Andy's Drak

[Andy Sayle]

Time is marching on, and I haven't finished my Drak yet!  So last night, I hinged the elevons, and started on the control rods too.

I decided to use some trusty diamond tape to do the hinges.  I used the "overunder" type hinge where two pieces of tape about an inch and half long are taped together (adhesive side to adhesive side) with about 5mm overlap.  One side goes on the top of the elevon, and the other side goes on the underside of the wing.  The next one goes on top of the wing, and under the elevon, and the third one goes on top of the elevon and under the wing.

I did three sets of three tape hinges, one at each end of the elevon, and one in the middle.  This gives a completely free hinge, that is held in the right place really tightly.  Obviously taking pictures of some crystal clear tape on a grey background is next to impossible.

Oh, and I gap sealed the hingeline with a length of diamond tape running along the top of the hinge, and a length running underneath the hinge.  This does reduce the movement a little, but I don't think the Drak will need 3D style throws anyway.

Next up, I fitted some rather snazzy robart control horns.  These are moulded plastic with a built in ball.  They bolt through the elevon (over the spars in there) and the ball takes out the twisty action due to the control rod not being at 90° to the hingeline.

The next job is to find the neutral angle for the elevon (I think Mr Ritewing has a jig for printing somewhere in internet land), and trim the control rods to length to fit the servo end clevis.

I've still not decided on covering/colourscheme too!  Sod it, I'll press on and sort it out later...

[Andy Sayle]

Another hour or so on the Drak last night.  This time I've finished the control rods off.  I cut the carbon rod to size, and glued the clevis adapter thing on with some CA.  Just the ticket.  With the 1.25" robart horns on the control surface, and the clevis on the inner servo horn hole, I can get around 25mm movement each way on the elevon.  That should be plenty I think.

Next up, was the fuselage.  I've decided to not bother laminating it.  It feels really sturdy, and some grass stains won't look too out of place from landing!  I may change my mind and out a strip of lam on the underside though, we shall see.

So, I've mounted the Vector, ESC, airspeed pitot thing, GPS/mag sensor, and tucked the wires down as neat as I can get them.  Hot glue worked wonders here!  I've also fitted a Jeti Duplex rx for now.  I'll do some LOS test flights, and vector tuning, before swapping the RX out for a TBS crossfire beastie.

I've also bonded the correx saddle bays in place with some goop.  A knife slit through one half makes a really nice hinge for access.

The next job is to get a little FPV cam mounted in the nose, wire that in with a VTX up front too, and then assemble the beast to see where the batteries need to be located to hit the correct CG.  If all goes well, I should be up for a test flight next week at some point!

Andy

[Coyote]

They really are that massive that the kit you put in it looks completely lost in space :)

Looking forward to seeing how you get on with the maiden.

[Andy Sayle]

They are almost too big to be honest.  There is so much room to mount stuff, it makes deciding where to put it all a nightmare!

I've been reading up in how to work a Vector this evening.  Think I've got the general gist of it. I'm planning in starting out with a LOS flight with no assistance at all, and then switch in stuff to try it out...

I need to buy some more 5s batteries too.  Only got one 5000mah pack at the moment...

[Ritewing]

Here is a good maiden vid. Enjoy!  https://youtu.be/yYwAzLVuVPQ

Sent from my SM-N910T using Tapatalk