Trex 450SE has ARRIVED

[extreme3d]

Very neat layout on the electrics. Hope you don't mind if I (try to) copy

No probs

If you need anymore, let me know.

Paul

[Twister3D]

Some more photo's of an install for you

http://www.rcheliaddict.co.uk/galler...MG_0405res.jpg

http://www.rcheliaddict.co.uk/galler...MG_0403res.jpg

http://www.rcheliaddict.co.uk/galler...MG_0401res.jpg

http://www.rcheliaddict.co.uk/galler...MG_0402res.jpg

Dave

[Snarf]

Well the HS65MGs arrived yesterday (thank you Midland) so I spent the day fitting them. I had already watched the Finless Bob videos from Helifreak and they were a godsend. The centre mounting hole on the servos is displaced outward slightly so I DID have to file the holes in the frames to avoid stressing the servo cases.

I hooked the three swash servos up to the receiver for the next step. Another Finless trick is to use a regular receiver battery pack rather than the ESC and flight pack. I don't know about you guys but, having watched these babies spool up, I have developed a significant respect (=fear) of what an unplanned burst of full power might do to me and my environment. So I made up a simple pack to power the RX, servos and gyro using a battery holder, two switches and four AA NiMH cells, all from Maplin. The harness doubles as a bind plug for my Spektrum set (second switch connects signal to -ve which triggers binding).

BTW Maplin have a deal on flight cases at the moment (£14.99 instead of £34.99). They have a pre-cut foam insert that lets you pull out what you need to make a TX shaped cut-out.

Anyway - power on - wiggle the sticks and "what the f**k?" The swash was all over the place. Fiddled with the connections to the receiver, swapping the servos round etc. before sense struck and it was back to Finless.

For all you Noobs out there (like me) the rear servo is driven by the elevator channel, the other two by aileron and pitch (either way round). The only place I found that stated explicitly was on the Finless video.

I've now made a good start on getting the mechanicals set up right and all the wiring is tidied away. Gyro is also fitted. I'll post some pictures later.

Thanks again to all you guys for advice, comment etc.

[jiberjaber]

Snarf - good call on the flight case from Maplin, popped down there this afternoon and picked up the last one in the Chelmsford branch

[Leebert]

PS...

Happy birthday Jason - Hope you got more than a maplin case!!

[Snarf]

OK - so here are a couple (=3) of shots showing how I put it together

015 Wiring and mechanicals LHS.jpg
016 Wiring and mechanicals underside.jpg
017 Wiring and mechanicals RHS.jpg

The head is set up with all the links the right length. Everything is square and true. Collective is -2 to +10 degrees with 0 at mid stick. Cyclic is set to +/- 6 degrees and exponential rates set at 20.

Rudder servo is working the right way round and gyro sense is OK too (had to reverse that).

Blades have been balanced but I had to relieve the grips as they were way too tight.

Just waiting on the voltage dropper (on its way from a model train store in Illinois would you believe) then I can connect the flight pack, programme the ECS (SCARY) and spool it up for the first time to check blade tracking.

Getting much help from the Finless vids and also from "kerhs" (thanks Leigh).

[Cobham]

Tight blades...

Hi been watching the build with interest as just got one. Nice layout. Noticed you mentioned you were waiting for the voltage dropper to come - what is that for? and also the blade grips were too tight and had to be loosened - how did you do that. Thanks for any help.

[Snarf]

I am using one of the new Robbe FS 61 BB digital servos on the tail as reviewed on Trex Tuning. It is nano rather than micro size but only handles 4.8V while the ESC puts out 6V so I have fitted an Align voltage dropper between the gyro and the servo to reduce the voltage and save burning out the servo.

On the main blades, I gently sanded the plastic grips to relieve the tightness. They should not flop back and forth but do need to be able to move without too much pressure. This allows them to move into balance when rotating. You could probably achieve the same by working the blades back and forth until they loosen up. BTW the tail blades should be just loose enough to drop under their own weight.

I have had quite a few flights now (including one crash when I was daft enough to take my eye off the bird to look down at my timer). I can handle a steady tail-in hover now and have dumped the training gear. Next challenge will be side-in hovering.

This is a GREAT heli but I should have bought more battery packs because the wait between flights is very frustrating.