Planks- R-Swept, Ellipsio- miniplank 1S brushless - Rear motor FPV - Page 8 - RC Groups
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Sep 07, 2017, 07:57 AM
Laughs at un-boxing videos...
basicguy's Avatar
I have updated the R-Swept . The dollar store foam fusleage had gradually deteriorated and thought that a nicer shaped fuselage would make a nice upgrade. Am gradually learning how manipulate shapes with a CAD software. Last night designed a slug shape body to fit over the motor mount and gear. It still needs a hatch and coupler.

I have been flying the plane with a 1600 4s and it will go nearly out of sight in a few seconds. I have not bothered with a rudder on this plane and still fly it with normal ailerons and elevator.

Quote:
Originally Posted by basicguy
I sent the Rswept into a tall tree. We cut down the tree to get the gear back and I rebuilt it as a RS2.

This one has the same span as the R_S but a deeper chord giving it 330 sq. inch wing area. It had some teething troubles but is well dialed in now. For more gusto I put on a KEDA 2220 motor, about 87 grams. On 2s I was running 23 amps with a 14x8 folding prop For more zip I put on an 11x8 blades on the hub and am running at 26 amps at max or about 300 watts of input power.

Here is a flight video:
https://youtu.be/B58Ka_xO28Y
Since the video I decided to trim down the vertical stabilizer reducing its area about an inch. looking for more speed. I think I was pulling back on the stick a bit when doing a roll, It flies inverted nicely without much back stick. The motor is mounted square with the wing although the motor center-line is a bit above the wing axis.

The main problem I had with this model was related to the motor position. The first version had the firewall at 3.25" from the wing root. It flew fine on the 50gram motor. Since I was increasing the motor size and weight I shortened the nose to 2.00". Initial flights had a tendency for being tail heavy so I moved the firewall out to 2.37". Perhaps it could be longer as there is room further back in the cabin. The overall weight is about 18 oz with it's flight battery being a 1300 40c 3s.

Before this flight I did test the plane with 10x6 prop blades on 4s . It pushed the overall weight to 24oz, I have not flight tested the model with that much voltage as I am concerned about control surface flutter.

Like the original R-Swept this one is made from dollar tree readi board. I did use a 1/4" wood dowel rod for main spar and a second short on behind it to stabilize the 3/8" motor mount tongue. The plywood motor mount is glued to the tongue
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Sep 12, 2017, 03:07 PM
Watt Waster
Tsavah's Avatar
Sure is an interesting design, that is for sure.
Latest blog entry: Center of Gravity - Airplanes
Sep 12, 2017, 08:24 PM
Laughs at un-boxing videos...
basicguy's Avatar
It flies great. Easy to launch fast turning and rolling.
Sep 14, 2017, 11:31 AM
Ft Lauderdale
Number_6's Avatar
Interesting thread!

I also like building and flying planks,
and slightly forward swept foamies.

The forward/under battery pod
is something I use also. Prefer not
having to butcher the wing and
weaken it with equipment bays.

Received some MPF and plan on
experimenting with designs like yours...
thanks for the pics.

Sep 14, 2017, 03:01 PM
Laughs at un-boxing videos...
basicguy's Avatar
Hi #6
I have gradually gone with gear on top of wing. on my new builds. Easier to build. The motor if on top of the wing does not need much down thrust. I was surprised initially at how little elevator it takes for control I have built many with too much pitch control at least for my control-ability.
Sep 14, 2017, 03:20 PM
Laughs at un-boxing videos...
basicguy's Avatar

Will it fly? I know it will land!




The wing is carbon tube reinforced Dollar store foam. Red on top and black on the bottom.

Has a 95 gram Keda motor 37 mm dia, 30mm long. Wound to 1033kv. I am using a 1600 4s battery that will have about 400 watts of draw with the 9" carbon prop.

The All Up Weight is 505 grams.
Wing area 176 sq inches.

The wing loading shakes out like this?
Wing Loading = 14.6 oz. / sq. ft.
Wing Cube Loading = 13.2

I should be able to control it although it will have higher wing loading than most of my wings.
I know it will land, they all do.
Dave
Sep 14, 2017, 03:40 PM
Registered User
Todd52's Avatar
Nice job! Looks great Dave,I look forward to
seeing it fly. It will be interesting to see how it glides compared to some of your lighter models.
It certainly won't be short on power.
Sep 14, 2017, 04:21 PM
Laughs at un-boxing videos...
basicguy's Avatar
Will let you all know

I have flown planes with higher cube loading but this will be right up there. If I have the elevon set wrong it is either going to loop or torque roll at launch. Maybe just dive in. Have the cg set for 20%
Sep 14, 2017, 06:01 PM
Build straight - Fly twisty
Whiskers's Avatar
Ya turnin' out more planks than an Amish sawmill.
This one is sweeeet!
Sep 14, 2017, 06:31 PM
Ft Lauderdale
Number_6's Avatar


Nice looking plank!

It should go!
Sep 14, 2017, 10:51 PM
Laughs at un-boxing videos...
basicguy's Avatar
Yeah it does run.
A pusher plank. maiden flight. (2 min 6 sec)


This flight had too much aileron control over half throttle and not enough elevator at lower speeds. Hopefully this will be better compensated for on the next flight.

I really like the shapes I can make with a 3D printer but to do a wing you add about 3x more time.

Most of my future foamies are going to have a printed fuselage.
Sep 15, 2017, 04:25 AM
Registered User
Hi Dave,

It is a cool combination of foam and printed parts. And it looks great!

Quote:
Originally Posted by basicguy
This flight had too much aileron control over half throttle and not enough elevator at lower speeds. Hopefully this will be better compensated for on the next flight.
Would it help if you extend the elevons at the center and reduce them at the outside?

Michael
Sep 15, 2017, 05:46 AM
Laughs at un-boxing videos...
basicguy's Avatar
Hi Michael
Yes good advice on giving it more elevator authority and less elevon.
That may be the best solution

I have the Turnigy i10 radio. It has programming to let me change the amount of throws based on input from the throttle. I may add a little of that into as well. The trouble with using a computer radio is that it does not using airspeed but throttle position. Hate to reduce contol sensitivity at takeoff.

Oh a note about the battery The two minutes of flight used 15% of the battery power. It looks like the plane should be good for about 6 minutes of flight.


Quote:
Originally Posted by wersy
Hi Dave,

It is a cool combination of foam and printed parts. And it looks great!



Would it help if you extend the elevons at the center and reduce them at the outside?

Michael
Last edited by basicguy; Sep 15, 2017 at 05:53 AM.
Sep 15, 2017, 06:01 AM
Laughs at un-boxing videos...
basicguy's Avatar
Thanks Graham
Yeah I sure make the Amish look up when they drive by in their horse drawn buggies.

I think they like them as in their vernacular these are not hooked to the electric grid but powered by batteries. We have lived among them for 10 years and know how they think. Of course no adult Amish would ever be caught playing with toys.

My camera lady mentioned that this one looked pretty much like a bird of prey. The white foam wing tips and black wing.

Quote:
Originally Posted by Whiskers
Ya turnin' out more planks than an Amish sawmill.
This one is sweeeet!
Sep 15, 2017, 04:44 PM
Build straight - Fly twisty
Whiskers's Avatar
Quote:
Of course no adult Amish would ever be caught playing with toys.
When talking to people I often refer to this hobby as, "Playing with toy airplanes," or something similar.
Once I said it in a group that was infested with several golfers and they smiled their patronizing smiles.
"Yeah," I said, "It's pretty silly. A bit like wacking a tiny ball and counting how many hits it takes to get it into a distant hole,"
That changed the patronizing smiles into looks of incredulous indignation.