Mini Telemaster Kit-Bashing

[Joker 53150]

The hinge on the Mini Telemaster can certainly be taped. Mine is done with Blenderm tape and it's held nicely since it was built at Flite Fest a couple years ago.

Maybe I missed it, but it looks like you're extending your rudder. Any reason(s) in particular? The stock one works pretty well for 3 channel, but it's certainly no aerobatic plane.

 

[rockyboy]

Yeah, I didn't get the words in for those pictures quickly enough...

Rudder hinges are properly slotted and in place - I did the xacto to lay down a little groove in the right place, and then the little saw to break through and cut the slot. Then I discovered the little saw was too thin and the hinge wouldn't fit. So I picked up a jig saw blade that was a better thickness and hand scratched the rest of the way through. Worked pretty good too.

And I couldn't resist a beauty shot of current progress as I was cleaning up the bench to lay out the wings.

And the extended rudder is to go along with the other STOL type modifications to increase responsiveness at a stalling speed. Going to try to have a 'spot landing' flying machine

 

[Michael9865]

Looking good.

 

[nhk750]

Interesting how different kit manufactures have you do sheeting, both the kits I have done just have you glue the fuse sheeting on the fuse in sections while this kit has you pre-glue the sheets together. Looks great so far.

 

[rockyboy]

Thanks guys!

Actually the tele instructions didn't give any info on how to install the sheeting. It didn't even mention that the sheeting should be installed cross-grain! So I went with my tried-and-true glue it first method to keep the seam really smooth since the seam is over an open area without any support under it.

 

[rockyboy]

Started the wing last night.

First there is some sheeting, bottom spar, and trailing edge pieces. Yes, I'm planning to add flaps and ailerons. But my plan for that is to build the wing pretty much as they suggest, and then cut off the trailing edge, extend the pieces a little, add hinge bracing, and put them back on as control surfaces.


Here's a deviation from the plans - they provided pieces here with an angle to set the amount of wing dihedral. I used the parts from the kit as templates and made nice square blocks to take out the dihedral. You can see the line up in the picture above of the stock and custom pieces.


And here's the ribs and leading edge drying up. I'll figure out the servo placement before doing the angled bracing.


I've got to say, at this point in my recent balsa building I've done wing designs by Steven's Aero, Zeke's Park Flyers, Mountain Models, Banggood, and Laine's Planes. And from an assembly perspective, the Telemaster is actually my least favorite.

The instructions are better than the Banggood ones, but not as clear as any of the others. The cut pieces don't match the plans size - and in every other line of the instructions it makes excuses for this saying 'the plans can shrink and expand from humidity'. But I didn't have this problem with any of the other manufacturers kits.

And it's not just that the plans are uniformly a little bigger or smaller - the trailing edge slots are spaced too close, the trailing edge is too short length wise, the curves on the trailing edge pieces don't fit together well, the sheeting pieces are a perfect fit, but the ribs are too short (except W1), and yet the slots on the leading edge are perfect. And because only every third step in the instructions has a picture to go along with it, a lot of time gets spent going back and forth trying to make sure this part that is labeled right but doesn't fit is really in the right place.

So at this point in the build, my recommendation to noob balsa builders is get a different kit to start with (Mountain Models, Steven's Aero, or Laine's Planes). The tail surfaces and fuse builds fine, but it goes from beginner to solid intermediate level at the wings due to the instructions and balsa cutting & quality control.

 

[rockyboy]

And a little more work last night. Before I proceed more with the wings, I need to get the servo locations and mounting worked out. I love doing flush mount servo installs (I believe I owe TurboJoe for this one )

First is gluing some mounting posts onto a rectangle of thin ply


Then cutting in a slot for the control horn


And here I have the little shot bags holding all the web sheeting between the spars in place.

Also starting the glue in for the servo mounts between the ribs. First comes the braces between the ribs, and next I'll do a beam between those that is lined up right where I'll screw through the corners of the servo mounting plate. This way there is a continuous surface of balsa that goes all around the servo mount plywood and is level with the bottom of the wing to attach the covering to properly.

 

[rockyboy]

Got up early on a rainy saturday morning. Here's putting in the second cross braces for the servo mounts.


And some triangle reinforcements at the corners where the screws will be


And using some 1/16 sheeting material level with the bottom of the ribs on the bottom side of the wing. This makes a snug fitting box around the plywood mounting plate, gives the covering a good place to stick to, and keeps the servo mount in the right place when screwing it in.


And adding the angled cross braces in the other rib bays


And gluing the front edge of the bottom sheeting snug to the back of the leading edge stock and ribs.


Next up will be the adventure of carving the wingtips from a solid block of balsa. Never done this before, so stay tuned for learning the hard way... :black_eyed:

 

[rockyboy]

Well this went a lot better than I thought it was going to!

I cut a big chunk of balsa in half, glued it end to end to make a blank long enough, and started at it with the power tools. I traced out the wingtip rib shape on the sides, cut the top arc off with the band saw, and then cut a corner off each bottom edge with a hand saw following sort of close to the line of the bottom edge of the rib, leaving a big chunk in the middle hanging low. Then I cut that overall block in half down the middle with the band saw again and I had two roughly shaped blocks for droopy wing tips that matched each other!

A few minutes at the 1" belt grinder, and a flat sanding plate (sandpaper glued down to a flat board) and a coarse flat sanding pad, and I had some shapes that curve pleasantly and look sort of aerodynamic.



The screw up (had to be at least one) was cutting too deep on the edge cutouts with the hand saw so I ended up with a square inside edge under the wing tip instead of the nice curve I want, so I'm gluing in a piece of 1/8 square balsa and once that's dry I'll attack it with a pencil wrapped in sandpaper to smooth out the inside edge.



Also need to use a gouge or dremel to hollow out the inside of the block a bit and reduce some weight - don't need all that extra material out at the end of the wings.

Overall, I'm pretty darn happy with how these turned out, and how closely matched they are, especially for my first balsa block carving job. :applause:

 

[rockyboy]

Double sided taped them together for a little more shaping. At this point I need to stop messing with the shape until I'm ready to install them onto the wing.



I think I'm going to focus on getting the other wing panel done next, and then cut in the control surfaces, and then attach the tips. Once I get the wing tips on, it's going to make laying the wing flat to work on more difficult, so I'll put that off to the end.

 

[nhk750]

It looks great so far. I have a few questions.

What kind of 1" belt sander do you use? I was thinking about getting a hand held belt sander.
I noticed your servo bays and wondered if you ever have problems with the posts coming off with the servo torque?

I may have over engineered mine, but I read that a few guys had problems with the posts coming loose and they screwed theirs on. So I screwed mine on plus reinforced with extra wood too. I think the Hog Bipe, having the servo drive two full length ailerons (4 ailerons total), needed extra reinforcement. But, I don't know if this is needed on non biplane models.

 

[rockyboy]

I've got one of these bench top belt sanders, and use the heck out of it

https://www.amazon.com/Generic-Mini-Belt-Sander-3400/dp/B004D96ZCG

I haven't had any problem with the servo mounting brackets coming up before, but I also haven't put these into 100mhp+ planes or bipes either - just lightweight sport stuff. Screws might not be totally necessary, but now that you've mentioned this as a concern I'm going to go back and put little buttresses on mine too

 

[nhk750]

Thanks for the sander tip. I'm learning new techniques as I build kits and every tip helps.

 

[rockyboy]

Thanks for the sander tip. I'm learning new techniques as I build kits and every tip helps.

Me too!

 

[rockyboy]

Rolling with the balsa... going together much quicker this time since I don't need to puzzle out the instructions again.

 

[nhk750]

The cross supports are interesting, never seen that before.

 

[rockyboy]

It's a neat look - although I have an old timer on the wall here (I think an older Stevens Aeromodel build) that has only the angled ribs, not the straight ones, and I think it looks even better

Should help prevent unwanted wing warping, but the top sheeting should do a lot for that too. Right now the wing is a bit twisty.

 

[rockyboy]

Here's the sordid tale of a couple semi-productive evenings...

Servo Mounting:

Finished up the bracing for the servo mounts, including some little triangle buttresses on the rib/brace connection.


And added the sheeting around the plywood servo mount outline so there is a nice level place to stick the covering.


Flaps Part 1 of several:

Control surface time! Started by cutting off most of the existing control surface material, leaving enough to brace the trailing edge of the wing.


That came off nicely - little more than 1/2" of material


Now I cut out some control surface material 1" wide. I'd rather have wider control surfaces that need less deflection as that causes less drag and better performance. Also, it should make the flaps more effective as it increases the overall wing chord a bit.


Yep - looks like a flap and an aileron are in there somewhere.


I cut down the new control surface material into appropriate lengths and glued in the end caps...


And started figuring out the right angles for the flap hinges. I want to have slotted flaps on this, where as the flap is extended down it opens up a slot between the wing and the flap. This is a more efficient flap system than normal or split flaps - not quite as good as fowler flaps, but I'm taking these design changes one step at a time

In this picture I did a couple holes in some scrap to see how the hinging would work out, and I think I've got it pretty good here.


What I didn't take a picture of is I drilled in all the angled holes in the left flap, drilled holes in a couple hinge mounting blocks, and glued the blocks into the wing. Then I stepped back to admire my work and realized I had the hinges on the top of the wing - slotted spoilers instead of flaps So I quickly unclamped the extra bracing, and glued it on the other way.

And I should have taken that as a clue to go to bed...

Wiring Routing:

Here's where I caution all you kids out there to not build when you're too tired to think straight. Cause it just causes issues.

It all started out good. Found a reasonable sized piece of brass tubing - a little smaller than a connector as I plan to pull the metal parts out of the plastic housing to thread the wires through and then put it back in the connector housing. If the ribs were bigger I'd make the hole bigger. Anyway, I chucked a round file in my drill and sharpened the inside of the end of the brass tube. Then I used a dremel cutoff wheel to make little teeth in the end of the tube. Then I put the brass tube into the drill and went to town making holes in ribs.


Because my tube wasn't long enough to go from the root end of the wing all the way to the aileron servo bay, I had to drill one line of holes from each end. Yes, in some ways it would have been easier to drill these holes before putting the ribs in the wings, but I figured I would have trouble getting the hole lined up correctly in the angled ribs so I would do it this way.

What I should have done was make some sort of jig to hold the drill and the wing in alignment to each other so the hole went straight. Cause what I ended up with was two lines of holes that didn't meet up in the middle. In the picture below of the worst of the two wings, you can see the difference between the hole where the angled rib bracing comes together near the top and the top rib in view.


Yes, wiring can bend, but I was also planning to put in a copy paper tube glued in place so I wouldn't have to fish the wires blindly - but with the holes out of alignment the best I could do now was the paper tube on the root side of the wing, and tape a string in place to fish through the aileron servo wire after covering.


So I did both wing halves this way and then went to bed.


And when I woke up in the morning, I slapped myself. You see, that's when I remembered these two wing halves are glued to each other, not bolted to the side of the fuselage. So the paper tubes going to the wing root are useless anyway, as I need to reinforce and cut an access hole through the bottom sheeting to route the wires into the fuselage. :black_eyed:

 

[willsonman]

Yeah man! LOL, sometimes we all need to realize when you need to walk away. It can be a fine line. Excellent work though.

 

[rockyboy]

Thanks!

I wonder why drill makers don't design a flat spot on the darn case so we can clamp them to something? It would make designing jigs using drills a heck of a lot easier...