BUILD THREAD: Sig RISER-100 wing on Topmodel PRELUDE fuselage

[G-man]

Wayne POST # 27> I was thinking about this and wonder if you might be willing to try something?

Steps taken to lighten the equipment and move the weight forward:
1. Move servos forward 9 mm, easy since mounts had broken loose anyway in a crash
2. Swap 184 gram motor for 148 gram motor
3. Swap 241 gram 2200 4S battery pack for 163 gram 1300 4S battery pack and move it WAY forward
4. Swap 43 gram ESC for 33 gram ESC
5. Swap 33 gram receiver for 6 gram receiver (behind the CG weight)
6. Wrap 60 grams of sheet lead around motor to re-balance at 88mm
(Sig spec for RISER_100 CG is 90-98mm from leading edge.)

RTF fuselage weight BEFORE: 806 grams
RTF fuselage weight AFTER: 776 grams

 

[Wayne]

Wow, you have the space to move the servos up under the hatch on a future build.

The Riser CG should be the same for this Prelude hybrid as it does not have a lifting tail.

With the full flying tail, trimming for a CG test is slightly different as you really need to find your correct trim, and that is going to be based on the correct CG. The full flying tails can mask issues with this balance of forces. Ultimately I'd expect this plane to need a rather small amount of elevator throw once things are in balance. If you find yourself needing a lot of elevator throw, then I'd move that CG back.

I have not flown a full flying elevator for a long time, but I have one on the build table now, so will be playing this game soon enough.

 

[G-man]

> Wow, you have the space to move the servos up under the hatch on a future build.

He said future build. Yay-o-yay. This is the stuff dreams are made of.
Will the circle be unbroken.

> The Riser CG should be the same for this Prelude hybrid as it does not have a lifting tail.

If you mean the Prelude hybrid should balance in the 90-98 mm range that Sig specifies, I agree.
My last Sig Riser-100 / Prelude hybrid, balanced about 95-98 mm back, flew wonderfully smoothly.
Until it flew away.


> With the full flying tail, trimming for a CG test is slightly different as you really need to find your correct trim, and that is going to be based on the correct CG.

I agree again. I will be very attentive and precise in trimming for straight and level gliding flight.

> I have not flown a full flying elevator for a long time, but I have one on the build table now, so will be playing this game soon enough.

The more the merrier.

 

[Sandman]

Dave
I'm glad your dialing all this in, I couldn't imagine a crash and burn on the maiden.
I've never tried the lead sheet method. How do you fasten the lead sheet wrap to the motor?
Thanks

Don

 

[G-man]

> I'm glad your dialing all this in, I couldn't imagine a crash and burn on the maiden.

We'll get it. And when we get it, we'll have the smoothest-flying R&E glider in the arsenal.
I know this from my last two home-made balsa wing on Topmodel fuselage projects.

> How do you fasten the lead sheet wrap to the motor?

Easier than it seems like it will be. With the lead wrapped around the motor by hand to get the shape,
releasing your grip expands it a little so it slides on and off easily. It is held in place without adhesives
by the motor mount in front, and the battery pack in back, and the molded fuselage on the sides.

This method makes it easy to vary the nose weight, say, as compared to lead shot in epoxy.

 

[Sandman]

Thanks for the tip on the lead sheet.
I noticed a counter balanced rudder, on the Riser 100 pictured above.
Is that the one you lost to the smoke from Canada
You mentioned no rudder authority issues, so it remains a CG dial in.


Don

 

[G-man]

I noticed a counter balanced rudder, on the Riser 100 pictured above.
Yes, that is the PRELUDE REF version fuselage.

Is that the one you lost to the smoke from Canada
That is the one that flew away.

You mentioned no rudder authority issues, so it remains a CG dial in.
That's what I'm figuring. Now just waiting for warmer weather.

 

[G-man]

REPAIR WIRE RECEIVER HOLES

When working with the fuselage I noticed that after the last crash the wing mount wire receiver holes had been eroded / chipped away.
My solution was to install brass tubing as a wear surface. I probably should have done this during construction.
If you decide to do this, epoxy the tubes in place AFTER covering the wing, as the covering between the wing halves separates them a little.

In other news, I got three flights with the Frankenplane yesterday, and I'm getting close to happy weight and balance.
For relaxing flying, I like to have a sailplane balanced and trimmed well enough to fly hands off for 15 seconds.
Well, this baby flew SIXTY SECONDS without touching the sticks. TWICE. With witnesses.

Try the dive test again, balanced at 92mm from LE. RESULT: SCARY TUCK UNDER.
I'm thinking of giving up on the dive test and just going with the 60 second fly-all-by-itself test.

 

[Sandman]

I was thinking of putting a hardwood block behind this bulkhead to strengthen this area, and provide more surface contact for the pins.
Your tube solution looks to be both strong, and lighter.
Nice upgrade.

 

[G-man]

My brass tubes are held by epoxy with milled fiberglass mixed in.
Remember to tape off the inside ends of the brass tubes to keep excess epoxy out.

What stage is your fuselage build in?
Maybe we get to fly together in the spring at Sterling or Canastota.

 

[Sandman]

I finished my wing, and waited to see how the CG things panned out, how moving everything forward, and lighter components, made a difference.
I still have most of the fuselage build ahead of me, thanks to your thorough build log, its all covered.
I look forward to meeting, and getting the 2 Risers airborne.

Don

 

[G-man]

8. FLIGHT REPORT - We have a floater

With some no-wind overcast weather this week we had a day highly suitable for flight testing.

On an unpowered hand launch this model will cruise 150 feet to land itself gently.
The powered climb is strong, about 70 degrees sustained on four cells and 12x6 prop.
Upon level off, and with motor off the model settles into a very solid cruise/glide, holding a line until commanded to deviate.

With rudder deflection 30 mm each side, and elevator deflection 10 mm up and 10 mm down maneuvering is smooth and positive.

With CG established at 92 mm back from leading edge I finally got the elevator super-trimmed.
In a very gentle dive test, the model pulls out slowly and gently - just what we want to see.

Another performance task I like to see with polyhedral gliders is if they can fly themselves with no stick input for 15 seconds.
Well, in no wind conditions, this model ran 90 seconds with no control input. I'm happy that I had a spotter/timer to verify the test.
The spotter/timer, also a balsa sticks glider builder and flyer, said "Dave, I don't think it lost 10 feet of altitude in that 90 seconds.

In order to get a 90 second free flight glide test, I find I need a little rudder trim cranked in, so it flys in a lazy circle.
Else, it gets small fast and I risk a flyaway. I hate when that happens.

Large loops under power, and medium size loops as a glider are pretty as ever. I did not try tight loops.
I was able to horse it into a clunky rudder roll, and demonstrate brief and awkward inverted flight - about like other polys I have flown.
I did lose the canopy during this flight, so I'm wondering about an improved canopy mount. Using rubber bands for now on a borrowed canopy.

The intentional forward stall test gave happy results.
Forced stall, and quick elevator correction: recovered with only 5-6 feet of altitude lost.
Forced stall, and then let go of the sticks: full self recovery after dropping 50-60 feet.

CONCLUSION: A wonderful lazy-day floater motorized sailplane. Well worth the components cost and the build time.

 

[jure]

congratulations ! you've got a winner !

 

[Red]

8. FLIGHT REPORT - We have a floater

With some no-wind overcast weather this week we had a day highly suitable for flight testing.

On an unpowered hand launch this model will cruise 150 feet to land itself gently.
The powered climb is strong, about 70 degrees sustained on four cells and 12x6 prop.
Upon level off, and with motor off the model settles into a very solid cruise/glide, holding a line until commanded to deviate.

With rudder deflection 30 mm each side, and elevator deflection 10 mm up and 10 mm down maneuvering is smooth and positive.

With CG established at 92 mm back from leading edge I finally got the elevator super-trimmed.
In a very gentle dive test, the model pulls out slowly and gently - just what we want to see.

Another performance task I like to see with polyhedral gliders is if they can fly themselves with no stick input for 15 seconds.
Well, in no wind conditions, this model ran 90 seconds with no control input. I'm happy that I had a spotter/timer to verify the test.
The spotter/timer, also a balsa sticks glider builder and flyer, said "Dave, I don't think it lost 10 feet of altitude in that 90 seconds.

In order to get a 90 second free flight glide test, I find I need a little rudder trim cranked in, so it flys in a lazy circle.
Else, it gets small fast and I risk a flyaway. I hate when that happens.

Large loops under power, and medium size loops as a glider are pretty as ever. I did not try tight loops.
I was able to horse it into a clunky rudder roll, and demonstrate brief and awkward inverted flight - about like other polys I have flown.
I did lose the canopy during this flight, so I'm wondering about an improved canopy mount. Using rubber bands for now on a borrowed canopy.

The intentional forward stall test gave happy results.
Forced stall, and quick elevator correction: recovered with only 5-6 feet of altitude lost.
Forced stall, and then let go of the sticks: full self recovery after dropping 50-60 feet.

CONCLUSION: A wonderful lazy-day floater motorized sailplane. Well worth the components cost and the build time.

Congrats! Sounds like a sweetheart.

 

[Sandman]

It looks like you have refined this fuselage/wing combo into a proven performer.
I can't wait to get mine in the air.

 

[G-man]

9 - FINAL WEIGHT AND BALANCE after flight report posted 03/05/2024

NOTE: there is plenty of room in this fuselage to install components.
There are many motors that will work, depending on your budget and how fast you want to climb.
I do favor the motors which feature plugs in the rear ("out-runner in a can")
I have run this plane with 25 amp ESC, 60 amp ESC, and now running a 40 amp ESC.
Many servos will work fine for rudder and elevator. I like to have 30 in/oz torque or more.
I'm flying now with 12x6 prop on four cells. For three cells, a larger diameter prop could be fitted.

Here are my measurements after successful tuning and test flying:

MOTOR: Turnigy Gliderdrive 4.6 840 KV - 185.5 grams

ESC: Turnigy 40 amp - 42.6 grams

PROP: AeroNaut 12x6 folder - 12.5 grams

SERVOS: PowerUp AS#513NG 48 in/oz - 23 grams each

BATTERY PACK: Gens Ace 2200 4-cell - 241 grams

RECEIVER: Airtronics 92515 - 15.2 grams - the only moveable weight behind the CG

ALL UP WEIGHT: 1650 grams

CG/ BALANCE POINT: 92 mm back from leading edge

RUDDER TRAVEL: 35mm left, 35mm right
ELEVATOR TRAVEL: 10mm up, 10 mm down

 

[Hoqiam]

Wayne
What is the status of the "100" wing and associated parts.
Are you planning to kit the entire system? or will you be
selling the total in an ala-carte fashion? (including the fuselage
and tail)
Tom








'

 

[Wayne]

What is the status of the "100" wing and associated parts.

Please see this thread:

ALOFT: AH-100 Build (new title)

OK - I'll admit I was not sure if my dihedral brace design was going to be easy to build or not. Was pretty sure I was going to have to tweak the design, but wow it works so well that even a dry fit is pretty much a perfect fit and hold the correct angle. The center ribs and brace are just dry...

forum.alofthobbies.com