Mike.
How does the flat wing afects the performance of your Telemaster? I have been thinking of building a new flat wing to improve the aileron response and the inverted flight caracteristics.
Calixto

Forgot include the following pics to add to the explanation re the landing gear and tail modifications.............

Mike

You and your build are associated with a lot of the mods I've made thus far (rudder size, clear cabin bay and at least half of the wing is flat). Just wanted to acknowledge and thank you for the contributions and sharing. Best, Blue

Please excuse my responding to your question also. I do not intend to speak for Mike. I've noted that several people have had excellent results building the wing flat (without dihedral). Of greater concern with regard to the inverted flight characteristics (I would think) would be the fact that both the Senior Telemasters very large wings and substantial horizontal stabilizer are both flat bottomed aerodynamic lifting "wings" in normal flight. It is NOT the kind of combination I would identify with being good at the "inverted flight" you desire to do. A symetrical or sem-symetrical configuration with a slab type stabilizer of some other plane might better fulfill your desires for inverted flight. Not saying that it can't be done BUT ....................Enjoy either way! Maybe some of the experts will weigh in on this question? Best, Blue

The wood in my kit was really quite good and straight and I was pleased to be building from another set of Joe Bridi drawn plans (I've always fancied old school engineering drawings) The biggest weakness of the kit in my opinion are the instructions. The kit would benefit greatly by re-done instructions tied into appropriate build pictures ala many of those we're familiar with Great Planes, Sig, Skyshark, BTE to name but a few I'm most familiar with.

I have never flown a TM with the stock wing but I did have a Senorita for a while. With the flat wing the TM will not self recover but it will fly inverted with the coaxing.

Left the wing alone, but did use 2 servos - 1 for each aileron. Can't stand rubber-band assembly. Used 4 1/2 x 20 nylon bolts to retain the wing. Added blocks of pine behind the LE to anchor the bolts, same inside the TE area. As anchor points in the fuse, I added 1/8" ply (not lite ply) inside the fuselage on both sides, and used two laminations of 1/4 AC ply with brass threaded inserts that the nylon bolts threaded into. Very solid. I would roll, spin, some limited inverted flight. Full down elevator, some altitude loss.

Added 3/4" width to the rudder. Might do more next time.

Removable tail feathers. See pics at: <ttp://www.rcuniverse.com/forum/m_3907030/anchors_3907030/mpage_1/key_senior+telemaster/anchor/tm.htm#3907030>

Added a glass window to the left fuselage side, and carried a plywood box w/ a 35 mm camera. See pic at: <http://www.rcuniverse.com/forum/m_36...tm#3637952>

Used a Magnum GP .65 for power.

In the midst of installing controls, it's time to set up the flaps. I've never built nor flown a plane with flaps! Each half of this wing will have a servo and torque rod linkage to a 20 inch flap in the center flat section of the polyhedral wing. The ailerons, also about 20 inches long are in the outboard dihedral section. My question is what should the set up maximum delfection be? My guess would be 30 to 45 degrees???? But I really don't have a clue. This picture might help............. Your thoughts, Please?

My 2 cents.... 45 degrees BUT.... You are really plowing new ground I think. 40 inchs of flap is a BIG flap. Ease them down in increments at first and be ready to increase power and give it alot of down elevator. Flaps down and the drag goes up & the nose goes up. Full flaps, lots of power and you can drag it in at about 2 MPH. With the ailerons you have you should have good control. But then again thats the new ground I was talking about. Just my 2 cents......... Richard

Thanks for the notice and comment. Looked some stuff up that I should have before...............ahem! Looks like it would be a good idea to cut and glue about half of that flap to the trailing edge and call it more wing. 10 inches of flap in each wing half should be plenty.

So.............as I was wondering would 45 degrees deflection on my 10 INCH FLAPS per the attached very recent picture be about right?

Sarcasm aside, I appreciate the alarm re the oversized flaps. Your concern caused me to do a search, ask some questions and seek some advice and get some more experienced opinions. One response went something like this......"You're putting what on your Senior Telemaster?" Flaps. "Flaps!" Yes, Flaps. "What's the matter with you Blue? A Senior Telemaster IS a flying flap!"

More indulgent advice suggested that I was intending at least twice too much flap. Thanks very much for drawing my attention to the excess.

Bomb Bay and peice of junk for the engine. Flew great

Here are a few pictures of the servo bay, rails and servos built in the bay just aft of the main cabin to leave the cabin area clear for utilization of various service modules I have in mind. Cameras, Glider Tow, Candy Drop Bin etc. The servos are high torque for a pull-pull rudder (linked to steerable tail wheel) and a semi-flexible giant scale push rod for the elevator.

Helo. I know this is an old thread, but maybe my question will stir up the hornet's nest of you expert builders. I have a 40-sized Telemaster and due to its weight and liking extra power, put a supertigre .61 on the nose. This Telly would fly mild to wild. The only thing I didn't like was the one-piece 72" wing.

Well, last year, I had a minor crash due to a low-altitude tip-stall from a touch-and-go and turning too sharply without gaining enough speed. :-( There was minor damage and I now have a plan to build a 3-piece wing. I am going to build the two wing sections 31.5" long as usual, but I will build two sets of center sections. One center section will be 5" long to make a total wingspan of 68" for more acrobatic "clipped wing" flight. The second center section will be 17" long to make the total wingspan 80" to qualify as a "big-bird". I don't want to put any dihedral in it to minimize complexity. The center sections will have dowels out the front and holes in the back to screw the wing in and not use rubber bands.

My actual question is about the wing joiner. I was told I should put the (a) wing joiner through the rib between the top and bottom main spar are located. On the 40-size plans, the main spars are 3/8" x 1/2" leaving 1/2" in between. Is less than 1/2" for a wing joiner tube or metal bar thick enough to support any wing loads. The joiner being less than 1/2" will be too small to be the only thing keeping the wing onto the airplane. Should I do like I saw in the photos in a previous post in this thread of using a front and back joiner, the front being well in front of the main spar and the back being about 3/4 way from the leading edge?

I intend to make a mount in the wing for a nylon bolt holding the wing to the center section and having the bottom of the center sections open to access the bolt.

I'd appreciate any input on this. Thank you,
Bryan

Hi Bryan..............My wing turned out to be way overkill and probably the strongest thing on the plane. Aluminum channel joiner, Two phenolic tubes and sleeves, plywood center ribs joined with nylon bolts. One tube, just aft of the spar, plywood ribs epoxied in and halves joined by two nylon bolts fore and aft would be my recommendation. Also keeps the weight down. Best of luck. That's a big engine for the Telemaster. I fly my Senior with about the same and it's plenty.... Best, Rex/Blue

Thanks for the quick reply! I'll do what you suggest. I was going to use 1/8 in ply in the center section and 1/8 in ply in the first, second and fourth ribs and 1/8 in balsa ribs in the others.

With that supertigre .61, i was almost able to hang the Telly on the prop!! If it had more control surfaces, I could probably do it, but I keep trying and or gliding around at low throttle with my 16 ounce fuel tank!! I haven't tried to run the engine at peak efficiency, but i have flown for about 45 minutes with this setup!

Thanks again,
Bryan

I haven't ordered my Senior Telemaster kit yet. But I've been reading and reading.

I really really like you polyhedral wing. And I was wondering about your flap and aileron. Did you use the stock aileron material for the flaps and ailerons? (Meaning they're not deeper front-to-back).

Second, how did the flap usage turn out. One post suggested the flaps were possibly too big.

I want to do the same polyhedral wing as you have done. Possibly making the bend a bay or two closer inboard. This would make the flaps smaller, and the ailerons bigger.

Do you have some construction photos of just the wings? I'd really like to see photos of just one side. Get better detail of just the left or the right wing.

Hi............I think I posted almost every relevant photo of the highly modified Senior Telemaster I built. Do a thorough look see and you'll note among other things that as a result of suggestions that the flaps were cut in half. From 20" to 10". Turned out to be more than enough.

Experience.........putting flaps on a Senior Telemaster is fun and entertaining but really not needed and adds the weight of 2 big servos.

If you add flaps, you can make them any size you want. If you look closely you'll see posted photos of both the 20" and 10" versions.

Opinion: Doing it again I wouldn't add flaps and would rather build more to save cost, weight and time. The two piece polyhedral wing however was/is a winner. Super strong and very, very stable. Trims out beautifully for hands off giant circle climbs at about half throttle.

I did NOT use the trialing edge stock supplied with the kit to make either the flaps or the ailerons but rather purchased a denser 1 1/2" TE stock.
I wanted to have about equal aileron control surface area with about 1/2 the length. Worked very well and I would repeat the design.

For what it may be worth.........I made extensive modifcations to the Senior Telemaster for added strength and of course I thereby added a lot of weight. In re-evaluation of what I was trying to do I think I would and likely will build BTE's Flying King. It is both a stronger design and a superbly prepared kit. In fact there's really no comparison it kit quality.

Don't know of your building experience level but doing what I did with the Senior Telemaster was virtually a scratch build......especially the wings.

Best of luck, Blue

If you are using ailerons, take all the dihedral out of the wing, works best with a perfectly flat wing. Any polydihedral or dihedral will cause the plane to be very poor in the roll axis. However, if not using ailerons, then the dihedral will be necessary.

Sorry to revive this thread...but for all the "mods" discussed here, I don't recall reading explicitly whether anyone is contemplating joining the elevator halves with 1/8" music wire, versus using the forked pushrod approach.
I'm converting an electric ARF to glow, and the forked pushrod included in the ARF design doesn't stand the hair up on my arms. I like the approach that 'bluebikerblan' showed in post #37 with the pull-pull rudder and semi-flexible giant scale push rod for the elevator. He didn't say how the pushrod terminated ... in a single clevis, or a double clevis on a 'fork'?
Any thoughts out there on tossing the 'fork' and using a music wire joiner between the elevator halves with a single horn?
Thanks!

pj wright
chattanooga

I ditched the forked pushrod thing when I mounted the servos in the tail area. I'm not exactly sure of the thickness of my "wire" but it came from my crashed STM kit. My setup only has one horn but I used some very thin ply on top and bottom under the covering to help distribute the load of the horn better.

Electric to glow huh? Can I ask why?

Thanks for validating my decision to join the elevator halves, Mike. I may go for the servos in the tail, as you did, or move 'em forward like 'bluebikerblan' depending upon balance issues.

As for why someone would insanely convert an STM from electric to glow? First, I bought the empty airframe from a guy who'd stripped it to electrify a Senior Kadet ... so there were no "sunk costs" in terms of removing equipment.

Consequently, there would have been a significant outlay for motor, esc, and battery for this honker. I sympathized with your thread from April '06: http://www.rcuniverse.com/forum/m_41...tm.htm#4111990
An "expensive and depressing day" indeed!

So...with all the equipment needed to put this plane back in the air already sitting on my workshop shelf, it wasn't a very hard decision.

One of the details I'm working on this weekend will be determining the "optimum" size for a new vertical stab and rudder, using Andy Lennon's method of calculating the "center of lateral area." Just up and doubling the size of the rudder may help with low-speed control issues, but it may be at the expense of lateral stability across the speed envelope.

That's the fun in "bashing" a model ... learning by doing!

PJ

Okay -- I followed Lennon's procedure to calculate the lateral (spiral) stability of a model design. I was skeptical, because it sounded so low-tech ... but it appears to work. You find the "center of lateral area" (CLA) of a model using a 100% profile that is suspended from 2 or 3 different points, and run a plumb line down the length of the model each time. Where the lines intersect is the CLA. See Chapter 9 of 'Basics of R/C Model Aircraft Design' for the procedure.
What I found for the Sr Telemaster (ARF) suggested that reducing dihedral and/or adding to the vertical tail area quickly increased spiral instability. One of the posters on the mod thread complained that his plane was hard to get out of a flat spin ... dunno if these conditions are related.
Lennon says you have "neutral spiral stability" when the CLA is at 28% of the vertical tail moment arm (see diagram). My test suggests the factory Telemaster's CLA is nearly 30% of VTMA ... making it mildly susceptible to entering a spiral. When I took out dihedral (as a number of folks have done) on the mock-up, the spiral stability margin increased dramatically - to 37% ... well into the "very spirally unstable" zone in Lennon's estimation.
My intended mods include filling in the space between the LG wires (like a Cub), which improves the CLA location; and adding about 20 sq.in. to the rudder, which degrades it. I'm looking at a spiral stability margin of 32% ... still in the "mild" zone ... and I'll leave the dihedral alone.
Having gone through this exercise ... I wouldn't take these numbers to the bank, but the principle is what's important: if you move the CLA too far aft (even with the model balanced), there may be unintended consequences.

PJ