Introducing the TwinThing

[dp106]

Ever since I first tried fixed wing FPV I've longed to have a Twinstar.  The videos from others as they pan the camera to look across the wing at their motors has always filled me with envy :)  The trouble is I don't really need another FPV plane and I already have too many LOS planes in the hanger already, (at least as far as my better half is concerned).  The solution was to build a Twinstar inspired scratch build, heavily inspired by the Experimental Airlines Photon glider.

I've done a small overview video including the maiden:  ! No longer available

I've started doing a more detailed overview here:  http://davesrc.blogspot.co.uk  Not sure if people are interested in more detail or not.  If people want I can add detail here as well.

[BlueFlyer]

looks like they're the exact same motors I've got for my Skymule build.

good work there on that scratchy bud.

[dp106]

I've looked at many Twinstar builds and they seemed to be the motors of choice.  Figured they'd work for a scratch build too  :)

[BlueFlyer]

I got the idea of those motors from looking at Coyote's Twinstar thread :)

[dp106]

Completed the first redesign post maiden and have moved the motors to mount them above the wing. This should give me clearance when landing and also shift the weight slightly forward



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[FPVSteve]

How come they're at such a weird angle?

[dp106]

Well I'm not sure at this point if they're at the correct angle.. As I understand it you want the thrust angle to be 'aimed'  at the cog position on the plane. If you think of the cog in terms of a pivot point if the motors were level they would try and pitch the nose down. If you look at the angle of the motor on a bixler for example it is angled down a fair bit.

Hopefully someone will jump in and tell me if I'm way off or explain it better..  :)

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[darlofranco]

I think you only aim the thrust angle at the CG if the motor is behind it.

I thought you were going for a vertical take off ...  :o

[dp106]

On a tractor prop the motor is normally angled down a small amount.

I may just have no angle on there for the first flight and then adjust depending on how it flies

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[darlofranco]

Sounds good to me

[dp106]

I've completed my first set of improvements following the maiden.

I have shifted the motors so they are mounted above the wing this will hopefully give enough clearance to stop the mounts being bent on landing.

I've also made room to shift the battery further forward and it now balances perfectly without having to add more weight on the nose.

Still need to work out what to do about the nose as I don't like the green tape and think this makes it look ugly..



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[dp106]

Tried to see if it would run on a 5000 4s, flew a treat!

! No longer available

[FPVSteve]

Very nice - it looks like it flies fairly quickly too at such a low throttle setting. Good job - you'd be hard pushed to need anything else (SW, Hunter, Z3 etc) after watching that.

:)

[dp106]

Yeah its quite slow if I crank back the throttle to try and maximise the efficiency but quite a nice compromise on 30% throttle flying down low.  Haven't really gone above 50% throttle, don't really need to!

[skyscraper]

That looks like a lovely smooth plane to fly...

Kharma!

regards
Andy