Got tail feathers built, waiting on more wood.
Pics on the way.
Got tail feathers built, waiting on more wood.
Pics on the way.
Oh, come on Mr. wing. Don't tease us like that. We want more! We want pictures!
Standing by ...
Not a true scratch build, as I have a set of plans here.
They seem basic, not much detail or instructions at all.
My previous building experience is kits starting from 1990, mostly CG, GP and SIG and TF kits, around 60 of them and then of course dozens of ARF's from small electrics to 50cc.
Using previous builds as a bit of a guide I will tackle this seemingly simple stick, sheet and ribs build.
Using a small 9 inch Ryobi bandsaw and soon a scroll saw, I am cutting all parts as I need them.
Some wood was sourced local and some of the longerons at 48 inch are coming from Balsa USA, with a hefty shipping fee for me.
So far the tail is mostly done and some ribs have been cut. The main spar is 1x 1/4 balsa. I will need to cut the ribs to allow the spar tp slip into them, that might be a task, or I could make 2 spars of 1/4 squred and shear web them.
I asume I will get into some grey areas and get stuck, but will try to plot along. Hopefully some builders can help out when needed.
I do not have a target date, but flying it late summer maybe a reality, maybe not.
Power will likely be 4 stroke Nitro, either single, twin or radial if $$ suddenly appears in my pocket.
Maybe 30cc gas, but not liking the sound for this plane, maybe a 4 stroke Saito gasser.
Looks like a cool project. The great thing about scratch building is that you can change things like the structure of the wing. I would do the 2 spars with the webbing. I have never built one with the spar thru the middle but it seems like it would be a pain. Looking foward to your build. Good luck.
Ultra Sport Brotherhood #114
Sig Kadet Brotherhood # 37
running into some grey areas regarding wing tips, many drawings and kits contradict design.
Do the tips taper up from the bottom only or does the taper start top and bottom with the wing tip bows in the middle of ribs???
I think its best if try to center the taper, I dont want to create some sort of weird washout at the tips.
It is a flat airfoil, making this part a bit more difficult. Plans are very vague and do not give reduced tip rib pics at all.
Plans suggest a tilted Aileron LE? what sort of hinge system would support that, or should I build it upright and bevl it.
To answer my own question, these full size images show a clear taper top and bottom on the aileron TE toward wing tip and also a tilted aileron TE.
I'll build per full size then.
I guess I can do a top hinged aileron using hinge points. I asume down deflection is limited by amount of angle I put into the aileron LE?
wing near completion. Tips are not an easy no brainer per this set of plans.
There is an unusual taper with wing tips fromTE to LE at the outer ribs.
If it was me, I would punch lightening holes between the ribs on the tail surfaces. With that short nose, you're going to want as light as you can get.
"I asume down deflection is limited by amount of angle I put into the aileron TE?"
Yes. and you would really like differential ailerons, where down is less than up. Down will act like flaps/drag and too much will create adverse yaw.
Did lightning holes on the ribs, not going to bother on tail as the sheet is only 1/16 balsa. I can also add them when fully framed and CG can be established.
Will run a servo per each wing half to get proper easy to set up differential.
Will have more pics this week.
After hours of studying pics and drawings on the full size, I was not happy with my wing tips.
I put the bow horizontal to the LE and let it meet a slightly raised aileron tip. This resulted in a double taper in the spars and just looked off.
Good thing all joints were only tacked, and breaking loose joints to reset was not too much issue.
Now I kept all ribs flush and level at the top surface, tilted wing tip bow up and let it meet a slightly raised aileron tip. This looks better and should hopefully not create any funny lift or drag tendencies.
Got notice that a pile of wood arrived, this means this build will see more action..
If using top hinged ailerons then just dial 'up' travel only into your radio for ailerons and forget the bevel.
Yes, no bevel, used the tilted aileron LE and installing top hinges.
slowly getting there. the plans are lacking and lots of online research is needed to get things as correct as possible.
the front upright is wrong, on most models its a dowel to duplicate the steel tubing. Its visible through the windshield. I hacked off the upper and glued in a dowel.
To further slow things and make things more complicated, I decided to add an operating door, on both sides [X(]
More wing work
Landing gear is next. Bought a wire bender. Hopefully that will go smooth.
the K&S wire bender is a simple but great tool. No way I could have done smooth bends without it.
My plans only show a side view of gear, leaving too much guesswork and cursing tonite..
Anyway, I got it set up and about right, comparing to the Lil Butch full scale.
Havent really Silver soldered in the past, so that was a new thing but worked OK, fluxed, wrapped in copper, and heated with small propane torch just enough to let the solder penetrate.
Its fairly square, may need to bend it here and there or reheat and adjust slightly. I left 3.5 inch axle length, hope fully that is enough tp fit tires and collars.
I only had enough wire to get it right onc e, and had to unbend a couple of areas, which makes for unsquareness and extra tweaking.
Using a cheap soft wire to get the shape and then copying it would be ideal in this situation.
Added functioning door, not on plans. Will add a second one on passenger side when I switch sides, learning all the blunders on left side first
passenger door added
some of the front cabin braces are made of steel wire, and also serve as hooks for wing attachment. I am trying to copy this from the plans but am undcided if I will use that set up.
The front wire cage, wing hold down set up is for donkeys, that will never work, impossible to solder all that to fit, unles you want your house/shop to burn down., and spend 40 hours messing around..
I did try and it was close and sort of worked, but its severly flawed in many ways.
will just make 1/4-20 rear bolts and dowel the front or 1/4 -20 nylon the whole thing.
Kinda thinking the designer never really build this at all, cause much of it is messed up and dont work.
Oh well, I'll get it done one day.
the overhead window was too wide built per plans, I will make 2 more sub ribs and make a scalish opening over the fuse.
Then will make the final wing hold down and shearwebs and final structual adjustments where needed.
Then its linkages and horns and servos
Have to make a cowl and fit engine, likely a 120 to 180 4 stroke.
"I only had enough wire to get it right onc e, and had to unbend a couple of areas,"
I would suggest keeping a close eye on those. Over time, may develop cracks.
will do, bends were minor, and used bender, not hammer and vice, which nicks the metal.
Made more ribs for correct size overhead window and making front hold down today.