Build Log Drake II: electric, with ailerons

[kepa]

Here's my picture of the day: The battery tray. I have also cut the nose former from sheet balsa, and glued pieces of thick (15mm) sheet (Is it sheet or a plank...?) together for the nose block. And the sides of the fuselage are almost ready for joining. I guess tomorrow will be the day when "the project" starts to look like an airplane for the first time!

-kepa

[Palmettoflyer]

Kepa, Good to see we are both hard at work today. Lots of rain here this afternoon so I found some shop time. My vertical outer fins are now done and I am about ready to tackle the wing.

[Modelholic]

Originally Posted by Palmettoflyer

Kepa,
looking great! glad to see you moving right along. I'm back again from the weekend travels and hope to get in some build time later this afternoon.

Modelholic,
Thanks for the CG concerns and tips. Well taken as I've had this issue many times. I've learned to keep a close eye on the CG as the build progresses. Once burned by a kit build that I could not get to balance well, I swore to not ever do that again. As early as possible I start the CG checking. Now, if I read your comments correctly, you stated you have your battery as far forward as possible and still want to add weight to the tail? Sounds like you need to move the battery backwards instead of adding tail weight?

Yes - if I could access the battery. It's buried behind the noseblock and in front of the first bulkhead. I put it there early in the build as I envisaged having to add nose weight because of the aft mounted motor and my already seemingly heavy tail. I'm not too worried about access in these small models as I cycle the batteries regularly. As its turned out this hasn't been the case and I have resorted to adding that dreaded dead weight - lead Still as you will be using lipos and need battery access you should have a bit more flexibility for c.g setting than I gave myself. You're already ahead of the 8 ball anyway having been giving this matter some forethought.

[Modelholic]

Oh and by the way your builds looking great!

[kepa]

I glued the fuselage sides together this morning, and just now glued some sheeting in front of the step to make it rigid for bending the nose and the tail together. I'm afraid I didn't get it completely straight. Those half-millimeter tolerances can add up quite badly. It's not a complete banana and I think I can sand the edges of the sides to make it almost straight. I'll shoot some pictures tomorrow morning when I remove it from under weight.

I have a question for all of you Drake (and similar) builders: What did you do with the tail wheel/water rudder? Did you just attach it only to the rudder? It seems it might place quite lot of stress on the vertical stabilizer and the hinges, especially on land. Or if you used a normal tail wheel and mounting bracket, how did you attach it to the tail? Screws could compromise the water-tightness...

-kepa

[jpgilbert]

kepa,
My Drake is at camp so I can't get a great photo of it (and I built it over 3 yrs ago!) but it appears I attached it to the rudder. I used Dubro style hinges for support. I have only flown from land for a few flights but had no issues. Many many flights from water without issue and some from snow also.

On my Depron Drakes, I used a piece of alum tubing attached to the tail and that supports the tail wheel bracket and keeps the strain off the rudder and hinges. Also, I inserted a piece of tubing into the rudder that receives the tail wheel bracket and that keeps a good fit between the rudder and bracket. Thought the wire alone might work loose after a while. Those photos included also.
HTH
Joe

[kepa]

Joe, thank you for your close-up pictures. It's simple once you figure it out, and your pictures did it for me.

As I said earlier, my fuselage didn't come out perfectly straight. This is my first non-box fuselage and as careful as I was trying to be, I managed to make one side more curved than the other. The bottom and wing saddles are basically lined up correctly, however. So it will ROW and fly, but if you look at it carefully, it's not symmetrical. And I haven't glued the tail end together yet. Must be very careful with that. Now I'm waiting for the glue on most of the bottom sheeting to cure, and in the meantime I'm working on the nose block.

-kepa

[Palmettoflyer]

Looks really good to me!

It is hard to tell from the picture but I would guess that some of that twist seen from the bottom view might be removed when the bottom sheet is put on. What type glue are you using? I am a big advocate of the right glue for the right purpose. A lot of times there are advantages to using aliphatic vs. CA vs. Epoxy and so on. For balsa pieces that have to be held perfectly in position it is a big advantage to use CA where as you can tack the pieces together. Then if you don't like the alignment you can pop the joint apart and go at it again. With that said, I'd like to show you my collection of banana shaped fuselages!

[kepa]

Originally Posted by Palmettoflyer

Looks really good to me!

Thanks. It looks good to me, too, if I only look at it from one side at a time...

Originally Posted by Palmettoflyer

It is hard to tell from the picture but I would guess that some of that twist seen from the bottom view might be removed when the bottom sheet is put on.

Well, it's too late now. I wish I would think also *while* I'm buildind, not just before and afterwards.

Originally Posted by Palmettoflyer

What type glue are you using?

I'm using Cascol 1809. It is a polyurethane-based waterproof wood glue. I don't know if it's the perfect glue for this job but it seems to work, and I'm kind of experimenting since I developed a bad reaction to CA.

Originally Posted by Palmettoflyer

With that said, I'd like to show you my collection of banana shaped fuselages!

Well, I like to collect things... And as I said, it's not too bad. Maybe if I don't say anything, nobody will notice. Oops! And speaking of secrets, here's my nose block. By hollowing it I saved a whole 3g and when looking at what will be a sealed cavity, I just had to...

-kepa

[Palmettoflyer]

Very cool idea to put the hidden message up front.
I just hope no one ever finds it!

I started to hollow out my nose block but wasn't sure how much I could take out. I used really light weight balsa on my block so it would not have accounted for much.

Sorry to hear you have a bad reaction to CA. I do too if I breath it or get the vapors in my eyes. I use a small desk fan sometimes and do my best not to hold my head directly over the work piece. Also, it helps to only apply the tinyest amount to the joint. A lot of the effects from CA can be reduced if you are carefull. Of course gluing your finger to the work piece is also a bad side effect of CA too! Don't ask me how I know that either.

I'm hoping to get going on my wing this weekend. I've been working out the details on the modifications I'm planning to incorperate.

[kepa]

Originally Posted by Palmettoflyer

A lot of the effects from CA can be reduced if you are carefull.

Yeah, and I do use it occasionally. But when I start gluing something major, I seem to forget to be careful.

Originally Posted by Palmettoflyer

Of course gluing your finger to the work piece is also a bad side effect of CA too! Don't ask me how I know that either.

You don't have to tell me. I once managed to glue *both* of my hands inside a fuselage...

Originally Posted by Palmettoflyer

I'm hoping to get going on my wing this weekend. I've been working out the details on the modifications I'm planning to incorperate.

How's it going? I didn't get to build during the weekend. On Friday I repaired my foam-winged glider that had an encounter with trees, and then I was otherwise busy. But now I've finished sheeting the bottom, made a battery hatch, and started work on the floats.

-kepa

[kepa]

I made quite good progress with the floats. In fact, one of them is almost ready. I didn't check the plans carefully before cutting the sides from 3/32" (2mm) sheet instead of 1/16" (1.5mm). Well, at least they are stiff enough and it's not much extra weight. The top and bottom are 1/16". I also added some 10x5mm balsa for the float spars to attach to, but left out the leading and trailing edge reinforcements. Oh, and I used CA this time. You should see my fingers! They are covered with it...

-kepa

[kepa]

And while on a roll, I made the other float too. This one didn't come out as nice as the previous one. I didn't get the sheeting to bend around the nose, it kept cracking instead. I should have moistened it first. Oh well... some more sanding to do.

-kepa

[Palmettoflyer]

Kepa,
You're on a roll for sure! Looking great and at this rate you will finish way before me.

I've had a very busy family week and I've been spending way too much time thinking about the wing. Based on input from some friends and my desire to tweak the flying characteristics to a STOL type plane, I’m going to change the stock airfoil to a NACA 3314. Then I plan to split the ailerons and create inboard flaps. To keep it lightweight, I’m going to attempt to rig one servo for the aileron and one servo for the flaps.

[Modelholic]

Originally Posted by Palmettoflyer

Kepa,
You're on a roll for sure! Looking great and at this rate you will finish way before me.

I've had a very busy family week and I've been spending way too much time thinking about the wing. Based on input from some friends and my desire to tweak the flying characteristics to a STOL type plane, I’m going to change the stock airfoil to a NACA 3314. Then I plan to split the ailerons and create inboard flaps. To keep it lightweight, I’m going to attempt to rig one servo for the aileron and one servo for the flaps.

4 mini servos please then you can really experiment with different flap configurations. The weight of the servos is minimal - just over 1oz using 9gm units, much reduced and straighter linkages and less likelihood for slop.