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#1 davidmc36 Sep 22, 2012 08:10 AM

Modified Telemaster 40 Build
 
1 Attachment(s)
About a year ago I was gifted an unfinished Telemaster 40 which has some construction issues.

Number one the shear webs were omitted from the front wing spar. Also the glass strip on the center section was much smaller than the plans called for and slathered in mounds of epoxy without the glass contacting the sheeting (read: big air pockets) over about 25% of the area. Much of the rib-to-sheeting glue is poor and rib-to-spar gluing the same. Should be fixable by wicking some CA into the mating spots. They are not gapped bad, just not glued solid.

The fuse is not horrific but needs some fixing.

Since I needed to get at the center section to add the shear webs anyway, it was not much of a stretch to peel off the glass and bottom sheeting.

While I looked at it I saw the epoxy holding the two wing halves together was a big mass with quite a gap and full of air pockets. This led me to the modification idea.

The Telemaster with its significant dihedral would fly fine with just rudder. I will certainly do ailerons, and flaps, so I thought what the heck. I ran the bandsaw down the middle, squared up the root ribs, and will rejoin as a flat wing.

Wings just need a bit more trimming of excess glue and I will start fitting new root ribs.

(Too bad I never thought of the thread idea before I started stripping and cutting.)

#2 davidmc36 Sep 22, 2012 08:52 AM

Root Ribs
 
1 Attachment(s)
Rough cut root ribs that will fit internal to sheeting and spars. Will add external 1/16 ply root ribs to join wing halves.

#3 Dereck Sep 22, 2012 09:48 AM

Sounds like you paid the ideal price for your new model ;)

Even though you are going to bandage the wings up without dihedral, you might want to look at some internal ply joiners along a couple of rib bays. You won't have to even draw them up, as they're straight. A couple of 1/16" ply strips to the depth of the mainspars, cut out the ribs and glue the ply to the back or front of the spars, as comes easiest.

You've done good. The way you describe how the wings were joined, they likely wouldn't have stayed joined for long under flight stresses.

D

#4 davidmc36 Sep 22, 2012 11:05 AM

Quote:

Originally Posted by Dereck (Post 22803821)
....you might want to look at some internal ply joiners along a couple of rib bays....

I think that is a good idea. I plan to mimic the joiner that is on the wing halves of my Bonanza at the main spar, similar to many others that I have seen/built.

#5 davidmc36 Sep 22, 2012 11:08 AM

1 Attachment(s)
Ribs shaped up and ready to glue except for some spaces for the ply spar joiners as mentioned above.

#6 AndyKunz Sep 22, 2012 11:49 AM

Way to go, David! While you're in there, run a conduit for the servo wires. I use McDonalds straws in my planes.

Add droop tips for a really cool look.

Depending on your receiver, you can also put a remote out in a wing. I have that in some of my models to get a better diversity on them. I usually put it out in the aileron servo bay.

Andy

#7 davidmc36 Sep 22, 2012 02:00 PM

Quote:

Originally Posted by AndyKunz (Post 22804575)
Way to go, David! While you're in there, run a conduit for the servo wires. I use McDonalds straws in my planes.

Add droop tips for a really cool look.

Depending on your receiver, you can also put a remote out in a wing. I have that in some of my models to get a better diversity on them. I usually put it out in the aileron servo bay.

Andy

Drop tips did come to mind last night when I was looking at one that has a bit of a crunched spot that needs repair anyway.

I like the straw idea, would make routing wires easier.

I was thinking of the remote in the wing a few days ago too discussing models that seemed to have a common theme of losing control while on landing. I wondered if all the Rx's in the fuse could get shadowed by the motor/battery when the plane was pointing right at the pilot.

#8 davidmc36 Sep 22, 2012 07:05 PM

1 Attachment(s)
Balsa rib, ply rib, and ply spar joiners. Close to re-marrying the wing halves.

#9 davidmc36 Sep 23, 2012 07:36 AM

Conduit
 
3 Attachment(s)
I like Andy's straw idea but since I cannot stomach anything from Rotten Ronnie's :p I remembered the tube in the Somethin' Extra.

Tape a piece of paper to a 1/4 brass tube. Roll it up nice and tight to give it a "set". Without unrolling any more than necessary, cut a strip just big enough to overlap inside the circumference of the rib holes. It should roll back up again fairly easy especially if you use the piece that was taped to the tube. If you can get it to roll onto the tube again (I experimented but did not perfect it yet) it will be very easy to slide into the ribs. I got it in fairly easy just rolling it in my fingers until it was a bit smaller than the holes. Ya know how you can tighten up a rolled poster if you roll alternately with both hands?

It looks like the diameter I have now may be just big enough for a servo connector but I am not sure if the finished product may need to be a bit bigger to get the second wire for the flap servo in and even the third for the remote Rx. If I run a couple strings in the tube before the wing is all closed up I should be able to pull the leads through quite easily.

A piece of 8.5 x 11 the long way gave me over half the length I need so a second one will overlap and finish it off.

#10 AndyKunz Sep 23, 2012 07:41 AM

Quote:

Originally Posted by davidmc36 (Post 22805370)
Drop tips did come to mind last night when I was looking at one that has a bit of a crunched spot that needs repair anyway.

I like the straw idea, would make routing wires easier.

And the price is right...

Quote:

I was thinking of the remote in the wing a few days ago too discussing models that seemed to have a common theme of losing control while on landing. I wondered if all the Rx's in the fuse could get shadowed by the motor/battery when the plane was pointing right at the pilot.
If the antennas are hidden, sure. For a bigger plane, you would use something like an AR600 or larger so you could position them away from one another. For me remotes are more handy, and I rarely take my planes apart for anything.

Andy

#11 davidmc36 Sep 24, 2012 09:21 AM

Shear Webs
 
1 Attachment(s)
Incredible the difference installing missing shear webs makes to the stiffness of a wing. I have seen before folks omit them thinking they are insignificant. Then they wonder why the covering keeps coming loose and they have to keep re-trimming the plane every time out. The wing keeps twisting!:eek:

Got the one half done, just a nice amount of flex now.

I wonder if by the end of this project I will determine the correct amount of Gorilla Glue to apply......probably not!tee hee hee:p

#12 Thermalin Sep 25, 2012 11:15 PM

Why are you using GG

#13 davidmc36 Sep 26, 2012 12:33 AM

Delete

#14 UberZogster Sep 26, 2012 06:14 AM

I thought gg was supposed to be weaker because it foams which creates air pockets and pushes the parts apart. I like tightbond because it sticks well and gives time to work.

#15 davidmc36 Sep 26, 2012 11:27 AM

Delete


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