Over the last couple years I've had a Sailfly-X, Mobula 7, and Crux3.
While seeking performance improvements and a replacement frame for the Crux 3 I started mucking around with 3d printing Aerodynamic motor pods strung together with carbon fibre rods.

Currently I am using ABS and 1mm solid carbon rods. The designs are my own and I used tinkercad. They hold the motors captive so in the 3 inch frame for example, they allow for only one screw to be used rather than 2 or 4 screws, saving 1-2 grams of AUW on top of the 1.8g of the crux.

The durability of the frames is yet to be fully determined but I crashed the smaller frame and broke the camera but not the frame.

My 65mm prop size frame is only 1.8 grams (compared to a mobula 7 frame which weighs 4.4 grams) and uses Mobula components. The AUW is currently 18.5g with a trashy 1.7g camera. Soon I will have the EX0802 motors which will shave off another 0.5 of a gram, and if I get a diamond fc then I will shave off about another gram, a runcam nano 3 will reduce it by 0.6

The 3 inch frame weighs 3.8 grams compared to the stock 5.6 grams.

I have more parts coming

This project is very much a work in progress, more is to come.

Hi, I announced my plans to make a super compact F5J class electric sailplane earlier this year for a school project. https://www.rcgroups.com/forums/show...-Super-Compact

Basic information and design constraints:
- A very compact disassembled size of 80x30x27cm in case. (I plan to be able to transport it in bag and on a bicycle.)
- Total wingspan of 3.7m
- Target weight of -+1400 grams
- Assembly of the plane should take 5 minutes or less
-Budget of $420AUD ($300USD) for BNF

Main Wing Airfoils: - SynerJ 100 - 30
Vertical Stabiliser - Z4D
Horisontal Stabiliser - Horisontal Freak v2

Electronics
-Surpass Hobby 3536 1050kv ($22)
-TTSRC 35A ESC ($10)
-EMAX ES3352 12.4g MG Digital Servos x7 ($91 all up)
-

Construction
XPS Foam Core, Fibreglass, Kevlar, and Carbon Fibre.

Materials
-200GSM unidirectional carbon fiber (30x400cm 30AUD, Aliexpress)
-48GSM fiberglass matt
-18GSM fiberglass matt
-135GSM Kevlar matt
-0.5x3x750 carbon strips
-4mm Carbon tubes,
-4mm Plywood sheet (Free cutoffs from classroom)
-10x10 OD 8x8mm ID ABS Square tube
-West Systems 206+105 slow hardening Epoxy 1.2l ($49)

5 Wing sections, 1 Fuse Section + 1 boom.

Following posts will be added to document the steps taken in the build.

Hi,
I've started designing my Super Compact F5J Sailplane Proposed here. This is the last Project of my last year in High School. Suggestions would be greatly appreciated. https://www.rcgroups.com/forums/show...-Super-Compact

Some specific constraints I have incorporated include;
- A very compact disassembled size of 75x30x20cm in case. (I plan to be able to transport it in bag and on a bicycle.)
- Total wingspan of 3750mm
- Total flying weight between 1200-1600 grams
- Assembly of the plane should take 5 minutes

I've finished calculating the basic dimensions using a Sailplane Calculator from RCG. (See attached images)

Can I please get suggestions and recommendations on the following, particularly the Airfoils. Keep in mind I have a Budget of $350 ($265 USD)

Candidate Airfoils:
SD7037
AG26

Vertical Stabiliser
HT12
HT13

Horizontal Stabiliser
HT14
HT15

Electronics
-Surpass Hobby 3536 910kv
-Racerstar 52A
-Power HD-DSM44 5.8g X4 (Stabs and Flaps)
-EMAX ES3302 12.4g x2 (Ailerons)

(Italics = not sure)

Construction
XPS Foam Core, fibreglassed and Carbon Fibered.
5 Wing sections, 5 Fuse Sections.

Sketches and design concepts will be uploaded in a couple days.
Any advice in general about F5J would be greatly appreciated.

I'm currently creating a design brief for an F5J class electric sailplane and would like to ask some questions about what other glider pilots seek from their thermalling flagships.

Some specific constraints I have incorporated include;
- A very compact disassembled size of 100-80x30x20cm in case. (I plan to be able to transport it in bag and on a bicycle.)
- Total wingspan of 3 - 3.8m's
- Total flying weight between 750-1500 grams
- Assembly of the plane should take 5 minutes

After a couple weeks of this design process I will eventually link to a build log.
I'm thinking of a 3-5 piece wing that incorporates a DLG style tail to increase compactness.
This is for my Product Design Tech class, in my last year of school. Any help would be greatly appreciated!
What design features would you like to see in an F5J sailplane?

Notes for impatient people!
- Do NOT run the stock ESC with 3s. It WILL burn!
- This is NOT a beginner plane! it is extremely stable in calm air, but does not take crashes particularly well in its stock form!
- If you want the plane, buy it as a kit. The stock ESC is rubbish, the prop, and servos are rubbish.

Introduction
I was very interested in this model, because I have not seen anything in this size with such a low weight. Having been bitten by the thermalling bug, I took the plunge and ordered it for the good of the RC Modelling community even though it has/had no reviews at that current time.

Background
I was once a CP heli nut (Hence my username), but since I flew my first plane, the Hisky HFW400, I was hooked. I flew that tiny plane since last Christmas several times a week, but I since decided to move up.
(Since then I have also flown a Bixler 3 so I have limited experience with larger planes for comparison.)
I wanted a good gliding floater that wasn't too big, so I poked around and found this! After some unnervingly fast shipping from Banggood, my plane arrived in time for Christmas!

Gallery
The plane was well protected in a double box.


The box included a tube of glue, the plastic assembly parts, the Aileron servo, a ton of screws, Linkages and fasteners, some fruity stickers, an instruction manual, a little card reporting the passing of QC, and of course all the bits of your plane. (Which I had already assembled.)
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