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Dakota Build and Gen. Questions

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Dakota Build and Gen. Questions Empty Dakota Build and Gen. Questions

Post  firstwordisee Mon Nov 08, 2021 6:49 pm

Building a BMJR Dakota kit. As others have mentioned I wouldnt call it a difficult build but the directions seems to focus mostly on the obvious and are lacking in the more complex tasks. I havent built in years so dont remember all the tricks. If any beginners buy this kit I highly recommend reading the entire direction book a few times before starting. The plan is pretty much useless. Used Titebond II for almost everything.
Questions:
Sliding the wings in is a little tricky, I pushed them and they seemed to find their happy spot, sort of locked in. It was late so I continued with connection to struts already glued in top wing. After everything dried I noticed the stuts slant outward at the bottom a bit. I cant find any pics of this model straight on so I dont know if this is wrong, should they be at 90 degree angle? If so how will it effect flight if they arent? It is difficult to see in pics.
Has anyone used EZ Dope, that seems to be the most readily avail, I plan to do clear, is there something better that is easy to get?
What should I use to fill very thin gaps in glue joints, what is the trick hear?
I still have a lot of sanding to do but I included some pics, I need advise on the cowling too. I will be putting a Pee Wee .020 on this and test mounting I could barely get my fingers on the needle as built (it will work though) but no room for additional cowling.
Dakota Build and Gen. Questions Plane_10
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What about shaping the fuse nose, does it look ok as is or should I round it out?
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Post  NEW222 Mon Nov 08, 2021 8:57 pm

While I cannot precisely answer your questions, I would like to say that your build looks great so far!
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Post  firstwordisee Mon Nov 08, 2021 9:15 pm

Thank you, nice of you to say.
Have another question, should probably edit above but will put it here.
There is a rudder tab. It is supposed to be installed with "flashing material" (so you can adjust it), have no idea what this- is (except for house roof) - nothing in box. There is also no instructions for installation.
Anyone have experience with this? What about epoxy with a little piece of soda can? I havent seen this addressed on any Dakota builds. Ideas?
The very last instruction has polyspan being used to attach the balsa landing gear fairings to wire, I dont have the little piece that came in box (long story) so any ideas here would be good too. Why cant I just epoxy them on?
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Post  Ken Cook Tue Nov 09, 2021 3:37 am

Yes, you need to make the rudder tab moveable. The torque of the engine will roll the plane to the left under power and when the power quits the plane may possibly turn the opposite direction. You use very little rudder as it can make it turn too tight and stall on takeoff and also on landing. The main thing is that this needs to be balanced. Put the prop on backwards and lean it up as you want this plane to climb slow not aggressively skywards. If you have some roof flashing, it should work but that type of metal can crack if bent too many times. A small piece of sheet brass works as well. However, once set it's not being moved. You can also notch in small pieces of soft wire and epoxy them in.

As for the landing gear fairings. Don't install them as they're going to break off in just a few flights. Epoxy, fiberglass, polyspan, none of them matter. The Dakota is a sport free flight plane which has the aerodynamics of a brick. It comes down hard and the gear takes very hard shots.

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Post  firstwordisee Tue Nov 09, 2021 11:24 am

Thanks Ken, I was hoping you would chime in, I've enjoyed reading your posts.
I think I will go with the brass sheeting for rudder tab, just need to find it.
Have you tried a Pee Wee 0.20 on the Dakota? Just wondering if you still need to reverse prop on the smaller engine.
I know this has been brought up a lot but wondering what you use to finish your free flight planes. LHS is about 50 miles away, they only have EZ Dope, if it works well I will go there however I have read about various spray on products you can get at hardware store (15 min away).
Any suggestions? I just plan to do clear with maybe some trim underneath.
Also thanks for info on fairings, very good tip!
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Post  Ken Cook Tue Nov 09, 2021 3:31 pm

I would always put the prop on backwards at first. 2 problems can occur with the prop on correctly. 1st being the prop is efficient and this can cause it to climb faster than one thinks and it stalls in a hammerhead and is now pointed to the ground. This is also why downthrust is important.  2nd is that when the fuel runs out, the engine leans and it picks the nose up high causing it too to stall. The easy solution to this is to lean the engine up more with the prop on backwards. It doesn't hurt to try.

               I have built 2 BMJR Dakota's in the past two years.  I'm flying one with a OK .074, another with a Atwood Wasp. Both needed some nose weight even the .074.

      One thing that my buddy did on his was to install clear covering on the underside of the wings. I personally feel that assisted the glide in his immensely.

         I do feel the Pee Wee would have no issues flying the Dakota. If the prop on backwards doesn't work initially, turning it around is a easy task.
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Post  fredvon4 Tue Nov 09, 2021 7:34 pm

as seldom as needs bent, strips from soda can will work ok

I always thought striped copper wire strands was the best DIY method
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Post  firstwordisee Wed Nov 10, 2021 6:48 pm

Thanks. Ending up using about a 1" long piece of soft thin wire I found in my garage, very pliable and sturdy. Put it in middle of tab notched in with epoxy as Ken suggested. Put a thin coat of glue on tab hoping to stiffen it, who knows, everything may break when I move it. I dont think Im going to bend it until I have to. Building is done, now I just need to figure out what to coat it with. I like Kens suggestion for covering the bottom of wings, I think I will do it with tissue, closest hobby store doesnt have it though.
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Post  Ken Cook Thu Nov 11, 2021 3:34 am

Don't wait until you need to bend the rudder tab, place a slight bit of right rudder into it from the start. I lost my first Dakota after 5 flights. It climbed to about 200 ft, leveled out and flew away. The rudder is going to open or close your turn in the climb, when the power cuts is when your going to need rudder additionally as well. The stab might also need to be tilted as this is more effective. When the plane is flying slow, the rudder isn't all that effective.
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Post  firstwordisee Mon Nov 15, 2021 6:49 pm

Thanks Ken, rudder adjusted well, wire works good so far, I put a little right in as you suggested.
Been very busy with other things but managed to get 3 coats of Eze dope over a little bit of trim I did with acrylics.
There is no shortage of finishing methods. I read all you painting posts Ken. I ended up just going to the hardware store and got a can of clear Rustoleum acrylic automotive lacquer, read lots of pros and cons but this seems like the easiest quickest method for me to give it a little more protection. Plan to lightly dust it a couple of coats.
I assume it will stick to Eze Dope without issues, I'll just go for it unless someone chimes in and tells me this is a stupid idea.
Ill post some pics when Im done.
.
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