Hi everyone,

Wanted to build a BD-8 ever since I saw a 30% version 40 years ago!
(By Dennis Tapsfield in RCM April 1983). Pic 1.

Pic 2 is of the real airplane N88DH.

Pic 3 is of a later model, a video of which was posted here 5 years ago by DominicM of Essential RC
http://www.rcindia.org/gas-glow-nitro-planes/giant-scale-bede-bd-8/msg288341/#msg288341

Made a rough sketch and was halfway through the build when I realised I should have taken photos along the way...

Started with a sheet of 3mm depron, 24x12.5 inches.

Ironed monokote (clone) on one side at low temperature (just enough to stick, not hot enough to melt the depron or shrink the film)

Folded the depron over a 1/4” balsa spar (as in Armin wing construction in videos by Experimental Airlines)

Since I didn’t have a heat gun to assist with the folding, ended up having some creases near the leading edge. Tolerable though.

Added 1/8” balsa tips.

This is how it looks...

Had some left over 10mm balsa that was 2” wide.
I could use that for making the bottom part of the fuselage.

The turtle deck (top half of the fuselage behind the cockpit) was made with 1/16” sheet seperated by 1/4” wide formers of 1/8” thick balsa. The top was covered with some 1/8” sheet.

Fin and rudder from 1/16” sheet.

Motor mount from 10mm balsa and 3mm ply.

(BTW, 1/16”=1.5mm, 1/8”=3mm, 3/8”=10mm)

This is how it looks...

Two piece removable undercarriage plugs into 10mm bits of CF tubing embedded in the fuselage and retained with zip ties  

For the horizontal tail the 1/16” sheet I had seemed to too flimsy and could have fluttered.
But I didn’t have any 2 or 3mm sheet.

Fortunately a friend brought over a 48x4x1/8 sheet.
Unfortunately it was very heavy (70gms). Over 13lb/cft instead of 6-7 lb/cft that I needed.

So instead of a simple sheet tailplane, had to make a built up one. Worth the effort as it weighs 5gms instead of 15gms for a sheet one. 10gms saved in the tail saves 30-40gms of nose weight to balance!

This is how it looks...

Looking good. Will follow the thread.

Very innovative Iyer sir! Looking forward to the rest of the build and the maiden video

 

Made a battery case with some fibreglass cloth and epoxy between two thin plastic sheets, wrapped around the lipo.

But I never showed the port side so far.

Here it is. My first electric control line model!

Completed at 3pm on Sunday, just in time for the rain to start.

Fortunately the rain stopped at 4:30, and I was able to have 4 successful flights.

Flies quite well on 30’ lines, though a bit over sensitive.

Unfortunately too heavy for aerobatics at 340gms (12oz/sqft).

Did one loop anyway, barely managing a save!


 

Nice build sir. How do you control the throttle? Do you have a receiver on it?.

No throttle, as is normal in control line models.

I've seen quite a few C/L models with a 3rd line for throttle

Some images

Throttle essential only for specific event like Carrier.
Only seen occasionally otherwise.

Hence ‘no throttle, as is normal in control line’

 

In IC engine powered 2 line C/L models, we normally land when the fuel gets over

How do you manage here? Wait for the battery to discharge?

Hi everyone,

This April, while ordering Cox spares fron Densmodelsupplies.co.uk, I saw that that they had something called E-ZEE timer for control line. Looked interesting, so I got one.

 

Clever!

Is that Harveer Sodha with you?

It can be used with any size motor, Esc and Lipo, and has the following adjustment options:

- immediate start or 30 sec delayed start
- power adjustable 0-100%
- run duration adjustable in increments of 1 min / 10 sec each
- 5 sec ramp down after the run duration

Here’s a short video with delayed start and 20 sec run duration.

Yes Sir.
(And wife, pointing out the pipe  )