Chamomile Glider

[ahdofu]

I don't have any experience with large folding type props so it is good to know that they act as brakes too.
I have not had good success with spoilerons on glow RC planes. In my case they made the model directionaly more unstable. I agree that using spoilers (i.e by misusing flaps) can cause a stall but it just needs to be dialed in properly. I did that with a Telemaster and got better landing profiles as opposed using flaps. With flaps actuated, the plane was taking longer to land versus the case with a clean wing ...

 

[Konrad]

Yep, it is a drag verses lift question. Also strip ailerons verses "barn door" ailerons. While both powered low aspect ratio planes and high aspect ratio gliders are airplanes they really are very different in much of their aerodynamics. Yes, they also have a lot of similarities. I'd like to see you start with a know proven set up, both the machine and the radio programing.

 

[ahdofu]

Hi Konrad,
I ended purchasing the TopModel Indian V glider. I am going to follow your suggestion and use the MP jet clevis for the single flap servo.
Matt

 

[Konrad]

Great! While not a floater (gas bag), I think you coming from a powered airplane background will like the added performance /flexability. Particularly if the thermals are hard to find. (Some days are just like that)!

Scanning over the manual there are 2 things I wouldn’t do! First don’t notch the canopy opening to detent the canopy retention wire. The notch will only start a crack. Make up a pile of micro balloons and epoxy wait until it has set but not hardened then push some wire into the epoxy to make a dent (trough) used to guide the canopy retention wire. See this.

TopModel Samsara 3.2 meter glider, build thread on Aloft's Forum.

Gotcha sorry I went astray there...must be old age..o_O. Well in a perfect situation I guess the rudder should have two seals. For convenience I make them like the wings - 1 hinge and 1 seal. Its not perfect as the hinge is offset but it really does save a hell of a lot of time end effort. But...

forum.alofthobbies.com

Next don’t solder the threaded coupler to the tail push rods with the plastic clevis attached. The plastic will melt!

What are you planning to use for power, 2 cell or 3 cell? Have you looked into a motor? At this size (0.7 Kg) I think a “400 size” to “450 size" motor will work fine.

The HS 55 servos are dated by todays standard. So I’ll ask what you are doing about servos?

 

[ahdofu]

Thanks for the comments Konrad. I am not sure I quite understand the retention wire on the canopy. I guess I'll wait till I have received the plane and will take a look.

Understand the warning with soldering.

I don't have a motor yet but I'm leaning toward an Axi Cyclone 550/1200 motor with a 2S battery and a 13.5x6 prop. For the kind of RC flying that I do, I figure the HS 55 servos may be OK. Do you have a preferred alternative?

Matt

 

[Konrad]

Wow, that looks like the kind of performance I like! Now I like the high voltage, low current system vs the low voltage, high current systems. This is just my preference. Here is what I did for a similar class of glider (Entry level 1.8m 7channel foam glider). The Indian-V is a step or two up from the Calypso.

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www.hippocketaeronautics.com

That Axi motor is real nice and way more than the Indian V needs. But I’d look at these as a 2 cell set up. While not as powerful as the AXi, they are smaller. I don't think you need the extended nose as the fuselage is rather large at 36mm. The motors have a 27mm diameter nose, going to 29mm for the body.

Dualsky XM2838EG-9, 1350KV

A longer stator and a higher wind count results in a motor that has the torque to spin the larger propellers generally found on electric gliders.This motor will best fit an electric glider that has some room in the nose. The motor wires will need clearance between the fuselage wall and the motor...

alofthobbies.com

Dualsky XM2838EG-9L, 1350KV

Here's a neat idea, an out-runner with an extended shaft for use in electric sailplanes with slender fuselages. The extended motor shaft and bearing housing allow the motor to be mounted 22mm aft of the firewall. The idea is to provide enough room between the motor bell and fuselage side for the...

alofthobbies.com

https://alofthobbies.com/dualsky-xm2838eg-7.html

AXi Cyclone 550/1200 Inrunner/Outrunner Brushless Motor

Anything and Everything for electric flight, your electric superstore, Helicopter store

www.espritmodel.com

Maybe use a 12x6 to 12x8 on 2 cells with a 40amp ESC. I think the motors are rated to 30 amps but I like some safety head room.

If running 2 cell then these servos are perfect. These are small enough that if you are willing to make a new servo tray? You can fit 4 servos in the fuselage to get independent flaps. If running the radio directly off the power battery (2 cell lipo) do remove the positive wire from the ESC RX lead.
I’d still like to see the Rx voltage a bit lower than the peak voltage one sees with 2 cell lipos (8.4V). So I recommend a UBEC (Switching BEC) set at 6v with these servos.

KS HD47MG Servo - 1.2Kg (16.66 oz in), .10/sec - High Voltage

High voltage (4.8 to 7.4V) digital servo with a coreless motor and tiny weight with reliable metal gears and good specs makes this a very nice servo that could sell for a lot higher price at some other store.

alofthobbies.com

Dualsky VR-3

A reliable well priced 3A UBEC from Dualsky. Features: Switchable between 5 and 6 volts Wide voltage and small size makes this unit ideal for a wide variety of builds

alofthobbies.com

If money is no object the KST X0-8 would be my servo.

KST X08 - 2.8Kg (38.88 oz in), .09-sec - Wide Voltage

KST's new tiny alloy servo, the X08 is just 8mm wide and weighs just 8 grams, but it packs a real punch!

alofthobbies.com

Remember that if you buy the aircraft from Aloft the "combo deal" gets you 10% off the price. This is a nice deal as you get to make up the “combo” (Electronics). You aren’t limited to some prepackaged combos where half the stuff you wouldn’t want. (I’m sorry to say that Aloft’s splash page doesn’t make this clear)!

 

[Konrad]

Not sure what posted on the subject of the retention indent / detent.

 

[ahdofu]

Since I had not committed to a motor yet, I did not bother with the prospects of the combo deal.

Thanks for the servo suggestion. If I were to use 2 instead of 1 for the flaps, I'd be installing them in the wing and not the fuselage and I'm not even prepared to do that (yet). As it stands now and with one flap servo in the fuselage, I have mentally prepared myself to add one linkage at the field. I don't think I can do two.

I have to read up on the motors so no decisions there but thanks for your critique.

Looking at the canopy opening picture I take it that you're suggesting that I, too, should be adding the canopy standoff but what is a canopy retention wire? Does this wire somehow hold the canopy down? The manual is cryptic there.

On a side note the manual seems to suggest that slots need to be cut into the carbon tubing for the v-tail pushrods or is it a hole. On page 7 I see a the picture of a drill head where as on the fuselage I see a slot. Which one is it? Can you tell?

 

[Konrad]

What I’m seeing on page 7, is a 2.1mm x 18mm slot. This is to allow the bowden tube to pass (outer sheath). This (bowden tube) is then glued to the fuselage.

Bowden cable - Wikipedia

en.wikipedia.org

No, the canopy stand off is because I made a much thinner canopy for my Samsara 3.2 meter glider. I also don’t recommened adding the crash damage cracks.

I understand the linkage issue. If only using one pushrod for the flaps there is the option of doing the Z bend "wing swing" when removing and installing the wing.

 

[Konrad]

On the web I found a very good photo of what not to do. While the Top Model manual says to do this, it is a very bad idea! This notch results in a stress riser right at the point of greatest weakness with glass fuselages. That is the seam is weak. It is best to add an epoxy blob to the flange. Then imprint the canopy hold down wire wire into this blob. This way the strengthening flange can be maintained especially at the fuselage part line!

 

[ahdofu]

On the web I found a very good photo of what not to do. While the Top Model manual says to do this, it is a very bad idea! This notch results in a stress riser right at the point of greatest weakness with glass fuselages. That is the seam is weak. It is best to add an epoxy blob to the flange. Then imprint the canopy hold down wire wire into this blob. This way the strengthening flange can be maintained especially at the fuselage part line!

View attachment 2528

Thanks. This helps.

 

[Mazeppa]

Considering the Chamomile for use as a glider style aerobat as in climbing to about 150', power off and dive for speed to perform big, open, glider-graceful basic aerobatic maneuvers.
Perhaps with slight power assist at needful points in the maneuver such as getting over the top in a barrel roll, for instance.
The size seems about right, I have a 300W, 200kv E-flite inrunner, 30A to 40A ESC's, 1500mah-2200mah 3S LiPos, HS-82MG and E-max 9g servos that may be usable in the Chamomile.
Initial glider experience was a Great Planes Kunai that didn't last long as I overstressed the wing retention pin at a critical moment.
Now I am flying an airmodsrc modified BoT with Cobra motor&ESC. It is a a delight to fly and I'm finally learning to find and exploit thermals with it. Flatland flying is I believe the term for the conditions I fly in. I have a good bit of experience in e-power and medium size glow rc.

I have yet to read any comments about the Chamomile flies and am curious as to whether anyone thinks the Chamomile has the fortitude to endure the rigors of aerobatics.
Comments would be appreciated.

 

[Mazeppa]

I'm also looking at the Cassiopeia SERA DS-X for the same purpose. I have Scorpion 180 W, 28mm outrunners of 987kv & 1131kv I hope would be usable in this airframe.
Would the nose have to be cut off and firewall installed for EP? Ad says it's designed for non-powered and EP both. Build thread has yet to get to E-power.
Recommended battery size of 450mah seems small for a 150W motor, does this point to a lack of internal space, or CG concern?

 

[Konrad]

What you mention are electric assist gliders. If you are looking to replace the Kanai. These aren't the ships you want. The Sera DS-X is much closer to what I think you want in a climb and dive glider.
For these models I'd think you would want the 6 gram to 9 gram servo.

The small battery recommendation is to try to protect the customer from himself, installing too large a battery and ruining the nice glider performance of these models. But yes you would want high "C" rated cells.

In the $200 range the ASK21 and the Swish might be more to your liking.

Mini ASK21 1.3m by Cassiopeia

Introducing the Mini ASK21produced by Japanese manufacturer Cassiopeia. The Mini ASK21 like the SERA Sailing is a very light, well constructed, full house, sailplane that flies as well as it looks! We're not kidding, this 60" ship tracks like it's on rails. The similarities between DS-X, and...

alofthobbies.com

Top Model Swish - 1.48 Meter Glider

The Swish is a fun and versatile glider that fits in small cars and rewards with pleasing flight performance.If you would like to peruse the build manual you can find it here.What's in the kit:light fuselage moulded in white tinted epoxy fiberglass with r

alofthobbies.com

 

[Mazeppa]

Thank you for the response, Konrad.
Should also have mentioned I quite favor a V-tail as I've never tried one before and quite like the look.

Roger that on adding more weight than is needed for an adequately powered airplane. I lean to the light side when equipping any plane I build, and that would seem doubly important in a glider, even a dive and climb effort lest the gracefulness through the air be compromised. Even with my nitro planes, I prefer to fly the wing rather than the prop.
I view the motor on my BoT as a necessary evil, the real enjoyment for me comes with the power off.

Believe I'll focus my research more on the DS-X, though I've never had t-tail plane, either and I notice the Mini ASK21 has firewall bulkheads already cut.
Hmmmm

 

[Konrad]

I love motor equipped gliders. To my mind they are the "TRUE" gliders. I know of no bird (professional soarers, they earn their keep on the wing) that leaves its launch system (legs) on the ground. The motorless Thermal Duration (TD) glider is a cheat as it isn't a complete flying system. It just looks ridiculous leaving a winch all over the field.

There is nothing magical about the tails.

Not sure about the dive part. That dive can get a glider to terminal velocity rather quickly. I like to perform "level" aerobatics. Here I'm trying a loop and roll with a 3.2m gas bag.

TopModel Samsara 3.2 meter glider, build thread on Aloft's Forum.

If by hi res you mean 1080, it’s there. You just have to select it for playback. Youtube seem to be doing everything it can to drive users to its premium service. Like defaulting all playback to the lowest res version of the video.

forum.alofthobbies.com

 

[Mazeppa]

Dive for speed needed to complete the desired maneuver is what I'm talking about. Silent but for the sound of air moving over the plane......

Your Samsara vid well illustrates the grace of movement through the air I love about gliders.
My BoT does a very nice loop from a dive, beautiful, actually and when handled just right, performs a very nice 60 deg or so banked turn.
Feel the need for ailerons, higher speeds, and a bit more overall robustness. The BoT is a fine thermal plane and I'd hate to damage it putting more g on the airframe than it can handle goofing around.

I figured as much about the tail feathers as far as functionality is concerned, just like the way V's look.

 

[Mazeppa]

Back to the Chamomile - Appears in the ad photo that the motor mount bulkhead/firewall is already installed; is that so?
Wish I could see the build manuals to help with researching.

 

[Konrad]

Yes. But preinstalled firewalls are an issue in my experience. I usually have to break them out and install to my liking. I think it best if the OEM left them off.

 

[Mazeppa]

Yes. But preinstalled firewalls are an issue in my experience. I usually have to break them out and install to my liking. I think it best if the OEM left them off.

"......install to my liking."
To get a thrust angle you prefer? Structural integrity lacking?