 they both run great. They are a favorite of mine if you prop them right they do fine and with 20% nitro once you set them you don't have to mess with them, they are luggers not screamers I am not as into speed any more like I was when I was a kid . They are easy starters and I have a jumpin bean ready to be built when I get the Skyray done, I am going to try them in my yard on 35 foot lines. TJ

Suggestion on the Jumpin' Bean project: Use a good running .049A with tank and modify tank by closing factory fueling holes and re-plumbing tank like a Golden Bee. Also, be sure to seal tank mating surface and screws with RTV.

If I may join in on the Cub discussion and add my experience to this great discussion. I have been flying OK Cub engines for 60 years now, going back to 1958. I have actually built and flown the Dakota with a Cub B .049 and had a lot of fun with it, sadly it was a fly away. I noticed the use of an after market needle valve as I had tried the Perfect flex version on my Cub's many rears ago but gave up on using them. The problem I found with these old aftermarket needle's is that they won't lean out the engine when using the stock Cub spray bar. Years ago, 35 40 maybe, the reason we found was in the thickness of the stock Cub needle, before the taper vs the Perfect needle. In the OK Cub needle, they all measure a thickness of .061. In the case of the Perfect needle, they mostly have a thickness of .055. So we found that the Perfect needle is still sucking fuel in the closed position. You can check this by doing the old fashion suck test. By placing a piece of spare fuel tubing on the fuel end of the spray bar and sucking on the end of the tubing with the needle closed. Now there is really nothing wrong with the stock Cub needles, except they were never finished at the factory. It would have been another step in the assembly that would only add more expense to the final product. The stock needles came in three lengths. The standard one was the ones with the knurl knob on the very end of the needle barrel, it came on most if not all Cub engines that were bought over the counter in a package. Next was the ones with a 1/2 inch extension from the end of the needle barrel to a knurl knob at the end. Finally they had ones with a 3/4 inch extension and same knob set up at the end. These 1/2 in. and 3/4 in extension needles had to be ordered from the factory. I have about a dozen each of the longer needles and only use those in my flying. This has been discussed here before as to adding tapper, I will share with you how I tapper a Cub needle. Looking at a stock needle, you can barely make out the tapper, if actually measured, it would be about 3/64 in. long. You only need to double the tapper to around 3/16 in long. Now remember the needle will travel longer into the spray bar to give one a nice steady lean run. What you might find now is you may not have enough needle turns as it may bottom against the base of the venturi now. The barrel of the needle now has to be shortened to give more travel. I do all my needle work chucked in a Dermal. So I have a set of jewelers files, one especially has three flat sides and the knurled side. With the flat side resting on the long side of the needle and the actual file part against the base of the needle barrel. You can safely remove enough of the spinning needle barrel, about the same amount of the added tapper that was added. You will find that you just did what the factory didn't do, and you will have a Cub engine that will lean out nicely. Check again using the suck test to see that the new needle will actually shut off. One more thing, OK Cub used a total of three different spray bars in their engines over the years. It is important you don't mix them. I have had great success with these little engines and they are my engine of choice. Much information but not enough space here to share.

Ken is that an early style .049 or a newer B engine, I love the looks of that plane I lost so many model rockets as a kid im a little gun shy of letting a plane go on its own TJ

My engine was given to me by a now deceased club member. His name was Pete and he was a avid free flight builder/ flyer. My new needle valve absolutely worked better than the stock unit. In addition, the stock unit was far too short to make it outside of the fuselage. I own lots of cubs and all but one are similar in which they all have the triangulated bolt patter. I have the .059 which has a tank.

The engine on Ken's Dakota looks like a B to me.

Ken - you make this sound so simple but trimming a free flight model is often not so easy but that looks like a magnificent model.

My early aeromodelling experiences were free flight. I cannot remember the model but it was a cabin with a high dihedral wing - powered by a DC Bantam. It climbed in a circle and when the engine stopped - it levelled out and like the experience Eddy had - the damn thing carried on in a straight line, still climbing and was a fly away.

My second attempt, after buidling the same model again this time with a DC Merlin, was a straight climb and a nice circle descent but it tip stalled as it approached the ground. The resulting cart wheel trashed the model.

You have to be brave to launch a free flighter with the trepidation that follows. Well done Ken.

And thanks Eddy for your post. That was informative and welcome.

Ian, I'm fortunate to have my buddy Dan. Dan did a little pre warping prior to flying. Dan is my go to person and my son received the kit from him. My son built the plane, I just sheeted the top and bottom of the fuse and doped the model. He had some fitment problems with the wing and the struts. To get the V portion to nestle into the top of the cabin required a bit more pressure than I would've liked. This caused the upper and lower wings to twist a bit. Fortunately, they twisted the same cancelling the issue out.

I do have some video of the flights which I need to get on here. We launched with just a tiny amount of fuel in the eye dropper for the first flight. It was obvious the plane was turning correctly. The problem I encountered was that I wanted to use a 6x3 black Cox prop. These won't fit onto the OK Cub without counterboring the hole.

We generally put the prop on backwards and lean the engine up a bit. I was using a Super M 6x3 Top Flite which to my surprise didn't get broken. I have the Cox prop on the model currently and were waiting for some decent weekend weather. Last week we had steady 25 mph winds with gusts over 30.

Interesting read about the needle and source that they still service engines and sell while looking into that i found they sell trains / ho/ O scale and cars too .. Good little read .. http://www.okengines.com/news.shtml https://www.google.com/search?sxsrf=ACYBGNRFrSByPfOMdfnOAgeyiebxG5I1ZA:1578399121294&q=OK+Streamliners&tbm=isch&source=univ&sa=X&ved=2ahUKEwj108D3uvHmAhVIn-AKHc7zBqoQsAR6BAgKEAE&biw=1493&bih=776&dpr=1.13#imgrc=_ I think i still have some cubs need to get them out and dustum off !

Tico, it's funny that you mention that, I ordered a couple extra A tanks from Ted last year at OK just for that purpose. It looks simple enough to do I just have to order some Brass Tubing . My original A that Ted Re-did for me didn't have a tank the 2 outside holes were drilled out and it was bolted to a plastic mount on an old well used Little Toot that someone gave to my Dad for me. I got a few good flights out of it but I got a little bit carried away and stuck it in pretty good cracking the case. TJ

Hello Ken
                    Nice looking Dakota I like it a lot. I have kit will build one some day but since I don`t have a large area to fly it I will go R/C.
                                                                                                                            Juan

Today, the flight gods took my Dakota from me. Everyone insisted I switch to the Cox 6x3 black prop. I did but I wasn't happy using it. It's heavier thus it needed to be leaned out just a tad more. Well in 5 seconds it put my Dakota every bit of 200' or better high. Usually it would still be in a upward attitude when the fuel would quit, then it would spiral back to the ground. Today it hooked up and flew out level, I just couldn't believe it, I had a real pit in my gut when I saw it level off. I figured at this point it would begin it's consistent spiral. It just flew away. There was no retrieving it as it flew into a wooded area with no access. I have to say I was pretty upset by it. At least I can enjoy the pictures here. Ken

Aw Ken. That's awful. I'm sorry brother.