bracesport DLG

[bracesport]

Hi Guys, So, I have been very impressed (as you all have) with the foamboard wing DLGs that 'flyboa' has been pumping out that I needed to get in on the action.

My design has a 1.2m wing as it will suit the length of a C/F boom currently in stock! Got me some new FB, some gorilla glue, some 5g servos, and a nano battery - hope my Rx will fit! The fuse body will be RP'd and I usually just go with ABS, but for this build, I will be trying a new filament compound (graphene-enhanced) - should be more dimensionally stable - we will see!

The tail is a V and by all accounts, it seems they are not favoured for DLGs - but well you live and you learn!

 

[Paracodespoder]

From my experience v-tail dlg’s have a crazy yawing and pitching effect when launched, might just be my launch though. Good luck!

 

[flyboa]

Javelin or bungee launch might help prevent a bad yaw tendency. Also the light wing will have less rotational weight adding to yaw on launch.

 

[bracesport]

I just realised my wing chord is based on a 1.5m wing so I’ll need to adjust that tomorrow!

 

[bracesport]

I had a little tickle with the overall dimensions and settled on the proportions that I like. The wing chord is 150mm and the ailerons will be 40mm at the root.

Please let me know what you think of the overall measurements given it is a 1.2m wing?

 

[bracesport]

Started printing the RPs for the fuse today - I decided to make it in three pieces with the grey part being the front cover - the blue and orange parts will be joined together with epoxy - the orange part is the tray to house the servos/Rx/battery - wall sections are 1.8mm.

@flyboa - like you, I may have to strip my Rx shell to fit it inside! Worse case this is a demo version!

 

[flyboa]

The 3D printed pod on my DLG is very thin. Acts only as a fairing and no components are attached to it.

 

[bracesport]

I’ll weigh the RPs and we can compare! All going well I can print thinner. I’m using PLA with a graphite additive (usually I use ABS) bought on a whim! No idea how it will turn out, so I’m flying blind so to speak!

 

[flyboa]

My 2 piece pod weighed 18g new. I did have to modify it to slide onto the boom. The PLA was easy to cut using a soldering iron.

 

[bracesport]

@flyboa - My fuse supports the boom and wing at the rear and the front tongue will mount the control gear. Sadly, I can't imagine it will weigh as light as yours!

 

[flyboa]

@bracesport It does look a bit complicated and heavy. The boom/pod connection might be a weak spot.
It is always good to experiment.

 

[bracesport]

The RPs made it through the print - weight is 75g with 1.8mm wall sections - they seem particularly strong in graphine enhanced PLA so I am printing them overnight again with a 1.0mm wall section - maybe I can get down to 40-42g?

 

[bracesport]

I am much happier with the second RP print at 1.0mm wall section - parts including C/F boom weight under 60g - My glued and folded wing (which I am making for my V tail TT) turned out pretty good for the first try and looks sweet with the RP fuse.

A few more surface imperfections with the 1.0mm wall section - I guess it was the vibration in the RP machine! I have to say it’s quite exciting being focused on weight out! Usually, at work, we are focused on cost out!

Also, I’m feeling the pressure on measuring up to flyboa’s mean machines!! I hope we can all benefit in the end!

I will be running 5g servos as was all the local shop had in stock and in the back of my mind I’m hoping the Rx will fit!

 

[bracesport]

@flyboa - I was looking at your AUWs and I will have to be realistic that my first attempt will not be the lightest!

I’m thinking to target under 200g this time around, so I was wondering if you know what your battery, Rx, and servo weigh as a package?

Also, it looks like you hard wire your servos to the Rx? I’m planning on stripping my Rx tonight to investigate the raw size!

 

[flyboa]

@flyboa - I was looking at your AUWs and I will have to be realistic that my first attempt will not be the lightest!

I’m thinking to target under 200g this time around, so I was wondering if you know what your battery, Rex, and servo weight is as a package?
Also it looks like you hard wire your servos to the Rx? I’m planning on stripping my Rx tonight to investigate the raw size!

Extra weight is probably a good thing based on your conditions (windy and wet). You might consider making it a slope glider instead.

 

[bracesport]

@flyboa - sorry to be a bother, but could you tell me what your C/G measurement is from the front edge of your wing, and is it a reasonably generic measurement for all your wings? Do you do a glide test to adjust the C/G for each build?

 

[flyboa]

I set CG to about 30% to 40% MAC. Test fly and adjust if necessary.

 

[bracesport]

I completed the fuse and boom assembly and it is weighing in at 75g.

 

[DamoRC]

Gliders are not my thing, but this thing looks really slick. How are you doing the wings? They look really thin but nicely shaped.

 

[bracesport]

@DamoRC - thanks for the nice comments! Strangely, ‘flyboa’ and I arrived at a similar place from different angles - we both shape the internal surfaces of the FB and then laminate the top and bottom to achieve the chord shapes. I tape my outer surfaces and ‘flyboa’ leaves them raw - It’s hard to compete on weight with his method!