Coyote`s X8

[Splashy]

Great idea, thanks for the tip.

Are your wings detachable? If so then how do you connect them. I have seen people use velcro but was wondering whether you had a cunning method.

[electricmick]

Nice mod Ian. I was suprised to hear you have moved the CofG so far back and still not had tip stall or spin issues. Have you done anything to improve this?

I have taken to launching with 2/3 throttle and slightly nose down, then full throttle as soon as it leaves my hand. As my CofG is still just aft of the two finger holes it naturally pitches up. So far so good with this technique but I would prefer more grip.

Splashy, mine are removable and I use the small screws supplied. The only time they have pulled out was on my crash following a bad launch, this was good and probably prevented further damage.

[Coyote]

Great idea, thanks for the tip.

Are your wings detachable? If so then how do you connect them. I have seen people use velcro but was wondering whether you had a cunning method.

Yes I use a cunning method :)

I drilled through the ply joiners and glued a blind nut to the underside of the wing, then a nylon bolt goes through the top of the wing, through the joiner and screws into the blind nut on the bottom f the wing. Works well ;)

[Coyote]

Nice mod Ian. I was suprised to hear you have moved the CofG so far back and still not had tip stall or spin issues. Have you done anything to improve this?

I have taken to launching with 2/3 throttle and slightly nose down, then full throttle as soon as it leaves my hand. As my CofG is still just aft of the two finger holes it naturally pitches up. So far so good with this technique but I would prefer more grip.

When the CG was 20mm behind the rear finger mould it stalled pretty easily in a turn, I moved it forward to the edge of the finger mold pictured below and its fine now. Red line was tip stall easy, black line no tip stall and still good glide

[electricmick]

Got it now, I thought you meant the rear most finger hole (the pusher), that would be seriously rearward CofG. I have mine somewhere between your black and red lines, it is hard to measure accurately but it flies well. I did the classic power off glide test i.e. 45 deg dive and let go of the sticks: it recovered back to straight and level reasonably quickly showing some excessive up-trim, as does the climb on power tendency but too many stories of tip stall and spin to be more adventurous.

Thanks, Mick

[Coyote]

Ok so after todays flying that went pretty well again a few lessons learnt. Even with 2.4Gz video after I thought the 5.8 was faulty the lipos were still blocking the antenna on the return leg.

Time to bite the big one and move the vtx to the wing like I had a feeling I should have done in the first place :)



First I melted out a slot through the thick foam near the front, then layed 2x shielded cables for video and audio the a power cable. Glued them into place and filled in the channel.

I then taped and reinforced the wing back to the way it was.



I cut a sunken bay for the vtx to sit in, but kept it so I can switch between vtx`s with no hassle and job nearly done :) Just need to make a new Skew-Planar up tonight

[g.collins]

Nice one Ian, I think I will put my one in the wing, when I finally build my ZII.
:) G

[Coyote]

Putting it out on the wing is always best G, even better is you rc receiver on the other wing too giving you excellent separation and balances the vtx on the other wing out ( as a handy bi-product )

After trying Skews more on my planes recently, Ive been finding that they do seem to have the edge over the cloverleaf, previously I had better results with clovers though, weird. But after yesterdays flight the next logical step was to move the vtx out onto the wing ( done ) then make up a Skew-Planar



No need for an extension of the coax for it, nice and low, lets see how this one does :)

[Coyote]

Well didn't last long :) I didn't like the Vtx spoiling the clean white on the wing and want the best cooling for the Vtx possible. So I removed the shrink wrap ( which I do all on my Immersion 5.8 Vtx`s now ) so it promotes cooling under the heatsink as well as above it. I also removed the sticker and put a few layers of white ultra thin tape on the silver. Now it does not stick out so much, matches better and will run much cooler too



You can see here below, with the heat shrink over the Vtx is stops and cooling air from passing through the Vtx cooling it and removes an insulating layer at the same time helping heat escape more efficiently. I also didn't sink the Vtx flush with the wing so the air passes both onto and below, but hardly creates any extra drag.

[pk-surfing]

Might be worth checking what is holding the heatsink plate to the chips now the heatshrink has gone, sometimes it's just something like Artic Silver thermal compound (or its thin tape equivalent) and the heatsink itself needs mechanically attaching.

Maybe warm the heatsink up with your soldering iron (or running the Vtx !) and try twisting it to see if it moves.

I stripped the heatshrink off an ESC that I mounted on top of the fuselage on my MiniSW and found the heatsink could be pulled off when it warmed up during testing the motor in the garage !

You can get Arctic Silver Thermal Adhesive which is just like epoxy

http://www.arcticsilver.com/arctic_silver_thermal_adhesive.htm

PK

[Coyote]

I guess someone`s going to ask how it wires up into my equipment so here`s how...............

All that`s used are 2x shielded RCA cables, one end cut off and soldered to the vtx plug.



A JST connector onto some 2 core provides the vtx power.

The cables sit flush in the channels so a bit of tape and no drag is caused.



The plugs go through the hole and simply plug in inside the fuse

[Coyote]

Might be worth checking what is holding the heatsink plate to the chips now the heatshrink has gone, sometimes it's just something like Artic Silver thermal compound (or its thin tape equivalent) and the heatsink itself needs mechanically attaching.

Maybe warm the heatsink up with your soldering iron (or running the Vtx !) and try twisting it to see if it moves.

I stripped the heatshrink off an ESC that I mounted on top of the fuselage on my MiniSW and found the heatsink could be pulled off when it warmed up during testing the motor in the garage !

You can get Arctic Silver Thermal Adhesive which is just like epoxy

http://www.arcticsilver.com/arctic_silver_thermal_adhesive.htm

PK

Excellent point Paul, glad you mentioned it because I had totally forgot, I was going to solder the edges to keep it on, but that links looking a better option cheers :)

[Coyote]

For a UK link : http://www.ebay.co.uk/itm/Artic-Silver-Alumina-ADHESIVE-Thermal-Paste-/170662374058?pt=UK_Computing_Thermal_Compounds_Supplies&hash=item27bc452aaa

£9.29

[Pr][nCe]

nice to see the build coming along Ian. all this rain makes for a good build i think :)

i use that Arctic Silver Thermal paste on my computer CPU heatsink real good stuff, well worth the extra coin.

my cpu average running temp was 41 added a nice heatsink was 29, with the Arctic paste was 24.

[Coyote]

As requested a few diagrams of the wiring for the X8

Power diagram : Showing all power connections from lipos to every piece of equipment on board




FPV diagram : Showing Video / Audio connections used and GPS connection for the Telemetry