Working Micro BL Powered Models - Page 3 - RC Groups
Shop our Airplanes Products Drone Products Sales
Thread Tools
Nov 04, 2009, 11:33 PM
Love the sport, not the plane
All very cool! Does anyone have any plans for a 11-15" 3D or F3P bipe? I just finished building the airframe for a micro 3D scratchbuilt but I dont really like it. I want a bipe becuase it should have a lighter wing loading. Here is my plane.
Last edited by dylantorquerol; Nov 04, 2009 at 11:38 PM. Reason: Clicked post by accident and didnt put down all the info
Sign up now
to remove ads between posts
Nov 05, 2009, 08:46 PM
Registered User
I'll keep the thread alive with another "Working Model"
2S 100Mamp battery
GWS 5x3,6x3
2.5g x3 Servos
44g weight with battery
36g weight with out battery.
Aug 25, 2010, 04:55 PM
Full Scale Piper Cub Driver
Piper J3's Avatar

Airframe for 2 gram HK BL

This is an airframe for testing the HobbyKing 2 gram 7700 kv BL motor with GWS3020 prop and HK-XP3A ESC. The DX7 has several mixes working together to make AR6400 on-board servos function as independent ailerons and gear channel is changed to elevator. Rudder is fixed position to reduce weight and servo count.

Foam is 1mm Depron. Wing span is 12” and cord is 4”. Tail feathers are made from flattened foam (baked at 190F in oven between glass plates). Foam for wing has natural curl - 1mm Depron comes in rolled form. I decided that 1mm flat foam was flimsy by itself so I used two curved sheets spaced by ribs for a stronger wing structure. Wing ribs are symmetric airfoil. I traced the curve from the 1mm foam sheets. The depth of the ribs allows the AR6400, ESC, and the S2000 servo to be buried in the wing. AUW with Hyperion 160 mAh is 27.36g. Flight tests will begin when weather permits.
Apr 30, 2012, 04:33 PM
Registered User

Build Log?

Originally Posted by Gordon Johnson
This plane started out as an actuator plane to test 2-cell M20 systems for the full fuselage Citabria project I've been collaborating on with Carl Martin for some time now. The wing span, plane length, wings, are the same as the full fuselage Citabria. After a loop indoors broke apart the major pieces of this plane it sat on a shelf for months. I resurected it to serve as a test bed for micro BL motors and converted it to micro servos. It is designed so motors with turned dowls can be slipped over the fuselage and adhered with a bit of tape to another dowl permanently glued to the fuselage stick. This means there is no down or right thrust, but it's easy to trim the plane to counteract the lack of this.

Span: 18-inches, area = 72 sq.inches, BSD 4" chord undercamber foam wings.
Motor: either Mighty Midget 2-cell motor or Gary Jones BL disc motor, or any other BL motor to be tested.
Receiver: JMP servo RX
Servos: Falcon, rudder/elevator
Battery: either 2-cell Kokam 145mAh or larger cell such as Worley 170 or ET-250.
Weight: 41g to 44g depending on motor and/or battery pack used.

This plane will fly comfortably in a single court gym. Outdoors in calm weather it really comes alive. It has an incredibly steep climb since the thrust from the typical BL motors I've flown it with range from about 40g to 60g. Loops are very easy, and it flies till I'm tired and land it. Not only is it a good test bed, but it's a very satisfying and stable flyer.

Since these pictures were taken I've added a CF rod pin on each pylon to loop a rubber band over to secure the wing for firmly for outdoor flying.

Is there a build log somewhere for anyone who would like to build this micro from scratch?
May 01, 2012, 08:21 AM
in persuit of low wing loading
Gordon Johnson's Avatar
No build log. Here's a thread from many years ago when this plane was controlled via actuators.
It currently sits on a shelf in my workshop with Falcon servos still in it, but other equipment removed.

As mentioned, the wings are foam wire cut wings from To get the proportions, just go to someplace such as, which has a Citabria paper model and also a 3-view of the original Citabria. Just scale those up to an 18-inch span, recognize that with 18-in span and BSD wings the chord will be greater, and you'll be fine. It's a stick fuselage, so the rest is pretty simple.

Here's a thread to an earlier "Quick" stick plane, the Quick Junior
A construction article is in this issue of the Inside Story in 2003
The Quick Junior and Quick Citabria are similar planes. So, this one should help.

I haven't done any CF tube stick planes in a while. Here's my latest Citabria.

May 01, 2012, 11:52 AM
Registered User

I failed to notice the dates of the posts.

Originally Posted by matchlessaero
Below is my Matchless Micro Edgeling. ...................... It also tracks very well in normal flight thanks to the built up wing...........................
Matchless - that wing, and its construction closely resembles the Todd Long Tiny of long ago!!
Last edited by 356Jim; May 01, 2012 at 03:37 PM.
May 01, 2012, 04:31 PM
Registered User
Can some one please help me? I bought a micro esc a dpy3 I believe. Never could figure the thing out it never worked right at all. The motor I was useing was a 2 gram motor. It would start after adding 90% throttle run for a few seconds and quit. Figured it was the motor and lost interest. I ordered an apo3 from hobby king for my umx extra 300. This motors doing the same as the 2 gram motor. Can someone please help.
May 03, 2012, 07:31 AM
Senior to who? Member
crossup's Avatar
3 main reasons for issue with ESC's- too small of a battery, bad connection and too big of a prop.
the recommended 3x2 seems to be too much for this motor, mine runs/starts fine with a 2.5x.08
Keep in mind that too much prop will cause a proper size pack to have a large voltage drop AND hurt performance.
This motor/controller combo seems to be more borderline than most so I've seen a fair number of people say they have to blow on the prop to get theirs started

I don't know where HK got their prop recommendation but as soon as I took my motors out of the box and broke out my prop box I noticed the 3x2 was simply huge on this motor. What I call TLAW- that looks all wrong . Think of it this way: we run 8-9" props on 15gr motors or even 7" , even multiplying the 3x2 by only 5(2gr x 5 = 10gr) that would mean a 15" prop!
Now in reality figuring prop load goes by area not diameter, so my example is crude in the extreme but hopefully makes one think...
Last edited by crossup; May 03, 2012 at 07:40 AM.
Feb 06, 2014, 01:54 PM
Registered User
Hi folks,

my name is Stephan and I am from Germany in Europe.

I was inspired to start micro modelling by a friend of mine who
showed me his Microinvent Tramp.
I decided to make a build of Gordon's Monocoupe from 3mm Depron including the printing tissue technique.
I used a brushed 7mm Motor and a spare WLToys Heli V911 brick to keep the costs low.
31g weight over all including battery.

Last week I had the first flight and was so happy that it was a full success.

Thanks a lot to Gordon that he shared 9 years ago his excellent pdf files.

Feb 06, 2014, 02:38 PM
Weltherrschaft will be mine
hi stephan, hier gibts n thread "cheap heli bricks in planes", der ist praktisch für den 911 brick... da ist dein model besser aufgehoben. bilder? das hier ist für bürstenlose motoren. grüsse aus leipzig
Mar 18, 2014, 09:30 AM
Registered User
Thank you borkencorter

my mistake. just wanted to thank Gordon
for sharing his ideas.

Indoor video can be found under my depronator71 youtube channel.

Last edited by Depronator71; Mar 18, 2014 at 09:44 AM.

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Cool Working Pager Powered Models Scratchbuilt Indoor and Micro Models 25 Oct 15, 2008 06:58 AM
Cool Working Pager Powered Models Graham Stabler Scratchbuilt Indoor and Micro Models 153 Jul 31, 2007 09:05 PM
Conversion of Rubber-Powered Models E-Challenged Scale Kit/Scratch Built 0 Nov 08, 2002 07:19 PM
Micro BL soarers, sub 10 Oz.? Looooeeee! Electric Sailplanes 4 Sep 17, 2002 08:58 PM
Sterling C/L and/or rubber powered models Martin Hunter Parkflyers 13 May 10, 2002 01:39 PM